Change search
Link to record
Permanent link

Direct link
BETA
Yao, Lun
Publications (3 of 3) Show all publications
Kaczmarzyk, D., Cengic, I., Yao, L. & Hudson, E. P. (2018). Diversion of the long-chain acyl-ACP pool in Synechocystis to fatty alcohols through CRISPRi repression of the essential phosphate acyltransferase PlsX. Metabolic engineering, 45, 59-66
Open this publication in new window or tab >>Diversion of the long-chain acyl-ACP pool in Synechocystis to fatty alcohols through CRISPRi repression of the essential phosphate acyltransferase PlsX
2018 (English)In: Metabolic engineering, ISSN 1096-7176, E-ISSN 1096-7184, Vol. 45, p. 59-66Article in journal (Refereed) Published
Abstract [en]

Fatty alcohol production in Synechocystis sp. PCC 6803 was achieved through heterologous expression of the fatty acyl-CoA/ACP reductase Maqu2220 from the bacteria Marinobacter aquaeolei VT8 and the fatty acyl-ACP reductase DPW from the rice Oryza sativa. These platform strains became models for testing multiplex CRISPR-interference (CRISPRi) metabolic engineering strategies to both improve fatty alcohol production and to study membrane homeostasis. CRISPRi allowed partial repression of up to six genes simultaneously, each encoding enzymes of acyl-ACP-consuming pathways. We identified the essential phosphate acyltransferase enzyme PlsX (slr1510) as a key node in C18 fatty acyl-ACP consumption, repression of slr1510 increased octadecanol productivity threefold over the base strain and gave the highest specific titers reported for this host, 10.3 mg g−1 DCW. PlsX catalyzes the first committed step of phosphatidic acid synthesis, and has not been characterized in Synechocystis previously. We found that accumulation of fatty alcohols impaired growth, altered the membrane composition, and caused a build-up of reactive oxygen species.

Place, publisher, year, edition, pages
Academic Press, 2018
Keywords
Acyl-ACP, Acyltransferase, CRISPRi, Cyanobacteria, Fatty alcohols, Membranes
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:kth:diva-220198 (URN)10.1016/j.ymben.2017.11.014 (DOI)000424292100007 ()2-s2.0-85036651462 (Scopus ID)
Funder
Swedish Foundation for Strategic Research , RBP14-0013Science for Life Laboratory - a national resource center for high-throughput molecular bioscience
Note

QC 20171218

Available from: 2017-12-18 Created: 2017-12-18 Last updated: 2019-04-23Bibliographically approved
Shabestary, K., Anfelt, J., Ljungqvist, E., Jahn, M., Yao, L. & Hudson, E. P. (2018). Targeted Repression of Essential Genes To Arrest Growth and Increase Carbon Partitioning and Biofuel Titers in Cyanobacteria [Letter to the editor]. ACS Synthetic Biology, 7(7), Article ID diva2:1239079.
Open this publication in new window or tab >>Targeted Repression of Essential Genes To Arrest Growth and Increase Carbon Partitioning and Biofuel Titers in Cyanobacteria
Show others...
2018 (English)In: ACS Synthetic Biology, E-ISSN 2161-5063, Vol. 7, no 7, article id diva2:1239079Article in journal, Letter (Refereed) Published
Abstract [en]

Photoautotrophic production of fuels and chemicals by cyanobacteria typically gives lower volumetric productivities and titers than heterotrophic production. Cyanobacteria cultures become light limited above an optimal cell density, so that this substrate is not supplied to all cells sufficiently. Here, we investigate genetic strategies for a two-phase cultivation, where biofuel-producing Synechocystis cultures are limited to an optimal cell density through inducible CRISPR interference (CRISPRi) repression of cell growth. Fixed CO2 is diverted to ethanol or n-butanol. Among the most successful strategies was partial repression of citrate synthase gltA. Strong repression (>90%) of gitA at low culture densities increased carbon partitioning to n-butanol 5-fold relative to a nonrepression strain, but sacrificed volumetric productivity due to severe growth restriction. CO2 fixation continued for at least 3 days after growth was arrested. By targeting sgRNAs to different regions of the gitA gene, we could modulate GItA expression and carbon partitioning between growth and product to increase both specific and volumetric productivity. These growth arrest strategies can be useful for improving performance of other photoautotrophic processes.

Place, publisher, year, edition, pages
American Chemical Society (ACS), 2018
Keywords
cyanobacteria, CRISPRi, bioproduction
National Category
Biochemistry and Molecular Biology
Research subject
Biotechnology
Identifiers
urn:nbn:se:kth:diva-235174 (URN)10.1021/acssynbio.8b00056 (DOI)
Funder
EU, Horizon 2020, 760994
Note

QC 20180920

Available from: 2018-09-17 Created: 2018-09-17 Last updated: 2018-09-20Bibliographically approved
Björk, S., Shabestary, K., Yao, L., Ljungqvist, E., Jönsson, H. & Hudson, E. P.Droplet microfluidic screening of a Synechocystis sp. CRISPRi library based on L-lactate production.
Open this publication in new window or tab >>Droplet microfluidic screening of a Synechocystis sp. CRISPRi library based on L-lactate production
Show others...
(English)Manuscript (preprint) (Other academic)
National Category
Engineering and Technology
Identifiers
urn:nbn:se:kth:diva-259487 (URN)
Note

QC 20191011

Available from: 2019-09-16 Created: 2019-09-16 Last updated: 2019-10-11Bibliographically approved
Organisations

Search in DiVA

Show all publications