Utilization of Phenol and Naphthalene Affects Synthesis of Various Amino Acids in Corynebacterium glutamicum

Abstract

This article reports multiple metabolic pathways of amino acid production via phenol and naphthalene use by Corynebacterium glutamicum. Biodegradation of phenol and naphthalene by C. glutamicum occurred in a mineral salt medium containing 1% yeast extract without any additional carbon sources. Among the amino acids synthesized via the TCA-cycle, glutamate synthesis increased in C. glutamicum supplemented with 8.5 mM phenol or with 4.2 mM naphthalene. Aspartate synthesis significantly increased when cultured with 4.2 mM naphthalene, and increased synthesis of threonine and histidine was observed only with the addition of phenol. In addition, synthesis of valine and leucine decreased considerably under both conditions. Moreover, the bioconversion of glutamate from phenol and naphthalene is regulated by a transcriptional regulator, FarR, at the transcription level of the gltBD and gdh genes. In this study, we found that the utilization of phenol and naphthalene enhances biosynthesis of several amino acids and that this mechanism is controlled by a transcriptional regulator.