一株耐碱变形假单胞菌ZY-3的鉴定及其脱氮特性

Identification of an alkali-tolerant Pseudomonas plecoglossicida ZY-3 and its nitrogen removal characteristics

【背景】目前缺少具有高效脱氮能力、较高生物安全性、能处理高碱含氮污水的好氧反硝化菌株,难以使用生物方法处理高碱性的工业、养殖废水。【目的】对前期于佛山市一水产养殖池塘底泥中分离得到的耐碱高效好氧反硝化细菌ZY-3进行研究,期望获得一株能用于不同酸碱环境脱氮的高效、安全的好氧反硝化细菌。【方法】通过形态学、生理生化试验及16S rRNA基因序列分析方法对菌株种属进行鉴定,采用抗生素试验及斑马鱼攻毒试验进行菌株的环境生物安全性评估,利用3种含不同氮素的含氮模拟废水进行脱氮能力的测定。【结果】确定ZY-3为假单胞菌属变形假单胞菌(Pseudomonas plecoglossicida),其对多种临床常用抗生素敏感,对水生生物的毒性低,该菌株在高浓度含氮模拟废水中以28℃、180 r/min振荡培养时,其对数期出现在4−12 h,在12 h时NH_(4)^(+)-N、NO_(3)^(-)-N和NO_(2)^(-)-N的去除率分别达到94.87%、81.44%和98.02%,其pH耐受范围为6.0−10.0。【结论】得到一株安全、高效、具有广泛pH适应范围的耐碱好氧反硝化细菌P.plecoglossicida ZY-3,其在有氧条件下对3种氮素(NH_(4)^(+)-N、NO_(3)^(–)-N、NO_(2)^(–)-N)具有快速去除能力。

[Background]At present,there is a lack of aerobic denitrification bacteria with significant nitrogen removal performance,high biological safety and alkali tolerance.Thus,it is difficult to treat high-alkaline industrial and aquaculture wastewater using biological methods.[Objective]The alkali-resistant and highly aerobic denitrification bacterium ZY-3 isolated from an aquaculture pond in Foshan city,Guangdong province was tested,in the hope of obtaining an efficient and safe aerobic denitrification bacterium which could be used in different pH environments for nitrogen removal.[Methods]The strain was identified by morphological observation,physiological and biochemical tests,and 16S rRNA gene sequence analysis.Antibiotic test and zebrafish challenge test were conducted to evaluate the environmental and biological safety of the strain.Three kinds of simulated wastewater containing different nitrogen levels were used to determine the nitrogen removal performance.[Results]ZY-3 was identified as Pseudomonas plecoglossicida,which was sensitive to a variety of clinically common antibiotics and had low aquatic toxicity.When this strain was cultivated in the three simulated wastewater with ammoniacal nitrogen,nitrite nitrogen or nitrate nitrogen as the sole nitrogen source at 28℃ and 180 r/min,the logarithmic phase appeared at 4−12 h.At 12 h,the removal rates of NH_(4)^(+)-N,NO_(3)^(–)-N and NO_(2)^(–)-N reached 94.87%,81.44%and 98.02%,respectively.The pH tolerance range of the strain was 6.0−10.0.[Conclusion]A safe and efficient aerobic denitrification bacterium P.plecoglossicida ZY-3 was obtained,with a wide range of pH adaptation and rapid removal ability against three nitrogen sources(NH_(4)^(+)-N,NO_(3)^(–)-N and NO_(2)^(–)-N)under aerobic conditions.