Oligotrophic bacteria can take advantage of solutions containing low concentrations of organic nutrients. This study investigated the growth and physiological characteristics of AT52 (Alteromonas stellipolaris sp. Nov. ) isolated from the Antarctic marine system, under an oligotrophic and a nutritious environment, respectively. Under nutrient-rich condition, cells of AT52 developed flagella and appendages of different lengths. These cells were surrounded by a plasma membrane layer and reproduction was performed through budding. Under starvation-survival conditions , AT52 cells were relatively small and subspheroidal in shape. The cell edges were rough without any appendages and no budding activities were observed. The optimal growing medium was found to consist of 5 g poptone, 1 g yeast extract and 1000 mL filtered Antarctic seawater. The optimal growing conditions were observed with 200 mL of this medium, placed in a 500 mL triangular flask (to ensure enough oxygen) at 12℃, pH 8.0, a rotation speed of 180 r/min and an inoculation density of 5%. The reproduction cycle of AT52 was shortened in our experiment under the above-mentioned conditions and hence provides the basis for industrial production.%寡营养细菌是一类能利用低浓度有机营养基质的细菌,通过研究1株分离自南极海洋的极地寡营养细菌AT52,发现富营养条件下AT52菌体细胞周身附肢,附肢长短不一,具鞭毛,菌体出芽生殖,由一层原生质膜包围.寡营养饥饿生存的菌体细胞相对较小,近球形,边缘不平滑,无鞭毛附肢等超微结构,细胞体眠未见出芽生殖过程.实验中采用寡营养环境和富营养环境分别研究AT52菌的生长生理特性.优化得到该菌富营养条件下的最佳培养条件为:1 L南极陈海求中加入蛋白胨5 g,酵母粉lg,培养温度12℃,液体培养基的pH值为8.0,转速为180 r/min,装液量为500 ml的三角瓶中装200 ml,通氧量充分.
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