Microbial production of surfactants and their commercial potential
Microbial production of surfactants and their commercial potential
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DOI：
10.1128/mmbr.61.1.47-64.1997
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发表时间：
1997-03
影响因子：
12.9
通讯作者：
J. Desai;I. Banat
中科院分区：
文献类型：
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作者：
J. Desai;I. Banat
许多微生物，尤其是细菌，在与水不混溶的基质上生长时会产生生物表面活性剂。生物表面活性剂比许多合成表面活性剂更有效、更具选择性、更环保且更稳定。最常见的生物表面活性剂是糖脂，其中碳水化合物连接到长链脂肪酸上，而其他的，如脂肽、脂蛋白和杂多糖则更为复杂。已经开发出用于筛选和选择产生生物表面活性剂的微生物以及评估其活性的快速可靠的方法。铜绿假单胞菌中参与鼠李糖脂合成（rhlAB）和调控（rhlI和rhlR）的基因已被鉴定，并且讨论了rhlAB在异源宿主中的表达。芽孢杆菌属中参与表面活性素生产（sfp、srfA和comA）的基因也已被鉴定。生物表面活性剂的发酵生产主要取决于微生物菌株、碳源和氮源、pH、温度以及氧和金属离子的浓度。向培养基中添加与水不混溶的基质以及培养基中氮和铁的限制会导致一些生物表面活性剂的过量生产。其他重要进展包括使用水溶性基质和农业工业废弃物进行生产、开发连续回收工艺以及通过生物转化进行生产。已经提出在化妆品、食品、医疗保健、纸浆和造纸加工、煤炭、陶瓷和金属工业中实现生物表面活性剂的商业化。然而，最有前景的应用是清洁被油污染的油轮、溢油管理、重质原油运输、提高石油采收率、从污泥中回收原油以及对被碳氢化合物、重金属和其他污染物污染的场地进行生物修复。还讨论了未来研究和应用的前景。
Many microorganisms, especially bacteria, produce biosurfactants when grown on water-immiscible substrates. Biosurfactants are more effective, selective, environmentally friendly, and stable than many synthetic surfactants. Most common biosurfactants are glycolipids in which carbohydrates are attached to a long-chain aliphatic acid, while others, like lipopeptides, lipoproteins, and heteropolysaccharides, are more complex. Rapid and reliable methods for screening and selection of biosurfactant-producing microorganisms and evaluation of their activity have been developed. Genes involved in rhamnolipid synthesis (rhlAB) and regulation (rhlI and rhlR) in Pseudomonas aeruginosa are characterized, and expression of rhlAB in heterologous hosts is discussed. Genes for surfactin production (sfp, srfA, and comA) in Bacillus spp. are also characterized. Fermentative production of biosurfactants depends primarily on the microbial strain, source of carbon and nitrogen, pH, temperature, and concentration of oxygen and metal ions. Addition of water-immiscible substrates to media and nitrogen and iron limitations in the media result in an overproduction of some biosurfactants. Other important advances are the use of water-soluble substrates and agroindustrial wastes for production, development of continuous recovery processes, and production through biotransformation. Commercialization of biosurfactants in the cosmetic, food, health care, pulp- and paper-processing, coal, ceramic, and metal industries has been proposed. However, the most promising applications are cleaning of oil-contaminated tankers, oil spill management, transportation of heavy crude oil, enhanced oil recovery, recovery of crude oil from sludge, and bioremediation of sites contaminated with hydrocarbons, heavy metals, and other pollutants. Perspectives for future research and applications are also discussed.