本文選題：莠去津 + 礦化　； 參考：《東北農(nóng)業(yè)大學(xué)》2016年碩士論文

【摘要】：莠去津又名阿特拉津,英文名:Atrazine,屬于三嗪類除草劑,在過去的40年中已被廣泛應(yīng)用于農(nóng)作物的雜草控制,如高粱、玉米和甘蔗。因為長期大范圍使用目前已造成了嚴(yán)重的環(huán)境污染,在作物生長的土壤、水體中均已檢測到莠去津存在,它不僅破壞生態(tài)環(huán)境,還嚴(yán)重危害著人類的健康。本論文的研究目的是篩選出污染土壤中的莠去津礦化群落,并進(jìn)行分離鑒定。在國內(nèi)外微生物礦化莠去津研究的基礎(chǔ)上對這些礦化微生物的礦化特性進(jìn)行較為系統(tǒng)的研究。本研究利用富集培養(yǎng)法,從黑龍江省伊春市南岔區(qū)長期施用莠去津的玉米地中篩選出莠去津高效礦化群落NC1,此群落可以在28 h時礦化MSM培養(yǎng)基內(nèi)99%的100 mg/L的莠去津,使其轉(zhuǎn)變?yōu)闊o毒的氰尿酸。通過MSM平板直接分離法,分離出5株形態(tài)、顏色各不相同的菌株。通過生理生化和16S rDNA鑒定,菌株YJY1、YJY2、YJY3、YJY4和YJY5分別被鑒定為腸道桿菌(Enterobacter sp.)、無色桿菌(Achromobacter sp.)、銅綠假單胞菌(Pseudomonas sp.)、希瓦氏菌(Shewanella sp.)和克雷白氏肺炎菌(Klebsiella sp.)。并將上述五種菌株分別命名為Enterobacter sp.YJY1、Achromobacter sp.YJY2、Pseudomonas sp.YJY3、Shewanella sp.YJY4和Klebsiella sp.YJY5。底物利用實驗及礦化實驗表明菌株YJY4和YJY5可以以莠去津為唯一氮源生長,所有群落成員均不能利用氰尿酸為唯一氮源生長,且菌株YJY4礦化莠去津效率明顯強于菌株YJY5,所以確定菌株YJY4為礦化菌落NC1的主要成員。菌株YJY4是第一個被發(fā)現(xiàn)可以礦化莠去津的希瓦氏菌(Shewanella sp.),這表明它對莠去津污染的土壤環(huán)境的修復(fù)具有巨大潛力。在此基礎(chǔ)上,我們對YJY4降解菌的特性進(jìn)行了研究。根據(jù)對已發(fā)表的莠去津礦化微生物基因序列設(shè)計引物,通過PCR技術(shù)對于菌株YJY4基因組進(jìn)行擴增,在菌株YJY4中分別發(fā)現(xiàn)了莠去津礦化基因atz A、atz B和atz C基因,通過序列比對,發(fā)現(xiàn)擴增出的三種礦化基因與已發(fā)表的假單胞菌ADP和節(jié)桿菌TC1中的礦化基因相似性很高,達(dá)到了98%以上,這也證明了菌株YJY4可以將莠去津礦化成無毒無害的氰尿酸。利用定時培養(yǎng),每隔4 h測定OD600nm處吸光值觀察菌株生長情況,證實菌株YJY4在近似中性的pH(6.0-8.0)范圍內(nèi)都可以很好生長,其最適碳源和氮源分別為蔗糖和硝酸銨。
[Abstract]:Atrazine, also known as atrazine, is a triazine herbicide and has been widely used in crop weed control in the past 40 years, such as sorghum, corn and sugar cane. Because the long-term extensive use has caused serious environmental pollution, atrazine has been detected in the soil and water body of crop growth, which not only destroys the ecological environment, but also seriously endangers human health. The purpose of this paper is to screen out the mineralized communities of atrazine in contaminated soil and to separate and identify them. On the basis of the research of microbial mineralization atrazine at home and abroad, the mineralization characteristics of these mineralized microorganisms are studied systematically. In this study, the enrichment culture method was used to screen atrazine highly effective mineralized community NC1 from the corn field of Nancha District, Yichun City, Heilongjiang Province, which could mineralize 99% of Atrazine 100 mg/L in MSM medium at 28 h. Turn it into a nontoxic cyanuric acid. Five strains with different color and morphology were isolated by MSM plate method. By physiological and biochemical identification and 16s rDNA identification, the strains YJY1, YJY2, YJY3, YJY4 and YJY5 were identified as Enterobacter sp., Achromobacter sp., Pseudomonas sp. and Shewanella sp., respectively. And Klebsiella sp. The above five strains were named as Enterobacter sp. YJY1Achromobacter sp. YJY2 Pseudomonas sp. YJY3 Shewanella sp.YJY4 and Klebsiella sp. YJY5. The substrate utilization and mineralization experiments showed that YJY4 and YJY5 could grow with atrazine as the only nitrogen source, and all the community members could not use cyanuric acid as the sole nitrogen source. The mineralized atrazine efficiency of strain YJY4 was significantly higher than that of strain YJY5, so strain YJY4 was the main member of mineralized colony NC1. Strain YJY4 is the first strain of Shewanella sp. found to be able to mineralize atrazine, which indicates that it has great potential for remediation of atrazine contaminated soil environment. On this basis, we studied the characteristics of YJY4 degrading bacteria. According to the published gene sequence of atrazine mineralized microorganism, primers were designed and amplified by PCR technique. The genes of atrazine mineralization gene atz Agnatz B and atz C were found in strain YJY4, respectively. It was found that the three mineralized genes were similar to the mineralized genes of Pseudomonas pseudomonas ADP and Arthrobacter TC1, reaching more than 98%, which proved that the strain YJY4 could mineralize atrazine into innocuous cyanuric acid. The absorptivity of OD600nm was measured every 4 hours. The results showed that YJY4 could grow well in the range of pH 6.0-8.0). The optimum carbon source and nitrogen source were sucrose and ammonium nitrate, respectively.
【學(xué)位授予單位】：東北農(nóng)業(yè)大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：X592;X172
，

本文編號：1836545