Optimizing the production of biosurfactants from marine bacteria for applications in personal care sector

从2022年5月开始的新计划：生物表面活性剂是一种两亲性化学品，几乎用于现代工业的每一个部门。然而，它们主要是通过使用以化石燃料为基础的前体进行化学合成而产生的，因此，这些化学品往往具有生态毒性和不可生物降解的特点。生产生物表面活性剂的微生物为这些化学品提供了更可持续、无毒和环保的来源。该项目将侧重于由海洋细菌产生的生物表面活性剂，重点是鼠李糖脂，这是一类糖脂，由一个或两个连接到一个或两个脂肪酸链上的鼠李糖糖基组成。鼠李糖脂的生产在铜绿假单胞菌中已经有了很好的特征，但这些化合物推向市场的一个主要限制因素往往与产生鼠李糖脂的主要来源铜绿假单胞菌的致病性有关，但这种微生物是致病的。其他非假单胞菌生物已被发现产生鼠李糖脂，但它们也是致病的，或者在某些条件下可以致病。因此，已经有许多关于鉴定具有合成非致病性鼠李糖脂潜力的微生物的研究。这个项目将探索在非致病的海洋细菌菌株中合成包括鼠李糖脂在内的生物表面活性剂，并试图利用合成生物学方法提高这些化合物的产量，并通过操纵发酵条件进一步优化，以生产足够数量的工业用。原始计划：回收、循环、再造：一种微生物和生物技术解决方案，以解决废旧轮胎问题使用的橡胶轮胎，特别是当被丢弃在垃圾填埋场时，已被认为迅速成为世界上最主要的环境废物问题之一。回收橡胶是一项非常具有挑战性的任务，到目前为止，还没有解决这个日益重要的问题的办法。工业合作伙伴Recircle Ltd开发了一种新的可持续技术，利用微生物将橡胶废料脱硫化和再利用，再加工成高价值的橡胶产品。橡胶的脱硫化依赖于酶的作用，而酶的作用尚未完全确定。这个博士项目将研究橡胶生物脱硫的关键过程。这位博士生将接受尖端技术方面的培训，以分析和识别所有负责生物脱硫的基因和酶，以便更好地了解和进一步改进脱硫过程。该项目还将致力于从轮胎倾倒场丰富和分离新的脱硫菌，并挖掘降解有机硫化合物的新基因。此外，学生将利用定点突变来创造细菌的突变株，这些突变株能够结构性地表达这些脱硫酶。

New programme as from May2022:Biosurfactants are amphiphilic chemicals used in almost every sector of modern industry. However, they are mainly produced by chemical synthesis using fossil fuel-based precursors, and as such these chemicals are often characterized as eco-toxic and non-biodegradable. Biosurfactant-producing microorganisms offer a much more sustainable, non-toxic, and eco-friendly source for these chemicals. This project will focus on biosurfactants produced by marine bacteria, with a focus on rhamnolipids, which are a class of glycolipids consisting of one or two rhamnose sugar groups attached to one or two fatty acid chains. Rhamnolipid production has been well characterized in Pseudomonas aeruginosa, but a major limitation in getting these compounds to market is often associated with the pathogenicity of the producing organism - i.e. Pseudomonas aeruginosa which is the main source of rhamnolipids, but this organism is pathogenic. Other non-Pseudomonas organisms have been found to produce rhamnolipids, but they too are pathogenic or can become so under certain conditions. As such, there have been numerous studies on identifying microorganisms with the potential to synthesize rhamnolipids that are non-pathogenic. This project will explore the synthesis of biosurfactants, including rhamnolipids, in non-pathogenic strains of marine bacteria, and attempt to enhance the production of these compounds using synthetic biology approaches and further optimization by manipulation of fermentation conditions in order to produce sufficient quantities for industrially use.Original programme: Recover, Recycle, Reengineer: A microbial and biotechnological solution to tackle the waste tyre problemUsed rubber tyres, particularly when disposed to landfill, have been recognised to fast becoming one of the foremost environmental waste problems in the world. The recycling of rubber is a very challenging task and to date there is no solution to this increasingly important problem. The industrial partner Recircle Ltd has developed a novel sustainable technology to devulcanise and reuse rubber waste for reprocessing into high value rubber products using microorganisms. The devulcanisation/desulfurisation of rubber relies on the work of enzymes which are not fully identified yet. This PhD project will investigate the key processes involved in biodesulfurisation of rubber. The PhD student will be trained in cutting-edge techniques to analyse and identify all genes and enzymes that are responsible for biodesulfurisation in order to get a better understanding and further improve the devulcanisation process. This project will also aim to enrich and isolate new desulfurising bacteria from tyre dump sites and mine for novel genes in the degradation of organosulfur compounds. In addition, the student will utilise site-directed mutagenesis to create mutant strains of the bacteria that constitutively express these desulfurisation enzymes.