Biodiversity of lactic acid bacteria isolated from fermented milk products in Xinjiang, China

ABSTRACT

Fermented dairy products have been produced and consumed for thousands of years in Xinjiang, China. In this study, traditional culture-dependent methods and 16S rRNA gene analyses were performed to analyze the composition of lactic acid bacteria (LAB) from 86 samples of traditional fermented dairy products collected from four regions of Xinjiang. Quantitative polymerase chain reaction (qPCR) was used to quantify Bifidobacterium and Lactobacillus species. The LAB isolates (N = 705) were identified as belonging to seven genera and 26 species or subspecies. The predominant species of all isolates were Lactobacillus (Lb.) delbrueckii subsp. bulgaricus, Lb. fermentum, and Lb. helveticus. The LAB counts of these samples ranged from 5.35 to 10.06 Log CFU/mL. The bacterial counts of seven lactobacilli species and Bifidobacterium ranged from 0.98 ± 0.14 Log CFU/mL (for Lb. sakei from fermented mare milk) to 9.91 ± 0.17 Log CFU/mL (for Lb. helveticus from fermented mare milk). While the microbiota was significantly different between yak and cow milk, there was no significant difference between the Tex and Zhaosu counties. In conclusion, LAB communities in traditional fermented dairy products are complex and differ among local regions within Xinjiang.

KEYWORDS:

• Traditional fermented dairy products
• lactic acid bacteria
• 16S rRNA gene
• quantitative PCR
• Xinjiang

Supplementary Material

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Compliance with ethics requirements

This article does not contain any studies with human or animal subjects, and authors declare that they have no conflict of interest.

Additional information

Funding

This study was supported by the China Agriculture Research System (Beijing, China; Grant CARS-36), the National Natural Science Foundation of China (Beijing, China; Grant No. 31601454) and the Excellent Young Scientist Foundation of Inner Mongolia Agricultural University of China (Grant No. 2017XYQ-4).