Fermentation

9 pages, 243 KiB

Open AccessArticle

Fermentation Ability of Bovine Colostrum by Different Probiotic Strains

by Ivana Hyrslova, Gabriela Krausova, Tereza Michlova, Antonin Kana and Ladislav Curda

Fermentation 2020, 6(3), 93; https://doi.org/10.3390/fermentation6030093 - 22 Sep 2020

Cited by 11 | Viewed by 3640

Over the past decade, the use of bovine colostrum and its bioactive components as the basis of functional food and dietary supplements for humans has substantially increased. However, for developing new products enriched with probiotics and bovine colostrum, the influence of colostrum composition [...] Read more.

Over the past decade, the use of bovine colostrum and its bioactive components as the basis of functional food and dietary supplements for humans has substantially increased. However, for developing new products enriched with probiotics and bovine colostrum, the influence of colostrum composition on the growth promotion of bacteria still needs to be tested. Therefore, we decided to study the influence of bovine colostrum chemical and mineral composition as well as the content of bioactive compounds (immunoglobulins, lactoferrin, lactoperoxidase) on the growth of ten selected strains from genera Lactobacillus, Lacticaseibacillus, Bifidobacterium, and Enterococcus. After 24 h of fermentation, the growth was assessed based on lactic and acetic acids production evaluated using isotachophoresis, bacterial counts determined by the agar plate method, and change of pH. The production of acids and bacterial counts were significantly (P<0.05) different between selected genera. The change of bacterial counts was correlated with pH, but the correlation between growth and bovine colostrum composition was not proven. The highest growth and production of lactic acid was observed after the fermentation of bovine colostrum by the strains Enterococcus faecium CCDM 922A and CCDM 945. Full article

(This article belongs to the Special Issue Lactic Acid Fermentation and the Colours of Biotechnology 2.0)

31 pages, 5140 KiB

Open AccessReview

A Comprehensive Understanding of Electro-Fermentation

by Drishti Dinesh Bhagchandanii, Rishi Pramod Babu, Jayesh M. Sonawane, Namita Khanna, Soumya Pandit, Dipak A. Jadhav, Santimoy Khilari and Ram Prasad

Fermentation 2020, 6(3), 92; https://doi.org/10.3390/fermentation6030092 - 21 Sep 2020

Cited by 51 | Viewed by 11290

Abstract

Electro-fermentation (EF) is an upcoming technology that can control the metabolism of exoelectrogenic bacteria (i.e., bacteria that transfer electrons using an extracellular mechanism). The fermenter consists of electrodes that act as sink and source for the production and movement of electrons and protons, [...] Read more.

Electro-fermentation (EF) is an upcoming technology that can control the metabolism of exoelectrogenic bacteria (i.e., bacteria that transfer electrons using an extracellular mechanism). The fermenter consists of electrodes that act as sink and source for the production and movement of electrons and protons, thus generating electricity and producing valuable products. The conventional process of fermentation has several drawbacks that restrict their application and economic viability. Additionally, metabolic reactions taking place in traditional fermenters are often redox imbalanced. Almost all metabolic pathways and microbial strains have been studied, and EF can electrochemically control this. The process of EF can be used to optimize metabolic processes taking place in the fermenter by controlling the redox and pH imbalances and by stimulating carbon chain elongation or breakdown to improve the overall biomass yield and support the production of a specific product. This review briefly discusses microbe-electrode interactions, electro-fermenter designs, mixed-culture EF, and pure culture EF in industrial applications, electro methanogenesis, and the various products that could be hence generated using this process. Full article

(This article belongs to the Special Issue Biorefineries)

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13 pages, 557 KiB

Open AccessArticle

Development of Selenized Lactic Acid Bacteria and their Selenium Bioaccummulation Capacity

by Gabriela Krausova, Antonin Kana, Ivana Hyrslova, Iva Mrvikova and Miloslava Kavkova

Fermentation 2020, 6(3), 91; https://doi.org/10.3390/fermentation6030091 - 21 Sep 2020

Cited by 27 | Viewed by 7916

Abstract

Selenized lactic acid bacteria (LAB) represent potentially safe and effective sources of selenium (Se), essential for human health, as lactic acid fermentation improves Se bioavailability and reduces its toxicity. LAB are generally recognized as safe (GRAS) and widely used in fermented dairy products. [...] Read more.

Selenized lactic acid bacteria (LAB) represent potentially safe and effective sources of selenium (Se), essential for human health, as lactic acid fermentation improves Se bioavailability and reduces its toxicity. LAB are generally recognized as safe (GRAS) and widely used in fermented dairy products. To facilitate selenized LAB implementation as a functional food, we developed and characterized new Se-enriched strains based on the food industry commercial strains Streptococcus thermophilus CCDM 144 and Enterococcus faecium CCDM 922A as representatives of two LAB genera. We evaluated Se bioaccumulation capacity, Se biotransformation and growth ability in the presence of different sodium selenite concentrations (0–50 mg/L), and antioxidant properties (2, 2-diphenyl-1-picrylhydrazyl (DPPH) method) and cell surface hydrophobicity between Se-enriched and parental strains in vitro. Sodium selenite addition did not negatively influence growth of either strain; thus, 50 mg/L was chosen as the optimal concentration based on strain accumulation capacity. Selenization improved the antioxidant properties of both strains and significantly increased their cell surface hydrophobicity (p < 0.05). To our knowledge, this represents the first report of Se-enriched strain hydrophobicity as well as the first on Se speciation in families Enterococcaceae and Streptococcaceae. Moreover, both tested strains demonstrated good potential for Se-enrichment, providing a foundation for further in vitro and in vivo studies to confirm the suitability of these Se-enriched strains for industrial applications. Full article

(This article belongs to the Special Issue Lactic Acid Fermentation and the Colours of Biotechnology 2.0)

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14 pages, 16331 KiB

Open AccessArticle

Snails as Taxis for a Large Yeast Biodiversity

by Madina Akan, Florian Michling, Katrin Matti, Sinje Krause, Judith Muno-Bender and Jürgen Wendland

Fermentation 2020, 6(3), 90; https://doi.org/10.3390/fermentation6030090 - 18 Sep 2020

Cited by 8 | Viewed by 3357

Abstract

Yeasts are unicellular fungi that harbour a large biodiversity of thousands of species, of which particularly ascomycetous yeasts are instrumental to human food and beverage production. There is already a large body of evidence showing that insects play an important role for yeast [...] Read more.

