BioChem - DOS

High-CO2 Requirement as a Mechanism for the Containment of Genetically Modified Cyanobacteria

ACS Synthetic biology

Clark, Ryan L.; Gordon, Gina C.; Bennett, Nathaniel R.; Lyu, Haoxiang; Root, Thatcher W.; Pfleger, Brian F.

<P>As researchers engineer cyanobacteria for biotechnological applications, we must consider potential environmental release of these organisms. Previous theoretical work has considered cyanobacterial containment through elimination of the CO<SUB>2</SUB>-concentrating mechanism (CCM) to impose a high-CO<SUB>2</SUB> requirement (HCR), which could be provided in the cultivation environment but not in the surroundings. In this work, we experimentally implemented an HCR containment mechanism in <I>Synechococcus</I> <I>sp</I>. strain PCC7002 (PCC7002) through deletion of carboxysome shell proteins and showed that this mechanism contained cyanobacteria in a 5% CO<SUB>2</SUB> environment. We considered escape through horizontal gene transfer (HGT) and reduced the risk of HGT escape by deleting competence genes. We showed that the HCR containment mechanism did not negatively impact the performance of a strain of PCC7002 engineered for L-lactate production. We showed through coculture experiments of HCR strains with <I>ccm</I>-containing strains that this HCR mechanism reduced the frequency of escape below the NIH recommended limit for recombinant organisms of one escape event in 10<SUP>8</SUP> CFU.</P><P><B>Graphic Abstract</B><BR><IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/asbcd6/2018/asbcd6.2018.7.issue-2/acssynbio.7b00377/production/images/medium/sb-2017-003773_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/sb7b00377'>ACS Electronic Supporting Info</A></P>

2018

American Chemical Society

2161-5063

7

2

pp.384-391

10.1021/acssynbio.7b00377.s001

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART80297423

https://europepmc.org/articles/pmc5793877?pdf=render

cyanobacteria; biocontainment; CO2-concentrating mechanism; carboxysome; horizontal gene transfer; natural competence