1株滩涂沉积物反硝化细菌的鉴定及其性能研究

Identification of a Denitro-Bacterium Strain from Low Beach Sediment

利用富集培养法从江苏沿海滩涂沉积物中分离筛选获得1株具有反硝化性能的细菌,命名为MD5。通过形态学观察、糖发酵及16S r DNA序列分析对其进行了分类鉴定、系统发育地位及反硝化性能等方面的研究。结果表明,该菌株能在厌氧条件下利用硝酸钠进行反硝化反应,在初始硝酸盐质量浓度为1 500 mg/L、30℃培养条件下,144 h后培养基中硝酸盐脱除率可达90.1%;在好氧培养条件下,该菌株可使能力测试管中硝酸盐质量浓度下降89.3%。菌株MD5的形态学、糖发酵结果与盐单胞菌一致,且基因序列与盐单胞属(Halomonas)细菌Halomonas sp.IW11-1(AB305262.1)的序列同源性达到99%,表明菌株MD5为1株盐单胞属细菌。本研究分离得到的菌株MD5在厌氧和好氧条件下均具有较强的反硝化能力,对海洋沉积物脱氮具有一定的意义。

A denitrification-possessing bacterium strain was isolated and screened with enrichment culture method from low beach sediment in Jiangsu coastal area.Through morphological observation,sugar fermentation as well as16 S r DNA sequence analysis,the classification characterization,phylogenetic site,denitrifying performance,and other aspects of the strain was studied,and named it as MD5.The results showed that the isolated strain from oceanic sediment by enrichment,isolation,screening possessed fairly strong denitrification reaction,under the conditions of30 ℃ with initial concentration of nitrate at 1 500 mg / L and after 144 h of cultivation,the nitrate in the medium could be removed by 90.1%; under the aerobic cultivation conditions the removal rate of concentration of nitrification acid mass declined to 89.3% in a ability test tube by the strain.The results of MD5 in morphology and sugar fermentation were in accord with that in Halomonas,in addition,the homology of its gene sequence was as high as 99% with Halomonas sp.IW11-1（AB305262.1）,suggested that was a Halomonas strain.Strain MD5 obtained by isolation in this experiment had fairly strong denitrifying ability both under anaerobic and aerobic conditions,therefore,it could be applied in the oceanic sediment environment denitrification application study.