生物表面活性剂是由动物、植物以及微生物产生的，是具有降低水的表面/界面张力的物质。它们具有优良的表面活性的同时，又能够很快的被生物降解，同时还具有环境友好、生物相容性好的特点，能够实现清洁化可再生生产，这些都是化学表面活性剂所不具备的，因此被广泛应用于石油开采等领域。如何将从环境中筛选获得的相对优秀的表面活性剂产生菌株，通过进一步的优化培养基以及分离提纯工艺，提高产量，降低生产成本，最终实现发酵工艺的产业化，成为生物表面活性剂能否替代化学型表面活性剂的重点所在。我公司处于山东东营胜利油田，对于能够应用于石油开采领域的生物表面活性剂研究有着迫切的需求。胜利油田油层多为高温高压高盐环境，而脂肽类生物表面活性剂相对于其他四种生物表面活性剂具有结构稳定、性能多样、功能强大但是产量相对较低(<5 g/L）、中国尚未产业化等特点，所以本课题主要对脂肽类生物表面活性剂的产生菌株进行了研究。针对其他同学前期从28个土样中经过筛选获得的8株生物表面活性剂高产菌株（THY-2~THY-9），选取了洗油性能突出以及石蜡乳化性能良好的野生枯草芽孢杆菌THY-6进行了培养基优化。通过对培养基中的C源、有机以及无机N源、无机盐等成分进行价格以及产量的优势比对，初步确定出最优的培养基组分，然后通过单因子优化以及后续的正交试验确定出优化的培养基配方。最后进行了培养转速、温度、时间等条件的优化。经过实验，野生菌株THY-6在优化培养条件下，生物表面活性剂产量为1.3g/L，比优化前提升了56%。进一步以启动子改造后获得的基因工程菌TS856为对象，以野生菌株THY-6的优化培养基为出发条件，进行了基因工程菌培养基和培养条件的优化，并与野生菌进行了比较。结果表明，在优化培养条件下的基因工程菌TS856，其生物表面活性剂产量达到11.2g/L，比优化前提高了16.8%，为将来实现工业化奠定了基础。本课题研究的方向来源于公司发展的实际需求，并希望最终能够实现工业化生产。因此，本课题在注重基础研究的同时，也对公司发展生物表面活性剂的工业化生产有着重要的意义。
Biosurfactants from animals, plants and microorganisms can reduce surface/interface tension of the water. Biosurfactants which mainly produced by the microorganism. They are widely applied in oil exploration and other fields with advantages such as excellent surface activity, biodegradable and environmentally friendly, good biocompatibility. Getting good biosurfactant strains and optimizing the medium and culture conditions to increase productivity and reduce production cost of biosurfactant is of great importance for industrialization of the fermentation proces.Baomo Biopolymer Company is in the Shengli oilfield with urgent needs for biosurfactant research for oil exploration direction. The common characteristic of Shengli oilfield reservoirs is high temperature, high pressure and high salt. The main research object of this project is the lipopeptide biosurfactants with stable structure, performance and diversity. However, The fermentation titer of lipopetide is universally low (< 5 g/L) and not industrialized in China so far.The project aims to 2 biosurfactant producing strains, THY-6 screened by the Other Student from 28 soil samples, and TS856 which is a genetically engineered for enhanced lipopeptide titer. The products of both strains showed outstanding washing-oil performance and good paraffin emulsification effect. Through price evaluation, single factor optimization and orthogonal experiments, the medium and culture conditions of THY-6 were optimized. After optimization, the final titer of lipopeptide increased by 56.0%. for THY-6, 16.8% for TS856, respectively. a The optimized fermentation culture conditions are more suitable for industrialization. The biosurfactant production reached 11.2 g.L for the genetically engineered TS856, which lays a foundation for future industrialization.
