Culturable fungal diversity in the fermented fish food ‘Nafam’ of the Bodo community of Assam

Nafam is a traditional, non-salted, alkaline-fermented fish product prepared by the Bodo community in Assam, India. Despite its cultural importance, the fungal diversity associated with nafam remains unexplored. This study aimed to isolate and identify culturable fungi from four nafam samples under aerobic, microaerobic, and anaerobic conditions using potato dextrose agar. Fungal isolates were characterized morphologically and identified by sequencing the internal transcribed spacer (ITS) region. A total of 36 distinct isolates were obtained, including yeasts such as Candida parapsilosis , Pichia kudriavzevii , and Saccharomyces cerevisiae , and filamentous fungi such as Aspergillus flavus , Penicillium compactum , Talaromyces sp., and Paecilomyces sp. Representative strains were screened for amylase, cellulase, protease, and urease activities using agar-based enzymatic assays. Nearly half of the isolates exhibited at least one enzymatic function, with several strains showing multiple hydrolytic activities. This study provides the first comprehensive account of culturable fungi in nafam and identifies enzymatically active species with potential functional roles in alkaline fish fermentation. These findings offer a foundation for future research on microbial contributions to fermentation, product safety, and biotechnological applications in traditional ethnic foods. ● This is the first comprehensive fungal diversity study on the ethnic food ‘ nafam ’ ● Nafam is non-salted and alkaline, unlike other acidic and salted fermented fish food ● CFU counts were higher in case of aerobic than microaerobic and anaerobic fungi ● Fungi with amylase, cellulase, protease and urease activities are recorded in nafam