【摘要】 为筛选能降解氨氮的芽孢杆菌并应用到养殖海水的净化中，以解决高密度养殖带来的氨氮超标问题，本研究利用硫酸铵为唯一氮源的筛选培养基，从烟台周边海域分离到61株能利用氨氮的菌株，复筛得到两株具有较高氨氮降解能力的芽孢杆菌菌株X6和X37。在氨氮初始浓度为63.27 mg/L的培养基中，X6和X37的48 h氨氮去除率分别为61.02%、50.96%,在氨氮初始浓度为27.00 mg/L的培养基中两者48 h氨氮去除率分别为35.30%、35.53%。通过形态特征、生理生化特征和16S rDNA序列比对，鉴定菌株X6为花津滩芽孢杆菌(Bacillus hwajinpoensis),菌株X37为巨大芽孢杆菌(Bacillus megaterium)。菌株X6的最适降解条件为温度32℃、pH 7.0、转速170 r/min,菌株X37的最适降解条件为温度27℃、pH 6.0、转速170 r/min,且两株菌在48 h的氨氮去除速率最高。两株菌的最佳复配比为1∶1,此比例下的复合菌剂在氨氮初始浓度约为27.00 mg/L、温度为30℃、pH 6.5、接种量6%、170 r/min时，48 h的氨氮去除率为54.768%,且该复合菌剂能同时去除培养基中的亚硝态氮和硝态氮。更多还原

【Abstract】 In order to screen Bacillus bacteria which could degrade ammonia nitrogen from the ocean and apply them to remove excessive ammonia nitrogen caused by high-density aquaculture, 61 strains capable of utilizing ammonia nitrogen were isolated from the sea area around Yantai by using the screening medium with ammonium sulfate as the only nitrogen source in this study. From them, two strains(named as X6 and X37) with higher ammonia nitrogen degradation ability were obtained. In the medium with the initial ammonia nitrogen concentration at 63.27 mg/L and 27.00 mg/L, the ammonia nitrogen removal rates of X6 and X37 at 48 h were 61.02% and 50.96%, 35.30% and 35.53%, respectively. By analyzing their morphological, physiological and biochemical features and 16S rDNA sequences, strain X6 and X37 were identified as Bacillus hwajinpoensis and B. megaterium, respectively. The optimum degradation conditions for strain X6 were 32℃, pH 7.0 and rotation speed at 170 r/min, while those for strain X37 were 27℃, pH 6.0 and rotation speed at 170 r/min. The two strains had the highest ammonia nitrogen removal rate at 48 h. The optimal mix ratio of the two strains was 1∶1, and at this ratio, when the initial ammonia nitrogen concentration was 27.00 mg/L, temperature was 30℃, pH 7.0 and rotation speed at 170 r/min, the ammonia nitrogen removal rate at 48 h was 54.768%. More importantly, the complex Bacillus bacteria could remove both nitrite nitrogen and nitrate nitrogen in the medium at the same time.更多还原