Yeasts are unicellular fungi that harbour a large biodiversity of thousands of species, of which particularly ascomycetous yeasts are instrumental to human food and beverage production. There is already a large body of evidence showing that insects play an important role for yeast ecology, for their dispersal to new habitats and for breeding and overwintering opportunities. Here, we sought to investigate a potential role of the terrestrial snails Cepaea hortensis and C. nemoralis, which in Europe are often found in association with human settlements and gardens, in yeast ecology. Surprisingly, even in a relatively limited culture-dependent sampling size of over 150 isolates, we found a variety of yeast genera, including species frequently isolated from grape must such as Hanseniaspora, Metschnikowia, Meyerozyma and Pichia in snail excrements. We typed the isolates using standard ITS-PCR-sequencing, sequenced the genomes of three non-conventional yeasts H. uvarum, Meyerozyma guilliermondii and P. kudriavzevii and characterized the fermentation performance of these three strains in grape must highlighting their potential to contribute to novel beverage fermentations. Aggravatingly, however, we also retrieved several human fungal pathogen isolates from snail excrements belonging to the Candida clade, namely Ca. glabrata and Ca. lusitaniae. Overall, our results indicate that diverse yeasts can utilise snails as taxis for dispersal. This courier service may be largely non-selective and thus depend on the diet available to the snails. Full article

(This article belongs to the Special Issue Yeast Biotechnology 4.0)

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17 pages, 1593 KiB

Open AccessArticle

Saccharomyces cerevisiae Strain Diversity Associated with Spontaneous Fermentations in Organic Wineries from Galicia (NW Spain)

by David Castrillo, Noemi Neira and Pilar Blanco

Fermentation 2020, 6(3), 89; https://doi.org/10.3390/fermentation6030089 - 15 Sep 2020

Cited by 12 | Viewed by 2430

Abstract

Yeast play an essential role in wine quality. The dynamics of yeast strains during fermentation determine the final chemical and sensory characteristics of wines. This study aims to evaluate the Saccharomyces cerevisiae strains diversity in organic wineries from Galicia (NW Spain). Samples from [...] Read more.

Yeast play an essential role in wine quality. The dynamics of yeast strains during fermentation determine the final chemical and sensory characteristics of wines. This study aims to evaluate the Saccharomyces cerevisiae strains diversity in organic wineries from Galicia (NW Spain). Samples from spontaneous fermentations were taken in five wineries over three consecutive years (2013 to 2015). The samples were transported to the laboratory and processed following standard methodology for yeast isolation. S. cerevisiae strains were differentiated by mDNA-RFLPs. A total of 66 different strains were identified. Some of them presented a wide distribution and appeared in several wineries. However, other strains were typical from a specific winery. Similarity analysis using two different statistical tests showed significant differences in strain diversity among wineries. The results also revealed high biodiversity indexes; however, only some strains showed an important incidence in their distribution and frequency. Our findings confirmed that spontaneous fermentation favored the existence of a high S. cerevisiae strain diversity in organic wineries from Galicia. The presence of different yeasts during fermentation, specially winery-specific strains, contribute to increased wine complexity and differentiation. Full article

(This article belongs to the Special Issue Yeast Biotechnology 4.0)

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10 pages, 3233 KiB

Open AccessArticle

Production of Proteins prM/M and E of Dengue Virus-3 in Pichia pastoris: Simplified Purification and Evaluation of Their Use as Antigens in Serological Diagnosis of Dengue

by Michelle D. O. Teixeira, Roberto S. Dias, John W. O. Prates, Juliana M. C. Monteiro, Mariana F. Xisto, Cynthia C. da Silva and Sérgio O. De Paula

Fermentation 2020, 6(3), 88; https://doi.org/10.3390/fermentation6030088 - 14 Sep 2020

Cited by 2 | Viewed by 2365

Abstract

Dengue is a major arbovirus affecting humans today. With the growing number of cases, it is essential to have large-scale production of antigens for the development of diagnostic kits for the rapid detection of patients infected by the virus and consequent proper medical [...] Read more.

Dengue is a major arbovirus affecting humans today. With the growing number of cases, it is essential to have large-scale production of antigens for the development of diagnostic kits for the rapid detection of patients infected by the virus and consequent proper medical intervention for them. In this work, we express the prM/M and E proteins of dengue virus-3 in yeast Pichia pastoris KM71H. The proteins were produced in soluble form in the supernatant of the culture and were purified by precipitation with ammonium sulfate. The fraction of 80% of ammonium sulfate was used as an antigen in an indirect enzyme-linked immunosorbent assay (ELISA), providing a sensitivity of 82.61% and a specificity of 89.25%. Thus, the methodology proposed here showed promise for obtaining antigens of dengue viruses and creating quick and inexpensive diagnostic tests, which is of great value since large portions of the areas affected by this disease are economically neglected. Full article

(This article belongs to the Special Issue Yeast Biotechnology 4.0)

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13 pages, 2763 KiB

Open AccessArticle

Anti-Inflammatory Effects and Their Correlation with Microbial Community of Shindari, a Traditional Jeju Beverage

by Su Bin Hyun and Chang-Gu Hyun

Fermentation 2020, 6(3), 87; https://doi.org/10.3390/fermentation6030087 - 07 Sep 2020

Cited by 4 | Viewed by 2515

Abstract

In this study, we investigated the microbial community and its correlation with anti-inflammatory effects during the fermentation procedure of shindari. Since shindari is traditionally manufactured through a fermentation process of 3–4 days in summer or 5–6 days in winter, the shindari materials applied [...] Read more.

In this study, we investigated the microbial community and its correlation with anti-inflammatory effects during the fermentation procedure of shindari. Since shindari is traditionally manufactured through a fermentation process of 3–4 days in summer or 5–6 days in winter, the shindari materials applied in this study were fermented for 1, 3, and 5 days, respectively. Microbial community structure in the shindari manufacturing process was analyzed by Illumina MiSeq sequencing. Results revealed different fermentation time had different influences on the community structure and microbial diversity in the shindari process. Ultimately, we found that pathogenic bacteria such as Enterococcus durans (9.3%) and Enterobacter asburiae (4.5%) dominate the shindari fermented for 1 day, while samples with a fermentation period of more than 3 days occupied lactic acid bacteria such as Pediococcus sp. (97.1%). In addition, to study the relationship between fermentation period and anti-inflammatory effect in the shindari manufacturing process, we applied RAW264.7 cells, a classic cell model for inflammation studies. First, we prepared an ethyl acetate extract of shindari fermented for 1 (S1), 3 (S3), or 5 days (S5), and then it was confirmed that all of these extracts inhibited the nitric oxide (NO) production in a concentration-dependent manner. In addition, these inhibitory effects were correlated with the suppressive effect of shindari extracts against overexpression of inducible nitric oxide synthase (iNOS). Furthermore, S3 and S5 also inhibited the production of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6. Overall, the anti-inflammatory effect of S3 was suggested to be mediated through the negative regulation of mitogen-activated protein kinase signaling (MAPKs) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathways. Full article

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15 pages, 1448 KiB

Open AccessArticle

Conversion of Xylose from Birch Hemicellulose Hydrolysate to 2,3-Butanediol with Bacillus vallismortis

by Anja Kuenz, Malee Jäger, Harri Niemi, Mari Kallioinen, Mika Mänttäri and Ulf Prüße

Fermentation 2020, 6(3), 86; https://doi.org/10.3390/fermentation6030086 - 02 Sep 2020

Cited by 11 | Viewed by 2831

Abstract

Biotechnologically produced 2,3-butanediol (2,3-BDO) is a potential starting material for industrial bulk chemicals, such as butadiene or methyl ethyl ketone, which are currently produced from fossil feedstocks. So far, the highest 2,3-BDO concentrations have been obtained with risk class 2 microorganisms and pure [...] Read more.

