本文選題：嗜熱地衣芽孢桿菌 + 黃原膠降解��； 參考：《中南林業(yè)科技大學》2017年碩士論文

【摘要】：黃原膠具有良好的流變性、乳化穩(wěn)定性、懸浮性、兼容性及增粘性,在原油開采中常被用作驅替劑,以提高鉆井、完井、調剖堵水及三次采油等過程中的采油率。在實際應用過程中發(fā)現,使用黃原膠后加大了后續(xù)處理工藝的難度,因此,有效地降解黃原膠是石油開采的重要工序。本研究以課題組前期鑒定的一株具有降解黃原膠能力的嗜熱地衣芽孢桿菌HT-1為材料,對其進行紫外微波復合誘變,測定復合誘變菌株溫度耐受性、pH耐受性以及對黃原膠的降解能力,并與原始菌株進行比較。最后,對復合誘變菌株的應用進行初步探索。本研究對后續(xù)黃原膠生物降解法以及黃原膠在石油工業(yè)的應用提供一定的參考依據。主要研究結果如下:原始菌株HT-1菌株的最適生長條件:溫度50℃,pH 7.5,0.1%的黃原膠,1%的葡萄糖(碳源),1%的酵母粉(氮源);最適黃原膠降解條件:0.3%黃原膠作為唯一碳源和氮源,溫度50℃,pH7.5。對原始菌株HT-1進行紫外誘變,選取一株較好的誘變菌株,命名為HT1UV-3,其對黃原膠的降粘率達到了 35.79%,較原始菌株提高了 14.42%。隨后,對篩選得到的HT1UV-3突變株進行微波誘變,最終得到5株突變型菌株HT1UM3-1、HT1UM3-2、HT1UM3-3、HT1UM3-4、HT1UM3-5。溫度耐受方面,5株突變菌株耐高溫性能較原始菌株明顯提高,其中HT1UM3-3菌株的最適生長溫度趨于55℃;pH耐受方面,復合誘變菌株與原始菌株無明顯差別;黃原膠降解方面,5株突變菌株的黃原膠降解能力較原始菌株均有提高,其中HT1UM3-5菌株的降粘率最高,達到42.02%,較原始菌株提高了 20.70%。在原油環(huán)境下,對原始菌株和復合誘變菌株的存活情況與黃原膠降解能力進行探索。結果顯示,不同原油濃度下,原始菌株和復合誘變菌株對原油的耐受程度都不高,半數致死率均在0.5g/L;在0.5g/L原油濃度下,原始菌株和復合誘變菌株對黃原膠降解能力均較差,原始菌株降粘率趨近于0%,復合誘變菌株降粘率約7.5%。探究原始菌株和復合誘變菌株對瓜爾膠、田箐膠、卡拉膠三種膠的降解能力。結果表明,對瓜爾膠的降解上,所有菌株降解能力微弱,最大降粘率不超過4%;對田箐膠的降解上,HT1UM3-1、HT1UM3-2、HT1UM3-4、HT1UM3-5的降解能力略高于原始菌株,降粘率在5%-8%之間;對卡拉膠的降解上,復合誘變菌株的降解能力顯著高于原始菌株,降粘率在10%-12%之間,較原始菌株提高了約60%。
[Abstract]:Xanthan gum has good rheology, emulsion stability, suspension, compatibility and viscosity. It is often used as a displacement agent in crude oil production to improve oil recovery rate in drilling, well completion, profile control, water shutoff and tertiary oil recovery. In the practical application, it is found that the use of xanthan gum increases the difficulty of subsequent treatment process. Therefore, the effective degradation of xanthan gum is an important process in petroleum exploitation. In this study, a strain of Bacillus licheniformis HT-1, which had the ability to degrade xanthan gum, was identified by our research group. The temperature tolerance and pH tolerance of the compound mutagenesis strain and its degradation ability to xanthan gum were determined and compared with the original strain. Finally, the application of compound mutagenesis strain was preliminarily explored. This study provides some references for the subsequent biodegradation of xanthan gum and the application of xanthan gum in petroleum industry. The main results were as follows: the optimum growth conditions of the original strain HT-1 were as follows: temperature 50 鈩，

本文編號：1798309