Ocean Research Institute, University of Tokyo, Nakano, 164, Tokyo.
Microb Ecol. 1989 Nov;18(3):249-59. doi: 10.1007/BF02075812.
Marine nitrogen-fixing bacteria distributed in the eelgrass bed and seawater of Aburatsubo Inlet, Kanagawa, Japan were investigated using anaerobic and microaerobic enrichment culture methods. The present enrichment culture methods are simple and efficient for enumeration and isolation of nitrogen-fixing bacteria from marine environments. Mostprobable-number (MPN) values obtained for nitrogen-fixing bacteria ranged from 1.1×10(2) to 4.6×10(2)/ml for seawater, 4.0×10(4) to 4.3×10(5)/g wet wt for eelgrass-bed sediment, and 2.1 × 10(5) to 1.2 × 10(7)/g wet wt for eelgrass-root samples. More than 100 strains of halophilic, nitrogen-fixing bacteria belonging to the family Vibrionaceae were isolated from the MPN tubes. These isolates were roughly classified into seven groups on the basis of their physiological and biochemical characteristics. The majority of the isolates were assigned to the genusVibrio and one group to the genusPhotobacterium. However, there was also a group that could not be identified to the generic level. All isolates expressed nitrogen fixation activities under anaerobic conditions, and no organic growth factors were required for their activities.
利用厌氧和微需氧富集培养方法，研究了分布在日本神奈川县油壶湾入口处的鳗草床和海水中的海洋固氮细菌。目前的富集培养方法简单高效，可用于从海洋环境中计数和分离固氮细菌。从海水中获得的固氮细菌最可能数（MPN）值范围为 1.1×10(2) 到 4.6×10(2)/ml，从鳗草床沉积物中获得的固氮细菌湿重值范围为 4.0×10(4) 到 4.3×10(5)/g，从鳗草根样品中获得的固氮细菌湿重值范围为 2.1 × 10(5) 到 1.2 × 10(7)/g。从 MPN 管中分离出 100 多株属于弧菌科的嗜盐固氮细菌。这些分离株根据其生理生化特性大致分为七组。大多数分离株被分配到弧菌属，一组被分配到发光杆菌属。然而，也有一组不能鉴定到属的水平。所有分离株在厌氧条件下均表达固氮活性，且其活性不需要有机生长因子。
