凡纳滨对虾养殖池塘硝化细菌的分离鉴定及脱氮效果研究

利用平板稀释涂布法和平板划线分离纯化法,自凡纳滨对虾养殖池塘中分离得到5株细菌,经过形态观察、生理生化特性以及16S rDNA序列分析,对分离菌株进行鉴定,同时对其硝化功能和氨氮去除特性进行研究。试验结果显示,分离得到的5株细菌分别为门多萨假单胞菌、嗜胺甲基杆菌、放射根瘤菌、施氏假单胞菌和氧化微杆菌。对其净化效果进行验证可知,门多萨假单胞菌和施氏假单胞菌对氨氮的去除率超过85%,分别为88.83%和91.73%;对亚硝态氮的去除率超过90%,分别为95.08%和97.39%;对硝态氮的去除率超过90%,分别为90.49%和91.22%。以上两种菌株有较高的氨氮和亚硝态氮去除效果,具有潜在的应用价值。

Isolation,Identification and Nitrogen Removal Effect of Nitrifying Bacteria in Sediment and Water of Pacific White Shrimp Litopenaeus vannamei Culture Ponds

Five strains of bacteria were isolated and purified from water and sediment in Pacific white leg shrimp Litopenaeus vannamei culture ponds using dilution-plate method and streak plate method, after Gram staining, and identified as Pseudomonas mendocin, Methylobacterium aminovorans, Rhizobium radiobacter, P. stutzeri and Microbacterium oxydans by morphological observation, physiological and biochemical characteristics and 16 S rDNA sequence analysis to investigate the component of bacteria of water and sediment in the Pacific white leg shrimp culture pond. The water from the shrimp ponds was filtered into 250 mL conical flasks and inoculated with the five strains(with final density of 2 ×10^7 cfu/mL) and cultured at 30 ℃ and 120 r/min for 48 hours to study their nitrification function and ammonia nitrogen removal rates.The ammonia nitrogen removal efficiency was shown to be all above 85%, 88.83% in P. mendocin and 91.73% in P. stutzeri;the removal efficiency of nitrite nitrogen were all above 90%, 95.08% in P. mendocin and 97.39% in P. stutzeri;and the removal efficiency of nitrate was above 90%, 90.49% in P. mendocin and 91.22% in P. stutzeri. The findings indicated that Pseudomonas has higher removal efficiency of ammonia nitrogen and nitrite nitrogen, and has potential application in treatment of shrimp effluent.