从浙江舟山桃花岛近海海域分离筛选到一株高活性氨氧化细菌,命名为THD-1.菌株THD-1为革兰氏阴性,球状至椭球状,大小约为(0.5～0.8) μm×(0.7～1.3) μm;菌落呈无色透明状,针尖大小,边缘光滑；可在盐度为0～50‰的培养基中生长.16S rDNA序列比对表明,菌株THD-1与Nitrosomonas europaea ATCC25978T的相似性为96.3％.培养液的pH值对菌体生长和氨氧化活性影响明显,当pH值降至6.0以下时,菌株的生长和氨氧化活性几乎完全被抑制,但这种抑制可通过回调pH值的方法解除；在所试的4种碱液中,碳酸氢铵调节pH值对菌体生长和氨活性改善效果最好.建立了菌株THD-1的分批补料式高密度培养方法,最终OD600可达0.214,最大活菌数可达7.5×108 cells/mL.%A strain of ammonia-oxidizing bacteria, THD-1 , was isolated from the coastal surface sediment of Taohua Island in Zhoush-an. Its cell is spherical or short rod with a size of 0. 5 ~ 0. 8 μm × 0. 7 ~ 1. 3 μm, gram-negative, and the colony is colorless and transparent, needle size with a smooth edge. The similarity between the 16S rDNA sequence of the srain THD-1 and that of Nitrosomonas eurapaea ATCC25978 is 96. 3% . The pH of culture solution significantly affects cell growth and ammonia oxidation of strain THD-1. Ammonia bicarbonate could improve the growth and ammonia oxidation activity when used for pH controlling. High-density culture for strains THD-1 was obtained by fed-batch adding of ammonia bicarbonate, with a maximum of 0. 214 OD600 and 7. 5 × 10s cells/mL.
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