Discovery of putative inhibitors of human Pkd1 enzyme: Molecular docking, dynamics and simulation, QSAR, and MM/GBSA.

Polycystic kidney disease is the most prevalent hereditary kidney disease globally and is mainly linked to the overexpression of a gene called PKD1. To date, there is no effective treatment available for polycystic kidney disease, and the practicing treatments only provide symptomatic relief. Discovery of the compounds targeting the PKD1 gene by inhibiting its expression under the disease condition could be crucial for effective drug development. In this study, a molecular docking and molecular dynamic simulation, QSAR, and MM/GBSA-based approaches were used to determine the putative inhibitors of the Pkd1 enzyme from a library of 1379 compounds. Initially, fourteen compounds were selected based on their binding affinities with the Pkd1 enzyme using MOE and AutoDock tools. The selected drugs were further investigated to explore their properties as drug candidates and the stability of their complex formation with the Pkd1 enzyme. Based on the physicochemical and ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) properties, and toxicity profiling, two compounds including olsalazine and diosmetin were selected for the downstream analysis as they demonstrated the best drug-likeness properties and highest binding affinity with Pkd1 in the docking experiment. Molecular dynamic simulation using Gromacs further confirmed the stability of olsalazine and diosmetin complexes with Pkd1 and establishing interaction through strong bonding with specific residues of protein. High biological activity and binding free energies of two complexes calculated using 3D QSAR and Schrodinger module, respectively further validated our results. Therefore, the molecular docking and dynamics simulation-based in-silico approach used in this study revealed olsalazine and diosmetin as potential drug candidates to combat polycystic kidney disease by targeting Pkd1 enzyme.

Modulating the pH profile of vanillin dehydrogenase enzyme from extremophile Bacillus ligniniphilus L1 through computational guided site-directed mutagenesis.

Vanillin dehydrogenase (VDH) has recently come forward as an important enzyme for the commercial production of vanillic acid from vanillin in a one-step enzymatic process. However, VDH with high alkaline tolerance and efficiency is desirable to meet the biorefinery requirements. In this study, computationally guided site-directed mutagenesis was performed by increasing the positive and negative charges on the surface and near the active site of the VDH from the alkaliphilic marine bacterium Bacillus ligniniphilus L1, respectively. In total, 20 residues including 15 from surface amino acids and 5 near active sites were selected based on computational analysis and were subjected to site-directed mutations. The optimum pH of the two screened mutants including I132R, and T235E from surface residue and near active site mutant was shifted to 9, and 8.6, with a 2.82- and 2.95-fold increase in their activity compared to wild enzyme at pH 9, respectively. A double mutant containing both these mutations i.e., I132R/T235E was produced which showed a shift in optimum pH of VDH from 7.4 to 9, with an increase of 74.91 % in enzyme activity. Therefore, the double mutant of VDH from the L1 strain (I132R/T235E) produced in this study represents a potential candidate for industrial applications.

Synthesis of novel metal silica nanoparticles exhibiting antimicrobial potential and applications to combat periodontitis.

Periodontitis is a severe form of gum disease caused by bacterial plaque that affects millions of people and has substantial worldwide health and economic implications. However, current clinical antiseptic and antimicrobial drug therapies are insufficient because they frequently have numerous side effects and contribute to widespread bacterial resistance. Recently, nanotechnology has shown promise in the synthesis of novel periodontal therapeutic materials. Nanoparticles are quickly replacing antibiotics in the treatment of bacterial infections, and their potential application in dentistry is immense. The alarming increases in antimicrobial resistance further emphasize the importance of exploring and utilizing nanotechnology in the fight against tooth diseases particularly periodontitis. We developed 16 different combinations of mesoporous silica nanomaterials in this study by ageing, drying, and calcining them with 11 different metals including silver, zinc, copper, gold, palladium, ruthenium, platinum, nickel, cerium, aluminium, and zirconium. The antibacterial properties of metal-doped silica were evaluated using four distinct susceptibility tests. The agar well diffusion antibacterial activity test, which measured the susceptibility of the microbes being tested, as well as the antibacterial efficacy of mesoporous silica with different silica/metal ratios, were among these studies. The growth kinetics experiment was used to investigate the efficacy of various metal-doped silica nanoparticles on microbial growth. To detect growth inhibitory effects, the colony-forming unit assay was used. Finally, MIC and MBC tests were performed to observe the inhibition of microbial biofilm formation. Our findings show that silver- and zinc-doped silica nanoparticles synthesized using the sol-gel method can be effective antimicrobial agents against periodontitis-causing microbes. This study represents the pioneering work reporting the antimicrobial properties of metal-loaded TUD-1 mesoporous silica, which could be useful in the fight against other infectious diseases too.

Metagenomic investigations on antibiotic resistance and microbial virulence in oil-polluted soils from China.

Engine oil spills have been associated with a wide range of human health problems. However, little is known about the effects of petroleum hydrocarbon pollution on soil microbial communities. In this study, three samples were collected from oil-polluted soils (OPS), and one control soil (CS) from Taolin town, China, near the old engine's scrapes was used. The aims of this study were to conduct metagenomic sequencing and subsequently perform resistome and virulome analysis. We also aimed to validate anti-microbial resistance and virulence genes and anti-bacterial sensitivity profiles among the isolates from oil-polluted soils. The OPS microbial community was dominated by bacterial species compared to the control samples which were dominated by metazoans and other organisms. Secondly, the resistosome and virulome analysis showed that ARGs and virulence factors were higher among OPS microbial communities. Antibiotic susceptibility assay and qPCR analysis for ARGs and virulence factors showed that the oil-polluted soil samples had remarkably enhanced expression of these ARGs and some virulence genes. Our study suggests that oil pollution contributes to shifting microbial communities to more resilient types that could survive the toxicity of oil pollution and subsequently become more resilient in terms of higher resistance and virulence potential.

Genomic and biotechnological potential of a novel oil-degrading strain Enterobacter kobei DH7 isolated from petroleum-contaminated soil.

In this study, a novel oil-degrading strain Enterobacter kobei DH7 was isolated from petroleum-contaminated soil samples from the industrial park in Taolin Town, Lianyungang, China. The whole genome of the strain was sequenced and analyzed to reveal its genomic potential. The oil degradation and growth conditions including nitrogen, and phosphorus sources, degradation cycle, biological dosing, pH, and oil concentration were optimized to exploit its commercial application. The genome of the DH7 strain contains 4,705,032 bp with GC content of 54.95% and 4653 genes. The genome analysis revealed that there are several metabolic pathways and enzyme-encoding genes related to oil degradation in the DH7 genome, such as the paa gene cluster which is involved in the phenylacetic acid degradation pathway, and complete degradation pathways for fatty acid and benzoate, genes related to chlorinated alkanes and olefins degradation pathway including adhP, frmA, and adhE, etc. The strain DH7 under the optimized conditions has demonstrated a maximum degradation efficiency of 84.6% after 14 days of treatment using synthetic oil, which comparatively displays a higher oil degradation efficiency than any Enterobacter species known to date. To the best of our knowledge, this study presents the first-ever genomic studies related to the oil degradation potential of any Enterobacter species. As Enterobacter kobei DH7 has demonstrated significant oil degradation potential, it is one of the good candidates for application in the bioremediation of oil-contaminated environments.

Genomic insights into the metabolic potential of a novel lignin-degrading and polyhydroxyalkanoates producing bacterium Pseudomonas sp. Hu109A.

Lignin is the most abundant heterogeneous aromatic polymer present on planet Earth and is recalcitrant to degradation due to its complex structure, therefore, imposing a challenge to biorefinery procedures. Identifying new microbial strains with the potential to valorize lignin into useful compounds is indispensable to achieving green sustainable consumption. In this study, a novel Pseudomonas strain designated as Hu109A was isolated from the termite gut and the genome was sequenced and analyzed further. The genome contains a circular chromosome with the size of 5,131,917 bp having a GC content of 62.6% and 4698 genes. Genome annotation reveals that the strain possesses lignin-oxidizing enzymes such as DyP-type peroxidases, laccase, dioxygenase, and aromatic degradation gene clusters. The genome also contains O-methyltransferases which function in accelerating the lignin degradation by methylating the free hydroxyl phenolic compounds which in high concentration can inhibit the lignin peroxidase. Furthermore, the genome exhibits two gene clusters encoding the enzymes related to polyhydroxyalkanoates (PHA) synthesis. Pseudomonas strains are generally assumed to produce medium chain length PHAs (mcl-PHAs) only, however, strain Hu109A contains both Class II PHA synthase genes involved in mcl-PHAs and Class III PHA synthase gene involved in short-chain length PHAs (scl-PHAs). Gas Chromatography-Mass Spectrometry (GC-MS) analysis showed that using 1 g/L lignin as the sole carbon source, the maximum production of PHA observed was 103.68 mg/L, which increased to 186 mg/L with an increase in lignin concentration to 3 g/L. However, PHA production while using glucose as the sole carbon source was significantly lower than the lignin source, and maximum production was 125.6 mg/L with 3 g/L glucose. The strain Hu109A can tolerate a broad range of solvents including methanol, isopropanol, dimethylformamide, and ethanol, revealing its potential for industrial applications.

Meta-omics approaches reveal unique small RNAs exhibited by the uncultured microorganisms dwelling deep-sea hydrothermal sediment in Guaymas Basin.

Small regulatory RNAs (sRNAs) are present in almost all investigated microbes, regarded as modulators and regulators of gene expression and also known to play their regulatory role in the environmentally significant process. It has been estimated that less than 1% of the microbes in nature are culturable in the laboratory, hindering our understanding of their physiology, and living strategies. However, recent big advancing of DNA sequencing and omics-related data analysis makes the understanding of the genetics, metabolic potentials, even ecological roles of uncultivated microbes possible. In this study, we used a metagenome and metatranscriptome-based integrated approach to identify small RNAs in the microbiome of Guaymas Basin sediments. Hundreds of environmental sRNAs comprising 228 groups were identified based on their homology, 82% of which displayed high similarity with previously known small RNAs in Rfam database, whereas, "18%" are putative novel sRNA motifs. A putative cis-acting sRNA potentially binding to methyl coenzyme M reductase, a key enzyme in methanogenesis or anaerobic oxidation of methane (AOM), was discovered in the genome of ANaerobic MEthane oxidizing archaea group 1 (ANME-1), which were the dominate microbe in the sample. These sRNAs were actively expressed in local Guaymas Basin hydrothermal environment, suggesting important roles of sRNAs in regulating microbial activity in natural environments.

Discovery and characterization of dual inhibitors of human Vanin-1 and Vanin-2 enzymes through molecular docking and dynamic simulation-based approach.

The vanins are ectoenzymes with pantetheinase activity and are involved in recycling pantothenic acid (vitamin B5) from pantetheine. Elevated levels of vanin have been linked with the development and severity of several diseases, including steatosis, diabetes, skin diseases, cancer, inflammatory diseases etc. Therefore, vanins have previously been used as a potential drug target to combat related diseases. In this study, we used a molecular docking and molecular dynamic simulation-based approach to screen dual inhibitors of hVnn1, and hVnn2 from a library of 120 chemical candidates. Molecular docking of drug candidates with hVnn1, and hVnn2 using GOLD and MOE revealed that the chemical compound "methotrexate (CID: 126941)" has the highest binding affinity against both the target enzymes which was further validated through molecular dynamic simulation. Toxicity profiling of drug candidates evaluated using Lipinski's rule of five and Molsoft tool, and AdmetSar 2.0 confirms the drug suitability of methotrexate, therefore, suggesting its use as a potential therapeutic agent to inhibit the activity of vainin enzyme in related disease conditions.

Diverse Subclade Differentiation Attributed to the Ubiquity of Prochlorococcus High-Light-Adapted Clade II.

