产表面活性剂菌与稠油降解菌复配对原油黏度的影响

稠油微生物降解是微生物采油的重要机理之一,但其效率较低,不能明显改变稠油化学组成,降低稠油黏度,从而影响采油效率。针对这一问题,将产表面活性菌与稠油降解菌复配,通过测定菌种作用前后原油的黏度确定产表面活性菌与稠油降解菌的最佳复配比例;通过原油四组分分析和变性梯度凝胶电泳,研究了生物表面活性剂对稠油生物降解的强化作用。结果表明,产表面活性菌T-1、X-3与稠油降解菌QB26、QB36适宜的复配体积比为2∶2∶1∶1。菌种复配作用后,稠油黏度明显降低,与单独使用降解菌相比降黏率平均提高33.1%,胶质与沥青质平均降解率提高8.0%和4.9%。产表面活性剂菌的加入增加了表面活性剂含量,降低了胶质沥青质等相对重质组分的含量;产表面活性剂菌通过产生表面活性剂,使原油降黏增溶,形成小液滴,易于被稠油降解菌捕获降解,不仅降低稠油黏度,还提高了稠油降解菌的数量。生物表面活性剂对稠油生物降解具有明显的强化作用,在微生物采油技术中具有良好的应用潜力。图1表1参19     

生物表面活性剂驱油性能研究

为探讨生物表面活性剂菌种采油性能及矿场应用潜力,在吉林油区广泛取样,采用特定培养基对菌种进行筛选,在建立生物表面活性剂检测方法的基础上,对菌种生长代谢及发酵环境条件进行了分析。采用色谱法对菌种作用原油后组分变化进行了定性分析,在室内物模驱油效率试验的基础上,进行了矿场清防蜡应用试验。原油经生物表面活性剂菌作用后,油水界面张力降低到10～mN／m,原油黏度下降50％;室内物模驱油效率试验提高采收率10％以上,矿场清防蜡有效率〉65％,单井平均增油73．5t;在微生物强化水驱、油井清防蜡及近井解堵等MEOR工艺方面具有良好的应用前景。     

复合生物表面活性剂处理含油污泥实验研究

从新疆油田含油污泥中分离3株石油降解菌,其代谢产物与化学助剂复配形成复合生物表面活性剂。复合生物表面活性剂与化学表面活性剂相比,能显著降低油、水界面张力,具有较低的临界胶束浓度(CMC)和更高的迁移油能力。优化复合生物表面活性剂与含油污泥的反应参数,得到最佳反应条件:温度80℃、时间24h、搅拌速率200r/min、加药质量分数为1.2%。污泥含油质量分数(干基)为46.2%,处理后降低至1.2%,原油回收率大于95%。     

微生物及其代谢物提高低渗透油藏渗吸采收率

自发渗吸是低渗透油藏采油的重要方法,微生物提高渗吸采收率的主要采油机理详细研究报导较少。使 用从油藏环境中分离得到的专利菌株波茨坦短芽孢杆菌BS3096和铜绿假单胞菌LZ3-2,通过自发渗吸实验研究 了细菌和培养基的选择、微生物的生长条件、细菌的代谢产物生物表面活性剂、菌体影响等因素对微生物提高采 收率的影响。研究结果表明,含有脂肽生物表面活性剂的渗吸液可以使油水界面张力从0.8848 mN/m降低至 0.2055 mN/m,接触角由116.4°减小至42.8°,使岩石的润湿性从油湿变为水湿。油水界面张力的降低和岩石润湿 性的改变对提高渗吸原油采收率影响显著,BS3096产的脂肽生物表面活性剂渗吸采收率可达60%;铜绿假单胞 菌PAO1产的鼠李糖脂渗吸采收率为56.26%;LZ3-2产的糖蛋白类生物乳化剂对原油的具有乳化效果,乳化率为 6.96%。渗吸实验中,BS3096菌体在岩心内大量累积,选择性地封堵大孔喉通道,使渗吸液分流至低渗区的小孔 隙中将原油驱替出来,可使采收率提高7.5百分点。在相同的实验条件和表面活性剂浓度下,生物表面活性剂和 化学表面活性剂自发渗吸作用强弱顺序为生物型＞阴离子型＞非离子型＞阳离子型,脂肽生物表面活性剂的渗 吸采收率比化学型表面活性剂高11.8百分点～41.5百分点。本研究为低渗透油藏提供了一种高效经济且环境 友好的提高原油采收率的方法,为微生物及其代谢产物在现场的应用提供了理论支持。     

