Multilocus Sequence Typing of Leuconostoc mesenteroides Strains From the Qinghai-Tibet Plateau.

Jun Chen,Zhongfang Tan,Huili Pang,Hua Zhang,Yuan Liu,Bei Zhang,Zhixia Zhang,Xing Wang,Guangyong Qin,Lei Wang,Haoxin Lv,Miao Zhang

doi:10.3389/fmicb.2021.614286

Abstract

Leuconostoc mesenteroides strains were a type of epiphytic bacterium widely used in fermented foods and products in the biochemical and pharmaceutical industries but data on its presence in foods from Qinghai-Tibet Plateau in China was scarce. In this study, molecular analysis based on multilocus sequence typing (MLST) with eight housekeeping genes (pyrG, groeL, rpoB, recA, uvrC, murC, carB, and pheS) was carried out on 45 L. mesenteroides strains isolated from different plants and dairy products from Qinghai-Tibet Plateau in China. The objective of this study was to perform genetic diversity analysis and explore the relationship between strains and isolate samples or separate regions. A total of 25 sequence types (STs) were identified with a diversity of up to 55.6%, which were grouped into one clonal complexes (CCs), 3 doublets and 17 singletons by eBURST. The results of minimum spanning tree and clustering analysis indicated these L. mesenteroides strains from the Qinghai-Tibet Plateau were relatively weakly related to the isolated region. However, there was a close relationship between the genotypes of L. mesenteroides strains and the type of the isolated sample, which was consistent with the results of API 50CH. The MLST scheme presented in this study provides a shareable and comparable sequence database and enhances our knowledge of the population diversity of L. mesenteroides strains which will be further used for the selection of industrial strains.

Highlights

Leuconostoc mesenteroides, a species of Leuconostoc, is usually found to be associated with plant, meat, dairy, and other food products
All 45 L. mesenteroides isolates were identified by 16S rRNA sequencing and a phylogenetic tree was constructed using the neighbor-joining method (Figure 2)
A total of 25 sequence types (STs) were generated from 45 strains of L. mesenteroides with a diversity of 55.6%. 25 STs were analyzed by eBURST to form a clonal complex CC9, three doublets and 15 singletons

Summary

Introduction

Leuconostoc mesenteroides, a species of Leuconostoc, is usually found to be associated with plant, meat, dairy, and other food products. Compared to other dairy production, the main component of Qula, has higher lipid, protein, lactose, and mineral levels (Zhang B. et al, 2015). In view of these excellent traits, the development of L. mesenteroides is of great potential in the application, so it is necessary to carry out diversity characterization analysis. Considering the important role in the fermented food industry and the production of dextrans and bacteriocins with promising developing prospect, the exploration of molecular character of L. mesenteroides was in great need to categorize candidate microorganisms for further safe utilization in production

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Conclusion