Microbial diversity in ngari, hentak and tungtap, fermented fish products of North-East India

Ngari, hentak and tungtap are traditional fermented fish products of North-East India. Eighteen samples of ngari, hentak and tungtap were collected and were analysed for microbial load. Lactic acid bacteria, endospore-forming rods, yeasts and aerobic mesophilic counts ranged from 4.0 to 7.2, 3.3-4.6, <1-3.5 and 4.3-7.3 log c.f.u./g, respectively. Lactic acid bacteria were identified as Lactococcus lactis subsp. cremoris, Lactococcus plantarum, Enterococcus faecium, Lactobacillus fructosus, Lactobacillus amylophilus, Lactobacillus coryniformis subsp. torquens and Lactobacillus plantarum. Endospore-forming rods were identified as Bacillus subtilis and Bacillus pumilus, aerobic coccal strains were identified as Micrococcus. Yeasts were identified as species of Candida and Saccharomycopsis. Pathogenic contaminants were detected in all samples, however, none of the sample contained more than 10(2) c.f.u./g of Bacillus cereus, 10(3) c.f.u./g of Staphylococcus aureus and enterobacteriaceae population, respectively. Enzymatic and antimicrobial activities of the isolates were tested. None of the strains produced biogenic amines in the method applied. Most strains of LAB had a high degree of hydrophobicity, indicating their 'probiotic' characters. This study has demonstrated the microbial diversity within the species of lactic acid bacteria, Bacillus and yeasts.