CysK Plays a Role in Biofilm Formation and Colonization by Vibrio fischeri.

TitleCysK Plays a Role in Biofilm Formation and Colonization by Vibrio fischeri.
Publication TypeJournal Article
Year of Publication2015
AuthorsSingh, P, Brooks, JF, Ray, VA, Mandel, MJ, Visick, KL
JournalAppl Environ Microbiol
Volume81
Issue15
Pagination5223-34
Date Published2015/08/31
ISSN1098-5336
KeywordsAliivibrio fischeri, Animals, Bacterial Proteins, Biofilms, Biosynthetic Pathways, Culture Media, Cysteine, Cysteine Synthase, Decapodiformes, Genetic Complementation Test, Genetic Testing, Mutation
Abstract

A biofilm, or a matrix-embedded community of cells, promotes the ability of the bacterium Vibrio fischeri to colonize its symbiotic host, the Hawaiian squid Euprymna scolopes. Biofilm formation and colonization depend on syp, an 18-gene polysaccharide locus. To identify other genes necessary for biofilm formation, we screened for mutants that failed to form wrinkled colonies, a type of biofilm. We obtained several with defects in genes required for cysteine metabolism, including cysH, cysJ, cysK, and cysN. The cysK mutant exhibited the most severe wrinkling defect. It could be complemented with a wild-type copy of the cysK gene, which encodes O-acetylserine sulfhydrolase, or by supplementing the medium with additional cysteine. None of a number of other mutants defective for biosynthetic genes negatively impacted wrinkled colony formation, suggesting a specific role for CysK. CysK did not appear to control activation of Syp regulators or transcription of the syp locus, but it did influence production of the Syp polysaccharide. Under biofilm-inducing conditions, the cysK mutant retained the same ability as that of the parent strain to adhere to the agar surface. The cysK mutant also exhibited a defect in pellicle production that could be complemented by the cysK gene but not by cysteine, suggesting that, under these conditions, CysK is important for more than the production of cysteine. Finally, our data reveal a role for cysK in symbiotic colonization by V. fischeri. Although many questions remain, this work provides insights into additional factors required for biofilm formation and colonization by V. fischeri.

DOI10.1128/AEM.00157-15
Alternate JournalAppl Environ Microbiol
PubMed ID26025891
PubMed Central IDPMC4495211
Grant ListR01 GM059690 / GM / NIGMS NIH HHS / United States
GM08061 / GM / NIGMS NIH HHS / United States
R25 GM079300 / GM / NIGMS NIH HHS / United States
T32 GM008061 / GM / NIGMS NIH HHS / United States
R25 GM086262 / GM / NIGMS NIH HHS / United States
R01 GM59690 / GM / NIGMS NIH HHS / United States
OD11024 / OD / NIH HHS / United States
R01 OD011024 / OD / NIH HHS / United States