土霉素對厭氧發(fā)酵過程古菌群落及抗性基因的影響
發(fā)布時間：2018-08-08 16:36
【摘要】：抗生素因其具有防病、促生長的作用被廣泛應(yīng)用于畜禽養(yǎng)殖業(yè)。但是,大部分抗生素會隨畜禽糞便排出。如果用含有抗生素的畜禽糞便進行厭氧發(fā)酵會對此過程產(chǎn)生一定的影響。中國畜禽養(yǎng)殖業(yè)主要使用四環(huán)素類抗生素(四環(huán)素,金霉素和土霉素),其中有關(guān)四環(huán)素和金霉素研究較多,土霉素研究較少。本研究采用小型厭氧發(fā)酵裝置,通過外源添加不同濃度土霉素,以此來探究土霉素對于厭氧發(fā)酵過程中甲烷產(chǎn)量,酶活性,微生物群落多樣性,四環(huán)素類抗性基因的影響以及土霉素在厭氧發(fā)酵過程中的含量變化。主要結(jié)果表明:1.土霉素對于甲烷累積產(chǎn)量、酶活性的影響以及土霉素的含量變化土霉素在厭氧發(fā)酵前期對于甲烷累積產(chǎn)量和脲酶活性有一定的促進作用,隨后表現(xiàn)為抑制作用。對于脫氫酶活性,在厭氧發(fā)酵前期所有添加土霉素處理均表現(xiàn)為抑制作用,至厭氧發(fā)酵中期,低、中濃度土霉素對于脫氫酶的抑制作用解除。土霉素的含量變化表明,土霉素的去除主要在發(fā)生前30天,30天之后其含量基本維持不變。2.土霉素對古菌群落多樣性的影響DGGE圖譜表明土霉素對于古菌作用較小,測序結(jié)果表明,厭氧發(fā)酵系統(tǒng)中的優(yōu)勢古菌主要為甲烷粒狀菌菌屬中的菌種(Methanocorpusculum labreanum Z)甲烷絲狀菌屬中的菌種(Methanosaeta concilii GP-6),中溫厭氧發(fā)酵對于不動桿菌(Acinetobacter sp)這類致病微生物有一定的去除作用。掃描電鏡結(jié)果表明,厭氧發(fā)酵系統(tǒng)中的菌群主要以短桿菌、球狀菌為主,同時有少量絲狀菌。3.土霉素對四環(huán)素類抗性基因的影響共檢出四種四環(huán)素類抗性基因,分別屬于核糖體保護蛋白保護基因(tet(M)、tet(Q)、tet(W))和外排泵基因(tet(C)),其中核糖體保護蛋白基因豐度均高于外排泵基因。低、中濃度土霉素處理對于四環(huán)素類抗性基因(除tet(W))的去除率均高于對照處理,高濃度土霉素處理去除效果最差�？剐曰虻呢S度變化可能與抗性基因宿主微生物的數(shù)量變化有關(guān)。厭氧處理不利于去除四環(huán)素類抗性基因,厭氧發(fā)酵產(chǎn)物需進一步處理以降低抗性基因?qū)τ诃h(huán)境帶來的風險。
[Abstract]:Antibiotics are widely used in livestock and poultry breeding because of their disease prevention and growth-promoting effect. However, most antibiotics are excreted in animal feces. Anaerobic fermentation of animal manure containing antibiotics may have an effect on this process. Tetracycline antibiotics (tetracycline, chlortetracycline and oxytetracycline) are mainly used in livestock and poultry breeding in China, in which tetracycline and chlortetracycline are studied more than oxytetracycline. In this study, a small anaerobic fermenter was used to investigate the effects of oxytetracycline on methane production, enzyme activity and microbial community diversity during anaerobic fermentation by exogenous adding different concentrations of oxytetracycline. Effects of tetracycline resistance genes and changes of oxytetracycline content during anaerobic fermentation. The main result is: 1. Effects of oxytetracycline on methane accumulation, enzyme activity and the content of oxytetracycline, oxytetracycline promoted methane accumulation and urease activity in the early stage of anaerobic fermentation, followed by inhibition. The activity of dehydrogenase was inhibited by oxytetracycline at the early stage of anaerobic fermentation, and the inhibition of midconcentration oxytetracycline on dehydrogenase was removed from the middle stage of anaerobic fermentation. The change of the content of oxytetracycline showed that the content of oxytetracycline was basically unchanged after 30 days before the occurrence of oxytetracycline. The effects of oxytetracycline on the diversity of ancient bacteria communities showed that oxytetracycline had little effect on ancient bacteria, and sequencing showed that oxytetracycline had little effect on ancient bacteria. The dominant ancient bacteria in the anaerobic fermentation system were mainly the (Methanocorpusculum labreanum Z) species in the genus (Methanocorpusculum labreanum Z). The medium temperature anaerobic fermentation could remove the pathogenic microbes such as Acinetobacter (Acinetobacter sp) to a certain extent. The results of scanning electron microscope showed that the microflora in the anaerobic fermentation system was mainly composed of Bacillus brevis, bulbous bacteria, and a small amount of filamentous bacteria. Effects of oxytetracycline on tetracycline resistance genes, four tetracycline resistance genes were identified, which belonged to ribosomal protection protein protection gene (tet (M) et (Q) (W) and efflux pump gene (tet (C),. The abundance of ribosomal protection protein gene was higher than that of efflux pump gene. The removal rate of tetracycline resistance genes (except tet (W) in low and middle concentration oxytetracycline treatment was higher than that in control treatment, and the removal efficiency of high concentration oxytetracycline treatment was the worst. The variation of resistance gene abundance may be related to the quantity change of resistance gene host microorganism. Anaerobic treatment is not conducive to the removal of tetracycline resistance genes, anaerobic fermentation products need to be further treated to reduce the risk of resistance genes to the environment.