产表面活性剂菌微生物驱工艺及提高采收率效果研究

生物采油技术中,微生物驱提高采收率的效果不佳,多年来一直处于探索阶段;而生物表面活性剂用于采油的几十年,地下发酵微生物驱提高采收率一般不超过5%。为了解决产表面活性剂菌微生物驱在实验室和现场应用效果不理想的问题,研究了产鼠李糖脂的铜绿假单胞菌菌株Bsw的生物表面活性剂合成积累规律,进行了以菌株Bsw为核心的微生物驱实验。30 cm方岩心驱油实验结果表明,采油工艺影响驱油效果,地下厌氧发酵法只能提高采收率2.83%,而采用地面好氧发酵充分积累产物的发酵液的工艺的方法可以提高采收率15.63%;Bsw菌株积累的有效产物是提高采收率的关键因素,该菌株厌氧降解原油的功能对提高采收率贡献较小。研究结果为生物采油技术提高油田采收率提供了技术支持。     

氟表面活性剂及其在石油工业中的应用

从氟表面活性剂的结构出发 ,论述了其特性、种类和合成工艺等。由于氟表面活性剂具有优良的高表面活性、高耐热稳定性、高化学稳定性、憎水憎油特性以及良好的复配性能 ,因而 ,在石油工业中有着广泛的应用。     

季铵盐型Gemini表面活性剂的合成应用研究进展

季铵盐型Gemini表面活性剂具有正电荷性、吸附性强、易形成亲油性膜层、易生物降解等优点,在原油开采、纺织、医药、造纸、皮革、日用化工等领域具有广泛的用途。介绍了季铵盐型Gemini表面活性剂的分类,综述了季铵盐型Gemini表面活性剂的合成方法及应用领域,展望了新型季铵盐Gemini表面活性剂的未来发展方向。     

热带假丝酵母菌对含油污泥的修复潜力研究

目的 从油田含油土壤中筛选出了一株石油高效降解菌株—热带假丝酵母菌,实验对其降解石油的特性进行研究。方法 通过红外光谱及薄层色谱对热带假丝酵母菌的代谢产物进行分析,并采用气相色谱法及四组分实验对热带假丝酵母菌降解前后的石油含量及组成进行了检测。结果 实验发现,该菌株的适宜生长温度为30～35℃,当温度为32℃时,其在7天内对石油的降解率可以达到81.6%,而且对较难降解的芳香烃和沥青质也有良好的降解效果。针对初始含油率为5.21%的含油污泥,其在90天内对石油的降解率达到80.5%。结论 实验所筛选的热带假丝酵母菌能够以葡萄糖和原油为唯一碳源代谢脂肽类生物表面活性剂,该脂肽表面活性剂具有很强的表面活性,对石油具有良好的乳化分散作用,且该菌株对原油具有很高的降解效率。实验所筛选的热带假丝酵母菌在含油土壤的修复方面具有良好的应用潜力。     

