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13 pages, 2024 KiB

Open AccessArticle

Monitoring the Microbiomes of Agricultural and Food Waste Treating Biogas Plants over a One-Year Period

by Sara Agostini, Francesco Moriconi, Mauro Zampirolli, Diego Padoan, Laura Treu, Stefano Campanaro and Lorenzo Favaro

Appl. Sci. 2023, 13(17), 9959; https://doi.org/10.3390/app13179959 - 3 Sep 2023

Cited by 1 | Viewed by 1091

Abstract

The knowledge of the microbiome in the anaerobic digestion (AD) is critical for stabilizing the process and optimizing the biogas yield. This work investigates the microbial ecology in four full-scale biogas plants with different feedstocks and process parameters. The three agricultural plants sharing [...] Read more.

The knowledge of the microbiome in the anaerobic digestion (AD) is critical for stabilizing the process and optimizing the biogas yield. This work investigates the microbial ecology in four full-scale biogas plants with different feedstocks and process parameters. The three agricultural plants sharing similar feedstocks’ composition (mostly rich in proteins, cellulose and hemicellulose), have several hydrolytic and methanogenic species in common, suggesting that their substrates specifically shape the microbiomes. Particularly, the hydrolytic and likely syntrophic Defluviitoga tunisiensis was detected as the most abundant species in one reactor, representing 21.2% of the community. On the other hand, the biogas plant treating the organic fraction of municipal solid waste (OFMSW), whose composition was much higher in hash and lower in proteins, displayed a quite different microbiome with a much lower abundance of Bacteroidales sp. much higher of Clostridiaceae. Moreover, this AD was clearly influenced by COVID-19 restrictions as both substrate availability and composition suddenly changed causing the wash-out of most bacterial and methanogenic species and leading to a deep modification of the microbial structure. The abundance of Methanosarcina flavescens greatly increased up to 36.5% of the total operational taxonomic units (OTUs), suggesting a switch from the hydrogenotrophic to the acetoclastic methanogenic pathway. This is the first report on the COVID-19 impact on the AD microbiome of a full-scale anaerobic digestor. Moreover, this paper demonstrated that the feedstock composition can differentially shape both bacterial and archaeal strains of the AD process. Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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19 pages, 2424 KiB

Open AccessArticle

Bioprocessing of Hempseed (Cannabis sativa L.) Food By-Products Increased Nutrient and Phytochemical In Vitro Bioavailability during Digestion and Microbial Fermentation

by Songtao Fan, Zhihong Zhang, Gary J. Duncan, Amanda Morris, Lorraine Scobbie, Donna Henderson, Philip Morrice, Wendy R. Russell, Sylvia H. Duncan and Madalina Neacsu

Appl. Sci. 2023, 13(9), 5781; https://doi.org/10.3390/app13095781 - 8 May 2023

Cited by 2 | Viewed by 2029

Abstract

Agricultural hemp (Cannabis sativa L.) is currently underutilised for food and could be pivotal to the development and expansion of a low-carbon food production system and to contribute to sustainable diets. Dehulling hempseed for food (for hempseed hearts) generates several by-products, including [...] Read more.

Agricultural hemp (Cannabis sativa L.) is currently underutilised for food and could be pivotal to the development and expansion of a low-carbon food production system and to contribute to sustainable diets. Dehulling hempseed for food (for hempseed hearts) generates several by-products, including hempseed “screenings”. This study assessed the effects of several bioprocessing treatments (using enzyme mixtures, yeast, and combinations of both) on hemp screenings nutrient and phytochemical content and their digestion and metabolism in vitro (using a gastrointestinal digestion model and incubations with human mixed microbiota-faecal samples from three healthy donors). The nutrients and phytochemicals’ metabolites were measured using targeted LC-MS/MS and GC analysis. The hempseed screenings are rich in insoluble NSP (16.46 ± 0.86%), protein (20.15 ± 0.11%, with 3.83% tryptophan), syringaresinol, p-coumaric and protocatechuic acids. The hempseed screenings are highly fermentable, resulting in a significant increase in acetic, propionic, and butyric acids following fermentation with faecal microbiota. The bioprocessing treatments significantly increased the extractability of the phytochemicals, especially in free and alkaline-labile forms, without improving the fibre fermentation. The findings from this study support the use of hempseed screenings as a source of dietary nutrients for biodiversification and development of potential functional foods for metabolic and gut health. Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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16 pages, 3549 KiB

