Double deletion of <i>murA</i> and <i>murB</i> induced temperature sensitivity in <i>Corynebacterium glutamicum</i>

Currently, the mechanism of temperature-sensitive production of glutamate in <i>Corynebacterium glutamicum</i> has not been clarified. We first found the <i>murA</i> and <i>murB</i> genes were potentially related to temperature-sensitive secretion of glutamate, which were not existed in a temperature-sensitive mutant. When replenishing <i>murA</i> or/and <i>murB</i> in the mutant, the temperature sensitivity was weakened. While, their knockout in a wild-type strain resulted in temperature-sensitive secretion of glutamate. Peptidoglycan analysis showed that deletion of <i>murA</i> and <i>murB</i> decreased the peptidoglycan synthesis. Comparative metabolomics analysis suggested that the variation in cell wall structure resulted in decreased overall cellular metabolism but increased carbon flow to glutamate synthesis, which was a typical metabolism pattern in industrial temperature-sensitive producing strains. This study clarifies the mechanism between <i>murA</i> and <i>murB</i> deletion and the temperature-sensitive secretion of glutamate in <i>C. glutamcium</i>, and provides a reference for the metabolic engineering of cell wall to obtain increased bioproduction of chemicals.