菌株P.aeruginosa BC1 的筛选、鉴定及其产生物表面活性剂的性能

为改善克拉玛依油田的微生物强化原油开采,从克拉玛依油田废水中筛选出一株性能优良的生物表面活性剂生产菌株BC1。根据菌株BC1 的理化指标和16S rDNA对其进行了属种信息鉴定,通过薄层层析（TLC）、傅里叶红外色谱（FT-IR）及高效液相色谱/质谱（HPLC-MS）对其产生物表面活性剂进行了分析,通过单因素摇瓶实验考察了发酵条件对菌株BC1 发酵合成生物表面活性剂的影响,研究了生物表面活性剂的性能。研究结果表明,菌株BC1 为铜绿假单胞菌属（Pseudomonas aeruginosa）,其产生物表面活性剂主要成分为单鼠李糖脂RhC₁₀C₁₀;在温度37℃、初始pH为8、初始葡萄糖浓度5 g/L 的条件下持续发酵96 h 后,用酸沉降法测得鼠李糖脂产量为0.788 g/L;菌株BC1 产生物表面活性剂能将发酵液表面张力从72 降至28.6 mN/m,对车用机油的乳化指数E24 高达93%。人工油砂剥油实验中,发酵液、发酵离心上清液和鼠李糖脂粗品溶液对人工油砂的剥油率均达到74%以上。菌株P.aeruginosa BC1 产生物表面活性剂在微生物强化采油等方面具有良好的应用潜能。图7 表3参21     

一株石油降解菌的生长特性研究

 为了强化石油污染土壤的原位微生物修复的应用并提供高效的微生物种源,从石油污染土壤中分离出一株细菌D7,考察了该细菌对原油的降解效果,采用GC-MS测定原油降解前后的组成,并进行了原油的降解动力学分析。结果表明,菌株D7能够自身产生表面活性剂,并通过降解石油来获得能量以维持自身的生长与繁殖。16SrRNA测序结果表明,菌株D7和桔黄假单胞菌Pseudomonas aurantiaca基因序列的相似性高达98%。菌株D7的动力学系数为0.13 d^-1,分别高于菌株C9的0.09 d^-1和菌株A1的0.035 d^-1。原油中低相对分子质量组分比高相对分子质量组分更容易被菌株D7降解。     

A Comparative Study of Biosurfactant Synthesis by Pseudomonas aeruginosa Isolated from Clinical and Environmental Samples

Abstract

Evaluation of emulsifying activities indicates that biosurfactants were produced by an environmental (strain EP1) and a clinical (strain CP1) species of Pseudomonas aeruginosa. During growth on hydrocarbons, the organisms produced biosurfactants. Both strains grew luxuriantly on motor oil and readily synthesized abundant surfactants at the expense of easily metabolizable substrates. During a 12-day cultivation on motor oil, the organisms produced growth-associated extracellular surfactants with emulsification activities of 71 and 38% for EP1 and CP1, respectively. The generation times obtained for EP1 and CP1 were 1.74 and 2.66 days. The biosurfactants that could not be secreted on glucose were partially purified and putatively identified as rhamnolipids. The surface-active compounds present high emulsification activity and stability in the pH range of 3.0–10.0, temperature range of 4°C–100°C, and salinity range of 16–44% and are capable of stabilizing oil-in-water emulsions with several hydrocarbons. Typical emulsions produced were stable for several weeks. The results also showed that the biosurfactants were able to remove a significant amount of crude oil from contaminated soil; for instance, strain EP1 surfactant removed 54%, CP1 41%, detergent 42%, and water 30%. The rhamnolipids from these strains represent a new class of biosurfactants that have potential for use in a variety of biotechnological and industrial applications where extremes of pH, thermal, and saline conditions would have little or no effect on activity.     

Evaluation of Biosurfactants and Surfactants for Crude Oil Contaminated Sand Washing

In this work, biosurfactants (rhamnolipid, surfactin) and commercial surfactants (SDS, Triton X-100) were evaluated for their ability to recover crude oil from sand in laboratory experiments. The rhamnolipid used in this study was produced by Pseudomonas aeruginosa PTCC 1310, while the surfactin was produced by Bacillus subtilis NLIM 0110. Both biosurfactants were able to reduce surface tension to less than 27 from 72 mN/m with critical micelle concentration values of 50 and 118 mg/L for surfactin and rhamnolipid, respectively. It also demonstrated that the biosurfactants and surfactants are useful for the sand washing with removal percentages of 80%, 77%, 65%, and 61% at the room temperature for rhamnolipid, surfactin, Triton X-100, and SDS, respectively. At room temperature produced rhamnolipid removed the most oil from the sand (80%) compared to the rest of the candidates and also formed an excellent emulsification of crude oil (88%).     

