4-Hydroxyisoleucine production of recombinant Corynebacterium glutamicum ssp. lactofermentum under optimal corn steep liquor limitation.
4-Hydroxyisoleucine (4-HIL) is a nonproteinogenic amino acid that exhibits insulinotropic biological activity. Here, L-isoleucine dioxygenase gene (ido) derived from Bacillus thuringiensis YBT-1520 was cloned and expressed in an L-isoleucine-producing strain, Corynebacterium glutamicum ssp. lactofermentum SN01, in order to directly convert its endogenous L-isoleucine (Ile) into 4-HIL through single-step fermentation. The effects of corn steep liquor limitation as well as ido and truncated idoΔ6 overexpression on 4-HIL production were researched. 4-HIL production by ido-overexpressing strain was improved to 65.44 ± 2.27 mM after fermented for 144 h under corn steep liquor-subsufficient condition, obviously higher than that under corn steep liquor-rich and insufficient conditions. The conversion ratio of Ile to 4-HIL increased to 0.85 mol/mol. In addition, 4-HIL production by ido-overexpressing strain was higher than that by idoΔ6-overexpressing strain, in accord with the relatively higher affinity of Ido as compared to IdoΔ6. This research generated a novel system for 4-HIL de novo biosynthesis and demonstrated corn steep liquor limitation as a useful strategy for improving 4-HIL production in recombinant C. glutamicum ssp. lactofermentum.
State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China, shifeng@jiangnan.edu.cn.
Feng
F
Shi
Tengfei
T
Niu
Huimin
H
Fang
D001407:Bacillus / Q000201:enzymology / Q000235:genetics; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000378:metabolism*; D049308:Dioxygenases / Q000235:genetics / Q000378:metabolism*; D005285:Fermentation; D015870:Gene Expression; D007532:Isoleucine / Q000031:analogs & derivatives* / Q000378:metabolism; D060847:Metabolic Engineering / Q000379:methods*; D030781:Organisms, Genetically Modified / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D003313:Zea mays / Q000378:metabolism*
C104672:4-hydroxyisoleucine; D011994:Recombinant Proteins; D007532:Isoleucine; D049308:Dioxygenases