Insight Into Genes Involved in the Production of Extracellular Chitinase in a Biocontrol Bacterium Lysobacter enzymogenes C-3

• Published in: The plant pathology journal Vol. 28; no. 4; pp. 439 - 445
• Main Authors: Choi, H.S., Chonnam National University, Gwangju, Republic of Korea, Kim, H.J., Chonnam National University, Gwangju, Republic of Korea, Lee, J.H., Chonnam National University, Gwangju, Republic of Korea, Kim, J.S., Chonnam National University, Gwangju, Republic of Korea, Park, S.K., Sunchon National University, Suncheon, Republic of Korea, Kim, I.S., Chonnam National University, Gwangju, Republic of Korea, Kim, Y.C., Chonnam National University, Gwangju, Republic of Korea
• Format: Journal Article
• Language: English
• Published: 한국식물병리학회 01.12.2012
• Subjects: BIOLOGICAL CONTROL; chitinase; CONTROL BIOLOGICO; LUTTE BIOLOGIQUE; polyamine; transposon mutagenesis; 농학; polyamine; chitinase; biological control; transposon mutagenesis
• ISSN: 1598-2254; 2093-9280
• DOI: 10.5423/PPJ.NT.07.2012.0115

The chitinase producing Lysobacter enzymogenes C-3 has previously been shown to suppress plant pathogens in vitro and in the field, but little is known of the regulation of chitinase production, or its role in antimicrobial activity and biocontrol. In this study, we Isolated and characterized chitinase-defective mutants by screening the transposon mutants of L. enzymogenes C-3. These mutations disrupted genes involved in diverse functions: glucose-galactose transpoter (gluP), disulfide bond formation protein B (dsbB), Clp protease (clp), and polyamine synthase (speD). The chitinase production of the SpeD mutant was restored by the addition of exogenous spermidine or spermine to the bacterial cultures. The speD and clp mutants lost in vitro antifungal activities against plant fungal pathogens. However, the gluP and dsbB mutants showed similar antifungal activities to that of the wild-type. The growth of the mutants in nutrient rich conditions containing chitin was similar with that of the wild-type. However, growth of the speD and gluP mutants was defective in chitin minimal medium, but was observed no growth retardation in the clp and dsbB mutant on chitin minimal medium. In this study, we identified the four genes might be involved and play different role in the production of extracellular chitinase and antifungal activity in L. enzymogenes C-3.