Biotechnologically produced 2,3-butanediol (2,3-BDO) is a potential starting material for industrial bulk chemicals, such as butadiene or methyl ethyl ketone, which are currently produced from fossil feedstocks. So far, the highest 2,3-BDO concentrations have been obtained with risk class 2 microorganisms and pure glucose as substrate. However, as glucose stays in competition to food and feed industries, a lot of effort has been done in the last years finding efficient alternative substrates. Thereby xylose from hydrolysed wood hemicelluloses is a promising substrate for the production of 2,3-BDO. The risk class 1 microorganism Bacillus vallismortis strain was identified as a very promising 2,3-BDO producer. The strain is able to utilize xylose almost in the same manner as glucose. B. vallismortis is less prone to common inhibiting compounds in lignocellulosic extracts/hydrolysates. When using a concentrated hemicellulose fraction from birch wood hydrolysate, which was produced with ultrafiltration and after which the acetate concentration was reduced, a yield of 0.43 g g⁻¹ was achieved and the xylose consumption and the 2,3-BDO production is basically the same as using pure xylose. Full article

(This article belongs to the Special Issue Biomass Conversion: Fermentation Chemicals and Fuels)

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22 pages, 980 KiB

Open AccessReview

The Effects of Halogenated Compounds on the Anaerobic Digestion of Macroalgae

by Birthe V Nielsen, Supattra Maneein, Md Mahmud Al Farid and John J Milledge

Fermentation 2020, 6(3), 85; https://doi.org/10.3390/fermentation6030085 - 27 Aug 2020

Cited by 12 | Viewed by 5248

Abstract

The urgent need to replace fossil fuels has seen macroalgae advancing as a potential feedstock for anaerobic digestion. The natural methane productivity (dry weight per hectare) of seaweeds is greater than in many terrestrial plant systems. As part of their defence systems, seaweeds, [...] Read more.

The urgent need to replace fossil fuels has seen macroalgae advancing as a potential feedstock for anaerobic digestion. The natural methane productivity (dry weight per hectare) of seaweeds is greater than in many terrestrial plant systems. As part of their defence systems, seaweeds, unlike terrestrial plants, produce a range of halogenated secondary metabolites, especially chlorinated and brominated compounds. Some orders of brown seaweeds also accumulate iodine, up to 1.2% of their dry weight. Fluorine remains rather unusual within the chemical structure. Halogenated hydrocarbons have moderate to high toxicities. In addition, halogenated organic compounds constitute a large group of environmental chemicals due to their extensive use in industry and agriculture. In recent years, concerns over the environmental fate and release of these halogenated organic compounds have resulted in research into their biodegradation and the evidence emerging shows that many of these compounds are more easily degraded under strictly anaerobic conditions compared to aerobic biodegradation. Biosorption via seaweed has become an alternative to the existing technologies in removing these pollutants. Halogenated compounds are known inhibitors of methane production from ruminants and humanmade anaerobic digesters. The focus of this paper is reviewing the available information on the effects of halogenated organic compounds on anaerobic digestion. Full article

(This article belongs to the Special Issue Biomass Conversion: Fermentation Chemicals and Fuels)

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27 pages, 5001 KiB

Open AccessArticle

Side-by-Side Comparison of Clean and Biomass-Derived, Impurity-Containing Syngas as Substrate for Acetogenic Fermentation with Clostridium ljungdahlii

by Alba Infantes, Michaela Kugel, Klaus Raffelt and Anke Neumann

Fermentation 2020, 6(3), 84; https://doi.org/10.3390/fermentation6030084 - 19 Aug 2020

Cited by 20 | Viewed by 2771

Abstract

Syngas, the product of biomass gasification, can play an important role in moving towards the production of renewable chemical commodities, by using acetogenic bacteria to ferment those gaseous mixtures. Due to the complex and changing nature of biomass, the composition and the impurities [...] Read more.

Syngas, the product of biomass gasification, can play an important role in moving towards the production of renewable chemical commodities, by using acetogenic bacteria to ferment those gaseous mixtures. Due to the complex and changing nature of biomass, the composition and the impurities present in the final biomass-derived syngas will vary. Because of this, it is important to assess the impact of these factors on the fermentation outcome, in terms of yields, productivity, and product formation and ratio. In this study, Clostridium ljungdahlii was used in a fed-batch fermentation system to analyze the effect of three different biomass-derived syngases, and to compare them to equivalent, clean syngas mixtures. Additionally, four other clean syngas mixtures were used, and the effects on product ratio, productivity, yield, and growth were documented. All biomass-derived syngases were suitable to be used as substrates, without experiencing any complete inhibitory effects. From the obtained results, it is clear that the type of syngas, biomass-derived or clean, had the greatest impact on product formation ratios, with all biomass-derived syngases producing more ethanol, albeit with lesser total productivity. Full article

(This article belongs to the Special Issue Microbial Production of Added-value Products from Renewable Resources 2.0)

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16 pages, 263 KiB

Open AccessReview

Improving Kefir Bioactive Properties by Functional Enrichment with Plant and Agro-Food Waste Extracts

by Francesca Aiello, Donatella Restuccia, Umile Gianfranco Spizzirri, Gabriele Carullo, Mariarosaria Leporini and Monica Rosa Loizzo

Fermentation 2020, 6(3), 83; https://doi.org/10.3390/fermentation6030083 - 16 Aug 2020

Cited by 31 | Viewed by 7674

Abstract

An increase in the number of novel fortified kefir-based beverages was observed in the last decades. Vegetables were often proposed as convenient resources of bioactive molecules able to improve nutraceutical benefits of these drinks and/or to confer them new significant features. These findings [...] Read more.

An increase in the number of novel fortified kefir-based beverages was observed in the last decades. Vegetables were often proposed as convenient resources of bioactive molecules able to improve nutraceutical benefits of these drinks and/or to confer them new significant features. These findings have been well accepted by the consumers, which generally reserve an important role to the quality of the assumed food and beverages. Specifically, functional fermented milk-based drinks enriched with vegetable extracts display significant biological properties, due to the presence of bioactive compounds exhibiting antimicrobial and antioxidant features. In addition, agro-industrial wastes have been also proposed as innovative resources of secondary metabolites to enrich kefir-based products. Eco-friendly extraction techniques were generally exploited to achieve the isolation of biomolecules and reducing, at the same time, economic and environmental loads. To this regard, this review deeply investigates the main findings to improve kefir bioactive properties by functional enrichment with plant and agro-food waste extracts. The nutraceutical characteristics related to the consumers’ health benefits, as well as their effects on the sensorial, chemical, and microbiological properties of the products were evaluated. Full article

(This article belongs to the Special Issue Fermentation and Bioactive Metabolites 2.0)

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16 pages, 323 KiB

Open AccessReview

By-Products in the Malting and Brewing Industries—Re-Usage Possibilities

by Andrea Karlović, Anita Jurić, Nevena Ćorić, Kristina Habschied, Vinko Krstanović and Krešimir Mastanjević

Fermentation 2020, 6(3), 82; https://doi.org/10.3390/fermentation6030082 - 08 Aug 2020

Cited by 53 | Viewed by 11172

Abstract

Beer production includes the formation of different by-products such as wastewater, spent grains, spent hops, and yeast. In addition to these well-known by-products, it is necessary to mention germ/rootlets, which also remain after the malting process. Given that a huge amount of beer [...] Read more.

