Prevalence and diversity of lactic acid bacteria in Chinese traditional sourdough revealed by culture dependent and pyrosequencing approaches

Abstract

Abstract The aim of this study was to investigate the microbiota of lactic acid bacteria (LAB) in fifteen different samples of Chinese traditional sourdough collected from different regions through culture dependent and pyrosequencing approaches. The median value of cell density of lactic acid bacteria was found to be 9.60 log cfu/g and the median values of pH and total titratable acidity were 3.69 and 11.77 ml, respectively. A total of 246 presumptive LAB strains were isolated and subjected to a clustering analysis based on (GTG) 5 -PCR fingerprinting profiles. Eleven species were found with an overwhelming predominance of Lactobacillus sanfranciscensis by culture dependent method. On the other hand, pyrosequencing revealed that more than 90% of the bacteria belong to LAB in thirteen sourdough samples out of the fifteen. A total of twenty-four species were found by pyrosequencing and seventeen of them belonged to lactobacilli. Pyrosequencing indicated that Lactobacillus sanfranciscensis was the only species found existing among all the fifteen sourdoughs and that other species most frequently encountered in the samples included Weissella confusa , Lactobacillus plantarum and an unclassified Lactobacillus species. We conclude that LAB dominate in Chinese traditional sourdough and Lactobacillus sanfranciscensis is the predominant species in this specific niche.