Isolation and Identification of Naphthalene-degrading Strains

[Objective] The aim was to research the degradation ability of degradation strain on naphthalene so as to apply for the bioremediation of soil,water etc.contaminated by petroleum.[Method] With the contaminat containing 2 benzene ring structure in polycyclic aromatic hydrocarbon as the tested material,the microorganism that could degrade the naphthalene was enriched,screened and separated in the petroleum-contaminated soil in the suburb of Xiangfan Country.The colony and mycelia morphology were observed through the physiology biochemistry experiment.[Result] 31 strains with naphthalene as only carbon source for of growth were separated from the samples of soil and waste oil among them,4 strains had greater colonies on the flat and they had the different colony character,which were named as L1,L8,L15 and L19,in which,the degradation ability of L1 strain was best.When L1 strain was cultured in the medium with the initial naphthalene concn.of 100 mg/L for 40 h,the degradation rate of naphthalene was 92% and the residue naphthalene was least in the medium liquid,which was only 8 mg/L.The L1 strain was primary identified as the microbacterium.[Conclusion] The domestication condition was the important restrictive factor for advantage strain screening.With the naphthalene as the only carbon source,the degradation strain which had the better degradation effect on the naphthalene could be domesticated and screened out.