一株表面活性剂产生菌的筛选及其特性研究

从氧化沟含油污水中分离得到1株能产生物表面活性剂菌株S6(Pseudomonas sp.),经生理生化实验和16SrDNA序列分析鉴定,S6为铜绿假单胞菌。红外光谱分析得知S6在代谢过程中能够产生糖脂类表面活性物质。其临界胶束浓度(CMC)为50mg/L,可将水的表面张力由72mN/m降到33.9mN/m。发酵液的表面张力和排油直径的测定结果显示发酵液在不同的盐度、pH和溶解氧量条件下,具有较稳定的表面活性。通过正交实验确定了优化培养基条件为葡萄糖10g、尿素5g、磷酸二氢钾1g、微量元素液2mL、pH8.0、水1000mL;S6在优化培养基中合成生物表面活性剂的产量为0.173g/L。     

肺表面活性物质相关蛋白的特性研究

肺表面活性物质相关蛋白的特性研究谢尔凡（第三军医大学烧伤研究所,重庆６３００３８）关键词肺表面活性物质,表面活性物质相关蛋白肺表面活性物质是由脂质和蛋白质组成的复合物,其主要生理功能是降低肺泡表面张力,维持肺泡结构相对稳定。近年来,特异性的肺表面活性...     

肺表面活性物质及其在肺感染作用中的研究进展

肺表面活性物质是位于肺泡上皮细胞表面的由关键性脂质蛋白质组成的具有多种功能的复合物。肺表面活性物质中各组成部分的联合效应是肺保持稳定性和宿主防御传染病病原体的基础。在此,就肺表面活性物质的主要成分、结构、功能及其与肺感染的关系做一简要综述。     

芽孢杆菌dhs-330-021对链状亚历山大藻的溶藻机理研究

目的:本实验室通过转座突变技术获得了一株高产表面活性物质的芽孢杆菌dhs-330-021,研究其对链状亚历山大藻的抑制效果,及其溶藻作用方式。方法:在链状亚历山大藻的培养液中添加dhs-330-021的发酵液等,间隔一定时间计数获得藻细胞的数量。结果:菌株dhs-330-021培养后期的发酵液溶藻效果好于培养前期和中期;在一定浓度范围内,dhs-330-021的发酵液对不同生长期的链状亚历山大藻均有溶藻效果,其中对延滞期和稳定期效果最好;菌株的发酵液和无菌上清液的溶藻效果明显,而菌悬液溶藻效果较差。结论:菌株dhs-330-021能显著抑制链状亚历山大藻的生长,其溶藻方式属于间接溶藻。     

嘧啶核苷类物质乳清酸产生菌的选育

以谷氨酸棒杆菌JSIM-201菌株为出发菌株,通过紫外线和甲基磺酸乙酯诱变处理,得到了一株尿嘧啶营养缺陷型突变体U-12菌株,能以葡萄糖为碳源,硫酸铵为氮源,在发酵液中积累一种紫外吸收物质。对U-12菌株的发酵液分离提取结晶,经物理、化学分析鉴定,证明是乳清酸物质。发酵液中积累乳清酸8．6g/L。     

肺表面活性物质相关蛋白D研究进展

肺表面活性物质相关蛋白Ｄ研究进展谢尔凡（第三军医大学西南医院烧伤研究所,重庆６３００３８）关键词肺表面活性物质相关蛋白Ｄ肺表面活性物质（ＰＳ）由脂质和蛋白质组成,其主要生理功能包括降低肺泡表面张力,维持肺泡结构相对稳定,防止肺萎陷和肺水肿,参与宿主呼...     

表面活性物质有细胞保护作用

表面活性物质(surfactant)是一类磷脂化合物,能降低表面张力,是维持正常呼吸功能不可少的物质。既往认为,只有肺泡Ⅱ型细胞才能分泌这类磷脂;但近年来发现,它们也存在于胃粘膜上皮的表面。胃内的表面活性物质究竟有什么功用呢?这是近来很多学者想了解的问题。最近,美国Texas大学医学院Lich-tenberger等发现,胃内的表面活性物质具有细胞保护作用。作者等用1ml 0.6molHCl灌入结扎幽门的大鼠以造成胃粘膜损伤模型,并作了下列观察:(1)如果预先用1ml表面活性物质混悬液注入胃,30min后再注入HCl,可明显减轻HCl引起的胃粘膜坏死和出血;(2)如果在表面活性物质灌胃之前45min于皮下注射消炎痛(5mg/kg)阻断前列腺素(PG)合成,虽然能加重对照组的胃粘膜损伤,但不能阻断表面     