Open AccessArticle

Potent Effect of Phlorotannins Derived from Sargassum linifolium as Antioxidant and Antidiabetic in a Streptozotocin-Induced Diabetic Rats Model

by Saly Gheda, Ragaa A. Hamouda, Mai Abdel Naby, Tarek M. Mohamed, Turki M. Al-Shaikh and Abeer Khamis

Appl. Sci. 2023, 13(8), 4711; https://doi.org/10.3390/app13084711 - 8 Apr 2023

Cited by 4 | Viewed by 1671

Abstract

Phlorotannins are phenolic compounds existing in large amounts in Phaeophyta, with this amount differing according to the season and collection area. There are many pharmacological properties of phlorotannins, such as being antioxidant, antidiabetic, and anti-cancer. In this work, phlorotannins from the Phaeophyta Sargassum [...] Read more.

Phlorotannins are phenolic compounds existing in large amounts in Phaeophyta, with this amount differing according to the season and collection area. There are many pharmacological properties of phlorotannins, such as being antioxidant, antidiabetic, and anti-cancer. In this work, phlorotannins from the Phaeophyta Sargassum linifolium were extracted, characterized, and identified, for use as an antioxidant and an anti-diabetic in a streptozotocin-induced diabetes rat model. Phlorotanins were characterized using ultraviolet (UV) and Fourier transform infrared (FT-IR) analysis, dimethoxy benzaldehyde assay (DMBA), and Folin–Ciocalteu assays. Groups of rats were tested as follows: normal control (negative control) (G1), normal rats treated with 60 mg/kg body weight of phlorotannins (G2), positive control diabetic rats injected with one dose of streptozotocin (G3), and a diabetic group treated with phlorotannins at 60 mg kg⁻¹ body weight (G4). The biochemical parameters were determined after 4 weeks of treatment. The results demonstrated that the extracted compound was a phlorotannin, which had antioxidant properties. An in vivo study confirmed that the glucose and insulin levels in G4 were relatively similar to those in the normal control G1. The glucosidase, alpha-amylase, glutathione, and catalase levels were 0.11 ± 0.097, 420.5 ± 13, 11.27 ± 3.3, and 8.01 ± 1.31 µmol/min/g in G1, and 0.04 ± 0.016, 184.75 ± 55.24, 12.78 ± 2.1, and 11.28 ± 1.74 µmol/min/g) in G4, respectively. There were no side effects in the kidney function of both G2 and G4, and the levels of cholesterol and triglyceride were also normal. The results demonstrated that phlorotannins have antioxidant properties in vivo and that the diabetic rats had an activated AMPK expression. According to the histological analysis, phlorotannins improved the islet size and reversed necrotic and fibrotic alterations in the pancreas. The results of the present study suggest the use of phlorotannins derived from Sargassum linifolium as an antioxidant and anti-diabetic for an in vivo study. They could be used in developing medicinal preparations for treating diabetes and its related symptoms. Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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17 pages, 3745 KiB

Open AccessArticle

The Effect of Antibiotics on Bacteriome of Sitophilus oryzae and Rhyzopertha dominica as a Factor Determining the Success of Foraging: A Chance for Antibiotic Therapy in Grain Stores

by Olga Kosewska, Sebastian Wojciech Przemieniecki and Mariusz Nietupski

Appl. Sci. 2023, 13(3), 1576; https://doi.org/10.3390/app13031576 - 26 Jan 2023

Cited by 4 | Viewed by 1362

Abstract

Rice weevil (Sitophilus oryzae) and the lesser grain borer (Rhyzopertha dominica) are very important warehouse pests and, therefore, their control is crucial. At a key moment in the life of adult Sitophilus spp., the obligatory symbiotic nature of the [...] Read more.

