Screening and evaluation of Monascus purpureus FJMR24 for enhancing the raw material utilization rate in rice wine brewing.

Abstract

The rapid development of the rice wine industry has increased the demand for raw materials worldwide. A fungal strain with good adaptability to rice wine brewing conditions, which can also enhance the utilization rate of raw materials (URRM), thus increasing the production efficiency, was sought in the present research. The strain FJMR24 was successfully isolated and screened from 35 fermentation starters and exhibited high amylase activity (2200.9 ± 18.5 U g-1 ) and high glucoamylase activity (2330.4 ± 31.9 U g-1 ). Based on a morphological examination and a sequence analysis of the internal transcribed spacer (ITS) gene and β-tubulin gene, FJMR24 was identified as Monascus purpureus, which is an edible and versatile fungus that plays a dominant role in the processing of Hong Qu. A moderate pH of 5-6 under incubation at 35 °C for 5-6 days was favorable for the growth and enzyme production of FJMR24. The strain could also tolerate the extreme conditions of 15-45 °C, 18% ethanol (v/v), and an acidity of pH 2. The excellent fermentation adaptability of FJMR24 might enable it to retain high enzyme activity during rice wine brewing. As a result of the action of FJMR24, the URRM of the base liquor increased by around 26% due to increased starch hydrolysis efficiency, which was mainly due to the high unit enzyme activity of FJMR24. This study provides perspectives for the application of a M. purpureus strain with high starch hydrolysis activity for enhancing the URRM in traditional rice wine brewing. © 2020 Society of Chemical Industry.