[Characterization of a carbendazim-degrading Trichoderma sp. T2-2 and its application in bioremediation].
OBJECTIVE
To obtain carbendazim-degrading microbial strains, and to use them for bioremediation of contaminated soil.


METHODS
A carbendazim-degrading bacterium T2-2 was isolated from the screening of drug-tolerated mutants Trichoderma strains. High-pressure liquid chromatography-mass spectrometry (HPLC-MS) analysis showed the presence of the metabolites after shake incubation of the Trichoderma T2-2 at temperature 25 degrees C, 200 r/min in mineral salt medium that contained 100 mg/ L carbendazim. We prepared T2-2 bioremediation agents from crop straw through solid fermentation. By inoculating T2-2 in soil, we performed a bioremediation test of sterilized soil and original soil at 0.1 mg/g dry soil of carbendazim concentration and 10(7) cfu/g dry soil of inoculating amount. In addition, we also conducted a control effect experiment of T2-2 against fusarium wilt of cucumber.


RESULTS
The metabolites detected by HPLC-MS were 2-aminobenzimidazole, benzimidazole, and 2-aminobenxinitrile in the culture filtrate after 2 days of incubation. Carbendazim and metabolites could no longer be detected through the High-pressure liquid chromatography (HPLC) analysis in the culture filtrate after 5 days of incubation. In the soil bioremediation test, carbendazim in the sterilized soil was degraded completely after 6 days of inoculation, whereas the process only needed 4 days in original soil. It showed crop straw could function as co-metabolic substrate and promote co-metabolism of T2-2 and indigenous microorganisms. Moreover, the efficiency of T2-2 against cucumber fusarium wilt might reach 81.7%, which is superior to chemical pesticide.


CONCLUSIONS
T2-2 could degrade carbendazim in soil and thus control plant disease.
Tian
Liansheng
L
Yangzhou Polytechnic Institute, Yangzhou 225127, China. lianshengt@163.com
Chen
Fei
F
D001562:Benzimidazoles / Q000737:chemistry / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002219:Carbamates / Q000737:chemistry / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D013058:Mass Spectrometry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000737:chemistry / Q000378:metabolism*; D014242:Trichoderma / Q000737:chemistry / Q000378:metabolism*
D001562:Benzimidazoles; D002219:Carbamates; D012989:Soil Pollutants; C006698:carbendazim