Rice weevil (Sitophilus oryzae) and the lesser grain borer (Rhyzopertha dominica) are very important warehouse pests and, therefore, their control is crucial. At a key moment in the life of adult Sitophilus spp., the obligatory symbiotic nature of the Sodalis pierantonius bacterium opens up a new perspective for natural antibiotics and bactericides. In this study, we used nanopore sequencing for 16S rRNA barcoding to evaluate the internal bacteriome of S. oryzae and R. dominica and sterilized the insects’ internal microbiome with gentamicin. The treatment of the interior of S. oryzae with gentamicin (30 mg·g⁻¹) hampered insect functioning (supposed lack of DOPA (4-dihydroxyphenylalanine) synthesis, stabilizing the exoskeleton by Sodalis pierantonius symbiont) and elicited a lethal effect in the first stages of this pest’s adult life. In addition, we identified biochemical biomarkers (enzymatic activity and substrate utilization) active in living individuals, but inactive in dead individuals (e.g., C8 esterase/lipase and α-chymotrypsin). Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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18 pages, 1346 KiB

Open AccessArticle

Isolation and Characterization of Biohydrogen-Producing Bacteria for Biohydrogen Fermentation Using Oil Palm Biomass-Based Carbon Source

by Abdullah Amru Indera Luthfi, Peer Mohamed Abdul, Jamaliah Md Jahim, Nurul Sakinah Engliman, Nur Syakina Jamali, Jian Ping Tan, Shareena Fairuz Abdul Manaf, Mohd Shaiful Sajab and Nurul Adela Bukhari

Appl. Sci. 2023, 13(1), 656; https://doi.org/10.3390/app13010656 - 3 Jan 2023

Cited by 5 | Viewed by 2249

Abstract

The effectiveness of biohydrogen conversion from biomass sources is governed by the selection of ideal biohydrogen-producing bacteria to achieve high and consistent production performance. The aim of this research was to isolate and identify a biohydrogen producer in local soil samples, as well [...] Read more.

The effectiveness of biohydrogen conversion from biomass sources is governed by the selection of ideal biohydrogen-producing bacteria to achieve high and consistent production performance. The aim of this research was to isolate and identify a biohydrogen producer in local soil samples, as well as to evaluate its fermentability in biohydrogen production from oil palm empty fruit bunches (OPEFB). To this end, preliminary identification was performed using morphological, phenotype, biological, and 16s rRNA analyses. The fermentability of the isolate was further evaluated in a serum bottle and then in a 1.5 L anaerobic column bioreactor (ACBR) to investigate the potential for biohydrogen production using two OPEFB-based carbon sources: hydrolysate of ammonia fiber expansion (AFEX)-pretreated OPEFB and molasses from dilute acetic acid (DAA)-pretreated OPEFB. The isolated strain, Enterobacter sp. KBH 6958, was found to be capable of producing biohydrogen from various carbon sources via the pyruvate:ferredoxin oxidoreductase (PFOR) pathway. The cumulative conversion of AFEX OPEFB hydrolysate was 45% higher than that observed in DAA OPEFB molasses fermentation in the production of biohydrogen. The biohydrogen yield after fermenting AFEX OPEFB hydrolysate with Enterobacter sp. KBH 6958 was 1.55 mol H₂/mol sugar, with a maximum productivity of 98.1 mL H₂/h (4.01 mmol H₂/L/h), whereas butyrate (10.6 mM), acetate (11.8 mM), and ethanol (4.56 mM) were found to be the major soluble metabolites. This study successfully demonstrated the biotechnological conversion of OPEFB into biohydrogen using a locally isolated strain, which not only solves environmental issues associated with the industry but may also offer a solution to the world’s energy insecurity. Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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17 pages, 3230 KiB

