微生物合成生物表面活性剂研究进展

生物表面活性剂一般是由微生物产生的一类两性分子的表面活性物质。与化学表面活性剂相比,微生物合成的表面活性剂拥有生物降解、环境友好、耐极端环境和低毒性等特点。生物表面活性剂主要包括糖脂、脂肽、脂蛋白、磷脂及中性类脂衍生物等。     

生物表面活性剂的合成(二)

(接上期)如前所述,糖脂是一类非常重要的非离子型生物表面活性剂,具有优良的表面性能。例如,多糖脂Emulsan的乳化性能非常好,能使原油和水的乳化液保持稳定,这对重油运输和油水乳化后作为燃料以节省能源有着重要意义。若以传统的化学方法     

糖脂类生物表面活性剂的性质及其潜在应用进展

与化学合成的表面活性剂相比微生物产生的生物表面活性剂具有表面活性高、良好的抑菌作用以及环境友好等独特的性质。其中糖脂类生物表面活性剂由于其高产量和多功能生化特性,成为最有发展前途的生物表面活性剂之一。本文综述了糖脂类生物表面活性剂的特性及潜在的应用。     

脂肪酶催化合成生物表面活性剂

脂肪酸单甘油酯、脂肪酸糖酯、聚甘油脂肪酸酯和长链脂肪酸蜡酯是重要的生物表面活性剂。传统化学法以碱为催化剂在高温下进行,不仅能耗高且产品纯度低。脂肪酶作为一种天然生物催化剂,可以温和条件下催化合成上述生物表面活性剂,能耗低且产品纯度高。综述对脂肪酶催化合成生物表面活笥剂工艺路线、反应体系及操作参数。     

生物表面活性剂催化合成蔗糖酯及其应用

蔗糖酯是一种有效的食品添加剂,它可由蔗糖与脂肪酸酯或甘油酯在碱性催化条件下由有机溶剂法或无溶剂法合成得到,报道了蔗糖酯的合成,分离和应用进展,还论述了生物表面活性剂作为均相催化剂在蔗糖酯合成中的作用。     

生物表面活性剂产生菌发酵液中糖含量的测定

采用苯酚-硫酸法测定鼠李糖脂生物表面活性剂产生菌发酵液中的总糖含量,研究了显色温度、显色时间、苯酚及硫酸用量对测定的影响。通过试验确定了较佳测定条件：100℃显色15min,苯酚用量1．0mL,硫酸用量5．0mL,于482肿处测定。结果表明,用此方法测定鼠李糖脂生物表面活性剂产生菌发酵液中的总糖含量时,其吸收值与鼠李糖质量浓度（在0～0．04g／L）呈良好的线性关系,相关系数为0．9969,加样回收率为100．5％（n=5）。     

来源于微生物的生物表面活性剂

越来越多的生产和使用表面活性剂的公司开始寻找石油衍生物的替代品,以实现可持续发展。微生物生产的生物表面活性剂为此提供了一个更有价值的解决方案,因为其通常以可再生资源如糖、植物油、甚至废水为原料,由细菌或酵母菌经过天然发酵工艺而生产出来。而且,这些表面活性剂可完全降解,生态毒性较低。研究最多的生物表面活性剂有鼠李糖脂、槐糖脂、海藻糖脂、纤维二糖脂、甘露糖赤藓糖醇酯、表面活性肽和     

生物表面活性剂的概况与发展

生物表面活性剂的概况与发展金陵石油化工公司研究院朱小兵南京，２１００４６生物科学是一门古老的科学，在制药工业、食品工业中已得到了很大的应用，如其产品有：食品稳定剂、乳化剂、维生素、氨基酸、蛋白质、食品酶、酶制剂、特种脂肪酸、保水剂、风味剂及发泡剂等。...     

