Bioengineering of Biosurfactants for Cleaning and Degreasing Applications

9525091需要对油有高亲和力并能形成稳定的水包油(O/W)乳状液的总表面活性剂，用于许多重要的应用，例如在清洁剂中，在制造/表面清洁过程中有效地清除油轮、各种储存容器和金属部件上的油类残留物。从减少有毒用途的角度来看，这类表面活性剂在其生产中使用无毒的可再生资源是可取的。此外，这些功能性产品应表现出低/无毒性，并且必须在处置后生物降解。此外，如果表面活性剂可以很容易地进行定制，从而能够根据不同的清洁和脱脂要求获得最佳的性能特性，那将是有利的。目前，环境因素是寻求“绿色”工艺和产品的制造商设计此类功能性表面活性剂产品的指导原则。例如，肥皂和洗涤剂生产商开始意识到，许多客户会为环保产品支付更高的价格。因此，本文提出了微生物发酵过程，包括各种可再生脂肪酸的转化，将被用作获得具有增强性能特征的新型生物表面活性剂的途径。这项工作的主要特点是通过改变所使用的脂肪酸碳源和抑制脂肪酸生物合成的从头合成途径来改变表面活性物质的结构。后者将通过在培养基中使用特定的和非特定的脂肪酸生物合成抑制剂来实现。我们实验室以前的工作是使用这些方法来生物合成所得到的聚合物表面活性剂的组成和取代度。因此，通过微生物生产系统可以形成一系列表面活性剂的想法现在已经得到证明。表面活性剂结构的生物工程具有重要意义，因为它表明，通过酰基转移酶系统对糖单元的环化可能会与广泛的酰基供体分子一起发生，以优化生产性能。该提案旨在将这一发现扩展到由假丝酵母菌和铜绿假单胞菌生产鼠李糖和苦参糖脂表面活性物质。这些微生物生产系统形成新的生物表面活性剂的灵活性将通过使用各种不同链长和不饱和度的脂肪酸碳源进行系统研究来探索。羟基酸的直接结合也将被研究。此外，还将选择和研究能够产生增强乳化重油能力的乳胶的醋酸钙突变株。生物表面活性剂结构的变化对表面张力和临界胶束浓度的影响将作为底物的函数进行评估。在……里面

9525091 Gross Surfactants are needed that have a high affinity for oil and can form stable oil-in-water (o/w) emulsions for a number of important applications such as in cleaners that will effectively remove oil-type residues from tankers, various storage vessels and metal parts during manufacturing/surface cleaning processes. From a toxic use reduction perspective, it would be desirable for such surfactants to use non-toxic renewable resources in their production. Furthermore, these functional products should show low/no toxicity and must biodegrade upon disposal. Moreover, it would be advantageous if the surfactants could easily be tailored so that optimal performance characteristics could be obtained for different cleaning and degreasing requirements. Currently, environmental factors are the guiding principles in the design of such functional surfactant products by manufactures that are looking towards "Green" processes and products. For example, soap and detergent producers are beginning to realize that many customers will pay more for products that are environmentally sound. Therefore, it is proposed herein that microbial fermentation processes that involve conversion of various renewable fatty acids will be used as routes to new biosurfactants that have enhanced performance characteristics. The key feature of this work is that the surfactant structure will be varied by alteration of the fatty acid carbon source used and by inhibiting de novo pathways for fatty acid biosynthesis. The latter will be accomplished by the use of specific and non-specific fatty acid biosynthesis inhibitors in cultivation media. Previous work in our laboratory using these approaches for the biosynthesis of the composition and degree of substitution of the resulting polymeric surfactants. Thus, the idea that a family of surfactants can be formed by a microbial production system has now been demonstrated. The bioengineering of surfactant structure is of fundamental important since it shows that the a cylation of sugar units by an acyltransferase enzyme systems can potentially take place with a wide range of acyl doner molecules to optimize produce performance. This proposal seeks to extend this finding to the production of rhamose and sophorose lipid surfactants by candida bombicola and pseudomonas aeruginosa. The flexibility of these microbial production systems for the formation of novel biosurfactants will be explored by systematic investigations using a wide range of fatty acid carbon sources of variable chain length and unsaturation. The direct incorporation of hydroxyacids will also be studies. Also, mutant strains of A.calcoaceticus that produce emulsans with enhanced ability to emulsify heavy oils will be selected and studied. The effects of changes in biosurfactant structure on surface tension and critical micelle concentration values as a function of substrate will be evaluated. In