"Front Microbiol": Overexpression of LuxS enhances the resistance of Lactobacillus plantarum and promotes biofilm formation

BACKGROUND INTRODUCTION

In recent years, people have learned that probiotics have many advantages. It is a hardworking and versatile person who can perform various functions including maintaining healthy intestinal flora, improving intestinal resilience, regulating lactose tolerance, and preventing diarrhea. Features. In addition, it can also bring good news to the foodies, probiotic powder, probiotic fermented foods, etc. in the functional food market accounted for a considerable proportion. It is important to note that probiotics should be sufficiently skin-stained before they exhibit glamour, have the ability to colonize the gastrointestinal tract and maintain a certain amount in them. Therefore, it is important to improve the stress resistance of probiotics.

Although there is no WeChat, the bacteria that like to live in groups, like people, chat with each other. Different bacteria use quorum sensing (QS) to communicate with each other. Autoinducer-2 (AI-2) is the intra- and inter-species communication of bacteria. The universal language is like the English common to humans. The protein responsible for production is determined by a gene called luxS, which is found in both Gram-positive and Gram-negative bacteria. Some studies have also found that luxS-mediated quorum sensing is present in a variety of bacteria. presence. This means that probiotics may also use this "universal language" and "universal signaling system" to regulate their behavior, including the formation of various anti-stress capabilities and biofilms. Lactobacillus paraplantarum L-ZS9 is a strain isolated from fermented sausages and produces class II bacteriocins that inhibit the growth of pathogenic bacteria.

In November 2018, Lei Liu et al. of China Agricultural University published an article entitled "Overexpression of luxS Promotes Stress Resistance and Biofilm Formation of Lactobacillus paraplantarum L" in Frontiers in Microbiology (IF2017=4.109, Bio 2). -ZS9 by Regulating the Expression of Multiple Genes" article.

Main method used

METHODS

1. Plasmid construction

2. qRT-PCR

3. AI-2 detection: Microplate detector for fluorescence analysis.

4. Growth curve determination

5. Total RNA extraction and transcriptome sequencing

ABSTRACT

Probiotics have attracted great interest in recent years due to their health conditioning effects. This study was designed to investigate whether the overexpression of LuxS gene can promote the anti-stress ability of Lactobacillus plantarum L-ZS9. This paper demonstrates that the overexpression of LuxS gene can increase the quorum sensing signal molecule AI-2 by Lactobacillus plantarum L-ZS9. At the same time, the overexpression of LuxS also enhances the heat tolerance and bile salt tolerance of the strain, and promotes the organism. Film formation. Transcriptome sequencing revealed that LuxS regulates a variety of genes encoding transporters, membrane proteins, and transcriptional regulators. These results reveal a new role for LuxS in promoting stress resistance and biofilm formation of probiotic starter.