Aims: This study was designed to investigate the effects of 10 heavy metals on the in vitro activities of β-glucosidase, cellobiohydrolase, β-xylosidase and endoxylanase enzymes for six strains of Trichoderma, and to isolate and characterize heavy metal-resistant mutants. Methods and Results: At a concentration of 1 mmol, only mercury showed significant inhibitory effects on the in vitro enzyme activities; in all other cases, the enzymes remained active. A total of 177 heavy metal-resistant mutants were isolated and tested for cross-resistance to other heavy metals. Some mutants were effective antagonists of Fusarium, Pythium and Rhizoctonia strains, even on media containing the respective heavy metals. Conclusions: Trichoderma strains could be developed as biocontrol agents that are effective against plant pathogenic fungi, even under heavy metal stress. Significance and Impact of the Study: Trichoderma mutants resistant to heavy metals might be of value for use with heavy metal-containing pesticides, as part of an integrated plant protection system.
ASJC Scopus subject areas
- Applied Microbiology and Biotechnology