Analysis of Molecular Diversity of Bacterial Chitinase Genes in the Maize Rhizosphere Using Culture-Independent Methods

DNA fragments of bacterial chitinase genes were successfully amplified from DNA extracts of maize rhizosphere and bulk soil. The molecular diversity of the bacterial chitinase genes in these soil samples was then evaluated by employing terminal-restriction fragment length polymorphism and sequencing analyses. Our results suggest the presence of novel groups of bacterial chitinase in both bulk and rhizosphere soils. Significant differences were observed, however, between the amplified chitinase genes from rhizosphere and bulk soils, and dominant clones obtained from the maize rhizosphere showed a high degree of similarity to the chitinases of Streptomyces avermitilis and close relatives there of. The current findings thus indicate the usefulness of culture-independent methods in the assessment of molecular diversity among the chitinolytic bacterial community in soils.