Open AccessArticle

Genomic Insights into Two Endophytic Strains: Stenotrophomonas geniculata NWUBe21 and Pseudomonas carnis NWUBe30 from Cowpea with Plant Growth-Stimulating Attributes

by Olawale Israel Omomowo and Olubukola Oluranti Babalola

Appl. Sci. 2022, 12(24), 12953; https://doi.org/10.3390/app122412953 - 16 Dec 2022

Cited by 3 | Viewed by 1456

Abstract

Endophytic microbiota are being researched as a vital source of beneficial attributes that are of immense importance for enhancing agroecological crop production. In this study, two endophytic strains: Pseudomonas carnis NWUBe30 and Stenotrophomonas geniculata NWUBe21, were isolated from cowpea tissue, and their plant growth-promoting [...] Read more.

Endophytic microbiota are being researched as a vital source of beneficial attributes that are of immense importance for enhancing agroecological crop production. In this study, two endophytic strains: Pseudomonas carnis NWUBe30 and Stenotrophomonas geniculata NWUBe21, were isolated from cowpea tissue, and their plant growth-promoting attributes were assessed. The 16S rRNA gene, as well as the key plant growth-promoting genes that they contain, were subjected to polymerase chain reactions (PCR). Furthermore, their genome was sequenced using the Illumina NovaSeq 6000 systems platform. The results indicated that they possess multiple plant growth-promoting attributes, including the solubilization of phosphates, the production of auxin, siderophore, hydrogen cyanide, exopolysaccharide, ammonia, and 1-aminocyclopropane-1-carboxylic acids. Additionally, the plant growth-promoting genes GCD and ASB were amplified via PCR at their expected base pair value. The genome bioinformatics analysis revealed assembled sizes of 5,901,107 bp for P. carnis NWUBe30, with an average G+C content of 60.2%, and for S. geniculata NWUBe21, 512,0194 bp, with a G+C content of 64.79%. Likewise, genes, such as exopolyphosphatase, ferribacilibactin, betalactone, and lassopeptide, that are responsible for promoting plant growth were identified. This study highlights the biotechnological potential of Stenotrophomonas geniculata strain NWUBe21 and the Pseudomonas carnis strain NWUBe30, which can be harnessed to achieve improvements in sustainable agroecological crop production. Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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10 pages, 895 KiB

Open AccessArticle

Aflatoxin B1 Binding by Lactic Acid Bacteria in Protein-Rich Plant Material Fermentation

by Sari Rämö, Minna Kahala and Vesa Joutsjoki

Appl. Sci. 2022, 12(24), 12769; https://doi.org/10.3390/app122412769 - 13 Dec 2022

Cited by 6 | Viewed by 1902

Abstract

At the same time as the strong ambition to improve sustainability and the healthiness of food systems through a transition towards a more plant-based diet, climate change is increasing the risk of plant diseases. Consequently, mycotoxigenic fungi have become a food safety issue [...] Read more.

At the same time as the strong ambition to improve sustainability and the healthiness of food systems through a transition towards a more plant-based diet, climate change is increasing the risk of plant diseases. Consequently, mycotoxigenic fungi have become a food safety issue of major importance. A variety of strategies to suppress fungal growth in the pre- and postharvest stages of plant production have been established, and the potential of various biological methods has been assessed to ensure food safety. Of the various food microbes, lactic acid bacteria are known for their capacity to suppress the growth of toxigenic fungi and adsorb free mycotoxins. The current study showed that lactic acid fermentation could mitigate aflatoxin risk in plant-based foods through a reduction in free aflatoxin B1. In line with previous studies, in which Lactiplantibacillus plantarum (formerly Lactobacillus plantarum) was shown to reduce the level of free aflatoxin B1 in vitro, L. plantarum was shown to achieve up to a 90% reduction in free aflatoxin B1 in food fermentation. The results showed that traditional lactic acid fermentation, using L. plantarum as the starter strain, could be applied to mitigate aflatoxin B1 contamination risk in proteinaceous plant-based foodstuffs. In a wider context, fermentation using selected strains of lactic acid bacteria as starters could also enhance the availability of nutritious and safer food in terms of mycotoxin risk in low-income countries. Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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17 pages, 13042 KiB