Beer production includes the formation of different by-products such as wastewater, spent grains, spent hops, and yeast. In addition to these well-known by-products, it is necessary to mention germ/rootlets, which also remain after the malting process. Given that a huge amount of beer is produced annually worldwide, by-products are available in large quantities throughout the year. Spent grains, spent hops, and spent yeasts are high-energy raw materials that possess a great potential for application in the branch of biotechnology, and the food industry, but these by-products are commonly used as livestock feed, disposed of in the fields, or incinerated. Breweries by-products can be utilized for microalgae production, biofuel production, extraction of proteins, polyphenolic, antioxidative substances, etc. This paper aims to address each of these by-products with an emphasis on their possible application in biotechnology and other industries. Full article

(This article belongs to the Special Issue Microbial Production of Added-value Products from Renewable Resources 2.0)

10 pages, 323 KiB

Open AccessArticle

Valorization of Value-Added Resources from the Anaerobic Digestion of Swine-Raising Manure for Circular Economy in Taiwan

by Yu-Ru Lee and Wen-Tien Tsai

Fermentation 2020, 6(3), 81; https://doi.org/10.3390/fermentation6030081 - 07 Aug 2020

Cited by 9 | Viewed by 2737

Abstract

Due to the benefits of mitigating greenhouse gas emission and upgrading farmland fertilization, the valorization of liquor and biogas digestate from the anaerobic digestion of swine manure has attracted much attention in recent years. This article is based on the updated data/information from [...] Read more.

Due to the benefits of mitigating greenhouse gas emission and upgrading farmland fertilization, the valorization of liquor and biogas digestate from the anaerobic digestion of swine manure has attracted much attention in recent years. This article is based on the updated data/information from the official websites for summarizing the status of the swine-raising industry and innovative manure management, relevant sustainable development indicators, and inter-ministry promotion regulations in Taiwan. The survey findings revealed that the carbon dioxide emission reduction in 2019 was equivalent to about 36,000 metric tons based on a total of 2.35 million metric tons liquor and biogas digestate applied and 2 million swine heads for the biogas-to-power. Obviously, the regulatory measures by the Council of Agriculture, the Environmental Protection Administration, and the Ministry of Economic Affairs have provided economic and financial supports towards the reduction of 67.39 × 10³ metric tons carbon dioxide equivalent by 2030. Using the principles of biorefinery and zero-waste, the integration of anaerobic digestion, by-products (liquor and digestate), and biogas-to-power for treating swine manure is a win-win-win option for environmental, energy, and economic benefits. Full article

(This article belongs to the Special Issue Biorefineries)

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13 pages, 946 KiB

Open AccessArticle

Selection of Wine Saccharomyces cerevisiae Strains and Their Screening for the Adsorption Activity of Pigments, Phenolics and Ochratoxin A

by Andrea Pulvirenti, Luciana De Vero, Giuseppe Blaiotta, Rossana Sidari, Giovanna Iosca, Maria Gullo and Andrea Caridi

Fermentation 2020, 6(3), 80; https://doi.org/10.3390/fermentation6030080 - 05 Aug 2020

Cited by 18 | Viewed by 2951

Abstract

Ochratoxin A is a dangerous mycotoxin present in wines and is considered the principal safety hazard in the winemaking process. Several authors have investigated the ochratoxin A adsorption ability of Saccharomyces cerevisiae yeasts, and specifically selected strains for this desired trait. In the [...] Read more.

Ochratoxin A is a dangerous mycotoxin present in wines and is considered the principal safety hazard in the winemaking process. Several authors have investigated the ochratoxin A adsorption ability of Saccharomyces cerevisiae yeasts, and specifically selected strains for this desired trait. In the present work, a huge selection of wine yeasts was done starting from Portuguese, Spanish and Italian fermenting musts of different cultivars. Firstly, 150 isolates were collected, and 99 non-redundant S. cerevisiae strains were identified. Then, the strains were screened following a multi-step approach in order to select those having primary oenological traits, mainly (a) good fermentation performance, (b) low production of H₂S and (c) low production of acetic acid. The preselected strains were further investigated for their adsorption activity of pigments, phenolic compounds and ochratoxin A. Finally, 10 strains showed the desired features. The goal of this work was to select the strains capable of absorbing ochratoxin A but not pigments and phenolic compounds in order to improve and valorise both the quality and safety of red wines. The selected strains are considered good candidates for wine starters, moreover, they can be exploited to obtain a further enhancement of the specific adsorption/non-adsorption activity by applying a yeast breeding approach. Full article

(This article belongs to the Special Issue Yeast Biotechnology 4.0)

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17 pages, 1435 KiB

Open AccessArticle

Nitrogen Sources Added to Must: Effect on the Fermentations and on the Tempranillo Red Wine Quality

by Pilar Santamaría, Lucía González-Arenzana, Patrocinio Garijo, Ana Rosa Gutiérrez and Rosa López

Fermentation 2020, 6(3), 79; https://doi.org/10.3390/fermentation6030079 - 05 Aug 2020

Cited by 10 | Viewed by 4175

Abstract

Nitrogen supplementation in musts or during the alcoholic fermentation is a common practice to promote fermentations. In this study, the impact of the supplementation of two different sources of nitrogen during Tempranillo red wine elaboration was studied. Mineral and organic nitrogen was added [...] Read more.

Nitrogen supplementation in musts or during the alcoholic fermentation is a common practice to promote fermentations. In this study, the impact of the supplementation of two different sources of nitrogen during Tempranillo red wine elaboration was studied. Mineral and organic nitrogen was added after the exponential yeast growth phase and during winemaking, examining its impact on the alcoholic and malolactic fermentation development, on the aromatic wine composition and on the nitrogenous wine composition. The nitrogen supplementation did not provide neither significant advantages in kinetics and fermentations time, nor differences in the chemical wine composition. The aromatic composition of the wines improved with the addition of inorganic nitrogen, although its organoleptic evaluation was not favored. Moreover, the concentration of amino acids in wines increased slightly after the malolactic fermentation and significantly during the stabilization time, especially with organic nitrogen addition. However, the synthesis of biogenic amines did not increase in wines neither after the malolactic fermentation, nor after the storage period. Full article

(This article belongs to the Special Issue Wine Fermentation 2.0)

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18 pages, 1927 KiB

Open AccessArticle

Comparison of the Glycolytic and Alcoholic Fermentation Pathways of Hanseniaspora vineae with Saccharomyces cerevisiae Wine Yeasts

by María José Valera, Eduardo Boido, Eduardo Dellacassa and Francisco Carrau

Fermentation 2020, 6(3), 78; https://doi.org/10.3390/fermentation6030078 - 03 Aug 2020

Cited by 11 | Viewed by 4698

Abstract

Hanseniaspora species can be isolated from grapes and grape musts, but after the initiation of spontaneous fermentation, they are displaced by Saccharomyces cerevisiae. Hanseniaspora vineae is particularly valuable since this species improves the flavour of wines and has an increased capacity to [...] Read more.