【學(xué)位授予單位】：西北農(nóng)林科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X172
本文編號：2172381
[Abstract]:Antibiotics are widely used in livestock and poultry breeding because of their disease prevention and growth-promoting effect. However, most antibiotics are excreted in animal feces. Anaerobic fermentation of animal manure containing antibiotics may have an effect on this process. Tetracycline antibiotics (tetracycline, chlortetracycline and oxytetracycline) are mainly used in livestock and poultry breeding in China, in which tetracycline and chlortetracycline are studied more than oxytetracycline. In this study, a small anaerobic fermenter was used to investigate the effects of oxytetracycline on methane production, enzyme activity and microbial community diversity during anaerobic fermentation by exogenous adding different concentrations of oxytetracycline. Effects of tetracycline resistance genes and changes of oxytetracycline content during anaerobic fermentation. The main result is: 1. Effects of oxytetracycline on methane accumulation, enzyme activity and the content of oxytetracycline, oxytetracycline promoted methane accumulation and urease activity in the early stage of anaerobic fermentation, followed by inhibition. The activity of dehydrogenase was inhibited by oxytetracycline at the early stage of anaerobic fermentation, and the inhibition of midconcentration oxytetracycline on dehydrogenase was removed from the middle stage of anaerobic fermentation. The change of the content of oxytetracycline showed that the content of oxytetracycline was basically unchanged after 30 days before the occurrence of oxytetracycline. The effects of oxytetracycline on the diversity of ancient bacteria communities showed that oxytetracycline had little effect on ancient bacteria, and sequencing showed that oxytetracycline had little effect on ancient bacteria. The dominant ancient bacteria in the anaerobic fermentation system were mainly the (Methanocorpusculum labreanum Z) species in the genus (Methanocorpusculum labreanum Z). The medium temperature anaerobic fermentation could remove the pathogenic microbes such as Acinetobacter (Acinetobacter sp) to a certain extent. The results of scanning electron microscope showed that the microflora in the anaerobic fermentation system was mainly composed of Bacillus brevis, bulbous bacteria, and a small amount of filamentous bacteria. Effects of oxytetracycline on tetracycline resistance genes, four tetracycline resistance genes were identified, which belonged to ribosomal protection protein protection gene (tet (M) et (Q) (W) and efflux pump gene (tet (C),. The abundance of ribosomal protection protein gene was higher than that of efflux pump gene. The removal rate of tetracycline resistance genes (except tet (W) in low and middle concentration oxytetracycline treatment was higher than that in control treatment, and the removal efficiency of high concentration oxytetracycline treatment was the worst. The variation of resistance gene abundance may be related to the quantity change of resistance gene host microorganism. Anaerobic treatment is not conducive to the removal of tetracycline resistance genes, anaerobic fermentation products need to be further treated to reduce the risk of resistance genes to the environment.
【學(xué)位授予單位】：西北農(nóng)林科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2015
【分類號】：X172
【參考文獻】
相關(guān)期刊論文 前2條
1 姚建華;牛德奎;李兆君;梁永超;張樹清;;抗生素土霉素對小麥根際土壤酶活性和微生物生物量的影響[J];中國農(nóng)業(yè)科學(xué);2010年04期
2 張樹清,張夫道,劉秀梅,王玉軍,鄒紹文,何緒生;規(guī)�；B(yǎng)殖畜禽糞主要有害成分測定分析研究[J];植物營養(yǎng)與肥料學(xué)報;2005年06期
，本文編號：2172381
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