Open AccessArticle

Metabolic Profiling of Streptomyces sp. Strain ess_amH1 Isolated from Apis mellifera yemintica’s Gut Microbiome, and Its Anticancer Activity against Breast Cancer (MCF7) and Hepatocarcinoma (HepG2) Cell Lines, as Well as Antimicrobial Activity

by Nouf Mohammed Al-Enazi, Neveen Abdel-Raouf, Reem Mohammed Alharbi and Essam Nageh Sholkamy

Appl. Sci. 2022, 12(23), 12257; https://doi.org/10.3390/app122312257 - 30 Nov 2022

Cited by 3 | Viewed by 1691

Abstract

Streptomyces is recognized as a crucial generator of bioactive molecules that benefit humanity, such as antibiotics and other medications. The Streptomyces strain obtained from the gut of Apis mellifera yemintica was utilized in this investigation to screen for antibacterial and antiproliferative activities using [...] Read more.

Streptomyces is recognized as a crucial generator of bioactive molecules that benefit humanity, such as antibiotics and other medications. The Streptomyces strain obtained from the gut of Apis mellifera yemintica was utilized in this investigation to screen for antibacterial and antiproliferative activities using secondary metabolites. On the basis of morphological and molecular identification, the isolated strain ess_amH1 was confirmed as Streptomyces sp., and phylogenetic tree construction revealed 96% sequence similarity with Streptomyces griseus. The ethyl acetate solvent extract generated from the strain ess_amH1 demonstrated high antibacterial activity against ATCC bacterial pathogens, as well as pathogenic yeast, according to the disc diffusion assay. The ethyl acetate solvent extract also induced dose-dependent cytotoxicity in breast cancer and hepatocarcinoma cell lines, with IC₅₀ concentrations at 50 and 75 µg/mL, respectively. The findings confirm that the Streptomyces sp. strain ess_amH1 isolated from a competitive symbiotic habitat, i.e., the gut of A. mellifera yemintica, produces promising bioactive chemicals. Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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15 pages, 3900 KiB

Open AccessArticle

Anaerobic Fermentation of Silage from the Above-Ground Biomass of Jerusalem Artichoke (Helianthus tuberosus L.) and Maize (Zea mayse L.) as a New and Promising Input Raw Material for Biogas Production

by Antonín Kintl, Tomáš Vítěz, Igor Huňady, Martin Brtnický, David Novák, Jan Lochman, Monika Vítězová, Tereza Hammerschmiedt, Jiří Holátko and Jakub Elbl

Appl. Sci. 2022, 12(22), 11417; https://doi.org/10.3390/app122211417 - 10 Nov 2022

Cited by 2 | Viewed by 1240

Abstract

Research of new input raw materials for biogas plants is a very actual topic. There are only a very few studies dealing with the possibility of using silage prepared from the above-ground parts of the Jerusalem artichoke (Helianthus tuberosus L.) and maize [...] Read more.

Research of new input raw materials for biogas plants is a very actual topic. There are only a very few studies dealing with the possibility of using silage prepared from the above-ground parts of the Jerusalem artichoke (Helianthus tuberosus L.) and maize (Zea mayse L.) for methane production. This study deals with the determination of methane production and methane content in biogas during the fermentation of maize silage with dissimilar additions of the biomass of the Jerusalem artichoke (JA). Except for the effect of the JA’s addition on the yield of methane, we also studied its potential influence on the inhibition of the process of anaerobic digestion and the bacterial and methanogenic archaeal composition of anaerobic digestate. There were five model silages prepared; two of them contained only maize or JAs, and the remaining three were mixtures of maize and JA silages (30%wt; 50%wt and 70%wt). The fermentation tests showed that the JA addition (from 30 to 70%wt) resulted in the production of biogas decreasing, on average, by 15%. Based on the performed metagenomic analysis, we cannot confirm an essential influence of JA biomass addition on the composition of the community of microorganisms during fermentation. Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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10 pages, 1344 KiB

