Ekpenyong Maurice George, Antai Sylvester Peter, Asitok Atim David, Ekpo Bassey Offiong
Environmental Microbiology and Biotechnology Unit, Department of Microbiology, Faculty of Biological Sciences, University of Calabar, P.M.B.1115 Calabar, Nigeria.
Exploration, Research and Services Section, Research and Development (R&D) Division, Nigerian National Petroleum Corporation (NNPC), Port-Harcourt, Nigeria.
Iran Biomed J. 2017 Jul;21(4):249-60. doi: 10.18869/acadpub.ibj.21.4.249. Epub 2017 Apr 23.
A glycolipopeptide biosurfactant produced by Pseudomonas aeruginosa strain IKW1 reduced the surface tension of fermentation broth from 71.31 to 24.62 dynes/cm at a critical micelle concentration of 20.80 mg/L. The compound proved suitable for applications in emulsion stabilization in food, as well as in cosmetic and pharmaceutical formulations.
In the present study, Plackett-Burman design (PBD) and response surface method (RSM) were employed to screen and optimize concentrations of trace nutrients in the fermentation medium, to increase surfactant yield.
The PBD selected 5 out of the 12 screened significant trace nutrients. The RSM, on the other hand, resulted in the production of 84.44 g glycolipopeptide/L in the optimized medium containing 1.25 mg/L nickel, 0.125 mg/L zinc, 0.075 mg/L iron, 0.0104 mg/L boron, and 0.025 mg/L copper.
Significant second-order quadratic models for biomass (P<0.05; adjusted R2=94.29%) and biosurfactant (R2=99.44%) responses suggest excellent goodness-of-fit of the models. However, their respective non-significant lack-of-fit (Biomass: F=1.28; P=0.418; Biosurfactant: F=1.20; P=0.446) test results indicate their adequacy to explain data variations in the experimental region. The glycolipopeptide is recommended for the formulation of inexpensive pharmaceutical products that require surface-active compounds.
铜绿假单胞菌IKW1菌株产生的一种糖脂肽生物表面活性剂，在临界胶束浓度为20.80 mg/L时，可将发酵液的表面张力从71.31达因/厘米降低至24.62达因/厘米。该化合物被证明适用于食品中的乳液稳定，以及化妆品和药物制剂。
在本研究中，采用Plackett-Burman设计（PBD）和响应面法（RSM）来筛选和优化发酵培养基中微量营养素的浓度，以提高表面活性剂产量。
PBD从12种筛选出的显著微量营养素中选出了5种。另一方面，RSM在含有1.25 mg/L镍、0.125 mg/L锌、0.075 mg/L铁、0.0104 mg/L硼和0.025 mg/L铜的优化培养基中，产生了84.44 g/升的糖脂肽。
生物量（P<0.05；调整后R2=94.29%）和生物表面活性剂（R2=99.44%）响应的显著二阶二次模型表明模型具有良好的拟合优度。然而，它们各自不显著的失拟（生物量：F=1.28；P=0.418；生物表面活性剂：F=1.20；P=0.446）测试结果表明它们足以解释实验区域的数据变化。推荐将该糖脂肽用于配制需要表面活性化合物的廉价药品。