Hanseniaspora species can be isolated from grapes and grape musts, but after the initiation of spontaneous fermentation, they are displaced by Saccharomyces cerevisiae. Hanseniaspora vineae is particularly valuable since this species improves the flavour of wines and has an increased capacity to ferment relative to other apiculate yeasts. Genomic, transcriptomic, and metabolomic studies in H. vineae have enhanced our understanding of its potential utility within the wine industry. Here, we compared gene sequences of 12 glycolytic and fermentation pathway enzymes from five sequenced Hanseniaspora species and S. cerevisiae with the corresponding enzymes encoded within the two sequenced H. vineae genomes. Increased levels of protein similarity were observed for enzymes of H. vineae and S. cerevisiae, relative to the remaining Hanseniaspora species. Key differences between H. vineae and H. uvarum pyruvate kinase enzymes might explain observed differences in fermentative capacity. Further, the presence of eight putative alcohol dehydrogenases, invertase activity, and sulfite tolerance are distinctive characteristics of H. vineae, compared to other Hanseniaspora species. The definition of two clear technological groups within the Hanseniaspora genus is discussed within the slow and fast evolution concept framework previously discovered in these apiculate yeasts. Full article

(This article belongs to the Special Issue Enological Repercussions of Non-Saccharomyces Species 2.0)

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22 pages, 325 KiB

Open AccessReview

The Effect of Non-Saccharomyces and Saccharomyces Non-Cerevisiae Yeasts on Ethanol and Glycerol Levels in Wine

by Nedret Neslihan Ivit, Rocco Longo and Belinda Kemp

Fermentation 2020, 6(3), 77; https://doi.org/10.3390/fermentation6030077 - 30 Jul 2020

Cited by 37 | Viewed by 7797

Abstract

Non-Saccharomyces and Saccharomyces non-cerevisiae studies have increased in recent years due to an interest in uninoculated fermentations, consumer preferences, wine technology, and the effect of climate change on the chemical composition of grapes, juice, and wine. The use of these yeasts [...] Read more.

Non-Saccharomyces and Saccharomyces non-cerevisiae studies have increased in recent years due to an interest in uninoculated fermentations, consumer preferences, wine technology, and the effect of climate change on the chemical composition of grapes, juice, and wine. The use of these yeasts to reduce alcohol levels in wines has garnered the attention of researchers and winemakers alike. This review critically analyses recent studies concerning the impact of non-Saccharomyces and Saccharomyces non-cerevisiae on two important parameters in wine: ethanol and glycerol. The influence they have in sequential, co-fermentations, and solo fermentations on ethanol and glycerol content is examined. This review highlights the need for further studies concerning inoculum rates, aeration techniques (amount and flow rate), and the length of time before Saccharomyces cerevisiae sequential inoculation occurs. Challenges include the application of such sequential inoculations in commercial wineries during harvest time. Full article

(This article belongs to the Special Issue Enological Repercussions of Non-Saccharomyces Species 2.0)

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18 pages, 956 KiB

Open AccessReview

Non-Saccharomyces in Winemaking: Source of Mannoproteins, Nitrogen, Enzymes, and Antimicrobial Compounds

by Ricardo Vejarano

Fermentation 2020, 6(3), 76; https://doi.org/10.3390/fermentation6030076 - 29 Jul 2020

Cited by 23 | Viewed by 5010

Abstract

Traditionally, non-Saccharomyces yeasts have been considered contaminants because of their high production of metabolites with negative connotations in wine. This aspect has been changing in recent years due to an increased interest in the use of these yeasts in the winemaking process. [...] Read more.

Traditionally, non-Saccharomyces yeasts have been considered contaminants because of their high production of metabolites with negative connotations in wine. This aspect has been changing in recent years due to an increased interest in the use of these yeasts in the winemaking process. The majority of these yeasts have a low fermentation power, being used in mixed fermentations with Saccharomyces cerevisiae due to their ability to produce metabolites of enological interest, such as glycerol, fatty acids, organic acids, esters, higher alcohols, stable pigments, among others. Additionally, existing literature reports various compounds derived from the cellular structure of non-Saccharomyces yeasts with benefits in the winemaking process, such as polysaccharides, proteins, enzymes, peptides, amino acids, or antimicrobial compounds, some of which, besides contributing to improving the quality of the wine, can be used as a source of nitrogen for the fermentation yeasts. These compounds can be produced exogenously, and later incorporated into the winemaking process, or be uptake directly by S. cerevisiae from the fermentation medium after their release via lysis of non-Saccharomyces yeasts in sequential fermentations. Full article

(This article belongs to the Special Issue Enological Repercussions of Non-Saccharomyces Species 2.0)

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4 pages, 186 KiB

Open AccessEditorial

Yeast Biotechnology 3.0

by Ronnie G. Willaert

Fermentation 2020, 6(3), 75; https://doi.org/10.3390/fermentation6030075 - 29 Jul 2020

Viewed by 2432

Abstract

This Special Issue is a continuation of the first and second “Yeast Biotechnology” Special Issue series of the journal Fermentation (MDPI) [...] Full article

(This article belongs to the Special Issue Yeast Biotechnology 3.0)

14 pages, 901 KiB

Open AccessArticle

Microbial and Sensory Analysis of Soy and Cow Milk-Based Yogurt as a Probiotic Matrix for Lactobacillus rhamnosus GR-1

by Syeda Maria Fatima and Sharareh Hekmat

Fermentation 2020, 6(3), 74; https://doi.org/10.3390/fermentation6030074 - 28 Jul 2020

Cited by 13 | Viewed by 7306

Abstract

Plant-based milk alternatives represent a growing sector of the functional food industry due to consumer demand for more nutritious and sustainable options. Soymilk is abundant in fibre, phytosterols, and isoflavones. In contrast, cow milk has a high cholesterol and caloric content, superior organoleptic [...] Read more.

