The food microbiology and biotechnology team of Henan University of science and technology made new progress in the direction of Luzhou flavor Baijiu brewing microorganisms
By: Date: 2022-07-14 Categories: foodtechnology Tags: ,
Recently, the food microbiology and biotechnology team of the school of food and bioengineering of Henan University of science and technology published a series of research papers (154 (2022) 112764) online in the international authoritative journal LWT food science and Technology (if=6.056, zone 1, Chinese Academy of Sciences); 163 (2022) 113502; 165 (2022) 113703), systematically revealed the microbial succession characteristics, interaction relationship and driving mechanism of Luzhou flavor Baijiu brewing from the perspectives of pit mud, Daqu and fermented grains. Postgraduates Mao Jingjing and Zhao Lina are the first authors of the thesis respectively, Professor Gu Shaobin is the independent corresponding author, and Henan University of science and technology is the first unit of the thesis.
 
As the functional carrier of pits, pit mud is not only the production basis of Luzhou flavor Baijiu, but also the key factor to determine the style and quality of Luzhou flavor Baijiu. Based on Illumina miseq high-throughput sequencing data, Professor Gu Shaobin’s team adopted inter- & Intra Kingdom co-occurrence network analysis technology reveals the relationship between bacteria fungi Archaea co-occurrence network in pit mud, in which the network complexity of bacterial community is much higher than that of fungi and archaea community. The key groups of pit mud mainly come from bacterial community rather than fungi and archaea community, and the positive correlation between groups is dominant; In addition, Mantel test results show that the physical and chemical characteristics of pit mud (especially pH, humic acid, available phosphorus and organic matter) are closely related to the composition and structure of microbial communities and their main ecological clusters. In order to better understand the microbiome structure of pit mud and the ecological rules guiding community assembly, this study is of great significance for manipulating microbial resources and (/or) controlling environmental factors of pit mud for pit management and sustainable brewing.
 
Daqu is the soul of liquor, and Daqu plays a vital role in the production of Luzhou flavor Baijiu. The team studied Daqu samples and found that cyanobacteria, Proteobacteria and Firmicutes were the dominant bacteria of bacterial community in Daqu; Lactobacillus, weissella, Leuconostoc and Staphylococcus are the dominant bacteria in the bacterial community; The bacterial community structure is closely related to the properties of Daqu (especially acidity, cellulase activity and water content). The above findings help to clarify the complex relationship between the bacterial community succession and its physical and chemical properties of Luzhou flavor Daqu, lay a theoretical foundation for improving the quality of Luzhou flavor Baijiu through biological enhancement and (/or) Regulation of environmental factors, and have guiding significance for improving the controllability, safety and quality of Baijiu production.
 
Fermented grains are important carriers of material circulation, energy flow and information transmission in Baijiu brewing, and are the key to determine the quality of liquor. The traditional solid-state fermentation of Luzhou flavor Baijiu is a complex process involving rich and rare microorganisms. For a long time, people have mainly focused on rich groups, and little is known about rare groups with relative abundance less than 0.01%, which may seriously underestimate the key role of rare groups in the brewing process of Luzhou flavor Baijiu. The team detected 176 rare fungal genera from the fermented grains samples studied, but only 9 rich fungal genera, and the co-occurrence network analysis found that 14 key groups in the fermentation process were rare fungi. In addition, environmental fungi (Daqu, pit mud and air fungi) and physical and chemical characteristics of fermented grains (especially reducing sugar content) jointly promoted the succession of rich and rare fungi in the fermentation process of Luzhou flavor Baijiu. This study provides new insights into the dynamic succession of fungal communities in the process of Baijiu fermentation, and lays a theoretical foundation for improving the quality and controllability of Baijiu production.
 
Paper link:https://doi.org/10.1016/j.lwt.2022.113703 ;
 
   https://doi.org/10.1016/j.lwt.2022.113502 ;
 
   https://doi.org/10.1016/j.lwt.2021.112764