Enhanced phenylpyruvic acid production with Proteus vulgaris by optimizing of the fermentation medium

Abstract

Alpha keto acids are important food additives, which commonly produced by microbial deamination of amino acids. In this study, production of phenylpyruvic acid (PPA), which is the alpha keto acid of phenylalanine was enhanced in 2-l bench scale bioreactors by optimizing of fermentation medium composition using the Box-Behnken Response Surface Methodology (RSM). Optimum glucose, yeast extract, and phenylalanine concentrations were determined to be 119.4 g 1−1, 3.7 g 1−1, and 14.8 g 1−1, respectively, for PPA production, and 163.8 g 1−1, 10.8 g 1−1, and 9.8 g 1−1, respectively, for biomass production. Under these optimum conditions, PPA concentration was enhanced to 1349 mg 1−1, which was 28% and 276% higher than the unoptimized bioreactor and shake-flask fermentations, respectively. Moreover, P. vulgaris biomass concentration was optimized at 4.36 g 1−1, which was 34% higher than under the unoptimized bioreactor condition. Overall, this study demonstrated that optimization of the fermentation media improved PPA concentration and biomass production in bench scale bioreactors compared to previous studies in the literature and sets the stage for scale up to industrial production.

Two-Step Production of Phenylpyruvic Acid from L-Phenylalanine by Growing and Resting Cells of Engineered Escherichia coli: Process Optimization and Kinetics Modeling

“…Among these strains, P . vulgaris was the most suitable production host and the titer reached 1.3 g·L −1 under the optimal conditions [17]. By fed-batch fermentation, the PPA production was further improved to 3.0 g·L −1 , which was 15.2% that of our growing cell biotransformation.…”

“…vulgaris , Morganella morganii , and Corynebacterium glutamicum [15]. However, the production titer was low although many optimization strategies were used [16, 17], probably owing to the multiple steps as well as low enzymatic activities in the natural bacterial producer. Growing cell biotransformation in this study is expected to realize high production due to one-step oxidative deamination reaction and high l -AAD activity.…”

Radiosynthesis, Preclinical, and Clinical Positron Emission Tomography Studies of Carbon-11 Labeled Endogenous and Natural Exogenous Compounds

“…It is distributed at very low concentrations throughout the central and peripheral nervous systems and has a crucial role in neurotransmission and neuromodulation Phenylpyruvic acid is the α-keto acid of phenylalanine, present in high levels in the urine of individuals with phenylketonuria due to the lack of phenylalanine hydroxylase Pyruvic acid, an endogenous compound, is essential in most biological pathways and can be converted from alanine to lactic acid by enzymes …”

“…Phenylpyruvic acid is the α-keto acid of phenylalanine, present in high levels in the urine of individuals with phenylketonuria due to the lack of phenylalanine hydroxylase…”