生物表面活性剂的分离提纯及其发展前景

生物表面活性剂主要是微生物在一定条件下培养时产生的具有高表面活性的生物分子。由于其对环境无毒害作用,因此,受到了广泛的青睐,然而从发酵液中分离和纯化生物表面活性剂是生物表面活性剂商业化的一个主要问题。为此提出多种分离纯化生物表面活性剂的方法,并对其发展前景作了展望。     

假单胞菌发酵液提高原油采收率的研究

筛选得到了一株假单胞菌D-1,其发酵液具有很高的表面活性,浓度为10%的发酵液的表面张力为45mN/m左右,则将其发酵液作为一种生物表面活性剂.经实验确定了发酵培养基的最适配方。在室内条件下,D-1的发酵液不仅能提高实验岩芯内原油的采收率10%左右,而且对原油2的防蜡率可以达到60%左右,因此,D-1在油田应用中会有很大的潜力。     

无患子水提皂素液发酵精制联产生物表面活性剂槐糖脂

无患子水提皂素液,经纤维二糖酶水解,以无患子水提水解液为底物,接种丘陵假丝酵母,将水提液中糖组分发酵转化为槐糖脂,得到天然皂素及生物表面活性剂复合产物。在发酵过程中,2%的丘陵假丝酵母菌种接种量,溶液中葡萄糖消耗速率最快;在水提水解液中额外添加大豆油作为补充碳源能较大幅度降低溶液表面张力。经过发酵转化,溶液中表面活性物质浓度达到52.48 g/L,比发酵前提高了23.4%,溶液表面张力值明显降低。无患子精制发酵液中不含糖类成分,是理想的液体洗涤剂生产原料。     

Isolation of biosurfactant-producing bacteria,product characterization,and evaluation

A gram-positive, nonfermentative, rod-shaped bacterium designated ST-5, identified as Rhodococcus, was isolated from Kuwait soil. Grown on hydrocarbon, such as kerosene and n-paraffin, the bacterium produced surface-active compounds (biosurfactants). Measurements of surface tension, critical micelle dilution and emulsifying activity indicated that the biosurfactant is produced as a primary metabolite. The ST-5 culture surface-active component is mainly glycolipid in nature. Whole-culture broth dropped surface tension to values below 27 mN/m and was stable during exposure to high salinity (10% NaCl), elevated temperatures (120°C for 15 min) and a wide range of pH values. The culture broth was effective in recovering up to 86% of the residual oil from oil-saturated sand packs, indicating potential value in enhanced oil-recovery processes.     

1株耐高温生物表面活性剂产生菌的特性研究

研究了耐高温生物表面活性剂产生菌ZY-3的生理生化特性,并通过测定发酵液的菌体密度、表面张力和乳化活性等指标,研究不同碳源和初始pH对菌株ZY-3生长和产生物表面活性剂的影响,同时对其所产生物表面活性剂进行了初步分离和性质分析。菌株ZY-3被初步鉴定为芽胞杆菌属(Bacillus),具有产酸、不产H_2S、还原硝酸盐等特性。在以淀粉为碳源、初始pH 6.0的培养基中发酵,产生物表面活性剂多且稳定;在种子培养基和发酵培养基中都有淀粉的条件下,菌体生长较多,降低表面张力和乳化的作用均较强,所产生物表面活性剂可以使发酵液的表面张力从72.1 mN/m降到53.1 mN/m,乳化活性从0升高到24%。初步判断产物为糖脂类阴离子表面活性剂。     

