Phenotypic and genomic analysis of inulin consumption byLactiplantibacillus plantarumstrains from Sichuan pickle

Abstract

Aims To investigate the capability, properties and molecular mechanism of inulin fermentation by lactic acid bacteria (LAB) from Sichuan pickle. Methods and Results Seventy-nine LAB strains were purified from thirty aged Sichuan pickle brine samples, and only twenty-one Lactiplantibacillus plantarum strains (26.58%, 21/79) derived from fifteen samples grew well through utilizing inulin as a carbon source. The fermentation tests through using long-chain inulin (lc-inulin) as a carbon source showed that only six L. plantarum strains grew well, while other fifteen strains could only utilize short-chain oligofructose (FOS), and thin-layer chromatography analysis evidenced a strain-specificity of inulin consumption patterns. L. plantarum YT041 is a vigorous inulin-fermenter, and whole genome sequencing data revealed that sacPTS1 and fosRABCDXE operons might be associated with the fermentation of FOS and lc-inulin respectively. Conclusions The phenotype of inulin consumption is commonly present in LAB from Sichuan pickle, which is strain-specific and largely depends on their specific ecological niche and degree of polymerization.