Biosurfactants: Recent advances

Surfactants find applications in a wide variety of industrial processes. Biomolecules that are amphiphilic and partition preferentially at interfaces are classified as biosurfactants. In terms of surface activity, heat and pH stability, many biosurfactants are comparable to synthetic surfactants. Therefore, as the environmental compatibility is becoming an increasingly important factor in selecting industrial chemicals, the commercialization of biosurfactant is gaining much attention. In this paper, the general properties and functions of biosurfactants are introduced. Strategies for development of biosurfactant assay, enhanced biosurfactant production, large scale fermentation, and product recovery are discussed. Also discussed are recent advances in the genetic engineering of biosurfactant production. The potential applications of biosurfactants in industrial processes and bioremediation are presented. Finally, comments on the application of enzymes for the production of surfactants are also made.     

生物表面活性剂在油田中的应用

生物表面活性剂和化学表面活性剂一样 ,有亲水基团和疏水基团 ,它是由微生物生长在水不溶的物质中并以它为食物源产生的。在油田中 ,生物表面活性剂是微生物提高采收率的重要机理 ,具有水溶性好、反应产物均一、无毒、安全、驱油效果好等特点。生物表面活性剂有 4种类型 :糖脂类、磷脂类、脂蛋白或缩氨酸脂和聚合物类。大多数生物表面活性剂是糖脂 ,是碳水化合物连接在长链脂肪酸上。目前 ,室内研究主要是研究各种反应条件对微生物产生生物表面活性剂和生物表面活性剂对原油的影响。矿场实验有地面发酵和地下发酵两种形式。从生物表面活性剂的特点、筛选产生生物表面活性剂的菌种、生物表面活性剂的类型、室内研究、矿场实验和今后的发展方向等 6个方面综述了油田中的生物表面活性剂的应用     

脂肽类生物表面活性剂研究进展

脂肽是由微生物代谢产生的一类具有很强表面活性的生物表面活性剂,在医药、环境保护、化妆品和微生物采油等方面有良好的应用潜力。该文对脂肽的生产、分离、鉴定及应用进展进行了综述。引用文献45篇。     

Biosurfactants for microbubble preparation and application

Biosurfactants can be classified by their chemical composition and their origin. This review briefly describes various classes of biosurfactants based on their origin and introduces a few of the most widely used biosurfactants. The current status and future trends in biosurfactant production are discussed, with an emphasis on those derived from plants. Following a brief introduction of the properties of microbubbles, recent progress in the application of microbubble technology to molecular imaging, wastewater treatment, and aerobic fermentation are presented. Several studies on the preparation, characterization and applications of biosurfactant-based microbubbles are reviewed.     

Yeast Lipid Produced through Glycerol Conversions and Its Use for Enzymatic Synthesis of Amino Acid-Based Biosurfactants

The aim of the present work was to obtain microbial lipids (single-cell oils and SCOs) from oleaginous yeast cultivated on biodiesel-derived glycerol and subsequently proceed to the enzymatic synthesis of high-value biosurfactant-type molecules in an aqueous medium, with SCOs implicated as acyl donors (ADs). Indeed, the initial screening of five non-conventional oleaginous yeasts revealed that the most important lipid producer was the microorganism Cryptococcus curvatus ATCC 20509. SCO production was optimised according to the nature of the nitrogen source and the initial concentration of glycerol (Glyc0) employed in the medium. Lipids up to 50% w/w in dry cell weight (DCW) (SCO_max = 6.1 g/L) occurred at Glyc0 ≈ 70 g/L (C/N ≈ 80 moles/moles). Thereafter, lipids were recovered and were subsequently used as ADs in the N-acylation reaction catalysed by aminoacylases produced from Streptomyces ambofaciens ATCC 23877 under aqueous conditions, while Candida antarctica lipase B (CALB) was used as a reference enzyme. Aminoacylases revealed excellent activity towards the synthesis of acyl-lysine only when free fatty acids (FAs) were used as the AD, and the rare regioselectivity in the α-amino group, which has a great impact on the preservation of the functional side chains of any amino acids or peptides. Aminoacylases presented higher α-oleoyl-lysine productivity and final titer (8.3 g/L) with hydrolysed SCO than with hydrolysed vegetable oil. The substrate specificity of both enzymes towards the three main FAs found in SCO was studied, and a new parameter was defined, viz., Specificity factor (Sf), which expresses the relative substrate specificity of an enzyme towards a FA present in a FA mixture. The Sf value of aminoacylases was the highest with palmitic acid in all cases tested, ranging from 2.0 to 3.0, while that of CALB was with linoleic acid (0.9–1.5). To the best of our knowledge, this is the first time that a microbial oil has been successfully used as AD for biosurfactant synthesis. This bio-refinery approach illustrates the concept of a state-of-the-art combination of enzyme and microbial technology to produce high-value biosurfactants through environmentally friendly and economically sound processes.     

