Silicon-Rich, Iron Oxide Microtubular Sheath Produced by an Iron-Oxidizing Bacterium, Leptothrix sp. Strain OUMS1, in Culture

Minerals

Hiromichi Ishihara¹  Hideki Hashimoto¹  Eisuke Taketa¹  Tomoko Suzuki¹  Kyoko Mandai¹  Hitoshi Kunoh¹ 

[1] Graduate School of Natural Science and Technology, Okayama University, Okayama 700-8530, Japan; E-Mails:

关键词: Leptothrix sp. strain OUMS1;    sheath formation;    iron oxide;    silicon-rich sheath;    phase change of iron oxides;   

DOI  :  10.3390/min4030565

来源: mdpi

【 摘 要 】

This study aimed to manipulate the texture and elemental composition of the novel sheaths produced by the iron-oxidizing bacterium Leptothrix in culture by altering components of the medium. When previously isolated strain OUMS1 was cultured in media (pH 7.0 throughout incubation) containing various levels of Si on a rotary shaker at 20 °C and 70 rpm for 14 days, the strain was able to reproduce in media with up to 300 ppm Si, and the hollow microtubular architecture of the sheath was maintained even at 300 ppm Si. The constitutional iron oxide phase changed from poorly crystalline lepidocrocite at 0 ppm Si to X-ray diffraction (XRD)-amorphous 2-line ferrihydrite at 100–300 ppm via their mixture phase with intermediate Si content (Si-30 and -50 ppm). The results strongly indicate that the chemical character and crystallinity of the sheath texture can be regulated by culture conditions, especially components of the medium.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.