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.     

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.     

Pseudomonas aeruginosa菌的原油除蜡降黏性能

采用单细胞Raman-D2O同位素标记技术确定了5种原油嗜蜡菌中的优势菌种;考察了其最佳生长条件,并对其代谢产物及其对原油的除蜡降黏性能进行测定.结果表明:优势原油嗜蜡菌种为SS1,属于铜绿假单胞菌属(Pseudomonas aeruginosa);其最佳生长条件为温度36℃、pH值7、NaCl质量浓度5 g/L;该菌...     

Studying Bacillus cereus's ability to biodegrade crude oil in hot areas

In this study, the biodegrading ability of three spices of Bacillus isolated from a soil, which was contaminated by crude oil, was studied. Isolated species are able to biodegrade crude oil carbohydrates by producing biosurfactants and lowering the rate of surface tension at different temperatures and pHs. The decrease of surface tension from 57 mN/m to 31 mN/m at 37°C and to 32.5 mN/m at 20°C by Bacillus cereus B1 in samples with 1% crude oil can be referred to as the results of this research.     

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.     

Using biosurfactant producing bacteria isolated from an Iranian oil field for application in microbial enhanced oil recovery

Microbial enhanced oil recovery (MEOR) is a useful technique to improve oil recovery from depleted oil reservoirs beyond primary and secondary recovery operations using bacteria and their metabolites. In the present study, the biosurfactant production potential of Bacillus licheniformis microorganisms that were isolated from oil samples of Zilaei reservoir in the southwest of Iran was explored under extreme conditions. Growth media with different temperatures of 40, 50, 60, and 70°C; salinities of 1, 3, 5, and 7 wt%; and yeast extract concentrations of 0.5, 1, 1.5, and 2 g/L were used to find the optimum growth conditions. The results demonstrated that bacteria grown in a mineral salt solution with temperature of 50°C, salinity of 1 wt% and yeast extract concentration of 1 g/L has the highest growth rate and therefore, these conditions are the optimum conditions for growing the introduced bacterium. This isolate was selected as the higher biosurfactant producer. The obtained biosurfactants by bacteria isolated in a medium with these conditions could reduce the interfacial tension of crude oil/water system from 36.8 to 0.93 mN/m and surface tension of water from 72 to 23.8 mN/m. The results of the core flooding tests showed that the tertiary oil recovery efficiency due to the injection of microorganisms was 13.7% of original oil in place and bacteria could reduce the oil viscosity by 41.242% at optimum conditions. Based on these results, the isolated microorganism is a promising candidate for the development of microbial oil recovery processes.     

微生物对含蜡原油的除蜡降黏效果

为提高含蜡原油的开采与运输效率,挖掘高效嗜蜡菌,笔者以石蜡为唯一碳源,从石油污染土壤中分离出一株嗜蜡菌,对其进行优化培养后,考察了该嗜蜡菌对大庆含蜡原油的除蜡降黏效果,并对其代谢产生的生物表面活性剂性能进行测定。结果表明：该嗜蜡菌能代谢产生脂肽类表面活性剂,具有较强的疏水性及乳化性能;其与含蜡原油作用7 d后,含蜡原油蜡质量分数降低43%、黏度下降18%。该嗜蜡菌对含蜡原油具有一定除蜡降黏作用,可以提高原油流动性能。     

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%).     

Studies on the Production of Biosurfactant for the Microbial Enhanced Oil Recovery by Using Bacteria Isolated from Oil Contaminated Wet Soil

Abstract

There are obvious advantages of biosurfactants over chemical surfactants. The developing shortage of oil and rapid increase of oil prices is putting pressure on oil companies to recover as much oil as possible from the wells to sustain the oil economy. Therefore, there is a need to research some “super bugs,” which can produce active and stable biosurfactants in good yields. Five bacterial strains presently isolated from the oil-contaminated soil were selected for the screening for biosurfactant production, via three different methods: surface tension measurements, drop-collapsing test, and emulsification index (EI₂₄) test. Two thermophillic isolates coded as SGI and LFA were found to be the suitable candidates for biosurfactant production. In fact, the biosurfactant produced by the isolate SGI led to the reduction of surface tension up to 26 m/N/m; thus, SGI was selected for the further studies. Biosurfactant production by the thermophillic isolate SGI was found to be growth-associated in all conditions tested. Biosurfactant production using different cheaper carbon substrates was studied. The production of biosurfactant was also studied using isolate SGI, under different conditions of high temperature, NaCl concentration, pH, carbon source, and initial nitrogen concentration. The biosurfactant was found to produce a relatively stable emulsion with hydrocarbons at a wide range of pH. It was also found to be stable at various pH ranges (7.0–14.0) for SGI and was also found to be thermostable for 1 hr at 125°C, based on the value of surface tension. There is a wide array of further studies in the area of microbial enhanced oil recovery (MEOR) including further boosting the activity of the isolate by using adaptation, enrichment, and nutrient enrichment techniques.     

