Department of Chemical Engineering, Federal University of Ceara, Fortaleza, Brazil.
Bioprocess Biosyst Eng. 2012 Aug;35(6):897-906. doi: 10.1007/s00449-011-0674-0. