Genomic insights from Lactiplantibacillus plantarum BRD3A isolated from Atingba, a traditional fermented rice-based beverage and analysis of its potential for probiotic and antimicrobial activity against Methicillin-resistant Staphylococcus aureus.

Lactiplantibacillus plantarum BRD3A was isolated from Atingba, a traditional fermented rice-based beverage of Manipur. Its genomic sequence has 13 contigs and its genome size is 3,320,817 bp with a guanine-cytosine (GC) ratio of 44.6%. It comprises 3185 genes including 3112 coding sequences (CDSs), 73 RNAs (including 66 tRNAs and others), and one clustered regularly interspaced short palindromic repeat (CRISPR) array. A comparative and phylogenetic analysis with the Lp. plantarum genome shows that this strain has close similarity with other Lp. plantarum strains and about 99% average nucleotide identity. Functional annotation using evolutionary genealogy of genes-non-supervised orthologous groups (EggNOG) and Kyoto Encyclopedia of Genes and Genomes (KEGG) reveals genes associated with various biological processes such as metabolism, genetic information processing, and transport functions. Furthermore, the strain harbors bacteriocins like plantaricin E, Plantaricin F, and Enterocin X categorized under class IIb by the BAGEL4 database, indicating its potential antimicrobial properties. Additionally, AntiSMASH web server predicted four secondary regions-T3PKS, terpene, cyclic lactone inducer, and ribosomally synthesized and post-translationally modified peptide (RiPP)-suggesting an even higher antimicrobial potential. We validated the antimicrobial activity of Lp. plantarum BRD3A through in vitro experiments in which it exhibited promising bactericidal effects on methicillin-resistant Staphylococcus aureus, inhibiting their biofilm growth. These findings indicate the potential of Lp. plantarum BRD3A to be used as an alternative to conventional antibiotics.

Isolation and Characterization of Bacteria from Natural Hot Spring and Insights into the Thermophilic Cellulase Production.

A thermophilic cellulase-producing bacterium, Bacillus velezensis strain MRC 5958, from Bakra natural hot Springs, India was characterized through genome sequencing. It has a genome size of 4,467,129 bp and a GC content of 45.7%. A cellulase purified from its fermentation broth has a molecular weight of about 18 kDa. The optimum temperature and pH for carboxymethyl cellulase activity were at 55 °C and pH ~ 7.0. The enzyme is stable over a wide range of temperatures from 30 °C to 70 °C with maximum activity observed at 48 h of incubation. The strain produces cellulase on alkali-treated sugarcane bagasse, rice straw, rice husk, rice bran, and sawdust. The sugarcane bagasse exhibited the most effective carbon source for cellulase production at (85 U/ml) followed by rice bran (68 U/ml), rice husk (60 U/ml), rice straw (48 U/ml), and sawdust (39 U/ml). Therefore, this strain can be a potential thermostable cellulase-producing candidate for converting the waste biomass into biofuel and other industrial enzymes.

Integrated genomics and proteomics analysis of Paenibacillus peoriae IBSD35 and insights into its antimicrobial characteristics.

Antimicrobial resistance has been developing fast and incurring a loss of human life, and there is a need for new antimicrobial agents. Naturally occurring antimicrobial peptides offer the characteristics to counter AMR because the resistance development is low or no resistance. Antimicrobial peptides from Paenibacillus peoriae IBSD35 cell-free supernatant were salted out and purified using chromatography and characterized with liquid chromatography-tandem-mass spectrometry. The extract has shown a high and broad spectrum of antimicrobial activity. Combining the strain IBSD35 genome sequence with its proteomic data enabled the prediction of biosynthetic gene clusters by connecting the peptide from LC-MS/MS data to the gene that encode. Antimicrobial peptide databases offered a platform for the effective search, prediction, and design of AMPs and expanded the studies on their isolation, structure elucidation, biological evaluation, and pathway engineering. The genome-based taxonomy and comparisons have shown that P. peoriae IBSD35 is closely related to Paenibacillus peoriae FSL J3-0120. P. peoriae IBSD35 harbored endophytic trait genes and nonribosomal peptide synthases biosynthetic gene clusters. The comparative genomics revealed evolutionary insights and facilitated the discovery of novel SMs using proteomics from the extract of P. peoriae IBSD35. It will increase the potential to find novel bio-molecules to counter AMR.

Analysis of Antimicrobial Peptide Metabolome of Bacterial Endophyte Isolated From Traditionally Used Medicinal Plant Millettia pachycarpa Benth.

Increasing prevalence of antimicrobial resistance (AMR) has posed a major health concern worldwide, and the addition of new antimicrobial agents is diminishing due to overexploitation of plants and microbial resources. Inevitably, alternative sources and new strategies are needed to find novel biomolecules to counter AMR and pandemic circumstances. The association of plants with microorganisms is one basic natural interaction that involves the exchange of biomolecules. Such a symbiotic relationship might affect the respective bio-chemical properties and production of secondary metabolites in the host and microbes. Furthermore, the discovery of taxol and taxane from an endophytic fungus, Taxomyces andreanae from Taxus wallachiana, has stimulated much research on endophytes from medicinal plants. A gram-positive endophytic bacterium, Paenibacillus peoriae IBSD35, was isolated from the stem of Millettia pachycarpa Benth. It is a rod-shaped, motile, gram-positive, and endospore-forming bacteria. It is neutralophilic as per Joint Genome Institute's (JGI) IMG system analysis. The plant was selected based on its ethnobotany history of traditional uses and highly insecticidal properties. Bioactive molecules were purified from P. peoriae IBSD35 culture broth using 70% ammonium sulfate and column chromatography techniques. The biomolecule was enriched to 151.72-fold and the yield percentage was 0.05. Peoriaerin II, a highly potent and broad-spectrum antimicrobial peptide against Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922, and Candida albicans ATCC 10231 was isolated. LC-MS sequencing revealed that its N-terminal is methionine. It has four negatively charged residues (Asp + Glu) and a total number of two positively charged residues (Arg + Lys). Its molecular weight is 4,685.13 Da. It is linked to an LC-MS/MS inferred biosynthetic gene cluster with accession number A0A2S6P0H9, and blastp has shown it is 82.4% similar to fusaricidin synthetase of Paenibacillus polymyxa SC2. The 3D structure conformation of the BGC and AMP were predicted using SWISS MODEL homology modeling. Therefore, combining both genomic and proteomic results obtained from P. peoriae IBSD35, associated with M. pachycarpa Benth., will substantially increase the understanding of antimicrobial peptides and assist to uncover novel biological agents.

Bio-mining the forest ecosystem of North East India for identification of antimicrobial metabolites from fungi through submerged fermentation.

In this study, fungi isolated from less explored forest soil ecosystem of Northeast India were studied for the production of potential antimicrobial metabolites (AMM). Out of the 68 fungi isolated from forest soil of Manipur, 7 of them showed AMA against the test pathogens. Among them, Aspergillus terreus (IBSD-F4) showed the most significant activity against Staphylococcus aureus (ATCC-25923), Bacillus anthracis (IBSD-C370), Pseudomonas fluorescens (ATCC-13525), Salmonella typhimurium (ATCC-14028), Escherichia coli (ATCC-25922) and Candida albicans (ATCC-10231). The active metabolite was harvested from the fermentation broth of Aspergillus terreus and purified by column chromatography and semi preparative-HPLC. The compound was identified as 'Sclerotionigrin A' on the basis of UV-vis spectra, MS and NMR analyses. This compound was reported for the first time from A. terreus. The study highlights, the importance of exploring microbes from forest soil for identification of bioactive metabolites for future drug development.