石油烃降解菌Pseudomonas sp.及其生物表面活性剂对原油处理效果分析

从辽河油田受石油污染土壤中筛选出1株能够以液体石蜡为唯一碳源产生生物表面活性物质的W12#菌株,研究其对原油流动性的作用效果。结果表明：W12#菌株在生长代谢过程中产生的表面活性物质可以形成排油圈,其疏水性达到89.55%,乳化指数高达62.5%。通过傅里叶红外光谱仪测定,其代谢产物为糖脂类。原油经过 W12#菌株处理,蜡质量分数由9.78%降至6.39%,除蜡率为34.66%;在40 ℃条件下,降黏率达到63.75%,提高了原油的流动性能。     

不同微生物对青海原油的降解效果

为研究不同微生物在实验条件下对青海原油的降解情况,筛选优良菌种,以此探讨微生物降解原油的机理。在实验条件下选用3种不同的菌种,以青海原油为唯一碳源,在37℃时摇床培养6d,培养液表面张力值都下降,菌种B的培养液表面张力值由55.3 mN/m降至47.4 mN/m;对经微生物作用后的原油中饱和烃进行了气相色谱分析,发现3种微生物都使原油中的长链烷烃含量相对增加,短链烷烃含量相对减小,菌种B使原油的Pr/nC17比值由0.542增加到3.262,Ph/nC18比值由1.351增加到10.748,正构烷烃优先降解。研究表明,菌种B是一种有应用前景的采油微生物。     

高效驱油菌Ⅰ的选育与岩芯模拟驱油实验研究

1. Introduction The majority of oil fields in China have entered the late stage of tertiary oil recovery with a high water cut, at which the chemical flooding and polymer flooding have been the main enhancing oil recovery technology and seen widespread us…     

氮气辅助稠油微生物冷采技术研究与应用

室内选择性富集、驯化、分离,从井楼油田污水中筛选出3株微生物菌种,分别为产气菌、烃氧化菌和生物表面活性剂菌,3株菌按接种量1:1:1配伍构建共生代谢体系。与单菌种相比,复合菌代谢产物中的表面活性剂含量由1.7%增至2.2%,产气量由95mL增至120mL,pH值由6.1降至5.9。针对井楼油田稠油开展的微生物室内评价实验表明,共生代谢体系对该油藏的适应性良好,稠油乳化降黏效果明显,对原油的降黏率最高可达63.9%,形成的水包油乳状液黏度在100～300mPa·s之间波动,胶质沥青质含量降低,发酵液表面张力下降9.4%～11.6%。在井楼油田7口稠油油井进行首轮氮气辅助微生物吞吐施工,设计单井菌液处理半径10～15m,氮气顶替段塞2000～10000Nm~3,菌液2.5～6.0t,措施后单井产液量增加1.8～9.8倍,产油量由0～0.1t/d增至最高2.7t/d,首轮施工生产115 d增油470 t,措施有效率85.7%,效果显著。     

降解原油微生物的筛选及其部分特性的研究

筛选得到4株可利用原油为碳源生长的菌株，初步鉴定为假单胞菌。这4株菌对原油有很好的降黏作用，它们能利用长链烷烃生长，并且能耐受一定的温度、压力和矿化度。其中的M－3菌除降黏外还能产生酸和生物表面活性剂，在以原油为碳源的培养基中进行培养时，可以使培养液的表面张力从72mN/m降至36mN/m，pH值从7.0降至约5.5。实验证明M－3菌液在室内条件下能提高原油采收率8.8%左右，在微生物采油中有很好的应用潜力。图1表4参19（李清心摘）     

表面活性剂对原油生物降解的强化作用

从降解原油的微生物种类与摄取模式及化学表面活性剂与生物表面活性剂对原油生物降解的强化作用等方面进行论述,指出化学表面活性剂有毒且难于降解,应用受限;而生物表面活性剂是由微生物生成的天然产物,其化学结构和物理性质相近或优于许多人工合成表面活性剂,具有无毒且易于降解等特性,在石油生物降解中具有极大的应用潜力;概述了生物表面活性剂的特性、种类及其在强化原油生物降解中的应用;探讨了在生物表面活性剂应用中存在的问题及解决途径.参50     

