TY  - JOUR
AB  - L-2-hydroxyglutarate (L-2HG) is a trifunctional building block and highly attractive for the chemical and pharmaceutical industries. The natural L-lysine biosynthesis pathway of the amino acid producer Corynebacterium glutamicum was extended for the fermentative production of L-2HG. Since L-2HG is not native to the metabolism of C. glutamicum metabolic engineering of a genome-streamlined L-lysine overproducing strain was required to enable the conversion of L-lysine to L-2HG in a six-step synthetic pathway. To this end, L-lysine decarboxylase was cascaded with two transamination reactions, two NAD(P)-dependent oxidation reactions and the terminal 2-oxoglutarate-dependent glutarate hydroxylase. Of three sources for glutarate hydroxylase the metalloenzyme CsiD from Pseudomonas putida supported L-2HG production to the highest titers. Genetic experiments suggested a role of succinate exporter SucE for export of L-2HG and improving expression of its gene by chromosomal exchange of its native promoter improved L-2HG production. The availability of Fe2+ as cofactor of CsiD was identified as a major bottleneck in the conversion of glutarate to L-2HG. As consequence of strain engineering and media adaptation product titers of 34 ± 0 mM were obtained in a microcultivation system. The glucose-based process was stable in 2 L bioreactor cultivations and a L-2HG titer of 3.5 g L−1 was obtained at the higher of two tested aeration levels. Production of L-2HG from a sidestream of the starch industry as renewable substrate was demonstrated. To the best of our knowledge, this study is the first description of fermentative production of L-2HG, a monomeric precursor used in electrochromic polyamides, to cross-link polyamides or to increase their biodegradability.
DA  - 2021
DO  - 10.3389/fbioe.2020.630476
LA  - eng
PY  - 2021
T2  - Frontiers in Bioengineering and Biotechnology
TI  - Fermentative production of ʟ-2-hydroxyglutarate by engineered Corynebacterium glutamicum via pathway extension of ʟ-lysine biosynthesis
UR  - https://nbn-resolving.org/urn:nbn:de:0070-pub-29496647
Y2  - 2024-11-22T03:15:14
ER  -