RhlA、RhlB基因表达对微生物采油的影响

Effect of RhlA and RhlB Gene Expression on Microbial Oil Recovery

王 慊 樊永红 郭 斌 麦迪努尔 秦新政

WANG Qie FAN Yonghong GUO Bin MEDINUEL QIN Xinzheng

为了探究RhlA、RhlB基因表达在微生物采油中对降黏效果的影响，建立了RhlA和RhlB基因实时荧光绝 对定量（Q-PCR）方法，测定不同培养时期的铜绿假单胞菌X7发酵液和克拉玛依油田不同地层水的RhlA、RhlB 基因表达量，并测定其鼠李糖脂产量、表面活性、乳化活性、乳化稳定性及原油降黏率。结果表明，RhlA、RhlB基 因表达量与鼠李糖脂产量、表面活性、乳化活性及原油降黏率呈正相关。随着发酵时间的延长，发酵液中RhlA、 RhlB基因表达量不断升高并在24 h时达到最大值，随后下降并于60 h趋于平稳，RhlA、RhlB基因表达量最大值 分别为2.51×106 和3.25×105 copies/μL，发酵液中12～60 h期间鼠李糖脂产量快速上升，并在60 h时达到最大值 （824.08 mg/L）；发酵液的表面活性、原油乳化活性及稠油降黏率也随着发酵时间的增长而升高，并分别在 24、48、60 h时达到最大。发酵液中的鼠李糖脂粗提物有良好的稳定性，能在一定的极端条件下稳定发挥作用。 RhlA、RhlB基因很可能通过影响鼠李糖脂产量、表面活性、乳化活性及原油降黏率对微生物采油产生影响。本 研究初步揭示了生物表面活性相关功能基因表达对稠油降黏效果的影响，对推进微生物采油的工业化应用具有 重要的意义。

In order to explore the effect of RhlA and RhlB gene expression on viscosity reduction in microbial oil recovery，a real-time fluorescent absolute quantitative（Q-PCR）method for RhlA and RhlB genes was established，and the Pseudomonas aeruginosa X7 fermentation broth and Karamay Oilfield at different culture stages were detected. The expression levels of RhlA and RhlB genes in different formation waters were measured，and their rhamnolipid production，surface activity，emulsifying activity， emulsifying stability，and crude oil viscosity reduction rate were determined. The results showed that the expression levels of RhlA and RhlB genes were positively correlated with rhamnolipid production，surface activity，emulsifying activity and crude oil viscosity reduction rate. With the increase of fermentation time，the expression levels of RhlA and RhlB genes in the fermentation broth increased continuously and reached the maximum at 24 h，then decreased and stabilized at 60 h，and the maximum expression levels of RhlA and RhlB genes were 2.51 × 106 and 3.25 × 105 copies/μL. The highest expression level of RhlA and RhlB genes reached the maximum value of 824.08 mg/L at 60 hours. The surface activity of the fermentation broth，crude oil emulsifying activity and heavy oil viscosity reduction rate also increased with the increase of fermentation time and reached the maximum value at 24 hours，48 hours and 60 hours，respectively. The rhamnolipid crude extract in the fermentation broth had good stability and could work stably under certain extreme conditions. RhlA and RhlB genes probably affected microbial oil recovery by affecting rhamnolipid production，surface activity，emulsifying activity and viscosity reduction rate of crude oil. This study preliminarily revealed the influence of functional gene expression related to biological surface activity on the viscosity reduction effect of heavy oil，which was important to promote the industrial application of microbial oil recovery.

10.19346/j.cnki.1000-4092.2024.02.013