Prochlorococcus is the key primary producer in marine ecosystems, and the high-light-adapted clade II (HLII) is the most abundant ecotype. However, the genomic and ecological basis of Prochlorococcus HLII in the marine environment has remained elusive. Here, we show that the ecologically coherent subclade differentiation of HLII corresponds to genomic and ecological characteristics on the basis of analyses of 31 different strains of HLII, including 12 novel isolates. Different subclades of HLII with different core and accessory genes were identified, and their distribution in the marine environment was explored using the TARA Oceans metagenome database. Three major subclade groups were identified, viz., the surface group (HLII-SG), the transition group (HLII-TG), and the deep group (HLII-DG). These subclade groups showed different temperature ranges and optima for distribution. In regression analyses, temperature and nutrient availability were identified as key factors affecting the distribution of HLII subclades. A 35% increase in the relative abundance of HLII-SG by the end of the 21st century was predicted under the Representative Concentration Pathway 8.5 scenario. Our results show that the ubiquity and distribution of Prochlorococcus HLII in the marine environment are associated with the differentiation of diverse subclades. These findings provide insights into the large-scale shifts in the Prochlorococcus community in response to future climate change. IMPORTANCEProchlorococcus is the most abundant oxygenic photosynthetic microorganism on Earth, and high-light-adapted clade II (HLII) is the dominant ecotype. However, the factors behind the dominance of HLII in the vast oligotrophic oceans are still unknown. Here, we identified three distinct groups of HLII subclades, viz., the surface group (HLII-SG), the transition group (HLII-TG), and the deep group (HLII-DG). We further demonstrated that the ecologically coherent subclade differentiation of HLII corresponds to genomic and ecological characteristics. Our study suggests that the differentiation of diverse subclades underlies the ubiquity and distribution of Prochlorococcus HLII in the marine environment and provides insights into the shifts in the Prochlorococcus community in response to future climate change.

Understanding Interaction Patterns within Deep-Sea Microbial Communities and Their Potential Applications.

Environmental microbes living in communities engage in complex interspecies interactions that are challenging to decipher. Nevertheless, the interactions provide the basis for shaping community structure and functioning, which is crucial for ecosystem service. In addition, microbial interactions facilitate specific adaptation and ecological evolution processes particularly essential for microbial communities dwelling in resource-limiting habitats, such as the deep oceans. Recent technological and knowledge advancements provide an opportunity for the study of interactions within complex microbial communities, such as those inhabiting deep-sea waters and sediments. The microbial interaction studies provide insights into developing new strategies for biotechnical applications. For example, cooperative microbial interactions drive the degradation of complex organic matter such as chitins and celluloses. Such microbiologically-driven biogeochemical processes stimulate creative designs in many applied sciences. Understanding the interaction processes and mechanisms provides the basis for the development of synthetic communities and consequently the achievement of specific community functions. Microbial community engineering has many application potentials, including the production of novel antibiotics, biofuels, and other valuable chemicals and biomaterials. It can also be developed into biotechniques for waste processing and environmental contaminant bioremediation. This review summarizes our current understanding of the microbial interaction mechanisms and emerging techniques for inferring interactions in deep-sea microbial communities, aiding in future biotechnological and therapeutic applications.

Microbial diversity and community structure in deep-sea sediments of South Indian Ocean.

Microbial communities composed of bacteria, archaea and fungi play a pivotal role in driving the biogeochemical cycles in the marine ecosystem. Despite the vastness of the South Indian Ocean, only a few studies reported the simultaneous analysis of bacterial, archaeal and fungal diversity therein, particularly archaeal and fungal communities in deep-sea environments received less attention previously. In this study, microbial diversity, community composition and dynamics in microbial community structure in eight deep-sea sediment samples collected from different sites at varying depths of the South Indian Ocean were explored using Next-Generation Sequencing. In total, 21 bacterial phyla representing 541 OTUs were identified from the eight samples, where phylum Proteobacteria was found as the most abundant bacterial phylum in five out of eight samples. Firmicutes and Chloroflexi were the dominant phyla in the rest of the three samples. In the case of archaea, uncultured species belonging to the phyla Thaumarchaeota and Euryarchaeota were the abundant taxa in all the samples. Similarly, Ascomycota and Basidiomycota were the most abundant fungal phyla present therein. In all the eight samples studied here, about 10-58% and 19-26% OTUs in archaeal and fungal communities were mapped to unclassified taxa respectively, suggesting the lack of representation in databases. Co-occurrence network analysis further revealed that bacterial communities tend to be more dynamic than archaeal and fungal communities. This study provides interesting insights into the microbial diversity, community composition and dynamics in microbial community structure in the deep-sea sediments of the South Indian Ocean.

