BioChem - DOS

Directed evolution of the 3-hydroxypropionic acid production pathway by engineering aldehyde dehydrogenase using a synthetic selection device

Metabolic engineering

Seok, Joo Yeon; Yang, Jina; Choi, Sang Jin; Lim, Hyun Gyu; Choi, Un Jong; Kim, Kyung-Jin; Park, Sunghoon; Yoo, Tae Hyeon; Jung, Gyoo Yeol

<P><B>Abstract</B></P> <P>3-Hydroxypropionic acid (3-HP) is an important platform chemical, and biological production of 3-HP from glycerol as a carbon source using glycerol dehydratase (GDHt) and aldehyde dehydrogenase (ALDH) has been revealed to be effective because it involves a relatively simple metabolic pathway and exhibits higher yield and productivity than other biosynthetic pathways. Despite the successful attempts of 3-HP production from glycerol, the biological process suffers from problems arising from low activity and inactivation of the two enzymes. To apply the directed evolutionary approach to engineer the 3-HP production system, we constructed a synthetic selection device using a 3-HP-responsive transcription factor and developed a selection approach for screening 3-HP-producing microorganisms. The method was applied to an ALDH library, specifically aldehyde-binding site library of alpha-ketoglutaric semialdehyde dehydrogenase (KGSADH). Only two serial cultures resulted in enrichment of strains showing increased 3-HP production, and an isolated KGSADH variant enzyme exhibited a 2.79-fold higher catalytic efficiency toward its aldehyde substrate than the wild-type one. This approach will provide the simple and efficient tool to engineer the pathway enzymes in metabolic engineering.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A synthetic selection device was designed responding to 3-HP concentration. </LI> <LI> ALDH in the 3-HP pathway was engineered through a simple selection method. </LI> <LI> An ALDH variant exhibited a 2.79-fold improvement in the catalytic efficiency. </LI> <LI> <I>E. coli</I> with ALDH variant showed a 25% higher productivity than the parental strain. </LI> <LI> The developed strategy was highly efficient for engineering the pathway enzymes. </LI> </UL> </P>

2018

Elsevier

1096-7176

1096-7184

47

pp.113-120

10.1016/j.ymben.2018.03.009

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART84813489

3-hydroxypropionic acid; Directed evolution; Transcription factor; Screening; Synthetic biology; Metabolic engineering