Abstract Biosurfactants are surface-active metabolites produced by microorganisms. Biosurfactants tend to solubilize hydrocarbons in the surrounding environment, by reducing surface tension and increasing carbon uptake. In this study, isolation of biosurfactant producing bacteria and effect of renewable, non-fossil fuel based carbon sources on production were assessed. Oil field produced water was collected from Potwar oil fields and thirteen strains were isolated. Strains were screened for biosurfactant production by hemolysis test, emulsification index test, emulsification assay, oil displacement test, drop collapse test, tilted glass slide test and oil coated agar emulsification test. Strains were further screened for maximum production on cost effective renewable carbon source e.g. glucose, waste glycerol and animal fat. Promising strains were identified as Bacillus subtilis (MH142143), Pseudomonas aeruginosa (MH142144), Bacillus tequilensis (MH142145) and Bacillus safensis (MH142146) by 16S rRNA gene sequencing. Among all isolates, highest biosurfactant production on glucose (37%), glycerol (48%) and animal fat oil (49%), after 24 h cultivation was by Pseudomonas aeruginosa. Biosurfactant showed similarity to rhamnolipids by Thin Layer Chromatography (TLC). Assessment of bioactive propertiaes of rhamnolipid showed strong antimicrobial activity against Bacillus spp. Future investigations can be focused on application of these strains in environmental as well as industrial sectors.

中文翻译：

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从 Potwar 油田分离生物表面活性剂产生菌：非化石燃料基碳源的影响

摘要 生物表面活性剂是微生物产生的具有表面活性的代谢物。生物表面活性剂倾向于通过降低表面张力和增加碳吸收来溶解周围环境中的碳氢化合物。在这项研究中，评估了生物表面活性剂产生细菌的分离以及基于可再生非化石燃料的碳源对生产的影响。从Potwar油田采集油田采出水，分离得到13株菌株。通过溶血试验、乳化指数试验、乳化试验、驱油试验、跌落塌陷试验、倾斜载玻片试验和涂油琼脂乳化试验筛选出生产生物表面活性剂的菌株。进一步筛选菌株以在具有成本效益的可再生碳源（例如葡萄糖、废甘油和动物脂肪）上获得最大产量。通过16S rRNA基因测序鉴定出有前景的菌株为枯草芽孢杆菌（MH142143）、铜绿假单胞菌（MH142144）、龙舌兰芽孢杆菌（MH142145）和安全芽孢杆菌（MH142146）。在所有分离物中，葡萄糖 (37%)、甘油 (48%) 和动物脂肪油 (49%) 的最高生物表面活性剂产量在培养 24 小时后是铜绿假单胞菌。生物表面活性剂通过薄层色谱 (TLC) 显示出与鼠李糖脂的相似性。对鼠李糖脂的生物活性特性的评估表明对芽孢杆菌属有很强的抗菌活性。未来的调查可以集中在这些菌株在环境和工业部门的应用上。在所有分离物中，葡萄糖 (37%)、甘油 (48%) 和动物脂肪油 (49%) 的最高生物表面活性剂产量在培养 24 小时后是铜绿假单胞菌。生物表面活性剂通过薄层色谱 (TLC) 显示出与鼠李糖脂的相似性。对鼠李糖脂的生物活性特性的评估表明对芽孢杆菌属有很强的抗菌活性。未来的调查可以集中在这些菌株在环境和工业部门的应用上。在所有分离物中，葡萄糖 (37%)、甘油 (48%) 和动物脂肪油 (49%) 的最高生物表面活性剂产量在培养 24 小时后是铜绿假单胞菌。生物表面活性剂通过薄层色谱 (TLC) 显示出与鼠李糖脂的相似性。对鼠李糖脂的生物活性特性的评估表明对芽孢杆菌属有很强的抗菌活性。未来的调查可以集中在这些菌株在环境和工业部门的应用上。