An evolutionary optimization of a rhodopsin-based phototrophicmetabolism in Escherichia coli

Collection with item attached
2017
Item details URL
http://open-repository.kisti.re.kr/cube/handle/open_repository/474591.do
DOI
10.1186/s12934-017-0725-6
Title
An evolutionary optimization of a rhodopsin-based phototrophicmetabolism in Escherichia coli
Description
This work was financially supported by the grants from the NationalResearch Foundation of Korea (NRF-2016R1E1A1A01943552,2015R1A2A2A01005402, 2015R1D1A1A01058917, and 2016R1A6A3A11934084) andthe KRIBB Research Initiative Program. P. Kim was supported from theresearch fellowship 2017 of the Catholic University of Korea.
abstract
Background: The expression of the Gloeobacter rhodopsin (GR) in a chemotrophic Escherichia coli enables the lightdriven phototrophic energy generation. Adaptive laboratory evolution has been used for acquiring desired phenotype of microbial cells and for the elucidation of basic mechanism of molecular evolution. To develop an optimized strain for the artificially acquired phototrophic metabolism, an ancestral E. coli expressing GR was adaptively evolved in a chemostat reactor with constant illumination and limited glucose conditions. This study was emphasized at an unexpected genomic mutation contributed to the improvement of microbial performance.
Results: During the chemostat culture, increase of cell size was observed, which were distinguished from that of the typical rod-shaped ancestral cells. A descendant ET5 strain was randomly isolated from the chemostat culture at 88-days. The phototrophic growth and the light-induced proton pumping of the ET5 strain were twofold and eightfold greater, respectively, than those of the ancestral E. coli strain. Single point mutation of C1082A at dgcQ gene (encoding diguanylate cyclase, also known as the yedQ gene) in the chromosome of ET5 strain was identified from whole genome sequencing analysis. An ancestral E. coli complemented with the same dgcQ mutation from the ET5 was repeated the subsequently enhancements of light-driven phototrophic growth and proton pumping. Intracellular c-di-GMP, the product of the diguanylate cyclase (dgcQ), of the descendant ET5 strain was suddenly increased while that of the ancestral strain was negligible.
Conclusions: Newly acquired phototrophic metabolism of E. coli was further improved via adaptive laboratory evolution by the rise of a point mutation on a transmembrane cell signaling protein followed by increase of signal molecule that eventually led an increase proton pumping and phototrophic growth.
provenance
Made available in Cube on 2018-09-28T10:50:05Z (GMT). No. of bitstreams: 0
language
English
author
Kim, Hyun Aaron
Kim, Hyun Ju
Park, Jihoon
Choi, Ah Reum
Heo, Kyoo
Jeong, Haeyoung
Jung, Kwang-Hwan
Seok, Yeong-Jae
Kim, Pil
Lee, Sang Jun
orcid
Seok, Yeong-Jae/0000-0003-0379-3619
accessioned
2018-09-28T10:50:05Z
available
2018-09-28T10:50:05Z
issued
2017
citation
MICROBIAL CELL FACTORIES(16)
issn
1475-2859
uri
http://open-repository.kisti.re.kr/cube/handle/open_repository/474591.do
Funder
과학기술정보통신부
Funding Program
한국생명공학연구원연구운영비지원
Project ID
1711063675
Jurisdiction
Rep.of Korea
Project Name
Microbe-Host Intergenomics
rights
openAccess
subject
Adaptive laboratory evolution
Strain optimization
Chemotroph
Phototroph
Rhodopsin
Proton pumping
type
article


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