红树林湿地土壤萘降解菌的分离与鉴定

Isolation and Identification of Naphthalene-degrading Strains from Mangrove Wetland Soil

[目的]研究降解菌株对萘的降解能力,为其应用于被石油污染滨海湿地的生物修复提供参考。[方法]采用富集培养方法,从珠海市淇澳岛被石油污染的红树林湿地土壤中富集、分离和筛选出能降解萘的菌株,观察各菌落及菌体形态特征;研究菌株N4的生理生化特征,并应用16S rDNA序列分析方法进行鉴定。[结果]从土壤样中分离得到26个能以萘为唯一碳源生长的菌株,其中4个在平板上菌落较明显且具有不同的菌落特征,分别命名为N1、N2、N3和N4。菌株N4对萘的降解能力最强,在初始萘浓度为100 mg/L的无机盐培养基中培养5 d,萘降解率为54.2%,而菌株N1、N2和N3的降解率分别为52.7%、52.5%和47.8%。菌株N4经16S rDNA序列分析方法鉴定为赤红球菌。[结论]从被石油污染的红树林湿地土壤分离筛选出对萘具有较高降解能力的菌株。

[Objective] The aim was to research the degradation abilities of naphthalene-degrading strains so as to provide references for its application to the bioremediation of coastal wetlands polluted by crude oil.[Method] With the enrichment culture method,some strains that could degrade naphthalene were enriched,separated and screened from the oil polluted mangrove soil on the Qi＇ao Island of Zhuhai city,and the colony and the cell morphology was observed;the physiological and biochemical characteristics of strain N4 were tested,and the 16S rDNA sequence analysis was used to identify the strain.[Result] 26 strains with naphthalene as the sole source of carbon were separated from the oily mangrove soil samples,4 strains formed obvious colonies with different characteristics,which were named as N1,N2,N3 and N4.When cultured in the medium with the initial naphthalene concentration of 100 mg/L for 5 days,the degradation rate of strain N4 was the highest of 54.2%,while strain N1,strain N2 and strain N3 were 52.7%,52.5% and 47.8% respectively.Strain N4 was identified as Rhodococcus rubber by 16S rDNA sequence analysis.[Conclusion] Several strains with high degradation abilities of naphthalene could be domesticated and screened from the mangrove soil polluted by curde soil.