Application of Biosurfactants to Wettability Alteration and IFT Reduction in Enhanced Oil Recovery From Oil–Wet Carbonates

To obtain potentially applicable microorganisms to an effective in situ microbial enhanced oil recovery operation, bacteria that were compatible with the harsh conditions of a petroleum reservoir were isolated from a crude oil sample. The application of an oil spreading technique showed that all of the isolates were capable of producing biosurfactants from both the glucose and crude oil as carbon sources. The secreted biosurfactants could at least reduce the surface tension 20 mN/m and for one of the isolates; the surface tension value dropped below 40 mN/m. In addition, the contact angle measurements revealed that the produced biosurfactants could effectively alter the wettability of the oil saturated rock samples. At last, the effect of isolates and their biosurfactants on improving oil production from oil saturated rock samples was investigated. It was observed that the presence of bacteria in the system could increase the amount of produced oil in comparison with the case where cell free biosurfactants were utilized.     

生物表面活性剂发酵液驱油效率研究

本研究参照国外生物表面活性剂在提高原油采收率方面的研究情况，用有机玻璃模型管对生物表面活性剂发酵液进行驱油方式和驱替速度实验，研究其对驱油效率、原油采收率的影响，从而为生物表面活性剂发酵液的深入研究和矿场应用提供参考和依据。     

Potential application of biosurfactants mixtures in high-temperature and high-salinity reservoirs

In this research, the interfacial behavior and emulsifying ability of biosurfactants mixtures were evaluated to investigate the potential application in high-temperature and high-salinity reservoirs. Results indicated that the mixtures of biosurfactants and betaine 4# gave the lowest interfacial tension values of ～10^?3 mN/m and emulsified crude oil more effectively. Core flooding tests showed that the binary systems gave the highest oil recovery of 11%, which is more efficient than any single biosurfactant or chemical.     

Characterization of biosurfactants produced by novel strains of Ochrobactrum anthropi HM-1 and Citrobacter freundii HM-2 from used engine oil-contaminated soil

Microbial surfactants are widely used for industrial, agricultural, food, cosmetics, pharmaceutical, and medical applications. In this study, two bacterial strains namely, Ochrobactrum anthropi HM-1 and Citrobacter freundii HM-2, previously isolated from used engine oil contaminated soil, and capable of producing biosurfactants, were used. Their cell-free culture broth showed positive results toward five screening tests (hemolysis in blood agar, drop collapse, oil displacement, emulsification activity (E₂₄), and surface tension (ST) reduction). They reduced the ST of growth medium (70 ± 0.9) to 30.8 ± 0.6 and 32.5 ± 1.3 mN/m, respectively. The biosurfactants were classified as anionic biomolecules. Based on TLC pattern and FT-IR analysis, they were designated as glycolipids (rhamnolipid). Waste frying oil was feasibly used as a cheap and dominant carbon source for biosurfactants production; 4.9 and 4.1 g/l were obtained after 96 h of incubation, respectively. Compared with non-irradiated cells, gamma-irradiated cells (1.5 kGy) revealed enhanced biosurfactant production by 56 and 49% for HM-1 and HM-2, respectively. The biosurfactants showed good stability after exposure to extreme conditions [temperatures (50–100 °C for 30 min), pH (2–12) and salinity (2–10% NaCl)], they retained 83 and 79.3% of their E₂₄, respectively, after incubation for a month, under extreme conditions. Biosurfactants effectively recovered up to 70 and 67% of the residual oil, respectively, from oil-saturated sand pack columns. These biosurfactants are an interesting biotechnological product for many environmental and industrial applications.     

