一株氨氧化菌的分离鉴定及其活性影响因子分析

Identification and Activity-affecting Factors of a Strand of Ammonia Oxidizing Bacteria

从浙江舟山南美白对虾养殖池塘底泥样品中筛选到一株具有氨氧化功能的细菌,命名为AOB-1.菌株AOB-1好氧,革兰氏阴性,球状至短杆状;菌落呈淡黄色、干燥、针尖状.16S rDNA序列分析表明,该菌株与Nitrosomonas eutropha C91T的相似性为100%.氨氧化的关键酶--氨单加氧酶的基因(amoA)序列比对表明,该菌株与N.eutropha C91T的相似性为98%.在30℃,100r·min-1时,25～200mL培养基装量范围内装液量越少氨氧化率越高,最适pH值为8.氨氮浓度在1～200mg·L-1范围内,氨氧化速率随氨浓度的升高而加快;在200～1200mg·L-1范围内,氨氧化速率基本保持不变;但当氨氮浓度高达2000mg·L-1时,氨氧化活性受到明显抑制.菌株AOB-1不仅对养殖水体,而且对高浓度氨氮废水的处理也具有潜在的应用价值.

A strand of ammonia oxidizing bacteria,AOB-1,was isolated from the surface sediment of coastal Penaeus vannamei rearing pond in Zhoushan,Zhejiang province.It features in aerobic,gram-negative,spherical or short rod,and the single colony is light yellow in color,dry and needle tip-like.Its 16S rRNA gene shows 100% similarity with that of Nitrosomonas eutropha C91 T and it is 98% similar with N.eutropha C91 T in ammonia monooxygenase gene（amoA）.Ammonia oxidizing rate is higher with less media in flasks within the range of 25～200 mL at 30 ℃,100 r·min-1.The optimum pH is 8 for ammonia oxidation.The rate of ammonia oxidation risen with the increase of ammonium concentration in the range of 1～200 mg·L-1,remained at similar level in the range of 200～1 200 mg·L-1,and was significantly inhibited in the presence of 2 000 mg·L-1 ammonia.The AOB-1 may be useful in the treating of both aquaculture wastewater with lower ammonium concentration and industrial wastewater contaminated with high concentration of ammonium.