高产生物表面活性剂菌株的紫外诱变选育

从新疆塔里木河边的土壤中筛选出1株产表面活性剂的菌株BIT-TLM1,该菌在以葡萄糖为碳源的无机盐培养基中,在150 r/min、40℃的条件下培养20 h,发酵液的表、界面张力分别降至29.29和0.61 mN/m。以菌株BIT-TLM1为原始菌株,对该菌进行紫外线诱变,选育出1株高产表面活性剂的诱变菌株UV-10,其产生表面活性剂的量达到0.309 7 g/g菌体,比原始菌株提高了9.22%,UV-10有较好的遗传稳定性,UV-10产表面活性剂的最佳培养条件:碳源为葡萄糖、氮源为NH4Cl、pH8.0和2%的盐度。     

产生物表面活性剂芽孢杆菌培养条件的优化

为了提高生物表面活性剂的表面活性,通过单因素及正交试验对已筛选的产生物表面活性剂芽孢杆菌的培养基及培养条件进行了优化,优化后的培养基成分为可溶性淀粉20 g/L,氯化铵2 g/L,KH2PO46 g/L,K2HPO42 g/L,MgSO4.7H2O 0.3 g/L,NaCl 2 g/L,CaCl20.08 g/L,EDTA 0.4 g/L。培养条件为4%接种量,种龄16 h,初始pH7,培养温度37℃,摇床转速160 r/min,发酵48 h。优化发酵条件后,发酵液表面张力由初始67.5 mN/m降低至24.8 mN/m,生物表面活性剂产量达到1.08 g/L。     

Production of biosurfactant and antifungal compound by fermented food isolate Bacillus subtilis 20B

A biosurfactant producing strain, Bacillus subtilis 20B, was isolated from fermented food in India. The strain also showed inhibition of various fungi in in-vitro experiments on Potato Dextrose Agar medium. It was capable of growth at temperature 55 degrees C and salts up to 7%. It utilized different sugars, alcohols, hydrocarbons and oil as a carbon source, with preference for sugars. In glucose based minimal medium it produced biosurfactant which reduced surface tension to 29.5 mN/m, interfacial tension to 4.5 mN/m and gave stable emulsion with crude oil and n-hexadecane. The biosurfactant activity was stable at high temperature, a wide range of pH and salt concentrations for five days. Oil displacement experiments using biosurfactant containing broth in sand pack columns with crude oil showed 30.22% recovery. The possible application of organism as biocontrol agent and use of biosurfactant in microbial enhanced oil recovery (MEOR) is discussed.     

Enhancement of stability of biosurfactant produced by <Emphasis Type="Italic">Candida lipolytica</Emphasis> using industrial residue as substrate

This work describes experimental results carried out on the fermentation of Candida lipolytica, which produced a new biosurfactant when grown on a vegetable oil refinery residue as substrate. The cell-free culture broth containing the biosurfactant formed stable emulsions with hydrophobic natural compounds. Emulsification properties of the biosurfactant were not affected by salinity; however, treatment at a higher temperature decreased the emulsification activity, indicating applications in oil recovery. The isolated biosurfactant corresponds to a yield of 4.5 g/l, and the surface tension of water was reduced from 71 to 32 mN/m. Preliminary chemical characterizations showed that the biosurfactant consisted of protein (50%), lipid (20%), and carbohydrate (8%).     

Distillery and curd whey wastes as viable alternative sources for biosurfactant production

Biosurfactant production from synthetic medium and industrial waste, viz. distillery and whey wastes was investigated by using an oily sludge isolate Pseudomonas aeruginosa strain BS2. In synthetic medium separately supplemented with glucose and hexadecane as water-soluble and -insoluble carbon sources, respectively, strain BS2 reduced the surface tension of the fermentation broth from 57 to 27 mN/m. The culture produced biosurfactant during the stationary growth phase and its yield was 0.97 g/l. The culture utilized distillery and whey wastes for its growth, as maximum cell counts reached to 54 × 10⁸ and 64 × 10⁹ c.f.u./ml from an initial inoculum size of 1 × 0⁵ c.f.u./ml, respectively, within 48 h of incubation and in these wastes the yields of biosurfactant obtained were 0.91 and 0.92 g/l, respectively. In synthetic medium, distillery and whey wastes, strain BS2 produced a crystalline biosurfactant which belonged to the category of secondary metabolites and its maximum production occurred after the onset of nitrogen-limiting conditions. After recovering biosurfactant from the fermented waste, the chemical oxygen demand (COD) of distillery and whey wastes was significantly reduced by 81 and 87%, respectively. Total acids, nitrogen and phosphate levels in distillery waste were reduced by 90, 92 and 92%, respectively, while in case of whey waste the concentration of these nutrients was reduced by 88, 95 and 93%, respectively. The isolated biosurfactant possessed potent surface active properties, as it effectively reduced the surface tension of water from 72 to 27 mN/m and formed 100% stable emulsions of a variety of water-insoluble compounds such as hydrocarbons, viz. hexadecane, crude oil, kerosene and oily sludge and pesticides, viz. dichlorodiphenyltrichloroethane (DDT) and benzene hexachloride (BHC). The effectiveness of biosurfactant was also evident from its low critical micellar concentration (CMC) which was 0.028 mg/ml.     