驱油菌株的筛选及其驱油效果评价

从大庆油田油水样中分离出能以原油为唯一碳源产生生物表面活性剂的9株驱油菌,通过考察生物表面活性剂的排油活性、乳化性能、发酵液pH值、发酵液表面张力、产气量和发酵原油粘度,筛选出一株高效驱油菌DQ11,并在不同温度、盐度和pH值条件下,通过驱油菌对原油降粘效果的测定,得出该菌株的适宜生长条件.模拟驱油实验结果表明,DQ11菌株可以使原油增产率高达25.6%,驱油效果较好,具有现场应用前景.     

Inactivation of Escherichia coli O157:H7 in vitro and on the surface of spinach leaves by biobased antimicrobial surfactants

This study was conducted to evaluate the effect of biosurfactants on the populations of Escherichia coli O157:H7 in suspension and on spinach leaves. Eight surfactants including four soybean oil-based biosurfactants, sodium dodecyl sulfate (SDS), polyoxyethylene sorbitan monooleate (Tween 80), sophorolipid (SO) and thiamine dilauryl sulfate (TDS) at concentrations of 0.1%, 0.5% and 1.0% were tested in bacterial suspension, and the most effective biosurfactants were applied on spinach leaves. Results showed that the soybean oil-based biosurfactants, SDS or Tween 80 did not significantly affect E. coli O157:H7 populations. SO and TDS at concentrations of 1.0% were effective in reducing E. coli O157:H7 populations in bacterial suspension. E. coli O157:H7 with an initial population of 7.1 log CFU/mL was not detectable (detection limit: 1 log CFU/mL) after 1 min in 1.0% TDS or after 2 h in 1.0% SO. On spinach leaves, SO at 1% did not significantly affect E. coli when compared to a water wash during 7 days post-treatment storage at 4 °C. However, TDS (1.0%) wash was as effective as 200 ppm chlorine in reducing population of spot inoculated E. coli O157:H7, achieving 3.1 and 2.7 log CFU/per leaf at day 0, and 1.4 and 1.9 log CFU/leaf at day 7 when compared with a water wash. No apparent change in spinach visual quality was observed. None of treatments caused changes in visual quality of spinach. Electron micrographs suggested ultrastructural damage of bacterial cells such as separation of the outer membrane from the cytoplasmic membrane. Overall, our results showed that SO and TDS may be potential sanitizers in inactivating human pathogens such as E. coli O157:H7 in wash water and on fresh produce.     

Rhamnolipid and surfactin: Anti-adhesion/antibiofilm and antimicrobial effects

Biofilm growth in food industrial processing environment increases the probability of product's microbial contamination by spoilage and pathogenic microorganisms. Biosurfactants represent a great strategy to reduce biofilms due to their environmental-friendly nature when compared to synthetic surfactants. In order to evaluate biosurfactants potential on controlling biofilms, surfactin and rhamnolipid were tested against Listeria monocytogenes and Pseudomonas fluorescens. Adhesion/biofilm formation on polystyrene and stainless steel 304 surfaces, and physicochemical parameters were used to analyze and discuss findings. Adhesion was reduced up to 79% and 54% on polystyrene, while biofilm formation was reduced up to 83% and 73% on stainless steel surfaces (rhamnolipids and surfactin, respectively). Surfactants altered surfaces physicochemical characteristics. When added to the culture medium, microbial adhesion was inhibited up to 100%, depending on the product. Biosurfactants showed antimicrobial activity. Results demonstrate good potential of tested biomolecules to decrease adhesion and biofilm formation on food-contact surfaces.     

Some biosurfactants used as pour point depressant for waxy egyptian crude oil

Two bacteria (B1 and B2) were isolated from soil-contaminated sites. The surface properties of biosurfactants produced by these bacteria were determined. These bacteria were given a good resistance to NaCl concentration up to 20%. The surface activity was detected with maximum value at pH7 with B1, whereas B2 was not affected by the change pH (3–12). The biosurfactants of these bacteria were added as a mixture or individual to crude oil given the good result in reducing the pour point. The infrared spectrum of wax or asphaltene fractions of Egyptian crude oil untreated and treated with biosurfactants was detected.