For the application of a heterotrophic nitrifying-aerobic denitrifying bacteria strain X3 in mariculture,the effects of several environmental factors,including temperature,salinity,pH,C ∶ N ratio,and carbon source on the growth and nitrogen removing ability of strain X3 were examined in the laboratory conditions,and its sensitivity to different antibiotics was also explored.The results showed that,the optimal condition for strain X3 to grow and remove nitrogen were 28℃,salinity of 30,pH 8.5,using sodium acetate as the carbon source and at a C ∶ N ratio of 10 ∶ 1.This strain grew well and kept over 80％ nitrogen removal rate at 25 ～37℃,20～80 salinity,pH 7.5～9.5 with a C ∶ N ratio range of 5 ∶ 1～15.∶ 1 and sodium acetate or glucose as the carbon source.Especially,this strain was able to grow in the medium with salinity of 150.The result of sensitivity to antibiotics indicated that strain X3 was only sensitive to norfloxacin,ofloxacin and polymyxa amphotericin B,while resistant to the other 27 antibiotics.Therefore,it can be concluded that strain X3 has excellent adaptability to the environment of mariculture and huge application potential in mariculture water purification.%测定了不同环境因子,包括温度、盐度、pH、碳源、C∶N等的变化对菌株的生长和脱氮能力的影响以及该菌株对不同抗生素的敏感性.结果表明,该菌株最适生长条件为温度28℃、盐度30、pH8.5、乙酸钠为碳源、碳氮比10∶1；在盐度20～80、温度25～37℃、pH 7.5～9.5、碳源为葡萄糖或乙酸钠、碳氮比5∶1～15∶1环境条件下均能良好生长,脱氮效率均可达到80％以上；在盐度为150的培养液中仍能生长.药敏试验结果表明,该菌株仅对诺氟沙星、氧氟沙星和多粘霉素B敏感,对其余27种常用抗生素具有抗药性.研究结果说明,该菌株对海水养殖环境适应性良好,在海水养殖水质处理方面具有巨大的应用潜力.
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