A Nanoinformatics Approach to Evaluate the Pharmacological Properties of Nanoparticles for the Treatment of Alzheimer's Disease.

BACKGROUND: Alzheimer's disease is a destructive nervous system disease which causes structural, biochemical and electrical abnormalities inside the human brain and results due to genetic and various environmental factors. Traditional therapeutic agents of Alzheimer's disease such as tacrine and physostigmine have been found to cause adverse effects to the nervous system and gastrointestinal tract. Nanomaterials like graphene, metals, carbon-nanotubes and metal-oxides are gaining attention as potential drugs against Alzheimer's disease due to their properties such as large surface area, which provide clinical efficiency, targeted drug designing and delivery. OBJECTIVES: Designing new drugs by using experimental approaches is a time-consuming, tedious and laborious process which also requires advanced technologies. This study aims to identify some novel drug candidates against Alzheimer's disease with no or less associated side effects using molecular docking approaches Methods: In this study, we utilized nanoinformatics based approaches for evaluating the interaction properties of various nanomaterials and metal nanoparticles with the drug targets, including TRKB kinase domain, EphA4 and histone deacetylase. Furthermore, the drug-likeness of carbon nanotubes was confirmed through ADME analysis. RESULTS: Carbon nanotubes, either single or double-walled in all the three-configurations, including zigzag, chiral, and armchair forms, are found to interact with the target receptors with varying affinities Conclusion: This study provides novel and clearer insights into the interaction properties and drug suitability of known putative nanoparticles as potential agents for the treatment of Alzheimer's disease.

Repurposing the inhibitors of COVID-19 key proteins through molecular docking approach.

The severe acute respiratory syndrome coronavirus 2, famous as COVID-19, has recently emerged as a novel virus and imposed an unrecoverable loss to global health and the economy. At present, no effective drug against COVID-19 is available and currently available viral drugs targeting the viral key proteins of related RNA viruses have been found ineffective against COVID-19. This study evaluated the inhibitors of the viral proteases and other structural proteins, including Mpro (Main protease), RdRp (RNA-dependent RNA polymerase), and spike glycoprotein from synthetic and herbal sources. The molecular docking-based approach was used to identify and evaluate the putative inhibitors of key proteins involved in viral replication and survival. Furthermore, the pharmaceutical properties of these inhibitors were explored to predict the drug suitability as a therapeutic agent against COVID-19 by considering adsorption, distribution, metabolism, and excretion (ADME) using Lipinski's rule or SwissADME. Trandolapril, Benazepril, and Moexipril were evaluated as the best non-carcinogenic and non-toxic potential inhibitors of spike glycoprotein, Mpro, and RdRp, respectively. The drugs showed significant binding affinities against the active sites of respective SARS_CoV-2 target proteins; hence, they can be used as potential therapeutic agents for the treatment of COVID-19.

Bio-purification of sugar industry wastewater and production of high-value industrial products with a zero-waste concept.

