Unveiling of Unique Microbiome Resource Having High Antimicrobial Peptide Activity Endowed With Agriculture and Industrial Applications From Pukzing Cave

Abstract Cave ecosystems are considered as a specific niche for the presence of the endemic and extremophilic microorganism. In this study, Pukzing cave documented as the biggest cave of Mizoram, Northeast India was explored for bacterial diversity using both culture-based and culture-independent methods. Culture dependent method revealed 235 bacterial isolates using three different treatments i.e. heat, cold and normal. The highest bacterial population was recovered from heat treatment (n=97; 41.2%) followed by normal (n=79; 33.6%) and cold treatment (n=59; 25.1%) which clearly indicates the dominance of extremophiles. The antimicrobial potential of all the isolates was checked and found that 48 (20.4%) isolates showing antimicrobial ability against all tested pathogens. Phylum Actinobacteria was found to be dominant and showed antimicrobial potential. Modular biosynthetic genes like PKS type II, PKS type I and NRPS genes were detected in 37, 46 and 57 respectively. Similarly, the community-based analysis also predicted the dominance of phylum Actinobacteria using the sequencing of both hyper-variable regions (HVR) i.e. V3 and V4. Subsystem annotation using the V4 region predicted two functions associated with amino acid and its derivatives and cofactors, vitamins, prosthetic groups, pigments functions. A positive strong correlation in relative abundance at the phylum level using Spearman correlation was observed in the V4 region. We conclude that the cave environment harbors unique microbial flora and hypervariable region V4 is more informative as compared to hyper-variable region III. These six microbial pathogens i.e. Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Micrococcus luteus, Bacillus subtilis, and Candida albicans was selected for screening as they are well known for different disease cause organism in various fields such as agriculture, domestic animals and human health. Higher activity of AMP assay against these microbes indicates that cave microbial communities could be a potential source of future genomic resources.