Anti-fungi activities of Bacillus thuringiensis H3 chitinase and immobilized chitinase particles and their effects to rice seedling defensive enzymes.

The chitinase producing bacterium H3 strain was screened from nature with the selective medium and was identified as Bacillus thuringiensis. The purpose of this investigation is to study the antifungi activity of Bacillus thuringiensis H3 chitinase and its immobilized particles, and the effects on growth of rice seedlings and activities of defensive enzymes. The rice seedlings qualities and several defense enzymes activity were measured after rice seedlings were treated by free chitinase and immobilized chitinase particles. The results show that the height and dry weight of the rice considerably increased in comparison with the control. Bacillus thuringiensis H3 chitinase and it's immobilized particles significantly inhibit several pathogenic fungi, and the anti-fungi rates of immobilized chitinase particles on Pyricularia grisea, Thantephorus cucumris, Fusarium vasinfectum, Fusarium gramineum, Fusarium oxysporum are 72.2%, 62.6%, 44.6%, 50.0%, 55.8%, respectively. Phenylalanine ammonia-lyase (PAL) and peroxidase (POD) activities of the rice seedling were significantly increased when it was treated by free chitinase and immobilized chitinase particles. From the results it could be concluded that Bacillus thuringiensis H3 free chitinase and immobilized chitinase particles can inhibit several pathogenic fungi and induce rice seedlings defense enzymes activity changes.