fulltext.study @t Gmail

Modification of aspartokinase III and dihydrodipicolinate synthetase increases the production of l-lysine in Escherichia coli

Paper ID Volume ID Publish Year Pages File Format Full-Text
2676 126 2016 8 PDF Available
Title
Modification of aspartokinase III and dihydrodipicolinate synthetase increases the production of l-lysine in Escherichia coli
Abstract

•Metabolic engineering E. coli LATR11 increases lysine production.•AK III with mutation T344M shows non-feedback control and high-activity.•DHDPS with mutation H56K shows non-feedback control and high-activity.•Increasing flux through biosynthetic pathway benefits to improve lysine production.•Heterologous expression of ddh in strain LATR11 benefits to increase productivity.

To develop an l-lysine high-yielding strain, the enzymes involved in the l-lysine biosynthetic pathway, including aspartokinase III (AK III) and dihydrodipicolinate synthetase (DHDPS) were investigated. Allosteric enzymes involved in l-lysine production from l-lysine producer Escherichia coli LATR11 were sequenced and showed that AK III with mutation T344M or DHDPS with mutation H56K is more conducive to l-lysine production than AK III with mutation M318I or E250K-M318I-G323D or DHDPS with mutation H118Y. Moreover, an l-lysine high-yielding strain was developed from E. coli LATR11 via overexpression of ppc, lysCT344M, asd, dapAH56K, dapB, and lysA combined with heterologous expression of Corynebacterium glutamicum ddh. The resulting strain LATR11/pWG-DCSMASMBHc.gLP showed high l-lysine production (37.2 ± 2.3 g L−1) with productivity (QP) of 1.16 g L−1 h−1 in shake flasks. In fed-batch fermentation, LATR11/pWG-DCSMASMBHc.gLP produced about 125.6 g L−1 of l-lysine with QP of 3.14 g L−1 h−1 and glucose conversion rate (α) of 58.97% after 40 h. From which we got the following conclusions: the enzyme with non-feedback control and high activity, and the high flux through biosynthetic pathway are beneficial to improve l-lysine production in E. coli. These results provide a definite theoretical foundation for breeding amino acid high-yielding strains via genetic engineering from classical producers.

Keywords
DAP, diaminopimelate; AEC, S-(2-aminoethyl)-l-cysteine; AEChr, AEC high resistant; Km, kanamycin; Rif, rifampicin; DCW, dry cell weight; LB, Luria-Bertani; LBG, LB + 5 g L−1 glucose; LBS, LB + 100 g L−1 sucrose; LBK, LB + 50 μg mL−1 Km; LBHIS, LB + brain
First Page Preview
Modification of aspartokinase III and dihydrodipicolinate synthetase increases the production of l-lysine in Escherichia coli
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us
Publisher
Database: Elsevier - ScienceDirect
Journal: Biochemical Engineering Journal - Volume 114, 15 October 2016, Pages 79–86
Authors
, , , ,
Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us