Breeding of mycoparasitic Trichoderma strains for heavy metal resistance.
OBJECTIVE
This study was designed to investigate the effects of 10 heavy metals on the in vitro activities of beta-glucosidase, cellobiohydrolase, beta-xylosidase and endoxylanase enzymes for six strains of Trichoderma, and to isolate and characterize heavy metal-resistant mutants.


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.


CONCLUSIONS
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.
Kredics
L
L
Hungarian Academy of Sciences and University of Szeged, Microbiological Research Group, Hungary. kredics@sirius.cab.u-szeged.hu
Antal
Z
Z
Manczinger
L
L
Nagy
E
E
D025141:Drug Resistance, Fungal; D018432:Drug Resistance, Multiple; D005656:Fungal Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D005658:Fungi / Q000187:drug effects / Q000472:pathogenicity; D017136:Ion Transport / Q000187:drug effects; D019216:Metals, Heavy / Q000494:pharmacology*; D009154:Mutation / Q000235:genetics; D010572:Pest Control, Biological / Q000379:methods; D010575:Pesticides / Q000494:pharmacology; D010944:Plants / Q000382:microbiology; D012641:Selection, Genetic; D014242:Trichoderma / Q000187:drug effects* / Q000201:enzymology* / Q000235:genetics / Q000254:growth & development
D005656:Fungal Proteins; D019216:Metals, Heavy; D010575:Pesticides