Rosenberg E, Ron E Z
Department of Molecular Microbiology and Biotechnology, Tel Aviv University, Ramat Aviv, Israel.
Appl Microbiol Biotechnol. 1999 Aug;52(2):154-62. doi: 10.1007/s002530051502.
Microorganisms synthesize a wide variety of high- and low-molecular-mass bioemulsifiers. The low-molecular-mass bioemulsifiers are generally glycolipids, such as trehalose lipids, sophorolipids and rhamnolipids, or lipopeptides, such as surfactin, gramicidin S and polymyxin. The high-molecular-mass bioemulsifiers are amphipathic polysaccharides, proteins, lipopolysaccharides, lipoproteins or complex mixtures of these biopolymers. The low-molecular-mass bioemulsifiers lower surface and interfacial tensions, whereas the higher-molecular-mass bioemulsifiers are more effective at stabilizing oil-in-water emulsions. Three natural roles for bioemulsifiers have been proposed: (i) increasing the surface area of hydrophobic water-insoluble growth substrates; (ii) increasing the bioavailability of hydrophobic substrates by increasing their apparent solubility or desorbing them from surfaces; (iii) regulating the attachment and detachment of microorganisms to and from surfaces. Bioemulsifiers have several important advantages over chemical surfactants, which should allow them to become prominent in industrial and environmental applications. The potential commercial applications of bioemulsifiers include bioremediation of oil-polluted soil and water, enhanced oil recovery, replacement of chlorinated solvents used in cleaning-up oil-contaminated pipes, vessels and machinery, use in the detergent industry, formulations of herbicides and pesticides and formation of stable oil-in-water emulsions for the food and cosmetic industries.
微生物能合成各种各样的高分子量和低分子量生物乳化剂。低分子量生物乳化剂一般为糖脂，如海藻糖脂、槐糖脂和鼠李糖脂，或脂肽，如表面活性素、短杆菌肽S和多粘菌素。高分子量生物乳化剂是两亲性多糖、蛋白质、脂多糖、脂蛋白或这些生物聚合物的复杂混合物。低分子量生物乳化剂可降低表面张力和界面张力，而高分子量生物乳化剂在稳定水包油乳液方面更有效。生物乳化剂的三个天然作用已被提出：（i）增加疏水性水不溶性生长底物的表面积；（ii）通过增加其表观溶解度或使其从表面解吸来提高疏水底物的生物利用度；（iii）调节微生物与表面的附着和脱离。与化学表面活性剂相比，生物乳化剂有几个重要优势，这应使其在工业和环境应用中占据显著地位。生物乳化剂的潜在商业应用包括油污染土壤和水的生物修复、提高石油采收率、替代用于清理受油污染管道、容器和机械的氯化溶剂、在洗涤剂行业的应用、除草剂和农药配方以及为食品和化妆品行业形成稳定的水包油乳液。