In recent years, biorefinery approach with a zero-waste concept has gained a lot research impetus to boost the environment and bioeconomy in a sustainable manner. The wastewater from sugar industries contains miscellaneous compounds and need to be treated chemically or biologically before being discharged into water bodies. Efficient utilization of wastewater produced by sugar industries is a key point to improve its economy. Thus, interest in the sugar industry wastes has grown in both fundamental and applied research fields, over the years. Although, traditional methods being used to process such wastewaters are effective yet are tedious, laborious and time intensive. Considering the diverse nature of wastewaters from various sugar-manufacturing processes, the development of robust, cost-competitive, sustainable and clean technologies has become a challenging task. Under the recent scenario of cleaner production and consumption, the biorefinery and/or close-loop concept, though using different technologies and multi-step processes, namely, bio-reduction, bio-accumulation or biosorption using a variety of microbial strains, has stepped-up as the method of choice for a sustainable exploitation of a wide range of organic waste matter along with the production of high-value products of industrial interests. This review comprehensively describes the use of various microbial strains employed for eliminating the environmental pollutants from sugar industry wastewater. Moreover, the main research gaps are also critically discussed along with the prospects for the efficient purification of sugar industry wastewaters with the concomitant production of high-value products using a biorefinery approach. In this review, we emphasized that the biotransformation/biopurification of sugar industry waste into an array of value-added compounds such as succinic acid, L-arabinose, solvents, and xylitol is a need of hour and is futuristic approach toward achieving cleaner production and consumption.

Cultivating microalgae in wastewater for biomass production, pollutant removal, and atmospheric carbon mitigation; a review.

Water shortage is one of the leading global problems along with the depletion of energy resources and environmental deterioration. Recent industrialization, global mobility, and increasing population have adversely affected the freshwater resources. The wastewater sources are categorized as domestic, agricultural and industrial effluents and their disposal into water bodies poses a harmful impact on human and animal health due to the presence of higher amounts of nitrogen, phosphorus, sulfur, heavy metals and other organic/inorganic pollutants. Several conventional treatment methods have been employed, but none of those can be termed as a universal method due to their high cost, less efficiency, and non-environment friendly nature. Alternatively, wastewater treatment using microalgae (phycoremediation) offers several advantages over chemical-based treatment methods. Microalgae cultivation using wastewater offers the highest atmospheric carbon fixation rate (1.83 kg CO2/kg of biomass) and fastest biomass productivity (40-50% higher than terrestrial crops) among all terrestrial bio-remediators with concomitant pollutant removal (80-100%). Moreover, the algal biomass may contain high-value metabolites including omega-3-fatty acids, pigments, amino acids, and high sugar content. Hence, after extraction of high-value compounds, residual biomass can be either directly converted to energy through thermochemical transformation or can be used to produce biofuels through biological fermentation or transesterification. This review highlights the recent advances in microalgal biotechnology to establish a biorefinery approach to treat wastewater. The articulation of wastewater treatment facilities with microalgal biorefinery, the use of microalgal consortia, the possible merits, and demerits of phycoremediation are also discussed. The impact of wastewater-derived nutrient stress and its exploitation to modify the algal metabolite content in view of future concerns of cost-benefit ratios of algal biorefineries is also highlighted.

A Molecular Docking Approach to Evaluate the Pharmacological Properties of Natural and Synthetic Treatment Candidates for Use against Hypertension.

Cardiovascular diseases (CVDs) have become the leading cause of disability and death worldwide, particularly in low- and middle-income countries. Hypertension, a major cause of CVD progression, is widely attributable to genetic, behavioral, and environmental risk factors. Among the genetic reasons, angiotensin II enzyme, produced as a result of abnormal functioning of the renin⁻angiotensin system, is reported as the foremost cause of hypertension. A cascade of genes, including those encoding for WNK kinases (WNK1 and WNK4), Bp1, Bp2, angiotensinogen, and other enzymes, is involved in the conversion of angiotensin I to angiotensin II. However, the angiotensin-converting enzyme (ACE) plays a crucial role in this pathway. Therefore, ACE could be a potential therapeutic target in regulating the conversion of angiotensin I to angiotensin II and eventually controlling hypertension. In this study, a molecular docking-based approach was utilized for identifying and evaluating potential inhibitors of ACE present in herbs, other natural sources, and synthetic sources, on the basis of these compounds' binding affinities and other physicochemical features. In addition, the suitability of these inhibitors as drugs for biological systems, considering their adsorption, distribution, metabolism, and excretion (ADME), was predicted using Lipinski's rule. In conclusion, our study provides a novel and clearer insight into the interaction properties of known putative inhibitors of ACE.