Plant-based milk alternatives represent a growing sector of the functional food industry due to consumer demand for more nutritious and sustainable options. Soymilk is abundant in fibre, phytosterols, and isoflavones. In contrast, cow milk has a high cholesterol and caloric content, superior organoleptic characteristics, and a well-established probiotic delivery matrix. Supplementing cow milk with soymilk to produce probiotic yogurt may enhance the nutritional value, sensory profile, and probiotic delivery capacity of the final product. In order to investigate the probiotic potential and sensory appeal of this blend, four yogurt mixtures were prepared by incorporating 0% (T1), 25% (T2), 50% (T3), or 75% (T4) soymilk in cow milk. The viability of Lactobacillus rhamnosus GR-1 and pH were evaluated during fermentation (6 h) and refrigerated storage (30 days). Additionally, consumer acceptability was determined through a sensory evaluation. L. rhamnosus GR-1 reached viable counts of 10⁸ colony forming units (CFU)/mL in all treatments. Sensory panellists provided higher hedonic scores to T1 for appearance and texture compared to T2–T4, but flavour and overall acceptability ratings amongst T1–T4 were comparable. These results serve as an indication for the successful fortification of cow and soymilk yogurt mixtures with L. rhamnosus GR-1. Full article

(This article belongs to the Special Issue Probiotic Delivery through Non-Bovine Milk and Milk Products: Trends, Novelties and Benefits)

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12 pages, 1849 KiB

Open AccessArticle

A Digital Approach to Model Quality and Sensory Traits of Beers Fermented under Sonication Based on Chemical Fingerprinting

by Claudia Gonzalez Viejo and Sigfredo Fuentes

Fermentation 2020, 6(3), 73; https://doi.org/10.3390/fermentation6030073 - 21 Jul 2020

Cited by 6 | Viewed by 2616

Abstract

The development of digital tools based on artificial intelligence can produce affordable and accurate methodologies to assess quality traits and sensory analysis of beers. These new and emerging technologies can also assess new products in a near real-time fashion through virtual simulations before [...] Read more.

The development of digital tools based on artificial intelligence can produce affordable and accurate methodologies to assess quality traits and sensory analysis of beers. These new and emerging technologies can also assess new products in a near real-time fashion through virtual simulations before the brewing process. This research was based on the development of specific digital tools (four models) to assess quality traits and sensory profiles of beers produced using sonication and traditional brewing techniques. Results showed that models developed using supervised machine learning (ML) regression algorithms based on near-infrared spectroscopy (NIR) were highly accurate in the estimation of physicochemical parameters (Model 1; R = 0.94; b = 0.91). Outputs from Model 1 were then used as inputs to obtain estimations of the intensity of sensory descriptors (Model 2; R = 0.99; b = 0.98), liking of sensory attributes (Model 3; R = 0.97; b = 0.99), and the classification of fermentation treatments using supervised classification ML algorithms (Model 4; 96% accuracy). These new digital tools can aid craft brewing companies for product development at lower costs and maintain specific quality traits and sensory profiles, creating original styles of beers to get positioned in the market. Full article

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14 pages, 998 KiB

Open AccessArticle

Combining Xylose Reductase from Spathaspora arborariae with Xylitol Dehydrogenase from Spathaspora passalidarum to Promote Xylose Consumption and Fermentation into Xylitol by Saccharomyces cerevisiae

by Adriane Mouro, Angela A. dos Santos, Denis D. Agnolo, Gabriela F. Gubert, Elba P. S. Bon, Carlos A. Rosa, César Fonseca and Boris U. Stambuk

Fermentation 2020, 6(3), 72; https://doi.org/10.3390/fermentation6030072 - 21 Jul 2020

Cited by 12 | Viewed by 3422

Abstract

In recent years, many novel xylose-fermenting yeasts belonging to the new genus Spathaspora have been isolated from the gut of wood-feeding insects and/or wood-decaying substrates. We have cloned and expressed, in Saccharomyces cerevisiae, a Spathaspora arborariae xylose reductase gene (SaXYL1) [...] Read more.

In recent years, many novel xylose-fermenting yeasts belonging to the new genus Spathaspora have been isolated from the gut of wood-feeding insects and/or wood-decaying substrates. We have cloned and expressed, in Saccharomyces cerevisiae, a Spathaspora arborariae xylose reductase gene (SaXYL1) that accepts both NADH and NADPH as co-substrates, as well as a Spathaspora passalidarum NADPH-dependent xylose reductase (SpXYL1.1 gene) and the SpXYL2.2 gene encoding for a NAD⁺-dependent xylitol dehydrogenase. These enzymes were co-expressed in a S. cerevisiae strain over-expressing the native XKS1 gene encoding xylulokinase, as well as being deleted in the alkaline phosphatase encoded by the PHO13 gene. The S. cerevisiae strains expressing the Spathaspora enzymes consumed xylose, and xylitol was the major fermentation product. Higher specific growth rates, xylose consumption and xylitol volumetric productivities were obtained by the co-expression of the SaXYL1 and SpXYL2.2 genes, when compared with the co-expression of the NADPH-dependent SpXYL1.1 xylose reductase. During glucose-xylose co-fermentation by the strain with co-expression of the SaXYL1 and SpXYL2.2 genes, both ethanol and xylitol were produced efficiently. Our results open up the possibility of using the advantageous Saccharomyces yeasts for xylitol production, a commodity with wide commercial applications in pharmaceuticals, nutraceuticals, food and beverage industries. Full article

(This article belongs to the Special Issue Microbial Production of Added-value Products from Renewable Resources 2.0)

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9 pages, 1445 KiB

Open AccessArticle

Antioxidant Content of Aronia Infused Beer

by Alexander Jahn, Juyeong Kim, Khawaja Muhammad Imran Bashir and Man gi Cho

Fermentation 2020, 6(3), 71; https://doi.org/10.3390/fermentation6030071 - 20 Jul 2020

Cited by 12 | Viewed by 4036

Abstract

Beer is a fermented beverage in which antioxidants can contribute to the oxidative stability and nutraceutical properties of the product. Aronia berries are antioxidant-rich fruits of distinct sour and astringent taste, limiting their culinary uses. Previously, fermentation has proven to be effective in [...] Read more.

Beer is a fermented beverage in which antioxidants can contribute to the oxidative stability and nutraceutical properties of the product. Aronia berries are antioxidant-rich fruits of distinct sour and astringent taste, limiting their culinary uses. Previously, fermentation has proven to be effective in the removal of astringent tastes from various fruit juices. In this study, a single malt pale ale was produced and infused with Aronia berries under various process conditions by adding the antioxidant-rich fruits at different stages of the beer brewing process. The polyphenol content, antioxidant potential and color were determined. There was a positive correlation between the Aronia amount added and antioxidant capacity. Higher concentrations of added Aronia also increased the polyphenol content and EBC color rating, while no change in the resulting pH was observed. An increase in the Aronia amount increased the attenuation, showing a positive effect on sugar utilization during fermentation. The addition of Aronia after the boil yielded the highest coloration and antioxidative capacity, while addition before the boil yielded a similar antioxidative capacity with a lower EBC rating. Taken together, the infusion of pale ale with Aronia berries can increase the EBC rating, polyphenol content and antioxidative capacity of the beer. Full article

(This article belongs to the Special Issue Fermentation and Bioactive Metabolites 2.0)

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10 pages, 1575 KiB

Open AccessArticle

Application of a Pyruvate-Producing Escherichia coli Strain LAFCPCPt-accBC-aceE: A Case Study for d-Lactate Production

by Keisuke Wada, Tatsuya Fujii, Hiroyuki Inoue, Hironaga Akita, Tomotake Morita and Akinori Matsushika

Fermentation 2020, 6(3), 70; https://doi.org/10.3390/fermentation6030070 - 17 Jul 2020

Cited by 3 | Viewed by 3480

Abstract

Pyruvate, a potential precursor of various chemicals, is one of the fundamental chemicals produced by the fermentation process. We previously reported a pyruvate-producing Escherichia coli strain LAFCPCPt-accBC-aceE (PYR) that has the potential to be applied to the industrial production of pyruvate. In this [...] Read more.

