| Popis: |
This study aimed to determine the ability of bacteria to produce the chitinase enzyme, purify and characterize the enzyme from the isolate with the best activity, and determine the use of this purified enzyme as a biocontrol agent. The chitinolytic bacterium was identified as Stenotrophomonas maltophilia. The chitinase enzyme was purified 1.4 times at a 30% ammonium sulfate concentration with a yield of 40.7%. Following partial purification, the enzyme was purified by ion-exchange chromatography using HiPrep Q XL 16/10 column and HiPrep ™ 26/10 desalting column with 25.34% and 18.12% yields, respectively. The molecular weight of the purified enzyme was calculated as 52 kDa by SDS-PAGE. The optimum temperature of the enzyme was determined to be 50°C, and the optimum pH was 7.0. While Fe2+ most induced the activity, it was most inhibited by Zn2+ at a 5 mM concentration. Km and Vmax values of the enzyme for colloidal chitin were calculated as 1.6419 mg/ml and 16.129 U/mg, respectively. The purified chitinase was used as a biocontrol agent against the fungus Fusarium oxysporum and potato beetle Leptinotarsa decemlineata. The enzyme was shown to be effective in reducing the growth of fungus and causing disruption of the chitin structure of potato beetle. |
