Analysis of Differences in Bacterial Community Structure and Physicochemical Indices between Yellow and Black High-temperature Daqu Produced in Handan

WANG Yurong; HOU Qiangchuan; TIAN Longxin; ZHANG Zhendong; HUANG Like; KONG Jinzhao; HAO Guangfei; GUO Zhuang

doi:10.13982/j.mfst.1673-9078.2024.10.1024

Abstract：Illumina MiSeq high-throughput sequencing was used to analyze the differences in bacterial community structure between yellow and black high-temperature Daqu.Subsequently,the physicochemical indices of Daqu samples were measured,and the correlations between bacterial community structure and physicochemical indices were analyzed.Finally,the pure culture technique was used to explore the bacterial populations present in the Daqu samples.The sequencing results showed that the average relative abundances of Thermoactinomyces(21.04％),Limosilactobacillus(14.30％),and Weissella(3.15％)in the yellow high-temperature Daqu were significantly higher(P＜0.05)than those(1.93％,0.036％,and 0.027％,respectively)in the black high-temperature Daqu,whereas the average relative abundances of Lentibacillus(3.30％)and Kroppenstedtia(2.81％)in the yellow high-temperature Daqu were significantly lower(P＜0.05)than those(34.45％and 20.75％,respectively)in the black high-temperature Daqu.In addition,LEfSe analysis showed that Thermoactinomyces and Lentibacillus could be used as biomarkers for yellow and black high-temperature Daqu,respectively.The measurement results of physicochemical indices showed that compared to the black high-temperature Daqu,the yellow high-temperature Daqu exhibited signifiicantly higher water content,liquefaction power,saccharification power,esterification power,and alcoholic power(P＜0.05),and significantly lower acidity(P＜0.05).Correlation analysis revealed significant correlations between the dominant bacterial genera and physicochemical indices in the two types of high-temperature Daqu(P＜0.05).A total of 33 bacterial strains were isolated from high-temperature Daqu samples using the pure culture technique.The strains comprised ten species under five genera,with Bacillus being the dominant genus and B.licheniformis being the dominant isolate(accounting for 30.30％of the total number of isolates).Hence,the two types of high-temperature Daqu exhibited significant differences in bacterial community structure and physicochemical indices,and their bacterial community structures were correlated with their physicochemical indices.