A Novel Process for the Continuous Production of Surfactin

粘在气体和液体界面上的化学物质被称为表面活性剂，或简称表面活性剂。当表面活性剂处于界面时，它们会以重要的方式改变其性质。它们对生命本身来说是必不可少的。例如，新生儿肺中的表面活性物质使她能够首先吸气。它们还出现在几乎所有的工业生产过程中，是我们使用的许多日常产品的幕后推手，从洗涤剂到喷墨打印。目前，我们在工业和家庭中使用的大多数表面活性剂都是从油源中生产的。然而，一些细菌在以一系列材料为食时会产生表面活性物质。用这种方法生产的表面活性剂称为生物表面活性剂。虽然单个细菌在显微镜下很小，只产生少量的产物，但数以百万计的细胞可以被培养成大量的产物。生物表面活性剂非常有趣。它们可以轻松超越合成油衍生的表面活性剂，同时具有由可再生资源制成的吸引力。此外，生物表面活性剂分子的结构比合成的要有趣得多，这赋予了它们许多合成表面活性剂所不具备的有用的性质。不幸的是，它们也非常非常昂贵，这确实限制了我们能够探索和利用它们的程度。这个跨学科的项目将设计一种新的工艺来生产一种名为表面活性物质的生物表面活性剂。其目的是从总体上推进生物表面活性剂生产的工艺工程；目标是将表面活性物质的成本削减到目前的十分之一。这一过程将结合过程工程和微生物学的四项创新。实验将使人们对这一过程有科学的认识，带来新的技术，并生产少量的表面活性物质。商业化将导致表面活性素用量的逐步增加和价格的逐步降低。表面活性素因其作为表面活性物质的优异性能而得名。1968年，从被称为枯草芽孢杆菌的细菌的产物中发现了表面活性物质。一旦发现，它对水和空气之间的界面的影响被认为比当时已知的任何其他表面活性剂都要大，而且浓度非常低。即使在今天，最强大的工业表面活性剂也难以与之匹敌，而且需要使用更多的化学物质。例如，需要超过250倍的Triton GR-5M(世界最大的化工公司陶氏化学公司销售的最强大的表面活性剂)才能与表面活性剂的作用相匹配。2003年全球表面活性剂市场为1200万吨，价值88亿美元。市场竞争非常激烈，因此具有明显优势的产品受到高度重视。表面活性素除具有优异的表面活性外，还具有可再生性、生物降解性、生物相容性和低毒等特点。因此，表面素在环境方面特别有吸引力，例如清除土壤中的污染物和提高油井的产量。目前的生产成本严重限制了表面活性物质的开发，世界上只有极少数的大型工厂，而表面活性物质在医药和生物技术方面的巨大潜力的勘探和开发也受到了很高的价格的制约。表面活性物质目前是一种精细化学品，价格相当于每克6500英镑，几乎是黄金的800倍。这一高价格是劳动密集型、小规模批量生产和复杂分离过程的结果。该项目将采用最新的创新技术来提高所有生物表面活性剂的生产效率，从而导致价格的逐步降低和可获得性的逐步提高。有了这一点，人们、行业和整个社会将能够更充分地从生物表面活性剂独特的有用特性中受益。

Chemicals which stick to the interface between gases and liquids are called surface active agents, or surfactants for short. When surfactants are at an interface they change its properties in important ways. They are essential for life itself. For example, it is the surfactants in a newborn baby's lungs which enable her to first draw breath. They also feature in almost every industrial production process, and are behind many everyday products we use from detergents to ink jet printing.Currently, most of the surfactants we use in industry and at home are produced from oil sources. However, some bacteria will produce surfactants whilst feeding on a range of materials. A surfactant produced in this way is called a biosurfactant. Although individual bacteria are microscopically small and produce only tiny amounts of product, many millions of millions of cells can be farmed to produce substantial amounts of product.Biosurfactants are very interesting. They can easily outperform synthetic oil derived surfactants, whilst having the attraction of being made from renewable resources. Also, the structures of biosurfactant molecules are much more interesting than synthetic ones, giving them many useful properties which synthetic surfactants just don't have. Unfortunately, they are also very, very expensive, and this really limits how much we can explore and take advantage of them.This interdisciplinary project will engineer a novel process for the production of one such biosurfactant called surfactin. The aim is to advance the process engineering of biosurfactant production in general; the objective is to slash the cost of surfactin to a tenth of what it is now. The process will combine four innovations in process engineering and microbiology. Experimentation will give scientific insight into the process, lead to new technology, and produce small quantities of surfactin. Commercialisation will lead to a step-increase in surfactin availability, and step-decrease in price.Surfactin was named after its outstanding properties as a surfactant. Surfactin was identified in 1968 from products of the bacteria known as Bacillus subtilis. Upon discovery it was seen to affect the interface between water and air more than any other surfactant known at the time, and at very low concentrations. Even today, the most powerful industrial surfactants struggle to match its power, and require the use of much greater amounts of chemical. For example, over 250 times as much TRITON GR-5M (the most powerful surfactant marketed by DOW, the world's largest chemical company) is required to match surfactin's action.The global surfactant market in 2003 was 12m tonnes, worth 8.8b. The market is extremely competitive, so products with a distinct advantage are highly prized. Aside from its superior surfactant power, surfactin is renewable, biodegradable, biocompatible and has low toxicity. Consequently, surfactin is particularly attractive for environmental uses, such as cleaning pollutants from soil and enhancing production from oil wells. Current production costs severely limit surfactin's exploitation; there are only a very small number of large scale plants in the world.Exploration and exploitation of surfactin's great potential in medicine and biotechnology has also been inhibited its very high price. Surfactin is currently available as a fine chemical with a price equivalent to 6500/g, that's almost 800 times more expensive than gold. This high price is a result of labour intensive, small scale batch production and complex separation processes.This project will employ the latest innovative techniques to increase the efficiency of all biosurfactant production, and thus lead to a step-decrease in price and step-increase in availability. With this people, industry and society in general will be able to benefit more fully from the uniquely useful properties of biosurfactants.