南极假丝酵母生产的生物表面活性剂的基本性质研究(英文)

对C .antarcticaWSH112在两类不同疏水性碳源 (豆油与正构烷烃 )中发酵生产生物表面活性剂进行了研究 ,发现该菌株在两类碳源中产生两种不同的生物表面活性剂 ,其中在豆油中产生的为曾报道过的甘露糖赤藓醇脂 (简称MEL) ,而在烷烃中产生的表面活性剂属于未知结构的新物质 ,经初步分离提取鉴定属甘油酯类表面活性剂 ,将其命名为BS -UC。在此基础上 ,对上述两种生物表面活性剂进行了表面活性性质鉴定     

Rhamnolipids as Effective Green Agents in the Destabilisation of Dolomite Suspension

In this paper, we describe an application of mono- and dirhamnolipid homologue mixtures of a biosurfactant as a green agent for destabilisation of a dolomite suspension. Properties of the biosurfactant solution were characterised using surface tension and aggregate measurements to prove aggregation of rhamnolipids at concentrations much lower than the critical micelle concentration. Based on this information, the adsorption process of biosurfactant molecules on the surface of the carbonate mineral dolomite was investigated, and the adsorption mechanism was proposed. The stability of the dolomite suspension after rhamnolipid adsorption was investigated by turbidimetry. The critical concentration of rhamnolipid at which destabilisation of the suspension occurred most effectively was found to be 50 mg·dm⁻³. By analysing backscattering profiles, solid-phase migration velocities were calculated. With different amounts of biomolecules, this parameter can be modified from 6.66 to 20.29 mm·h⁻¹. Our study indicates that the dolomite suspension is destabilised by hydrophobic coagulation, which was proved by examining the wetting angle of the mineral surface using the captive bubble technique. The relatively low amount of biosurfactant used to destabilise the system indicates the potential application of this technology for water treatment or modification of the hydrophobicity of mineral surfaces in mineral engineering.     

Biosurfactants: Multifunctional Biomolecules of the 21st Century

In the era of global industrialisation, the exploration of natural resources has served as a source of experimentation for science and advanced technologies, giving rise to the manufacturing of products with high aggregate value in the world market, such as biosurfactants. Biosurfactants are amphiphilic microbial molecules with hydrophilic and hydrophobic moieties that partition at liquid/liquid, liquid/gas or liquid/solid interfaces. Such characteristics allow these biomolecules to play a key role in emulsification, foam formation, detergency and dispersal, which are desirable qualities in different industries. Biosurfactant production is considered one of the key technologies for development in the 21st century. Besides exerting a strong positive impact on the main global problems, biosurfactant production has considerable importance to the implantation of sustainable industrial processes, such as the use of renewable resources and “green” products. Biodegradability and low toxicity have led to the intensification of scientific studies on a wide range of industrial applications for biosurfactants in the field of bioremediation as well as the petroleum, food processing, health, chemical, agricultural and cosmetic industries. In this paper, we offer an extensive review regarding knowledge accumulated over the years and advances achieved in the incorporation of biomolecules in different industries.