本文關(guān)鍵詞： 降解菌篩選 正構(gòu)烷烴 微生物修復(fù) 細菌組成　出處：《沈陽大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：本研究利用遼河油田石油污染土壤篩選分離正十六烷降解菌,并對所分離菌株進行理化性質(zhì)分析及分類鑒定,同時監(jiān)測其對正十六烷的代謝活性。利用模擬土壤的泥漿體系的正十六烷降解實驗驗證功能菌株對土壤污染環(huán)境的適應(yīng)性。通過遼河油田油井周邊石油污染土壤的微生物及電動修復(fù)實驗,觀測污染土壤修復(fù)過程中目標(biāo)降解菌及微生物整體群落的生長及代謝活性變化特征,由此明確目標(biāo)降解菌在有機污染土壤修復(fù)中的應(yīng)用價值。研究的主要結(jié)論包括:(1)以遼河油田石油污染土壤為菌源,以正十六烷為唯一碳源,篩選分離出3株具有較強的正十六烷代謝功能的降解菌,分別記為T1、T2和T5,依據(jù)菌落的生長形態(tài)及16s r DNA測序分析確定T1、T5為銅綠假單胞菌(Pseudomonas aeruginosa),T2為鞘氨醇菌(Spingopyxis terrae)。搖瓶培養(yǎng)的正交實驗確定混合菌株在溫度30℃,p H為7,C:N:P為100:10:2,鹽度為1.5%的溶液體系中獲得對正十六烷的最佳降解效果。(2)土壤模擬(泥漿)體系中的正十六烷降解實驗表明,前述篩選所得正十六烷功能降解菌具有較好的正十六烷降解特性,微生物處理30天,正十六烷降解率達到29.3%。試驗初期,T2(Spingopyxis terrae)細菌數(shù)量豐度較高,中期替換為T1與T5(Pseudomonas aeruginosa)的數(shù)量增多,各菌株數(shù)量的變化結(jié)合正十六烷降解率的變化特征,反映了多菌株組合應(yīng)用所產(chǎn)生的共代謝優(yōu)勢。DGGE群落組成分析表明,各降解菌株在直流弱電場條件下均具有一定程度的電場耐受性,但適應(yīng)速率存在差異。弱場強梯度(1.2 V·cm-1)刺激功能降解菌的代謝活性,電動-微生物處理30天,正十六烷降解率達到65.10%,較微生物處理降解率提高35.80%,表現(xiàn)出電動與微生物的協(xié)同降解作用。(3)遼河油田石油污染場地土壤修復(fù)實驗表明,功能降解菌對遼河油田石油組分中飽和烷烴的降解作用效果明顯,處理48天后降解率達到37.58%。直流弱電場的施用進一步提高正十六烷的降解能力,處理48天后降解率達到61.97%,較單獨微生物處理降解率提高24.39%。土壤脫氫酶(DHA)活性分析表明,微生物組(BIO)及電動-微生物(EK-BIO)組中DHA活性遠高于電動(EK)組,反映了功能降解菌具有較好的污染物代謝活性。相關(guān)性分析表明,施加功能降解菌的土壤脫氫酶活性與烷烴的降解速率呈現(xiàn)顯著的正相關(guān)性。EK-BIO處理中脫氫酶的活性高于BIO組,驗證了功能降解菌受弱電場刺激,其烷烴代謝能力得到提高。DGGE圖譜分析表明,電動處理有效增強了土壤微生物群落多樣性,同時提高功能降解菌對污染土壤環(huán)境的適應(yīng)性。本研究分離得到的烷烴降解菌不僅適用于石油污染土壤的微生物修復(fù)處理,而且適用于電場條件下的微生物-電動聯(lián)合修復(fù)技術(shù)的應(yīng)用。本研究為石油污染土壤微生物修復(fù)過程的調(diào)控及新的聯(lián)合方法的建立提供理論基礎(chǔ)。
[Abstract]:In this study, n-hexadecane degrading bacteria were isolated from oil-contaminated soil in Liaohe Oilfield, and their physicochemical properties were analyzed and classified. At the same time, the metabolic activity of cetane was monitored. The adaptability of the functional strain to soil pollution was verified by the n-cetane degradation experiment of simulated mud system. Oil contaminated soil around the oil well of Liaohe Oilfield was used to verify the adaptability of the functional strain to soil pollution. Microbiological and electric repair experiments, The characteristics of growth and metabolic activity of the target degrading bacteria and microbial community during the remediation of contaminated soil were observed. The main conclusions of the study include: the petroleum contaminated soil in Liaohe Oilfield was used as the bacterial source and the hexadecane as the sole carbon source. Three strains of biodegradable bacteria with strong function of cetane metabolism were screened out. It was recorded as T _ 1 T _ 2 and T _ 5, respectively. According to the growth morphology of colony and 16s r DNA sequencing analysis, it was confirmed that T _ 1 T _ 5 was Pseudomonas aeruginosafida T _ 2 as sphingosine sphingosporium. The orthogonal experiment of shaking flask culture confirmed that the mixed strain was 7C / N: P = 100: 10: 2 at 30 鈩，

本文編號：1491969