Hydrobiology, Volume 1, Issue 3 (September 2022) – 6 articles

The study of lipopeptides and their related compounds produced by various living organisms from bacteria to marine invertebrates is of fundamental interest for medicinal chemistry, pharmacology, and practical clinical medicine. Using the principles of retrosynthetic analysis of linear and cyclic peptides, the pharmacological activity of unique, unusual, and rare fatty acids (FA) that are part of natural lipopeptides was investigated. To search for new biologically active natural metabolites from natural sources, more than 350 FA incorporated into linear and cyclic peptides isolated from bacteria, cyanobacteria, microalgae, marine invertebrates, fungal endophytes, and microorganisms isolated from sediments are presented. Biological activities have been studied experimentally in various laboratories, as well as data obtained using QSAR (Quantitative Structure-Activity Relationships) algorithms. According to the data obtained, several FA were identified that demonstrated strong antibacterial, antimicrobial, antifungal, or antitumor activity. Along with this, FA have been found that have shown rare properties such as antiviral, antidiabetic, anti-helmintic, anti-inflammatory, anti-psoriatic, anti-ischemic, and anti-infective activities. In addition, FA have been found as potential regulators of lipid metabolism, as well as agents for the treatment of acute neurological disorders, as well as in the treatment of atherosclerosis and multiple sclerosis. For 36 FA, 3D graphs are presented, which demonstrate their predicted and calculated activities. Full article

Methane is produced by various natural processes that directly or indirectly contribute to the entire Earth’s methane budget. If the Earth’s overall methane budget becomes imbalanced, CH₄ has an impact on climate change. Wetlands, rice fields, animals, factories, and fossil fuels are major sources of methane emissions. Among all the resources, wetlands and rice fields are more prominent factors in methane emission, dependent on the water table, temperature, and vegetation. Our study employed the GIS remote sensing technique to analyze methane emissions from 2003 to 2021 in the northern part of India, East Uttar Pradesh and Bihar, and the northeast region of India that is Assam. We also predicted the water table, temperature, and vegetation as raw materials for methane creation. Water table, temperature, and vegetation are essential for wetland ecosystem life, particularly for methanogenic organisms; however, the water table and temperature are critical for rice plant growth and development. With the help of GIS remote sensing, India’s monthly rainfall pattern and the water table, vegetation, and temperature pattern over 41 years were analyzed. Our key findings highlight the importance of GIS remote-sensing-based monitoring of methane gas emissions from wetlands and rice fields for their management. Full article

The concentrations of 29 elements in the soft tissues and of 24 elements in the shells of mussels (Mytilus galloprovincialis) collected in one selected recreational and two relatively polluted zones were determined and are presented. The high levels of elements in the mussels from a relatively polluted zone of the harbor (Kamyshovaya Bay) could be associated with phytoplankton, terrigenous matter and anthropogenic sources, but did not harm the mussel population, according to the calculated average condition factors. The low levels of the studied elements and condition factors in the mussels from another harbor (Sevastopol Bay) can be explained by the high circulation and influence of submarine desalinated waters in this zone. The mussels from a recreational site in the South coast of Crimea (Foros) showed high levels of the examined elements, commonly due to the coastal weathering of typical local rocks. The found levels of the radionuclides ⁴⁰K, ¹³⁷Cs, ²³²Th, ²²⁶Ra and ²³⁵U in mussel soft tissues were below the minimum detectable concentrations. The calculated enrichment factors and soft tissue/shells ratios demonstrated differences between groups of elements among the studied sites. Full article

Industrialization, natural processes, and urbanization have potentially accelerated the pace and the level of heavy metals (HMs) in soil and underground water. These HMs may be accumulated in plants and animals when they take up such contaminated water, and then make their way into human food chains. Several remediation technologies have been employed to take up HMs. Diverse conventional means such as ion exchange, electrolytic technologies, and chemical extraction have been employed in the past, but the majority of these techniques are not economical for extensive projects and they need stringent control and continuous monitoring. These technologies also have low efficiency for effective removal of HMs. In this context, algae offer an eco-friendly and sustainable alternative for remediation of HMs from polluted water. The accumulation of HMs by macro and microalgae is advantageous for phycoremediation compared to other approaches that are not economical and not environmentally friendly. So, there is an urgent necessity to refine the chances of accumulation of HMs in algae, employing the techniques of genetic engineering to create transgenic species for over-expressing metallothioneins and phytochelatins, which may form complexes with HMs and store them in vacuoles to make the maximum use of phytoaccumulation while also removing hazardous metals from the aquatic habitats. This review outlines the major sources of HMs, their adverse effects on humans, the potential of algae in phytoremediation (called phycoremediation), and their uptake mechanism of HMs. Full article

On the quest of discovering novel local strains of microalgal species that can be effectively cultured with industrial perspectives, two cyanobacterial strains Anabaena sp. and Cyanothece sp. were isolated from the lagoonal and saltworks waters of the Messolonghi lagoon (W. Greece). They were batch cultured at 20–21.5 °C in six combinations of three salinities (20, 40 and 60 ppt) and two light intensities (2000 and 8000 lux) resulting in: (a) Anabaena grew best at 20 and 40 ppt at high light of 8000 lux. (b) Cyanothece grew best at 40 and 60 ppt at high light. (c) Low light of 2000 lux resulted in much reduced growth in all treatments. (d) Maximal biomass yield was 1.27 and 1.77 g d.w./L for Anabaena and Cyanothece, respectively. Overall, both species have culture potential yielding biomass comparable to the average (or above) relevant values reported in the literature for various cultured cyanobacteria. Full article

In this work, staurozoans of two distinct morphotypes are reported in Kitsunezaki (Ishinomaki City, Miyagi, Japan) in the years following the Great East Japan Earthquake and Tsunami. Staurozoa specimens were collected from Eisenia and Gelidium macroalgal beds at the Kitsunezaki survey site (October 2019–July 2021). Morphological observations indicated that the Kitsunezaki staurozoans represented two species, Haliclystus inabai and Calvadosia nagatensis, but molecular analyses of the genetic markers 16S rRNA and COI suggested that the former actually encompasses two distinct lineages, H. inabai and a cryptic as yet unnamed species. Phylogenetic analysis reveals the two H. inabai lineages are separated by significant divergences for both gene markers. H. inabai lineage 1 includes specimens sampled with molecular sequences from Hokkaido (Japan) and Kitsunezaki (Japan), whereas H. inabai lineage 2 includes sequences from Victoria (Australia), Kitsunezaki, as well as populations that appeared in a lab in Germany and aquariums in Tsuruoka and Kagoshima (Japan) and Québec (Canada). Conversely, C. nagatensis from Kitsunezaki appears to be a species distributed only in the temperate NW Pacific. Observations on early life stages of H. inabai lineage 2 within aquarium tanks permitted confirmation of the presence of “microhydrula” settled larva, frustules, and elongated settled larvae. C. nagatensis was collected from the Kitsunezaki survey site in warm months only, and always exhibited gonads, while H. inabai stauromedusae were collected in most months throughout the year, with gonads usually present irrespective of season. An extensive literature review covering more than 100 years and observations in this study revealed seaweed and seagrass as the primary substrates for these two Staurozoa species. Our findings show C. nagatensis is associated with just two types of algal substrates and seagrass, while H. inabai has a much broader substrate preference, consistent with its wider geographic distribution. These findings have contributed to our understanding of Staurozoa epibiotic associations in exposed bays during the recovery period following a major natural disaster. Full article