Integrated genome and transcriptome sequencing reveals the molecular mechanisms of organic acid biosynthesis in Lactobacillus plantarum YC1-1-4B and Lactobacillus buchneri PC-C1

Abstract

Lactic acid bacteria (LAB) species are gaining recognition in fermentation-related biotechnologies due to their rapid growth and beneficial organic acid production. This study integrated genome and transcriptome sequencing to understand the molecular mechanisms of organic acid biosynthesis in Lactobacillus plantarum YC1-1-4B and Lactobacillus buchneri PC-C1. We identified several novel culture time-induced pathways associated with organic acid biosynthesis, including metabolic equilibriums and the expression of growth-related proteins. Lactic and acetic acid concentrations dominated other acids, with YC1-1-4B containing the highest concentrations (29.18 ± 2.17 mg/L) of beneficial organic acids at 12h. The reconstruction of organic acid metabolic pathways uncovered novel genes, including ldh and ackA, upregulated in YC1-1-4B at 12h and unregulated in PC-C1 at 6h and 12h. Also, the massive induction of differential gene expressions at 12h, including sucC and sucD gene overlap, suggests translational coupling, which could potentially benefit the combination of the two LAB species during industrial fermentation.