日本三宅岛火山土壤中硫代硫酸盐氧化菌的分离、生物学特性及鉴定

Isolation, characterization and identification of thiosulfate-oxidizing strain MU2A-22 isolated from volcanic deposits in Miyake-jima island, Japan

摘要:

【目的】利用培养法从日本三宅岛火山土壤(堆积年限131年)中分离到一株能氧化分解硫代硫酸盐的细菌MU2A-22T。【方法】用培养法对该菌株MU2A-22T进行了生理生化性质以及分类学位置上的确定。【结果】菌株MU2A-22T为革兰氏阴性, 短杆状或球状。理化性质表明该菌株能利用葡萄糖、L-阿拉伯糖、葡萄糖酸盐、己二酸酯、dL-苹果酸钠、硫代硫酸钠(最适浓度为2.5 mmol/L)为唯一碳源进行自养生长。最适生长温度为25 °C?30 °C, 最适pH为6.0?8.0。菌株MU2A-22T的16S rRNA 序列与菌株Paracoccus solventivorans 6637T亲缘关系最近, 序列相似性为97%, 编码核酮糖-1,5-二磷酸羧化酶/加氧酶(Rubisco)的基因也被确定。对Paracoccus属内几种近缘菌的脂肪酸分析, 证明菌株MU2A-22T中含有Paracoccus属的特征氨基酸, 其中含量大于10%的分别为C18:1(74.7%) 和 C18: 0(12.1%)。DNA-DNA杂交实验表明, 菌株MU2A-22T与Paracoccus solventivorans 6637TDNA的相似度为49.3%。MU2A-22T菌株G+C含量为66.5%?66.7%。【结论】菌株MU2A-22T为Paracoccus属内的一新种菌(登录号GQ452286), 命名为Paracoccus scorialis sp. nov.。

Abstract:

[Objective] A bacterium MU2A-22T, which was isolated from 131-year-old volcanic deposits of Miyake-jima island (Japan), has been characterized for its capability of thiosulfate oxidizing. [Methods] The culture-based method was used to isolate and identify strain MU2A-22T for its phenotypic characteristics and taxonomic position. [Results] The strain MU2A-22T was Gram-negative, short rod- to coccus-shaped. This bacterium could utilize D-glucose, L-arabinose, gluconate, adipate and dL-malate as sole carbon source. Strain MU2A-22T was able to use thiosulfate as an energy source with the optimum concentration of 2.5 mmol/L. The optimum growth condition was 25 °C?30 °C and pH was 6.0?8.0 respectively. 16S rRNA gene sequence analysis indicated that this strain was closely related to Paracoccus solventivorans 6637T within Alphaprotebacteria (97% 16S rRNA gene sequence similarity). Its possess of the large-subunit gene of ribulose 1,5-bisphosphate carboxylase/oxygenase (rbcL) has also been identified. The cellular fatty acid profiles was characterized of the genus Paracoccus. The major fatty acids (>10%) were C18:1(74.7%) and C18:0(12.1%). DNA-DNA relatedness between strain MU2A-22T and P. solventivorans 6637T was 49.3%. G+C contents was 66.5%?66.7%. [Conclusion] As for the above results, strain MU2A-22T seemed to be a novel species in the genus Paracoccus with its accession number of GQ452286 and the name of Paracoccus scorialis sp. nov. was proposed.