Study On Microbial Diversity Of Suantangzi Sourdough In Liaodong Region And Its Effect On The Quality Of Bread

Suantangzi is a natural corn fermented food,which is mainly popular in eastern Liaoning.Its delicate and smooth texture is popular with everyone.Suantangzi dough is corn-based sourdough.At present,there is no systematic research on the microbial composition of Suantangzi sourdough and its effect on bread quality.This article collected Suantangzi sourdough in Dandong,Anshan,and Benxi of Liaoning Province,and analyzed the microbial diversity using high-throughput sequencing technology.The effects of different Suantangzi sourdough on bread were compared by measuring the baking quality and storage quality of bread,and the correlation between the proportion of main microorganisms in the sourdough and bread quality was analyzed.Through high-throughput sequencing technology,34 bacterial genera?relative abundance> 0.1%?were identified.The main bacterial genera were Lactobacillus,Acetobacter,Leuconostoc,Lactococcus,Clostridium_sensu_stricto₁,Acinetobacter,Bifidobacterium,Streptococcaceae.Lactic acid bacteria were dominant in the bacterial structure of Suantangzi sourdough.Among them,Lactobacillus was the main dominant genus,and the others were Leuconostoc and Lactococcus.The number of acetic acid bacteria in a small amount of Suantangzi sourdough was higher in the bacterial structure.Acetobacter,Acinetobacter,Bifidobacterium,Clostridium_sensu_stricto₁ were the main different genus.The 32 bacterial genera were mainly positively correlated,and no correlation was found in the other bacterial genera.Membrane transport,energy metabolism,carbohydrate metabolism,amino acid metabolism,replication and repair were the five KEGG pathways of gene expression in a variety of bacteria.A total of 35 fungal genera?relative abundance> 0.1%?were identified.The main fungal genera were Candida,Pichia,Dipodascus,Zygosaccharomyces,Naumovozyma,Trichosporon,Guehomyces,Podospora,Bullera.Yeasts were dominant in the structure of Suantangzi sourdough fungi.Candida and Pichia werethe main dominant genera,the others were Dipodascus,Zygosaccharomyces,and Naumovozyma.Candida,Pichia,Dipodascus,Guehomyces,Naumovozyma,Trichosporon,Zygosaccharomyces were the main different fungi.In addition,18.2%of the gene sequence was not identified at the genus level,indicating that Suantangzi sourdough contained a large number of fungal resources and there were still many fungi that had not yet been discovered.There were positive correlations among 14 fungal genera,but no correlation was found among the other fungal genera.There were differences in the quality of bread added with different Suantangzi sourdough.The total content of lactic acid bacteria and yeast in Suantangzi sourdough was high,and the higher the content of yeast,the lower hardness,stickiness,and mastication,the lower the change of hardness and moisture during the storage,that was,the better quality of bread.The reason why WMSB-E and WMSB-F?both from Anshan Xiuyan?sourdough bread were superior and similar in baking quality and storage quality was that they have similar flora structure,with Lactobacillus as the main bacterial genus,and Pichia as the main fungi genus.Other Suantangzi sourdoughs from the same area had different microflora structures,and there were differences in bread quality.