Ligninolytic behavior of the white-rot fungus Stereum ostrea under influence of culture conditions, inducers and chlorpyrifos.

ABSTRACT

The production of three ligninolytic enzymes, laccase (LAC), manganese peroxidase (MnP) and lignin peroxidase (LiP) by the white-rot fungus, Stereum ostrea, was significantly more in Koroljova liquid medium in the presence of chlorpyrifos under shaking conditions than under stationary conditions. These enzymes were secreted into the broth to the extent of 214.37, 82.75 and 8.05 U/ml under influence of chlorpyrifos on 10th day of incubation in comparison with 138.06, 51.85 and 6.44 U/ml, respectively, under similar conditions in control. Maximum production of LAC, MnP and LiP on liquid medium with/without chlorpyrifos under stationary conditions did not exceed 80-85, 33-40, 0.6-0.7 U/ml, respectively. Among lignosulfonic acid, veratryl alcohol (VA), gallic acid (GA) and tannic acid tested, GA induced maximum production of LAC (300.53 U/ml) and MnP (181.66 U/ml) after 10 days of growth in the presence of chlorpyriphos, while maximum LiP (1.134 U/ml) was produced when grown with the inducer VA during this period. Our data suggest that chlorpyrifos and inducers interacted positively in producing higher amounts of the ligninolytic enzymes in S. ostrea.