Identification Of A Polycaprolactone Degrading Fungus And Characterization Of Its Depolymerase

poly caprolactone(PCL)is a kind of semi crystalline aliphatic polyestersynthesis, because of its many excellent performance, become the hotspot research, and It has been applied in many fields.A fungal strain DSWJ1201with polycaprolactone(PCL) degrading ability was isolated from the activated sludge. In this study, identification and fermentation conditions optimization of the strain was done. The strain DSWJ1201was identified with morphological characteristics and phylogenetic analysis. Its fermentation conditions optimizing was studied by single factor experiments.And studied its enzymology properties,The results were as follows:(1) The screening and identification of PCL degradation fungus.The strain DSWJ1201was isolated with the dilution coating method from the industrial sewage. Through the morphological analysis and ITS sequence analysis, the strain DSWJ1201was identified as Penicillium brevicompactum.(2) The growth temperature of the strain DSWJ1201measurement.The optimum growth temperature is20℃.And to be able to grow under the temperature of4℃,The highest growth temperature is30℃,It is a cold resistant bacteria.(3) The strains of DSWJ1201enzyme production conditions were optimized. The single fator optimization results:The carbon is0.1%(w/v).fluid volume is75mL/250mL.culture medium for pH5,Fermentation temperature is20℃. inducer twain80was0.5%(v/v).In order to further optimize the enzyme production of the strain a five factors and for levels orthogonal experiment was designed.For the best enzyme production conditions:the final determination DSWJ1201strains the best enzyme production conditions for incubation temperature is20℃, the medium initial pH value of7.0, loaded liquid is100mL/250mL, medium initial carbon content is0.06g/100mL, Tween80content is0.25%(V/V)(4) The main characteristics of the PCL depolymerase. The optimal reaction temperature of crude enzyme is40℃, the temperature stability is better from4℃to50℃. The optimum reaction pH is7, in the ranging of pH from5to9,it has high stability.(5) The degradation products of PCL by DSWJ1201strains crude enzyme detected by mass spectrometry analysis, we can find detect caprolactone monomer and caprolactone dimer and caprolactone trimer and Caprolactone tetramer.