Khalifa Ashraf, Nakasuji Yuta, Saka Norikuni, Honjo Hiroki, Asakawa Susumu, Watanabe Takeshi
1Biological Sciences Department, Faculty of Sciences, King Faisal University, Al-Ahsaa, Saudi Arabia.
2Botany and Microbiology Department, Faculty of Sciences, Beni-Suef University, Beni-Suef 65211, Egypt.
Int J Syst Evol Microbiol. 2018 Aug;68(8):2587-2592. doi: 10.1099/ijsem.0.002882. Epub 2018 Jun 26.
An iron-oxidizing bacterium, designated strain An22, which was isolated from a paddy field soil in Anjo, Japan, was described taxonomically. Strain An22 was motile by a single polar flagellum, curved-rod, Gram-negative bacterium that was able to grow at 12-37 °C (optimally at 25-30 °C) and at pH 5.2-6.8 (pH 5.9-6.1). The strain grew microaerobically and autotrophically by oxidizing ferrous iron, but did not form stalks, a unique structure of iron oxides. The major cellular fatty acids were C16 : 0 and C16 : 1ω7c/C16 : 1ω6c. The major respiratory quinones were UQ-10 and UQ-8. The strain possessed ribulose-1,5-bisphosphate carboxylase/oxygenase indicating an autotrophic nature via the Calvin-Benson-Bassham cycle. The total DNA G+C content was 61.4 mol%. 16S rRNA gene sequence analysis revealed that strain An22 was affiliated with the class Betaproteobacteria and clustered with iron-oxidizing bacteria, Gallionella ferrugineaJohan (94.8 % similarity) and Ferriphaselus amnicola OYT1 (94.4 %) in the family Gallionellaceae. Based on the low 16S rRNA gene sequence similarity to the phylogenetically closest genera and the combination of unique morphological, physiological and biochemical characteristics, strain An22 represents a novel genus and species within the family Gallionellaceae, for which the name Ferrigenium kumadai gen. nov., sp. nov. is proposed. The type strain is An22 (=JCM 30584=NBRC 112974=ATCC TSD-51).
对从日本安城的稻田土壤中分离出的一株铁氧化细菌（命名为菌株An22）进行了分类学描述。菌株An22通过单一极生鞭毛运动，呈弯杆状，革兰氏阴性菌，能够在12-37°C（最适温度为25-30°C）和pH 5.2-6.8（pH 5.9-6.1）条件下生长。该菌株通过氧化亚铁进行微需氧自养生长，但不形成铁氧化物的独特结构——柄。主要细胞脂肪酸为C16 : 0和C16 : 1ω7c/C16 : 1ω6c。主要呼吸醌为UQ-10和UQ-8。该菌株具有1,5-二磷酸核酮糖羧化酶/加氧酶，表明其通过卡尔文-本森-巴斯姆循环具有自养性质。总DNA G+C含量为61.4 mol%。16S rRNA基因序列分析表明，菌株An22隶属于β-变形菌纲，与铁氧化细菌铁锈嘉利翁氏菌Johan（相似度94.8 %）和栖河铁相菌OYT1（相似度94.4 %）在嘉利翁氏菌科中聚类。基于与系统发育关系最密切的属的16S rRNA基因序列相似性较低，以及独特的形态、生理和生化特征组合，菌株An22代表了嘉利翁氏菌科内的一个新属和新种，为此提出新属名为Ferrigenium kumadai gen. nov.，新种名为Ferrigenium kumadai sp. nov.。模式菌株为An22（=JCM 30584=NBRC 112974=ATCC TSD-51）。
