Enhanced Synthesis of Poly Gamma Glutamic Acid by Increasing the Intracellular Reactive Oxygen Species in the Bacillus licheniformis Δ1-pyrroline-5-carboxylate Dehydrogenase Gene ycgN Deficient Strain

Abstract

35Importance γ-PGA is an anionic polyamide with various applications in biomedical and industrial fields. 36Proline metabolism influences the intracellular reactive oxygen species (ROS) and is involved in a wide 37 range of cellular processes. Here, we report the effects of proline metabolism on γ-PGA synthesis. Our

Investigation of Glutamate Dependence Mechanism for Poly-γ-glutamic Acid Production in Bacillus subtilis on the Basis of Transcriptome Analysis

“…The procedure of qRT-PCR was performed as described before. 40 The specific primers used for qRT-PCR are presented in Table S2. The 16 s rRNA gene was used as the internal standard to normalize the gene expression.…”

“…Li et al revealed that the overexpression of the gene ycgM (encoding proline dehydrogenase) and ycgN (encoding Δ 1 -pyrroline-5carboxylate dehydrogenase) decreases the production of γ-PGA by B. licheniformis WX-02 by disturbing the intrinsic reactive oxygen species level. 40 In contrast to B. licheniformis WX-02, overexpression of both putM (encoding proline dehydrogenase) and rocA (encoding Δ 1 -pyrroline-5-carboxylate dehydrogenase) increased γ-PGA production in B.…”

Enhanced synthesis of poly gamma glutamic acid by increasing the intracellular reactive oxygen species in the Bacillus licheniformis Δ1-pyrroline-5-carboxylate dehydrogenase gene ycgN-deficient strain

“…1). In the previous research, knocking out of P5CDH encoded gene Ldp5cdh in the Colorado potato beetle Leptinotarsa decemlineata could significantly reduce the ATP content, and further inhibit flight capacity (42). This study implied that deletion of ycgN in B. licheniformis WX-02 led to an 85.22% increase of γ-PGA yield.…”

“…Proline is a multifunctional amino acid which can be used as carbon, nitrogen and energy source (18). Also, it plays an important role in protecting against osmotic and oxidative stresses, since it is a compatible solute and a free-radical scavenger (42). In addition, proline catabolism has been found to be involved in protection of intracellular redox homeostasis and virulence in microorganisms (26,43).…”

“…They mediate a number of significant cell processes, including impaired cellular homeostasis, enzyme inactivation, DNA damage and cell death (27). ROS could also implicate in pathologies, such as cancer, atherosclerosis, diabetes, Down's syndrome, and in neurodegenerative diseases like Parkinson's and Alzheimer's diseases (25,27,28). In addition, ROS could serve as the secondary messengers to activate the downstream defense against invaded microorganisms in plants (29,30), and played an important role in plant secondary metabolism (31).…”