Enantioselective Biosynthesis of l-Phenyllactic Acid by Whole Cells of Recombinant Escherichia coli.
BACKGROUND
l-Phenyllactic acid (l-PLA)-a valuable building block in the pharmaceutical and chemical industry-has recently emerged as an important monomer in the composition of the novel degradable biocompatible material of polyphenyllactic acid. However, both normally chemically synthesized and naturally occurring phenyllactic acid are racemic, and the product yields of reported l-PLA synthesis processes remain unsatisfactory.


METHODS
We developed a novel recombinant Escherichia coli strain, co-expressing l-lactate dehydrogenase (l-LDH) from Lactobacillus plantarum subsp. plantarum and glucose dehydrogenase (GDH) from Bacillus megaterium, to construct a recombinant oxidation/reduction cycle for whole-cell biotransformation of phenylpyruvic acid (PPA) into chiral l-PLA in an enantioselective and continuous manner.


RESULTS
During fed-batch bioconversion with intermittent PPA feeding, l-PLA yield reached 103.8 mM, with an excellent enantiomeric excess of 99.7%. The productivity of l-PLA was as high as 5.2 mM·h-1 per OD600 (optical density at 600 nm) of whole cells. These results demonstrate the efficient production of l-PLA by the one-pot biotransformation system. Therefore, this stereoselective biocatalytic process might be a promising alternative for l-PLA production.
['Zhu|Yibo|Y|', 'Wang|Ying|Y|', 'Xu|Jiayuzi|J|', 'Chen|Jiahao|J|', 'Wang|Limei|L|', 'Qi|Bin|B|']
D001410:Bacillus megaterium D001426:Bacterial Proteins D061249:Batch Cell Culture Techniques D001711:Biotransformation D004926:Escherichia coli D005818:Genetic Engineering D042843:Glucose 1-Dehydrogenase D006863:Hydrogen-Ion Concentration D007770:L-Lactate Dehydrogenase D007773:Lactates D019344:Lactic Acid D048191:Lactobacillus plantarum D010667:Phenylpyruvic Acids
glucose dehydrogenase ">l-Lactate dehydrogenase ">l-Phenyllactic acid NADH regeneration whole-cell transformation