Northeast Biotechnology Network (RENORBIO), Federal Rural University of Pernambuco, Rua Dom Manoel de Medeiros, s/n, Dois Irmãos. Zip Code: 52171900, Recife, Pernambuco, Brazil.
Catholic University of Pernambuco (UNICAP), Rua do Príncipe, n. 526, Boa Vista, Zip Code: 50050-900, Recife, Pernambuco, Brazil.
Colloids Surf B Biointerfaces. 2018 Dec 1;172:127-135. doi: 10.1016/j.colsurfb.2018.08.034. Epub 2018 Aug 17.
The need to remediate areas contaminated by petroleum products has led to the development of novel technologies for treating such contaminants in a non-conventional manner, that is, without the use of chemical or physical methods. Biosurfactants are amphipathic biomolecules produced by microorganisms that can be used in bioremediation processes in environments contaminated by petroleum products due to their excellent tensioactive properties. The aim of the present study was to produce a biosurfactant from Pseudomonas aeruginosa UCP 0992 cultivated in 0.5% corn steep liquor and 4.0% vegetable oil residue in a 1.2-L bioreactor employing a central composite rotatable design to optimize the cultivation conditions for maximum yield. The best results were achieved with aeration rate of 1.0 vvm and 3.0% inoculum at 225 rpm for 120 h, resulting in a surface tension of 26.5 mN/m and a biosurfactant yield of 26 g/L. Kinetic and static assays were then performed with the biosurfactant for the removal of motor oil adsorbed to sand, with removal rates around 90% and 80%, respectively, after 24 h. Oil degradation experiments with the bacterium and the combination of the bacterium and biosurfactant were also conducted to simulate the bioremediation process in sand and seawater samples (duration: 75 and 30 days, respectively). In both cases, oil degradation rates were higher than 90% in the presence of the biosurfactant and the producing species, indicating the potential of the biomolecule as an adjuvant in petroleum decontamination processes in the marine environment.
需要修复受石油产品污染的区域，这导致了开发用于非常规处理此类污染物的新技术，即不使用化学或物理方法。生物表面活性剂是微生物产生的两亲生物分子，由于其出色的表面活性特性，可用于受石油产品污染的环境中的生物修复过程。本研究的目的是从假单胞菌 UCP 0992 生产生物表面活性剂，该菌在 1.2-L 生物反应器中使用中心复合旋转设计，在 0.5%玉米浆和 4.0%植物油残渣中培养，以优化培养条件以获得最大产量。最佳结果是在 225 rpm 下以 1.0 vvm 的通气率和 3.0%的接种量培养 120 h 实现的，得到的表面张力为 26.5 mN/m，生物表面活性剂产率为 26 g/L。然后对生物表面活性剂进行了动力学和静态吸附去除砂中吸附的发动机油的实验，24 h 后分别达到了约 90%和 80%的去除率。还进行了细菌和细菌与生物表面活性剂组合在沙和海水中的油降解实验（持续时间分别为 75 和 30 天），以模拟生物修复过程。在这两种情况下，在存在生物表面活性剂和产生该生物表面活性剂的物种的情况下，油的降解率均高于 90%，表明该生物分子在海洋环境中石油污染修复过程中的辅助作用。