Use of different methods for detection of thermophilic biosurfactant-producing bacteria from hydrocarbon-contaminated and bioremediated soils

Sixteen bacterial strains were isolated from petroleum hydrocarbons contaminated soils and screened for biosurfactants/bioemulsifiers production in liquid culture containing crude oil under thermophilic conditions. The bacterial strains grew in wide range of temperature, from 37 °C to 100 °C. Six of them were Gram positive. Their biosurfactant-production was evaluated at 45 °C.Blood agar lysis, drop-collapse method, oil spreading and stalagmometric techniques and surface tension (ST) measurements were used to detect biosurfactant production. Emulsification activity for culture broth was also tested using xylene, toluene, petroleum and diesel oils.All isolates reduced surface tension at varying degrees with strains: T/1 resulting in the highest reduction (35 mN/m). The drop-collapse, oil spreading and stalagmometric and reduction techniques all seem to give clear indicative results for biosurfactant production while blood hemolytic activity did not. The use of both the drop-collapse and oil spreading techniques were easy and quick to screen for biosurfactant producers but were not always conclusive.Although surface tension reduction was a good measure of biosurfactant production, it did not correlate well with emulsion ability. Several of our isolates had good emulsifying abilities with all hydrocarbon tested. The simplicity of the above techniques allows effective screening of biosurfactant-producing microorganisms. Although hemolytic activity have been reported as an initial selection criterion for biosurfactant producers, other more conclusive tests such as surface tension measurements should be carried out for confirmation of the obtained results.     

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.     

Remediation of oil spill polluted water from Niger Delta Nigeria by sorption onto ammonium sulfate modified Dialium guineense seed husk

The abstraction of crude oil molecules from aqueous solution (produced water) and from real petroleum polluted water (collected from River State, Nigeria) by Dialium guineense Seed Husk (DGSH) and its ammonium sulfate functionalized form (AS-DGSH) was studied using a batch technique. The sorbents were characterized using Fourier transform infrared (FTIR), BET surface area analysis and the Scanning electron microscopy (SEM). Crude oil characterization revealed a light crude oil based on the API gravity of 35.6⁰. The Langmuir and Freundlich models gave good fits for crude oil sorption on DGSH and AS-DGSH respectively. The sorbents were found to remove over 50% of crude oil from the real polluted water at the natural pH of 6.1 and showed increase in removal with increase in sorbent dose. The potential of DGSH and its ammonium sulfate modified derivative as effective low cost sorbents for oil spill treatment was established.     

复合驱油菌株提高安塞低渗透油田采收率实验

从安塞油藏环境中分离到两种高产生物表面活性剂的优良驱油菌株,经鉴定为铜绿假单胞菌DN001和枯草芽孢杆菌DN002. 通过室内和现场试验评价了驱油微生物及其复合菌株降低表面张力和界面张力的能力、对原油的乳化性能以及对当地油藏的环境适应性。结果表明,复合菌株发酵液可将水的表面张力从72 mN/m降低到25.1 mN/m,并且发酵液的油水界面活性较高,平衡界面张力为0.954 3 mN/m.筛选的微生物菌体在安塞油田油藏环境中可大量繁殖。室内驱油模拟实验表明,经复合微生物驱替作用后,采收率可提高17.38%,说明筛选的菌株驱油性能较强,微生物驱油室内评价结果为其在安塞油藏现场应用提供了可靠的试验依据。     

Selection of Pseudomonas aeruginosa for biosurfactant production and studies of its antimicrobial activity

Biosurfactants are generally microbial metabolites with the typical amphiphilic structure of a surfactant. This study investigated potential biosurfactants production of Pseudomonas aeruginosa ATCC-10145 and Bacillus subtilis NCTC-1040 using glucose and n-hexadecane as substrates separately and compared it with the production in conventional medium. Pseudomonas aeruginosa growing in BHMS (Bushnell hass mineral salt) medium with glucose as substrate decreased the surface tension from 72 of distilled water to 32 mN/m, this strain had higher reduction than Bacillus subtilis among all the substrates tested. The selection of Pseudomonas aeruginosa for the separation of biosurfactant was determined. The crude biosurfactant was extracted from the supernatant and the yield of the crude biosurfactant was about 1 g/l. Some surface properties of rhamnolipids biosurfactant were evaluated. It also showed antimicrobial activity against different bacteria and fungi strains. The crude biosurfactant showed good action as antimicrobial activity against different bacterial and fungal species.