Cloning of a Chitinase Gene chiSH1 Cloned from Gram-positive Bacterium Kurthia zopfii and Control of Powdery Mildew of Barley

Abstract

The bacterium capable of efficiently digesting chitin was isolated from chitin-amended field soil. It was identified as Kurthia zopfii, and extracellular chitinases secreted into respective culture filtrates were electrophoretically analyzed using a polyacrylamide gel containing glycol chitin. The result indicated that K. zopfii produced the 72, 58, and 44 kilodalton chitinases. The gene (chiSH1) encoding chitinase was cloned from K. zopfii KI2-119 and the entire nucleotide sequence (2097 bases) was determined. In order to evaluate the feasibility of chitinolytic microbes on the protection of chitinous fungal diseases, viable cells of E. coli transformed with the chiSH1 were applied to barley leaves inoculated with the powdery mildew pathogen. The result indicated that the growth of the pathogen was effectively suppressed by the present treatment, suggesting the importance and effectiveness of chitinolytic microbes as a biocontrol agent.