网箱养殖沉积环境中硫氧化菌的分离鉴定及生长特性

从网箱养殖区沉积物中分离硫氧化细菌,并研究其生长特性。从以硫代硫酸钠为唯一能源底物的培养基中分离得到一株硫氧化菌B1-1,经过平板菌落形态观察及其形态学特征研究,并结合16S rRNA基因序列分析及分子系统发育树的构建结果,确定菌株的种类。结果表明,菌株B1-1呈革兰氏阴性,短杆状,鉴定为Halothiobacillus hydrothermalis(GenBank登录号为KU362926)。在28℃、初始pH=8、150 r/min培养条件下,细菌在12 h进入对数生长期,36 h开始氧化硫代硫酸盐(S_2O_3~(2-)),至60 h培养液p H下降到4.8,S_2O_3~(2-)浓度从最初的2.28 g/L降到0.36 g/L,氧化率达84.2%。

Isolation,identification and characteristics of a sulfide-oxidizing bacterium in sediment of marine cage culture area

Screening sulfide-oxidizing bacteria from sediments of marine cage culture area, then exploring the growth characterization of the bacteria. The medium with sodium thiosulfate as the sole energy substrate was used to isolate a sulfide-oxidizing bacterium. The species of the strain were identified by a variety of methods of Gram staining, plate colony morphologic observation, morphological characteristics research, 16S rRNA gene sequence analysis and the molecular phylogenetic tree construction. An efficient thiosulphate-oxidizing bacterium was isolated from Bachimen of Fujian, named B1 -1. The strain was Gram-negative bacteria, short rod and identified as Halothiobacillus hydrothermalis ( GenBank accession no. KU362926 ) . Under the culture conditions of 28°C, pH 8 and 150 r/min, the phases of logarithmic of strain B1 -1 had come in 12 h, then the thiosulfate was oxidated in 36 h, the medium pH was down to 4. 8 and the concentra-tion of S2 O2-3 was reduced from initial 2. 28 g/L to 0. 36 g/L in 60 h. The strain of sodium thiosulfate oxida-tion was up to 84. 2%, which showed great application prospect.