發(fā)布時(shí)間：2018-04-13 10:46

  本文選題：生物降解 + 混合菌群��； 參考：《新疆師范大學(xué)》2015年碩士論文

【摘要】：新疆地區(qū)棉花長(zhǎng)期大面積栽培造成當(dāng)?shù)赝寥乐修r(nóng)藥等的面源污染,同時(shí)也孕育了豐富的農(nóng)業(yè)污染物降解微生物資源。本研究以新疆地區(qū)連作10 a以上的棉田土壤作為研究材料,以高效氯氰菊酯作為唯一碳源和能源,首先采用逐漸加量和連續(xù)傳代該菌源的馴化方式,從土壤中初步獲得并確定能穩(wěn)定傳代且可以持續(xù)降解氯氰菊酯的菌群。其次,利用稀釋涂布的方法,從高效氯氰菊酯降解菌群中篩選可培養(yǎng)微生物,根據(jù)菌落形態(tài)觀察,初步確定篩選出11株可培養(yǎng)微生物,分別編號(hào)為GX2-GX12。采用CTAB/Na Cl法提取細(xì)菌總DNA,PCR擴(kuò)增得到各菌株的16Sr DNA。測(cè)序所得全部序列經(jīng)16Sr DNA同源性分析該菌群結(jié)構(gòu)組成,結(jié)果表明該菌群由10株銅綠假單胞菌(Pseudomonas aeruginosa)和1株無色桿菌屬(Achromobacter)構(gòu)成。11株菌中10株與綠銅假單胞菌(Pseudomonas aeruginosa)相似性為99%,1株與無色桿菌(Achromobacter mucicolens)相似性達(dá)到99%。通過對(duì)獲得的菌株序列比對(duì)分析,可以了解棉田土壤中能降解高效氯氰菊酯的可培養(yǎng)微生物種類較少,其中優(yōu)勢(shì)微生物是綠銅假單胞菌的菌株,占到90.91%。而無色桿菌的菌株占9.09%。因此推斷本實(shí)驗(yàn)中所獲得的降解高效氯氰菊酯的微生物主要是綠銅假單胞菌。第三,以初始農(nóng)藥濃度(100、150、250 mg/L)、溫度(27、32、37℃)、初始p H(6.5、7.0、7.5)、裝樣量(100、200、300 m L/500 m L)為試驗(yàn)因素,采用四因素三水平的正交試驗(yàn)方法,對(duì)該菌群降解高效氯氰菊酯的特性做了初步研究,每組試驗(yàn)做3個(gè)重復(fù)。試驗(yàn)結(jié)果表明,該混合菌群具有較寬的環(huán)境適應(yīng)性,以LB培養(yǎng)基做種子液,極差分析,最優(yōu)條件:初始農(nóng)藥濃度250 mg/L,溫度27℃,初始p H 7.5,裝樣量300 m L;方差分析:只有p H這一因素不顯著,最適條件:初始濃度250 mg/L,溫度27℃,裝樣量300 m L;測(cè)得在培養(yǎng)48 h時(shí),降解率為96.15%,144 h,降解率為84.27%,204 h,降解率為86.98%;以無機(jī)鹽培養(yǎng)基做種子液,極差分析:最優(yōu)條件:初始農(nóng)藥濃度250 mg/L,溫度27℃,初始p H 7.0,裝樣量200 m L;方差分析:初始農(nóng)藥濃度不顯著,主體間效應(yīng):溫度裝樣量p H,最適條件:溫度27℃,初始p H7.0,裝樣量200m L。測(cè)得在培養(yǎng)24 h時(shí),降解率為68.81%,132 h時(shí),降解率為92.39%�；旌暇航到飧咝惹杈挣サ漠悩�(gòu)體選擇性結(jié)果表明,混合菌群對(duì)高效氯氰菊酯的降解并沒有明顯的立體異構(gòu)體選擇性。本研究獲取了適合新疆地區(qū)土壤類型、氣候環(huán)境條件下高效氯氰菊酯農(nóng)藥面源污染修復(fù)的微生物資源,旨在為新疆地區(qū)土壤環(huán)境修復(fù)、恢復(fù)及開發(fā)該地區(qū)環(huán)境條件下的生物資源打下基礎(chǔ)。
[Abstract]:Cotton cultivation in Xinjiang for a long time resulted in non-point pollution of pesticides in local soil and abundant microbial resources for degradation of agricultural pollutants.In this study, the soil of cotton field in Xinjiang area was used as the research material, and the high efficiency cypermethrin was used as the sole carbon source and energy source. Firstly, the acclimation mode of the bacteria source was gradually added and subcultured continuously.A stable subculture and sustainable degradation of cypermethrin was obtained from soil.Secondly, the culturable microorganisms were screened from the high efficiency cypermethrin degrading bacteria by the method of dilution coating. According to the colony morphology observation, 11 culturable microbes were preliminarily selected and numbered GX2-GX12.The 16Sr DNA of each strain was obtained by CTAB/Na Cl method.The sequence was analyzed by 16Sr DNA homology.Through the sequence alignment analysis of the obtained strains, we can find out that there are few culturable microorganisms in cotton field soil that can degrade high efficiency cypermethrin, among which the dominant microorganism is Pseudomonas aeruginosa, which accounts for 90.91%.But the strain of colorless bacillus accounted for 9.09%.Therefore, we infer that the main microorganism for degradation of cypermethrin in this experiment is Pseudomonas chloridii.Three repetitions were made in each group.The results showed that the mixed bacteria had wide adaptability to the environment. Using LB medium as seed solution, the optimum conditions were as follows: initial pesticide concentration 250 mg / L, temperature 27 鈩，

本文編號(hào)：1744163