Open AccessArticle

Comparison of Three DNA Extraction Kits for Assessment of Bacterial Diversity in Activated Sludge, Biofilm, and Anaerobic Digestate

by Maciej Florczyk, Agnieszka Cydzik-Kwiatkowska, Aleksandra Ziembinska-Buczynska and Slawomir Ciesielski

Appl. Sci. 2022, 12(19), 9797; https://doi.org/10.3390/app12199797 - 29 Sep 2022

Cited by 4 | Viewed by 2111

Abstract

Direct DNA analysis is the most widely used approach for microorganism characterization in natural and built environments; therefore, reliable and effective methods of nucleic acid extraction for samples from particular types of environments are needed. In this study, we compared three commercial kits [...] Read more.

Direct DNA analysis is the most widely used approach for microorganism characterization in natural and built environments; therefore, reliable and effective methods of nucleic acid extraction for samples from particular types of environments are needed. In this study, we compared three commercial kits for metagenomic DNA extraction from three types of biomass: activated sludge, biofilm, and anaerobic digestate. The yield, purity, and quality of DNA were measured, and the effect that the DNA kit had on the subsequent microbial community analysis was assessed with amplified ribosomal intergenic spacer analysis (ARISA). Amplicons were analyzed automatically utilizing capillary electrophoresis. For the activated sludge and digestate, the suggested kit is FastDNA™ Spin Kit for Soil (MP Biomedicals). This kit allowed the highest DNA yield to be obtained and provided the highest biodiversity. For biofilm with a high content of extracellular polymeric substances, the FavorPrep™ Soil DNA Isolation Mini Kit (FAVORGEN) is recommended. This kit allowed to obtain the highest biodiversity and provided the most reliable results of genetic distance assessment in this type of biomass. Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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13 pages, 1713 KiB

Open AccessArticle

Anaerobic Digestion in the Presence of Antimicrobials—Characteristics of Its Parameters and the Structure of Methanogens

by Małgorzata Czatzkowska, Izabela Wolak, Ewa Korzeniewska and Monika Harnisz

Appl. Sci. 2022, 12(17), 8422; https://doi.org/10.3390/app12178422 - 24 Aug 2022

Viewed by 1245

Abstract

Antibiotics are widely used in human and veterinary medicine, and they are accumulated in various types of waste, including sewage sludge (SS) and cattle slurry (CS), processed by anaerobic digestion (AD). Anaerobic treatment is a method enabling the stabilization of these substrates before [...] Read more.

Antibiotics are widely used in human and veterinary medicine, and they are accumulated in various types of waste, including sewage sludge (SS) and cattle slurry (CS), processed by anaerobic digestion (AD). Anaerobic treatment is a method enabling the stabilization of these substrates before transferring to the environment. The presence of contaminants, such as antimicrobials, in organic substrates processed by AD is not regulated by law. The accumulation of antimicrobials in SS and CS is a crucial issue because it may reduce the effectiveness of their stabilization. This study aimed to evaluate the long-term impact of growing concentrations of a mixture of antibiotics on the AD of SS and CS. Methane (CH₄) yield, which is the main indicator of the efficiency of AD, was determined. Antibiotic exposure significantly decreased CH₄ production only in SS (by 5–8% relative to control; p < 0.05). The copy numbers of the mcrA gene, a functional marker of methanogenesis, were not reliable indicators of CH₄ yields in either substrate. During long-term AD, the average concentrations of the mcrA gene were determined at 10⁸ in 1 g of SS digestate and from 10⁸ to 10⁹ in 1 g of CS digestate samples. At the end of long-term AD, methanogens belonging to the family Methanosarcinaceae were more prevalent than methanogens of the family Methanosaetaceae both in SS and CS samples (10⁷ and 10⁸–10⁹ gene copies in 1 g of digestate, respectively). Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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15 pages, 3218 KiB

