一株分离自网箱养殖区沉积物的硫氧化菌B1-1的鉴定及其硫氧化特性

【背景】海水网箱养殖是一种高密度、高投饵的人工养殖方式,其产生的硫化物污染严重影响了海水养殖业的经济效益及可持续发展。【目的】鉴定从网箱养殖区沉积物中分离得到的硫氧化菌B1-1并研究其硫氧化特性,为利用生物技术修复网箱养殖环境提供理论依据。【方法】通过形态观察、生理生化特征及16S rRNA基因序列分析对硫氧化菌B1-1进行鉴定;通过摇床培养对该菌株氧化硫代硫酸盐的最适培养条件(pH、温度、底物浓度、外加碳源、外加氮源、金属离子)进行研究。【结果】该菌株被鉴定为HalothiobacillushydrothermalisB1-1。菌株B1-1生物氧化硫代硫酸盐的最适pH为8.0,最适生长温度为30°C,最适底物浓度为5.0g/L;外加碳源对该菌株氧化能力无显著影响,外加铵盐(硫酸铵或草酸铵)可以将延滞期缩短至12 h,添加Mg~(2+)可以显著提高菌株的氧化能力,氧化率达100%。【结论】Halothiobacillus hydrothermalisB1-1耐盐性较强,对硫代硫酸盐氧化率高,可作为修复受硫化物污染网箱养殖环境的潜在菌株资源。

Identification and characterization of a sulfur-oxidizing bacterium B1-1 isolated from the sediment of marine cage culture area

Background] Marine cage culture is a high-density and high feeding artificial breeding method. Sulfide pollution in marine cage culture environment seriously restricts the economic benefits and sustainable development of aquaculture. Objective] The identification and analysis of the oxidation characteristics of sulfur-oxidizing bacterium B1-1 from the sediment of marine cage culture area, is to provide theoretical basis for sulfide pollution control of sediment in the marine cage culture area. Methods] The species of strain B1-1 were identified by a variety of methods including Gram staining, plate colony morphologic observation, morphological characteristics research, 16S rRNA gene sequence analysis and the molecular phylogenetic tree construction. The optimal culture conditions (pH, temperature, substrate concentration, additional carbon and nitrogen source, and metal ion) for the oxygenation of strain B1-1 were determined. Results] Strain B1-1 was Gram-negative, short rod and identified as Halothiobacillus hydrothermalis (Genbank accession number: KU362926). The optimal culture conditions for strain B1-1 in the shaking flasks were pH 8.0, 30 °C, and substrate concentration 5.0 g/L. The additional carbon source did not change the oxidation ability of strain B1-1. With the additional ammonium salt, such as ammonium sulfate and ammonium oxalate, the delay period could be shortened to 12 h. Besides, the addition of Mg2+ could significantly improve oxidation ability of strain B1-1, the oxidation rate could reach 100%. Conclusion] Based on the high haloduric ability and the high ability of oxidation rate of the sodium thiosulfate, Halothiobacillus hydrothermalis B1-1 is of potential in the fields of bioremediation of polluted marine cage culture area.