Pyruvate, a potential precursor of various chemicals, is one of the fundamental chemicals produced by the fermentation process. We previously reported a pyruvate-producing Escherichia coli strain LAFCPCPt-accBC-aceE (PYR) that has the potential to be applied to the industrial production of pyruvate. In this study, the availability of the PYR strain for the production of pyruvate-derivative chemicals was evaluated using a d-lactate-producing strain (LAC) based on the PYR strain. The LAC strain expresses a d-lactate dehydrogenase-encoding gene from Lactobacillus bulgaricus under the control of a T7 expression system. The d-lactate productivity of the LAC strain was further improved by limiting aeration and changing the induction period for the expression of d-lactate dehydrogenase-encoding gene expression. Under combined conditions, the LAC strain produced d-lactate at 21.7 ± 1.4 g·L⁻¹, which was compatible with the pyruvate production by the PYR strain (26.1 ± 0.9 g·L⁻¹). These results suggest that we have succeeded in the effective conversion of pyruvate to d-lactate in the LAC strain, demonstrating the wide versatility of the parental PYR strain as basal strain for various chemicals production. Full article

(This article belongs to the Special Issue Lactic Acid Fermentation and the Colours of Biotechnology 2.0)

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15 pages, 3631 KiB

Open AccessArticle

Effect of Substrate Characteristics on the Growth and Sporulation of Two Biocontrol Microorganisms during Solid State Cultivation

by Ga Young Lee, Wenqi Li, Ulalo M. Chirwa and Jian Shi

Fermentation 2020, 6(3), 69; https://doi.org/10.3390/fermentation6030069 - 17 Jul 2020

Cited by 3 | Viewed by 4318

Abstract

Biocontrol agents are a group of naturally occurring organisms capable of interrupting the lifespan and suppressing the propagation of disease organisms. The use of biocontrol agents offers an environment-friendly and sustainable solution to the synthetic agrochemicals. In this study, we investigated parboiled rice [...] Read more.

Biocontrol agents are a group of naturally occurring organisms capable of interrupting the lifespan and suppressing the propagation of disease organisms. The use of biocontrol agents offers an environment-friendly and sustainable solution to the synthetic agrochemicals. In this study, we investigated parboiled rice and millets as substrates for spore production of two model biocontrol microorganisms (Bacillus pumilus and Streptomyces griseus) under solid state cultivation (SSC) conditions. The effects of cultivation parameters such as initial moisture content, water activity, and cultivation time on microbial growth and spore production were studied. Furthermore, texture profile analysis was performed to test the stress and strain curve and the hardness and stickiness of the substrates. The greatest spore production occurred at 50% moisture content with millets as a substrate, yielding a count of 1.34 × 10⁸ spores/g-wet-substrate enumerated with plate count analysis and 1.70 × 10⁸ events/g-wet-substrate using flow cytometry analysis. Substrate texture profile was highly correlative to the initial moisture content and substrate type and all proved to be essential process variables in controlling the bacterial growth and sporulation during SSC processes. Full article

(This article belongs to the Special Issue Solid State Fermentations)

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12 pages, 3420 KiB

Open AccessArticle

Simulation and Performance Analysis of Integrated Gasification–Syngas Fermentation Plant for Lignocellulosic Ethanol Production

by Sahar Safarian, Runar Unnthorsson and Christiaan Richter

Fermentation 2020, 6(3), 68; https://doi.org/10.3390/fermentation6030068 - 14 Jul 2020

Cited by 18 | Viewed by 6646

Abstract

This study presents a new simulation model developed with ASPEN Plus of waste biomass gasification integrated with syngas fermentation and product recovery units for bioethanol production from garden waste as a lignocellulosic biomass. The simulation model includes three modules: gasification, fermentation, and ethanol [...] Read more.

This study presents a new simulation model developed with ASPEN Plus of waste biomass gasification integrated with syngas fermentation and product recovery units for bioethanol production from garden waste as a lignocellulosic biomass. The simulation model includes three modules: gasification, fermentation, and ethanol recovery. A parametric analysis is carried out to investigate the effect of gasification temperature (500–1500 °C) and equivalence ratio (0.2–0.6) on the gasification performance and bioethanol production yield. The results reveal that, for efficient gasification and high ethanol production, the operating temperature range should be 700–1000 °C, as well as an equivalence ratio between 0.2 and 0.4. At optimal operating conditions, the bioethanol production yield is 0.114 kg/h per 1 kg/h input garden waste with 50% moisture content. It is worth mentioning that this parameter increases to 0.217 kg_bioethanol/kg_{garden waste} under dry-based conditions. Full article

(This article belongs to the Special Issue Biorefineries)

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14 pages, 1930 KiB

Open AccessArticle

Increased Selectivity for Butanol in Clostridium Pasteurianum Fermentations via Butyric Acid Addition or Dual Feedstock Strategy

by Garret Munch, Justus Mittler and Lars Rehmann

Fermentation 2020, 6(3), 67; https://doi.org/10.3390/fermentation6030067 - 09 Jul 2020

Cited by 5 | Viewed by 2620

Abstract

Volatility of the petroleum market has renewed research into butanol as an alternate fuel. In order to increase the selectivity for butanol during glycerol fermentation with Clostridium pasteurianum, butyric acid can be added to the medium. In this manuscript, different methods of [...] Read more.

Volatility of the petroleum market has renewed research into butanol as an alternate fuel. In order to increase the selectivity for butanol during glycerol fermentation with Clostridium pasteurianum, butyric acid can be added to the medium. In this manuscript, different methods of extracellular butyric acid addition are explored, as well as self-generation of butyric acid fermented from sugars in a co-substrate strategy. Molasses was used as an inexpensive sugar substrate, and the optimal molasses to glycerol ratio was found to allow the butyric acid to be taken back up into the cells and increase the productivity of butanol from all carbon sources. When butyric acid is added directly into the media, there was no significant difference between chemically pure butyric acid, or butyric acid rich supernatant from a separate fermentation. When low concentrations of butyric acid (1 or 2 g/L) are added to the initial media, an inhibitory effect is observed, with no influence on the butanol selectivity. However, when added later to the fermentation, over 1 g/L butyric acid is taken into the cells and increased the relative carbon yield from 0.449 to 0.519 mols carbon in product/mols carbon in substrate. An optimized dual substrate fermentation strategy in a pH-controlled reactor resulted in the relative carbon yield rising from 0.439 when grown on solely glycerol, to 0.480 mols C product/mols C substrate with the dual substrate strategy. An additional benefit is the utilization of a novel source of sugars to produce butanol from C. pasteurianum. The addition of butyric acid, regardless of how it is generated, under the proper conditions can allow for increased selectivity for butanol from all substrates. Full article