Seasonal succession and spatial distribution of bacterial community structure in a eutrophic freshwater Lake, Lake Taihu.

In aquatic ecosystems, both phytoplankton and bacteria play pivotal roles. Based on 16S rRNA gene sequencing, considerable research focused on phytoplankton colony attached and free-living bacteria has revealed the close relationship between them, and indicated that the entire bacterial community mediates crucial biogeochemical processes in aquatic ecosystems. However, our understanding of their distribution patterns and response to environmental factors remains poor. Besides, picocyanobacteria, which were omitted from attached bacteria analysis, were reported to be important in cyanobacterial blooms. To explore the spatiotemporal variation of the entire bacterial community with their driving environmental factors and detect the relationships among them, we collected 61 water samples spanning one year and the entire Lake Taihu regions for surveying the entire bacterial community. Our results indicated: 1) seasonal variation of the bacterial community composition was stronger than spatial variation due to the clearly seasonal variation of Microcystis, Synechococcus (pico-cyanobacteria) and other bacteria (Actinomycetales, Pirellulaceae and Sphingobacteriaceae); 2) the spatial distribution of the bacterial community showed that different phyla were dominant in different regions; 3) the bacterial co-occurrence networks varied seasonally and were dominated by Microcystis, ACK-M1, Chthoniobacteraceae, Synechococcus, Pirellulaceae and Pelagibacteraceae; 4) phytoplankton density, chlorophyll a, water temperature and total nitrogen were the major factors that drove the spatiotemporal variation of bacterial community composition. This study revealed the seasonal succession and spatial distribution of the entire bacterial community in Lake Taihu, providing new insights into the relationship between water bloom-forming cyanobacterial species and other bacteria, and their response to environmental factors in eutrophic freshwater ecosystem.

Biogenic Nanoparticle‒Chitosan Conjugates with Antimicrobial, Antibiofilm, and Anticancer Potentialities: Development and Characterization.

In the 21st century, with ever-increasing consciousness and social awareness, researchers must tackle the microbial infections that pose a major threat to human safety. For many reasons, the emergence/re-emergence of threatening pathogens has increased and poses a serious challenge to health care services. Considering the changing dynamics of 21st-century materials with medical potentialities, the integration of bioactive agents into materials to engineer antibacterial matrices has received limited attention so far. Thus, antimicrobial active conjugates are considered potential candidates to eradicate infections and reduce microbial contaminations in healthcare facilities. In this context, eco-friendly and novel conjugates with antimicrobial, antibiofilm, and anticancer potentialities were developed using biogenic silver nanoparticles (AgNPs) from Convolvulus arvensis (C. arvensis) extract and chitosan (CHI). A range of instrumental and imaging tools, i.e., UV-Vis and FTIR spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDX), and X-ray diffraction (XRD), were employed to characterize the freshly extracted C. arvensis AgNPs. Biogenic AgNPs obtained after a 24-h reaction period were used to engineer CHI-based conjugates and designated as CHI‒AgNPs1 to CHI‒AgNPs5, subject to the C. arvensis AgNPs concentration. After the stipulated loading period, 92% loading efficiency (LE) was recorded for a CHI‒AgNPs3 conjugate. Gram+ and Gram- bacterial isolates, i.e., Staphylococcus aureus, and Escherichia coli, were used to test the antibacterial activities of newly developed CHI‒AgNPs conjugates. In comparison to the control sample with bacterial cell count 1.5 × 108 CFU/mL, a notable reduction in the log values was recorded for the CHI‒AgNPs3 conjugate. The antibiofilm potential of CHI‒AgNPs conjugates was tested against Pseudomonas aeruginosa. Moreover, the CHI‒AgNPs3 conjugate also showed substantial cytotoxicity against the MCF-7 (breast cancer) cell line. In summary, the newly engineered CHI‒AgNPs conjugates with antibacterial, antibiofilm, and anticancer potentialities are potential candidate materials for biomedical applications.

