Antimicrobial, antioxidant and probiotics characterization of dominant bacterial isolates from traditional fermented fish of Manipur, North-East India

Utonga-kupsu, Hentak and Ngari are traditional fermented fish products produced by the Manipuri people living in the North-Eastern part of India. The present study was designed with the aim to isolate, identify and characterize the microorganisms present in these fermented foods. Bacterial pure cultures were isolated using serially diluted samples and were further identified by conventional biochemical tests and Sanger sequencing of 16s rRNA gene. Results show that the number of bacterial count in Nutrient agar and Starch casein agar was 14-20 and 10-16 CFU/g, respectively. A total of 46 morphologically different bacterial strains were identified and assigned under the phylum Firmicutes. Identified bacterial strains belonged to the genus Bacillus and Staphylococcus and majority of the isolates were Bacillus subtilis and Staphylococcus nepalensis. Bacterial isolate HNS60 isolated from Hentak and identified as Bacillus subtilis was shown to possess high antimicrobial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. Most of the identified bacteria were shown to possess DPPH radical scavenging as well as phosphatase, amylase, protease and cellulose activities. The isolate HNS60 contain high antimicrobial, enzymatic and probiotics activity which might responsible for the possible health benefits of the fermented foods. Utonga-kupsu, Hentak and Ngari thus can be further exploited as a potential source of probiotics and natural antioxidants.