Microbial Diversity Analysis Of Naturally Fermented Cow Milk In Russia Based On Metagenomics Technology

Naturally fermented cow's milk not only contains a rich microbial community,but also has lots of nutriments and health benefits,which gradually becomes a focus of the researches in recent years.In this study,the diversity of bacterial and fungal community of nineteen NFCM samples from local Mongolian families residing in Kalmykia and Chita of Russia was investigated by means of 454 pyrosequencing.The aim of this study was not only to reveal the diversity of the NFCM microbial information,but also to lay the foundation for the development and utilization of NFCM.Specifically,the results were shown as follows:At the phylum level,there was a total of 7 phylum of bacterium and 3 phylum of fungi in these 19 NFCM samples.The major bacteria phyla found in the NFCM were Proteobacteria,Actnobacteria,Bacteroidetes and Acidobacteria.The major fungal phyla found in the NFCM were Ascomycota,Basidiomycota and Chytridiomycota.The Firmicutes(89.62%)was the most abundant phylum;The fungal community was dominated with Ascomycota(99.77%).At the genus level,Lactobacillus(47.69%),Lactococcus(29.91%)and Streptococcus(9.75%)were the dominant genera for bacteria(at least 0.1%of the total fungal gene pool)across all samples from Kalmykia and Chita.Pichia(52.66%),Galactomyces(20.45%)and Vanderwaltozyma(17.38%)were the dominant fungal genera(at least 1.0%of the total fungal gene pool)across all samples.The Shannon index and Simpson index of each sample were used to evaluate the species diversity of bacterial and fungal in NFCM samples,the results showed that the diversity of bacteria and fungi in the NFCM samples of Kalmykia was higher than that of in Chita.At the same time,the species richness of bacteria and fungi in the samples of NFCM was analyzed by Observed species and Chaol index,the results suggested that the abundance of bacteria and fungi in NFCM samples of Kalmykia was higher than that of in the Chita.Due to a multivariate statistical method,there was a significant difference existed in the community structure of the bacterial and fungal between the Kalmykia and Chita sample groups.Therefore,geographical location was the main factor affecting microbial diversity and community structure changes.