【作者】 刘芳；

【导师】 和文祥；

【作者基本信息】 西北农林科技大学 ， 农业资源利用， 2014， 硕士

【摘要】 水产养殖中，含氮污染物主要有NH4+-N和NO2--N两种，对养殖水体水质产生不良影响而且对养殖动物具有强烈毒性。严重时，会导致养殖动物大量死亡，造成巨大的损失。因此如何高效去除各种含氮污染物，特别是降低的氨氮和亚硝态氮，是水产养殖中长期面临的关键问题之一。在各种脱氮方法中，生物脱氮具有成本低、环境副作用低，度养殖动物无害等诸多优势而广受重视。异养反硝化菌具有生长速度快、要求溶解氧浓度低、能忍受较酸环境等优点，而且异养微生物兼具有硝化能力及反硝化能力,相对成本较低，因此，在生物脱氮过程中的重要作用越来越被广泛认同。在水产养殖中有广阔的应用前景。本文取昌黎海边的海水，通过筛选培养基、获得脱氮效果好的微生物，研究了不同条件下该微生物的生长情况，其生物脱氮能力以及固态发酵条件优化，获得的固态发酵产品进行了养殖厂实验。主要取得如下成果：1通过筛选获得一株反硝化细菌，进一步研究了初始pH值、不同温度、C/N对该菌生长的影响。获得该微生物生长发育条件为：pH值7.5，温度35℃、C/N7:1，适当溶解氧的条件下能够快速生长。3对该微生物转化亚硝酸盐、氨氮的条件进行初步研究，其脱氮的最适pH值约为7.5，在25～40℃的范围内都有较好的转化效果，在温度为30～35℃的范围内对亚硝酸盐的转化率达到了94%以上，对氨氮的转化率达到了78%以上。该细菌适合的C/N为7:1。4通过对培养基的种类、配比、接种量、培养基含水量、发酵温度、发酵时间等因素的单因素试验及关键因素的正交试验一系列筛选，最终得出玉米粉和麦麸4:6、5:5、6:4，接种量为10%，发酵时间为5d、含水量为60%、发酵温度35℃，为最佳发酵条件。5投放固态发酵的反硝化细菌能够显著降低养殖水池的铵态氮和亚硝态氮，添加量0.5kg/亩水面。更多还原

【Abstract】 NH4+-N and NO2--N are two kinds of main pollutants that containing nitrogen in breedmarine lives. It has a negative impact on the water quality and has strong toxicity to aquaticanimal，even cause animal death and cause huge loss. Therefore, how to effectively removenitrogen pollutants, especially reducing ammonia nitrogen and nitrite nitrogen, is one of thekey problems faced in aquaculture.Biological nitrogen removal has been paid wide attentionin a variety of method of denitrification, which has the advantages of low cost, low sideeffect, many advantages of aquaculture animal harmless.Heterotrophic denitrifying bacteria has advantages of fast growth, low dissolved oxygenconcentrations, can endure acid environment, low cost and heterotrophic microorganisms bothnitrification and denitrification ability.Therefore, an important role in biological nitrogenremoval process is more and more widely recognized, has a broad application prospect inaquaculture.In this paper, taking the sea of Changli, to obtain good denitrification effect ofmicroorganisms by screening culture medium, the growth of the microorganism underdifferent conditions, the biological nitrogen removal ability and solid-state fermentationcondition optimization, fermentation products obtained were plant breeding experiment.Theresults are as follows:1Obtained a strain of denitrifying bacteria by screening, and further study of the initial pHvalue, temperature, C/N effect on the bacterial growth.The microbial growth conditions were:pH7.5, temperature35℃, C/N7:1, properly dissolved oxygen conditions.2Preliminary study on the microbial degradation of nitrite, ammonia nitrogen condition, theoptimum pH value about7.5, in the range of25~40℃have good degradation effect, at atemperature of30~35℃within the degradation rate of nitrite reached more than94%, theammonia nitrogen degradation rate of more than78%. The bacteria for C/N7:1.3Through orthogonal test, single factor test and key factors on species, culture medium,inoculation ratio, water content of culture medium, fermentation temperature, fermentationtime and other factors of a series of screening,the best fermentation conditions: corn flour andwheat bran4:6,5:5,6:4, inoculum10%, fermentation time5d, moisture content of60%,fermentation temperature35℃. 4On the solid state fermentation denitrifying bacteria can significantly reduce the breedingpool of ammonium nitrogen and nitrite nitrogen, adding amount of0.5kg/mus of surface.更多还原