title: Cloning, identification, and characterization of the rpoS-like sigma factor rpoX from Vibrio alginolyticus.
abstract: Vibrio alginolyticus ZJ-51 displays phase variation between opaque/rugose colonies (Op) and translucent/smooth colonies (Tr). These colony variants show great differences in biofilm formation and motility. In this study, a gene encoding for an rpoS-like sigma factor, rpoX, has been cloned and characterized. The absence of rpoX did not affect colony switching rate but did decrease biofilm formation in both the Op and the Tr variants. When challenged with hydrogen peroxide, the DeltarpoX in the Op background showed a slightly higher survival rate compared with the wild type, whereas survival was decreased in the Tr background. Deletion of rpoX in the Tr background resulted in a higher ability to resist ethanol challenges and to survive hyperosmolarity challenges, and in the Op background the opposite phenotype was observed. This indicates that the rpoX gene is involved in biofilm formation and stress response but the effects are controlled by colony phase variation in V. alginolyticus.
authors.affiliation: Key Laboratory of Marine Bio-resources Sustainable Utilization (LMB), South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
authors.forename: Jing-jing
authors.initials: JJ
authors.lastname: Zhao
authors.forename: Chang
authors.initials: C
authors.lastname: Chen
authors.forename: Lv-ping
authors.initials: LP
authors.lastname: Zhang
authors.forename: Chao-qun
authors.initials: CQ
authors.lastname: Hu
mesh_terms: D000595:Amino Acid Sequence; D018441:Biofilms / Q000254:growth & development; D003001:Cloning, Molecular; D015169:Colony Count, Microbial; D007700:Kinetics; D050296:Microbial Viability; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D012808:Sigma Factor / Q000737:chemistry / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism*; D013312:Stress, Physiological; D044149:Vibrio alginolyticus / Q000166:cytology / Q000235:genetics* / Q000254:growth & development / Q000502:physiology
chemical_list: D012808:Sigma Factor