Purification and structural characterization of glycolipid biosurfactants fromPseudomonas aeruginosa YPJ-80

Glycolipids produced byPseudomonas aeruginosa YPJ-80 were characterized by chromatographic and spectroscopic techniques as a mixture of two rhamnolipids. For recovery of glycolipids from the culture broth, various isolation methods including ultrafiltration, adsorption and solvent extraction were compared. Ultrafiltration showed the best results in terms of glycolipids recovery. Further purification for spectroscopic analysis was carried out by adsorption chromatography and preparation thin layer chromatography. From the spectroscopic analysis, such as IR spectroscopy, FAB-MS,¹H-NMR and¹³C-NMR and hydrolysis analysis, the glycolipids were identified as L-α-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoate and 2-O-α-L-rhamnopyranosyl-α-L-rhamnopyranosyl-β-hydroxydecanoyl-β-hydroxydecanoate. Monorhamnolipid and dirhamnolipid lowered the surface tension of water to 28.1 mN/m and 29.3 mN/m, respectively.     

Screening of biosurfactant-producing Bacillus strains using glycerol from the biodiesel synthesis as main carbon source

Glycerol, a co-product of biodiesel production, was evaluated as carbon source for biosurfactant production. For this reason, seven non-pathogenic biosurfactant-producing Bacillus strains, isolated from the tank of chlorination at the Wastewater Treatment Plant at Federal University of Ceara, were screened. The production of biosurfactant was verified by determining the surface tension value, as well as the emulsifying capacity of the free-cell broth against soy oil, kerosene and N-hexadecane. Best results were achieved when using LAMI005 and LAMI009 strains, whose biosurfactant reduced the surface tension of the broth to 28.8?±?0.0 and 27.1?±?0.1?mN?m(-1), respectively. Additionally, at 72?h of cultivation, 441.06 and 267.56?mg?L(-1) of surfactin were produced by LAMI005 and LAMI009, respectively. The biosurfactants were capable of forming stable emulsions with various hydrocarbons, such as soy oil and kerosene. Analyses carried out with high performance liquid chromatography (HPLC) showed that the biosurfactant produced by Bacillus subtilis LAMI009 and LAMI005 was compatible with the commercially available surfactin standard. The values of minimum surface tension and the CMC of the produced biosurfactant indicated that it is feasible to produce biosurfactants from a residual and renewable and low-cost carbon source, such as glycerol.     

一株产生脂肽的枯草芽孢杆菌的分离鉴定及脂肽对原油的作用

从大庆油田地层水中分离到一组能高效产生生物表面活性剂的菌株,采用sfp基因PCR鉴定的方法从中分离到一株芽孢杆菌ZW-3,该菌株能够产生大量表面活性物质,采用细菌生理生化鉴定结合16S rDNA序列的系统发育学分析确定该菌株为枯草芽孢杆菌(Bacillus subtilis),通过薄层层析色谱(TLC)、高效液相色谱(HPLC)分析其代谢产物,初步鉴定为脂肽(Lipopeptide);该脂肽生物表面活性剂理化性质显示它能使培养基的表面张力从68.92mN/m降低25.19mN/m、原油/水的界面张力从23.53mN/m降低到4.57mN/m,与1.8%的NaOH溶液复配可以将油水界面张力降低到1.2×10-3 mN/m,其临界胶束浓度为33.3mg/L(3.24×10-5 mol/L),并具有较好的乳化活性和发泡性能,说明该菌株代谢的脂肽生物表面活性剂在提高石油采收率中具有广泛的应用前景.