Isolation and Identification of Fungi with Glucoamylase Activity from Loog-pang-khao-mak (A Thai Traditional Fermentation Starter)

Loog-pang-khao-mak is a Thai traditional fermentation starter that has been used for production of Thai fermented foods for decades. This research aimed to isolate and identify the fungi that produce effective glucoamylase but low ethanol content from the starter. A total of 166 isolates were screened from twelve samples of Loog-pang-khao-mak accumulated from 12 provinces in Thailand using dichloran rose bengal chloramphenicol agar (DRBC Agar). Seventy-nine isolates that effectively hydrolyze starch were selected for glucoamylase activity and alcohol production assay. Three yeast isolates exhibited high glucoamylase activity ranging from 139.14 to 140.94 unit/ml and lowest alcohol yield of 0.41% (v/v) were Saccharomycopsis fibuligera using morphological and molecular identification. The five isolates of mold exhibited high glucoamylase activity (149.20 to 152.60 unit/ml) were identified as Aspergillus niger, Aspergillus oryzae and Amylomyces rouxii. These findings provide further knowledge on the fungi and their potential use as traditional inocula for fermentation of food products.