Received: 18-05-2020 / Accepted: 10-08-2020
This experiment was conducted to find the fungal strains with high saccharification activity isolated from the alcohol fermentation starters collected in Nga Son, Hau Locdistrict, Thanh Hoa province and growing well under normal conditions to increase the alcohol yield and decrease fermentation time in alcohol production. The contents of the study include the isolation of mold strains from traditional alcoholic fermentation starters, evaluation of amylase production, and saccharification of the isolated fungal strains using methods described by Xu-Cong & cs., (2012); Scheherazed & cs., (2016); Samson & Hoekstra(2002). Besides, the effects of cultural conditions on the saccharification of selected fungal strains were surveyed. Seventeen strains of fungi isolated from alcoholic fermentation starter samples produced amylase with activitiesfrom 2.0 to 4.5 U/ml. Among them, two mold strains NS1.1 and HL2 exhibited the highest saccharification when they grew on the block of sticky rice. The sugar content in the solution obtained from the fermented rice block of the NS 1.1 strain reached 7.02µM, 6.18µM with the HL2 strain. The appropriate temperature for the selected strains exhibited amylase activity ranging from 25C-35C, optimum at 30C. The comparative result of the 18S rRNA nucleotide sequence showed that the strain NS 1.1 has 99% similarity to the one of Rhizopus oryzea strain 150138 and was named Rhizopus oryzaestrain NS1.1.