AUTHOR=Kharnaior Pynhunlang , Tamang Jyoti Prakash 

TITLE=Metagenomic-Metabolomic Mining of Kinema, a Naturally Fermented Soybean Food of the Eastern Himalayas

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.868383

DOI=10.3389/fmicb.2022.868383

ISSN=1664-302X

ABSTRACT=<p><italic>Kinema</italic> is a popular sticky fermented soybean food of the Eastern Himalayan regions of North East India, east Nepal, and south Bhutan. We hypothesized that some dominant bacteria in <italic>kinema</italic> may contribute to the formation of targeted and non-targeted metabolites for health benefits; hence, we studied the microbiome–metabolite mining of <italic>kinema</italic>. A total of 1,394,094,912 bp with an average of 464,698,304 ± 120,720,392 bp was generated from <italic>kinema</italic> metagenome, which resulted in the identification of 47 phyla, 331 families, 709 genera, and 1,560 species. Bacteria (97.78%) were the most abundant domain with the remaining domains of viruses, eukaryote, and archaea. <italic>Firmicutes</italic> (93.36%) was the most abundant phylum with 280 species of <italic>Bacillus</italic>, among which <italic>Bacillus subtilis</italic> was the most dominant species in <italic>kinema</italic> followed by <italic>B. glycinifermentans</italic>, <italic>B. cereus</italic>, <italic>B. licheniformis</italic>, <italic>B. thermoamylovorans</italic>, <italic>B. coagulans</italic>, <italic>B. circulans</italic>, <italic>B. paralicheniformis</italic>, and <italic>Brevibacillus borstelensis</italic>. Predictive metabolic pathways revealed the abundance of genes associated with metabolism (60.66%), resulting in 216 sub-pathways. A total of 361 metabolites were identified by metabolomic analysis (liquid chromatography-mass spectrophotometry, LC-MS). The presence of metabolites, such as chrysin, swainsonine, and 3-hydroxy-L-kynurenine (anticancer activity) and benzimidazole (antimicrobial, anticancer, and anti-HIV activities), and compounds with immunomodulatory effects in <italic>kinema</italic> supports its therapeutic potential. The correlation between the abundant species of <italic>Bacillus</italic> and primary and secondary metabolites was constructed with a bivariate result. This study proves that <italic>Bacillus</italic> spp. contribute to the formation of many targeted and untargeted metabolites in <italic>kinema</italic> for health-promoting benefits.</p>