甲苯降解真菌选育及应用其强化生物过滤运行性能研究

发布时间：2018-06-11 22:20

本文选题：甲苯 + 生物降解　；参考：《浙江工业大学》2015年硕士论文

【摘要】：甲苯类VOCs广泛应用于染料、医药、农药、有机合成等化工和制药行业中,化学性质较为稳定,具有生物积累性和生物毒性,对人体具有不同程度的危害作用,是美国环保局(EPA)优先控制的污染物名单之一。对于这类污染物,生物法净化技术由于具有高效、低耗能、反应条件温和、二次污染小等优点,因此它受到越来越多的研究者们的关注和探索。本论文筛选得到了一株能以甲苯为唯一碳源和能源的降解菌株LW-1,经过基于菌株的形态、生理生化特性、18s RNA基因序列分析及其系统发育树和Biolog鉴定,可确定菌株为绿色木霉Trichoderma viride,初步判断其为新发现的降解甲苯的菌株。在摇瓶试验中,真菌LW-1对甲苯虽然有一定降解能力,但是降解效率较低,不能降解完全。菌株LW-1降解甲苯最佳生长条件是温度为30℃、pH值约为4.8。在菌株底物广谱性研究过程中,发现菌株LW-1对乙酸乙酯有很高的降解效率。在摇瓶试验中,可能瓶内湿度太大,不利于真菌的生长繁殖,因为真菌一般喜欢较为干燥的环境。在生物过滤塔中,利用菌株LW-1接种到生物滤塔反应器中,来强化生物过滤降解甲苯废气。为了研究菌株强化效应,分别采用单独真菌、真菌+细菌构成的复合菌种启动生物过滤塔,在运行18天后,两个塔(f-bf、fb-bf)挂膜启动基本完成。复合菌种启动生物过滤塔,其启动的速度较快,并且对甲苯的去除性能较好,不同的运行条件下其去除率和最大去除负荷都是最大,这都体现出“真菌+细菌”的接种模式具有较高的去除性能,复合菌株具有明显的强化效应。由于含有真菌和细菌,在处理较高浓度废气时较单独真菌启动的过滤塔具有明显优势。本论文通过实时荧光定量pcr和高通量测序等分子生物学手段,来研究两套不同的生物过滤塔里生物膜相生物种群结构、多样性及动态变化规律。实时荧光定量pcr检测数据表明,启动期f-bf塔内的细菌明显少于fb-bf塔内的细菌数量,因为f-bf塔内循环营养液中添加了硫酸链霉素,抑制了大部分细菌的生长。两塔古菌的数量相差无几,然而在真菌数量上,f-bf塔真菌数量大概是fb-bf塔真菌数量的2倍多。在稳定运行阶段,fb-bf塔的细菌数量较f-bf塔有了很大程度上提升,古菌数量大致相当,f-bf塔的真菌数量明显比fb-bf塔多出一个数量级。高通量测序结果表明,当以817f/1196r为引物时,在接种单独真菌来启动的生物滤塔f-bf塔中,属于zygomycota、hypocreales、saccharomycetales、eurotiales、conthreep目的菌株占据主导地位。在真菌+细菌复合菌种启动的生物滤塔fb-bf塔中,属于chaetothyriales、tremellales、hypocreales、eurotiales目的菌株占据主导地位。当以338f/806r为引物时,在接种单独真菌来启动的生物滤塔f-bf塔中,属于burkholderiales、xanthomonadales、lactobacillales目的菌占据主导地位。在真菌+细菌复合菌种启动的生物滤塔FB-BF塔中,属于Burkholderiales、Corynebacteriales、Rhodospirillales、Xanthomonadales目的菌占据主导地位。
[Abstract]:Toluene VOCs is widely used in chemical and pharmaceutical industries, such as dyes, medicine, pesticides, organic synthesis, and other chemical and pharmaceutical industries, which have more stable chemical properties, biological accumulation and biological toxicity, and have different harmful effects on human body. It is one of the list of pollutants in the United States Environmental Protection Bureau (EPA). Because of its advantages of high efficiency, low energy consumption, mild reaction conditions and small two pollution, it has attracted more and more researchers' attention and exploration. This paper has screened a strain LW-1 which can take toluene as the only carbon source and energy, which is based on the form, physiological and biochemical characteristics of the strain, and the sequence analysis of the 18S RNA gene and its sequence analysis and The phylogenetic tree and Biolog identification can determine the strain of Trichoderma viride Trichoderma viride, initially judging its newly discovered strain of toluene. In the shake flask test, the fungal LW-1 has certain degradation ability to toluene, but the degradation efficiency is low and the degradation of toluene can not be completely degraded. The optimum growth condition for the LW-1 degradation of toluene is 30. The pH value is about 4.8. in the wide spectrum study of strain substrate. It is found that strain LW-1 has high degradation efficiency to ethyl acetate. In shake flask test, it is possible that the humidity in the bottle is too large and is not conducive to the growth and reproduction of fungi, because fungi generally prefer a more dry environment. In the biofilter, the strain LW-1 is used to inoculate the biofilter reaction. In order to study the intensifying effect of the strain, the biological filtration tower was started by the compound fungus composed of separate fungi and fungi and bacteria, and two towers (f-bf, fb-bf) were started to start the biofilter for 18 days. The removal efficiency is better and the maximum removal rate and maximum removal load are all under different operating conditions. This shows that the inoculation mode of "fungi + bacteria" has high removal performance, and the compound strain has obvious strengthening effect. The pagoda has obvious advantages. In this paper, the biological population structure, diversity and dynamic changes of two different biological filtration towers were studied by real time fluorescence quantitative PCR and high throughput sequencing. The real-time fluorescence quantitative PCR detection data showed that the bacteria in the f-bf tower were obviously less than those in the fb-bf tower. The number of bacteria, because streptomycin sulfate is added to the circulating nutrient solution in the f-bf tower, inhibits the growth of most of the bacteria. Two the number of bacteria in the tower is almost the same, but in the number of fungi, the number of fungi in the f-bf tower is about 2 times more than the number of fungi in the fb-bf tower. In the stable operation stage, the number of bacteria in the fb-bf tower is much more than that of the f-bf tower. The number of palaebacteria was approximately equal, and the number of fungi in the f-bf tower was more than one order of magnitude more than that of the fb-bf tower. High throughput sequencing results showed that when the primers were primed with 817f/1196r, the f-bf tower of the biofilter, which was initiated by the individual fungi, belonged to the main Zygomycota, hypocreales, Saccharomycetales, Eurotiales, and conthreep purposes. Chaetothyriales, Tremellales, hypocreales and Eurotiales are dominant in the biological filter tower fb-bf tower, which are activated by fungi + bacteria compound bacteria. When 338f/806r primers are primed, the biological filter tower f-bf tower, which is vaccinated by individual fungi, belongs to burkholderiales, xanthomonadales, lactobacillales orders. The bacteria occupy the dominant position. In the biological filter tower FB-BF tower which is activated by the fungal + bacteria compound bacteria, the Burkholderiales, Corynebacteriales, Rhodospirillales, and Xanthomonadales are dominant.
【学位授予单位】：浙江工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X172;X701

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