Fujitani Hirotsugu, Ushiki Norisuke, Tsuneda Satoshi, Aoi Yoshiteru
Department of Life Science and Medical Bioscience, Waseda University, 2-2 Wakamatsu-cho, Shinjuku-ku, Tokyo, 162-8480, Japan.
Environ Microbiol. 2014 Oct;16(10):3030-40. doi: 10.1111/1462-2920.12248. Epub 2013 Sep 24.
Nitrification is an important process in the biogeochemical nitrogen cycle and is widely exploited in biological wastewater treatment. Recently, Nitrospira has been recognized as the numerically dominant nitrite-oxidizing bacterial genus and is primarily responsible for the second step of aerobic nitrification. Nevertheless, the physiological properties of Nitrospira remain poorly understood because the organisms are difficult to isolate and culture. Here, we report a novel cultivation strategy for obtaining members of the Nitrospira sublineage I in pure culture. The method combines: (i) selective enrichment of Nitrospira using a continuous feeding reactor and (ii) purification followed by sub-cultivation via a cell sorting system by focusing on the unique characteristics of Nitrospira forming spherical micro-colonies. This strategy is potentially applicable to other uncultured or unisolated Nitrospira and could accelerate the physiological and biochemical understandings of this important group of organisms.
硝化作用是生物地球化学氮循环中的一个重要过程，在生物废水处理中得到广泛应用。最近，硝化螺旋菌属被认为是数量上占主导地位的亚硝酸盐氧化细菌属，并且主要负责好氧硝化作用的第二步。然而，由于这些微生物难以分离和培养，硝化螺旋菌属的生理特性仍然知之甚少。在此，我们报告了一种用于获得纯培养的硝化螺旋菌亚系I成员的新型培养策略。该方法结合了：(i) 使用连续进料反应器对硝化螺旋菌进行选择性富集，以及 (ii) 通过细胞分选系统进行纯化并继代培养，重点关注形成球形微菌落的硝化螺旋菌的独特特征。该策略可能适用于其他未培养或未分离的硝化螺旋菌，并可能加速对这一重要生物群体的生理和生化理解。
