Functional Lactiplantibacillus plantarum MT213 screened from traditional sourdough and its promising in-situ preservation in steamed bread.

Abstract

In-situ preservation using lactic acid bacteria (LAB) as starter is a promising alternative to delay fermented food spoilage. Hence, 55 antimicrobial LAB were isolated from traditional fermented foods, of which MT213 sourced from sourdough showed broad-spectrum antimicrobial activity, especially against fungi. The 16S rDNA and whole-genome sequencing analysis demonstrated that MT213 was identified as Lactiplantibacillus plantarum, and possesses functional genes responsible for synthesizing functional metabolites, including antimicrobial, flavor-enhancing, and health-promoting compounds. UPLC-MS-based metabolomics and protease hydrolysis analysis revealed key antimicrobial metabolites: lactic acid, propionic acid, acetic acid, succinic acid, malic acid, phenyllactic acid, hydroxyphenyllactic acid, 2-hydroxycinnamic acid, tyrosol, and plantaricin; MT213 enhanced UMP, GMP, and AMP levels, demonstrating its capability as umami enhancer; MT213 up-regulated functional organic acid and ornithine, and down-regulated inosine, indicating its potential such as anti-inflammatory, immunoregulation, and urate-lowering effect. MT213 as starter applied in steamed bread production resulted in reduction of fungi counts by 4.66 Lg CFU/g compared with that without MT213, extending the mold-free shelf life of steamed bread to 6 days. This investigation could offer scientific evidence for using MT213 as functional starter in fermented food.