Omics Technologies for Microalgae-based Fuels and Chemicals: Challenges and Opportunities.

BACKGROUND: Microalgae have been suggested as promising feedstocks of significant biotechnological interest due to their enormous potential for the sustainable production of industrially valuable compounds such as lipids/fatty acids, proteins, metabolites, pigments, and biofuels. However, exploitation of algal biomass for commercial purposes is still in its infancy due to the dearth of the knowledge regarding state-of-the-art sophisticated technologies. OBJECTIVES: The main objective of the study was to review the explosions of innovative strategies that biological sciences have witnessed over the past several years, enabling the scientific community and research-based organizations to scrutinize entire classes of biomolecules from a cell type or whole organism, collectively titled as 'Omics, including genomics, transcriptomics, proteomics and lipidomics. METHODS: An effort has been made to analyze the relative advantages and drawbacks of these technologies by reviewing and consulting the available literature. RESULTS: Nevertheless, these 'Omics strategies have played a key role in the better understanding of the underlying mechanisms of specific gene products, regulatory constraints, metabolic pathways and potential genes and protein targets which might be employed in tailoring microalgae for enhanced productivity. In this critical review, an understanding of recent omics technologies, their potential applications, and limitations for microalgae-based fuel and other commodity chemicals are comprehensively discussed. CONCLUSION: In the scenario of uncertain petro-based reserves, global warming and energy insecurity, the exploration of metabolic potentialities of microalgae using "Omics" are believed to be a green and environmentally-responsive approach that will further expand its industrial and environmental scope.

Engineering Ligninolytic Consortium for Bioconversion of Lignocelluloses to Ethanol and Chemicals.

BACKGROUND: Rising environmental concerns and recent global scenario of cleaner production and consumption are leading to the design of green industrial processes to produce alternative fuels and chemicals. Although bioethanol is one of the most promising and eco-friendly alternatives to fossil fuels yet its production from food and feed has received much negative criticism. OBJECTIVE: The main objective of this study was to present the noteworthy potentialities of lignocellulosic biomass as an enormous and renewable biological resource. The particular focus was also given on engineering ligninolytic consortium for bioconversion of lignocelluloses to ethanol and chemicals on sustainable and environmentally basis. METHODS: Herein, an effort has been made to extensively review, analyze and compile salient information related to the topic of interest. Several authentic bibliographic databases including PubMed, Scopus, Elsevier, Springer, Bentham Science and other scientific databases were searched with utmost care, and inclusion/ exclusion criterion was adopted to appraise the quality of retrieved peer-reviewed research literature. RESULTS: Bioethanol production from lignocellulosic biomass can largely satisfy the possible inconsistency of first-generation ethanol since it utilizes inedible lignocellulosic feedstocks, primarily sourced from agriculture and forestry wastes. Two major polysaccharides in lignocellulosic biomass namely, cellulose and hemicellulose constitute a complex lignocellulosic network by connecting with lignin, which is highly recalcitrant to depolymerization. Several attempts have been made to reduce the cost involved in the process through improving the pretreatment process. While, the ligninolytic enzymes of white rot fungi (WRF) including laccase, lignin peroxidase (LiP), and manganese peroxidase (MnP) have appeared as versatile biocatalysts for delignification of several lignocellulosic residues. The first part of the review is mainly focused on engineering ligninolytic consortium. In the second part, WRF and its unique ligninolytic enzyme-based bio-delignification of lignocellulosic biomass, enzymatic hydrolysis, and fermentation of hydrolyzed feedstock are discussed. The metabolic engineering, enzymatic engineering, synthetic biology aspects for ethanol production and platform chemicals production are comprehensively reviewed in the third part. Towards the end information is also given on futuristic viewpoints. CONCLUSION: In conclusion, given the present unpredicted scenario of energy and fuel crisis accompanied by global warming, lignocellulosic bioethanol holds great promise as an alternative to petroleum. Apart from bioethanol, the simultaneous production of other value-added products may improve the economics of lignocellulosic bioethanol bioconversion process.