Open AccessArticle

Constitutive High Expression Level of a Synthetic Deleted Encoding Gene of Talaromyces minioluteus Endodextranase Variant (r–TmDEX49A–ΔSP–ΔN30) in Komagataella phaffii (Pichia pastoris)

by Roberto Carlos Arísticas Ribalta, Lisandra Martínez Valdés, Meinardo Lafargue Gámez, Sonia Rodríguez Davydenko, Eric Dubreucq, Veronique Perrier, Benoît Moreau and Reinaldo Fraga Vidal

Appl. Sci. 2022, 12(15), 7562; https://doi.org/10.3390/app12157562 - 27 Jul 2022

Viewed by 1732

Abstract

In the sugar industry, dextran generates difficulties in the manufacturing process. Using crude dextranase (EC 3.2.1.11) to eliminate dextran in sugar is an effective practice. In this study, a synthetic dextranase-encoding gene of the filamentous fungus Talaromyces minioluteus, lacking its putative native [...] Read more.

In the sugar industry, dextran generates difficulties in the manufacturing process. Using crude dextranase (EC 3.2.1.11) to eliminate dextran in sugar is an effective practice. In this study, a synthetic dextranase-encoding gene of the filamentous fungus Talaromyces minioluteus, lacking its putative native signal peptide (1–20 amino acids) and the next 30 amino acids (r–TmDEX49A–ΔSP–ΔN30), was fused to the Saccharomyces cerevisiae prepro α–factor (MFα–2) signal sequence and expressed in Komagataella phaffii under the constitutive GAP promoter. K. phaffii DEX49A–ΔSP–ΔN30, constitutively producing and secreting the truncated dextranase, was obtained. The specific activity of the truncated variant resulted in being nearly the same in relation to the full-length mature enzyme (900–1000 U·mg⁻¹ of protein). At shaker scale (100 mL) in a YPG medium, the enzymatic activity was 273 U·mL⁻¹. The highest production level was achieved in a fed-batch culture (30 h) at 5 L fermenter scale using the FM21–PTM1 culture medium. The enzymatic activity in the culture supernatant reached 1614 U·mL⁻¹, and the productivity was 53,800 U·L⁻¹·h⁻¹ (53.8 mg·L⁻¹·h⁻¹), the highest reported thus far for a DEX49A variant. Dextran decreased r–TmDEX49A–ΔSP–ΔN30 mobility in affinity gel electrophoresis, providing evidence of carbohydrate–protein interactions. K. phaffii DEX49A–ΔSP–ΔN30 shows great potential as a methanol-free, commercial dextranase production system. Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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26 pages, 1461 KiB

Open AccessReview

An Overview of the Relevance of Human Gut and Skin Microbiome in Disease: The Influence on Atopic Dermatitis

by Maria Pia Ferraz

Appl. Sci. 2023, 13(18), 10540; https://doi.org/10.3390/app131810540 - 21 Sep 2023

Cited by 2 | Viewed by 1024

Abstract

It is acknowledged that humans have a diverse and abundant microbial community known as the human microbiome. Nevertheless, our comprehension of the numerous functions these microorganisms have in human health is still in its early stages. Microorganisms belonging to the human microbiome typically [...] Read more.

It is acknowledged that humans have a diverse and abundant microbial community known as the human microbiome. Nevertheless, our comprehension of the numerous functions these microorganisms have in human health is still in its early stages. Microorganisms belonging to the human microbiome typically coexist with their host, but in certain situations, they can lead to diseases. They are found in several areas of the human body in healthy individuals. The microbiome is highly diverse, and its composition varies depending on the body site. It primarily comprises bacteria that are crucial for upholding a state of well-being and equilibrium. The microbiome’s influence on atopic dermatitis development was, therefore, analyzed. The importance of maintaining a balanced and functional commensal microbiota, as well as the use of prebiotics and probiotics in the prevention and treatment of atopic dermatitis were also explored. The skin microbiome’s association with atopic dermatitis will allow for a better understanding of pathogenesis and also exploring new therapeutic approaches, making the skin microbiome an increasingly relevant therapeutic target. Full article

(This article belongs to the Special Issue Applied Microbiology for Biotechnology, Environment, Medicine, and Food)

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