Abstract:

【Objective】The objective of this study was to optimize the composition of enzyme protectant of chlorpyifos- biodegradation fungi and determine its stability.【Method】Based on the screening of chlorpyrifos biodegrading fungal strain, Cladosporium cladosporioides (the ID of fungi preservation CCTCCM207111. Accession number of ITS sequence analysis Genebank EF405864), extracellular enzymes were extracted. Applying the composite rotatable design, a model of the optimal mixture protect agents was established. After the optimal composition was validated, the enzyme preparation storage experiment was tested to determine the stability of biodegradation by high performance liquid chromatography analysis. 【Result】 The results showed that the optimal composition was 0.70% NaCl, 0.35% glycine, 0.03% sodium benzoate, 0.17% Cosmetic, and 8.38% glycerol. When 9.90 mg?L-1 of final concentration of emzyme protein was added into the 50 mg?L-1 of chlorpyrifos, results of HPLC analysis after biodegradation 10 min indicated that the degradation rate of the enzyme preparations was more than 80% after storage 5 months under the temperature from 20℃ to 50℃and the light almost has no effect on the degradation rate. 【Conclusion】 It is concluded that an economical and stable enzymic protectant of chlorpyifos-biodegradation fungi is got, which has provided a foundation for commercial production of enzymic preparation in dealing with pesticide residues of agricultural products.

Key words: chlorpyifos, biodegradation enzyme protectant, optimization, stability