几株光合细菌的分离鉴定及在养殖罗非鱼中的应用

从渔场底泥样品中分离纯化得到5株紫色非硫光合细菌，根据分离菌株的细胞形态结构、光合内膜结构、活细胞光吸收特征以及生理生化特征，参照伯杰氏细菌分类学手册，5个分离株分别属于沼泽红假单胞菌（Rhodopseudomonas palusteris）和类球红细菌（Rhodobacter spheroides）。利用它们的纯培养物及混合培养物进行的水产养殖试验表明，光合细菌可以明显提高养殖鱼的成活率以及生长速度，罗非鱼经过2周的养殖后，加入光合细菌的试验组比没加入光合细菌的对照组（成活率80％）成活率显著提高，最高达100％；平均体长、体重分别提高了3％-5％、20％-30％，效果显著；而同时加入光合细菌纯培养物的试验组和加入混合培养物的试验组，差别不大。

Isolation and Identification of Several Photosynthesis Bacteria and Their Application in the Culture of Tilapia sp.

Five purple non-sulfur bacterial strains were isolated from the sediments of the rearing pond. According to the cultural, morphological, cellular spectra, physiological properties and inner intracytoplasmic membrane structures, strain AS-31 that was short rod and contained lamellar intracytoplasmic membrane was identified as Rhodopseudomonas palustris, and other four isolates (AS-32, DA-32, SY-32, and SY34) which were spheroid and contained vesicular intracytoplasmic membranes were identified as Rhodobacter spheroids. Pure cultures of strains AS-31 and SY-32 were used as additive in aquiculture of Tilapia sp.. After weeks of incubation, the weight and surviving percentage of experimental fishes increased about 20% than those of the control group without any additive. However, the mixed culture of strains AS-31 and SY32 have no obvious effect than that of the pure one. It demonstrated that the cultures of purple non-sulfur bacteria are of benefit to aquiculture and could be used as an additive.