(This article belongs to the Special Issue Biorefineries)

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15 pages, 1710 KiB

Open AccessArticle

Impact of Hanseniaspora Vineae in Alcoholic Fermentation and Ageing on Lees of High-Quality White Wine

by Juan Manuel Del Fresno, Carlos Escott, Iris Loira, José Enrique Herbert-Pucheta, Rémi Schneider, Francisco Carrau, Rafael Cuerda and Antonio Morata

Fermentation 2020, 6(3), 66; https://doi.org/10.3390/fermentation6030066 - 01 Jul 2020

Cited by 18 | Viewed by 4761

Abstract

Hanseniaspora vineae is an apiculate yeast that plays a significant role at the beginning of fermentation, and it has been studied for its application in the improvement of the aromatic profile of commercial wines. This work evaluates the use of H. vineae in [...] Read more.

Hanseniaspora vineae is an apiculate yeast that plays a significant role at the beginning of fermentation, and it has been studied for its application in the improvement of the aromatic profile of commercial wines. This work evaluates the use of H. vineae in alcoholic fermentation compared to Saccharomyces cerevisiae and in ageing on the lees process (AOL) compared to Saccharomyces and non-Saccharomyces yeasts. The results indicated that there were not significant differences in basic oenological parameters. H. vineae completed the fermentation until 11.9% v/v of ethanol and with a residual sugars content of less than 2 g/L. Different aroma profiles were obtained in the wines, with esters concentration around 90 mg/L in H. vineae wines. Regarding the AOL assay, the hydroalcoholic solutions aged with H. vineae lees showed significantly higher absorbance values at 260 (nucleic acids) and 280 nm (proteins) compared to the other strains. However, non-significant differences were found in the polysaccharide content at the end of the ageing process were found compared to the other yeast species, with the exception of Schizosaccharomyces pombe that released around 23.5 mg/L of polysaccharides in hydroalcoholic solution. The use of H. vineae by the wineries may be a viable method in fermentation and AOL to improve the quality of white wines. Full article

(This article belongs to the Special Issue Enological Repercussions of Non-Saccharomyces Species 2.0)

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10 pages, 1081 KiB

Open AccessArticle

Effect of Candida intermedia LAMAP1790 Antimicrobial Peptides against Wine-Spoilage Yeasts Brettanomyces bruxellensis and Pichia guilliermondii

by Rubén Peña, Jeniffer Vílches, Camila G.-Poblete and María Angélica Ganga

Fermentation 2020, 6(3), 65; https://doi.org/10.3390/fermentation6030065 - 01 Jul 2020

Cited by 7 | Viewed by 2690

Abstract

Wine spoilage yeasts are one of the main issues in the winemaking industry, and the control of the Brettanomyces and Pichia genus is an important goal to reduce economic loses from undesired aromatic profiles. Previous studies have demonstrated that Candida intermedia LAMAP1790 produces [...] Read more.

Wine spoilage yeasts are one of the main issues in the winemaking industry, and the control of the Brettanomyces and Pichia genus is an important goal to reduce economic loses from undesired aromatic profiles. Previous studies have demonstrated that Candida intermedia LAMAP1790 produces antimicrobial peptides of molecular mass under 10 kDa with fungicide activity against Brettanomyces bruxellensis, without affecting the yeast Saccharomyces cerevisiae. So far, it has not been determined whether these peptides show biocontroller effect in this yeast or other spoilage yeasts, such as Pichia guilliermondii. In this work, we determined that the exposure of B. bruxellensis to the low-mass peptides contained in the culture supernatant of C. intermedia LAMAP1790 produces a continuous rise of reactive oxygen species (ROS) in this yeast, without presenting a significant effect on membrane damage. These observations can give an approach to the antifungal mechanism. In addition, we described a fungicide activity of these peptides fraction against two strains of P. guilliermondii in a laboratory medium. However, carrying out assays on synthetic must, peptides must show an effect on the growth of B. bruxellensis. Moreover, these results can be considered as a start to develop new strategies for the biocontrol of spoilage yeast. Full article

(This article belongs to the Special Issue Enological Repercussions of Non-Saccharomyces Species 2.0)

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10 pages, 10453 KiB

Open AccessArticle

Nitrogen Sources Effect on Lactobacillus reuteri Growth and Performance Cultivated in Date Palm (Phoenix dactylifera L.) By-Products

by Amira A. Ayad, Deiaa A. Gad El-Rab, Salam A. Ibrahim and Leonard L. Williams

Fermentation 2020, 6(3), 64; https://doi.org/10.3390/fermentation6030064 - 30 Jun 2020

Cited by 10 | Viewed by 4316

Abstract

Lactic acid bacteria (LAB) are fastidious microorganisms that have specific nutritional requirements. The de Man, Rogosa, and Sharpe (MRS) is an expensive standard growth medium for LAB to produce lactic acid, and the industry is always looking for an alternative low-cost medium. The [...] Read more.

Lactic acid bacteria (LAB) are fastidious microorganisms that have specific nutritional requirements. The de Man, Rogosa, and Sharpe (MRS) is an expensive standard growth medium for LAB to produce lactic acid, and the industry is always looking for an alternative low-cost medium. The date palm (Phoenix dactylifera L.) is naturally full of essential nutrients that lead to stimulate or promote the growth of Lactobacillus spp. The date fruit industries generate a large amount of unwanted date by-product. Thus, the objective of this study was to examine the effect of different nitrogen sources on the growth of Lactobacillus reuteri grown in a date base medium. In this study, date palm fruit was pressed, and the fiber was blended with distilled water, centrifuged, and the supernatant was autoclaved to obtain date palm extract (DPE). The date palm medium (DPM) was formed by mixing the DPE with buffer solution. The DPM was then supplemented with different concentrations of different nitrogen sources. Lactobacilli MRS was used as a standard growth medium. Three different L. reuteri strains were individually inoculated into batches of MRS and DPMs at an initial inoculum 2.5 Log CFU/mL, and then incubated at 37 °C for 18 h. Bacterial growth was monitored by measuring the optical density readings (O.D 610 nm) for up to 18 h. At the end of the incubation period, final populations of each individual strain were verified by enumeration of the MRS agar. Our results showed that the bacterial population in DPM (control; without nitrogen), reached 3.55 ± 0.5 Log CFU/mL. However, the bacterial populations that reached 7.03 ± 0.1 Log CFU/mL in the DPM medium were supplemented with 0.8% phytone peptone, compared to the MRS 7.90 ± 0.24 Log CFU/mL. Our findings thus suggest that date by-products could be used as a low-cost alternative for the LAB growth medium. Full article

(This article belongs to the Special Issue Food Wastes: Feedstock for Value-Added Products: 2nd Edition)

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