Label-free quantitative proteomic analysis of the mechanism of salt stress promoting selenium enrichment in Lactobacillus rhamnosus

Lactobacillus rhamnosus can metabolize selenite into organic selenium and Se0. In this paper, label-free quantitative proteomics was applied to explore the mechanism of salt stress promoting selenium enrichment of L. rhamnosus. 397 proteins were up-regulated and 147 proteins were down-regulated of selenium-enriched L. rhamnosus under salt stress. The differentially expressed proteins (DEPs) were mainly involved in metabolism, membrane transport and genetic information processing. The results of quantitative real-time PCR showed that gene opuA, metN, trxR and ldh of Se-enriched L.rhamnosus with salt stress were significantly up-regulated. However, the expression levels of gene luxS, groEL, dnaK and pgk were down-regulated. It was indicated that L.rhamnosus promoted part of amino acids combining with selenium into selenoamino acids with salt stress. Secondly, sodium chloride stimulated the expression of key enzymes involved in metabolism to provide energy for the process of Se-enrichment. In addition, NaCl induced the expression of enzymes and genes involved in the synthesis of selenoproteins. Significance: It was indicated that L.rhamnosus promoted part of amino acids combining with selenium into selenoamino acids with salt stress. Secondly, sodium chloride stimulated the expression of key enzymes involved in metabolism to provide energy for the process of Se-enrichment. In addition, NaCl induced the expression of enzymes and genes involved in the synthesis of selenoproteins.

Automated summary

This study explored the mechanism of salt stress on selenium enrichment in Lactobacillus rhamnosus. The results showed that the expression of proteins and genes was regulated, involving metabolism, membrane transport, and genetic information processing. In addition, salt stress promoted the combination of amino acids and selenium into selenoamino acids, as well as provided energy and induced the synthesis of selenoproteins.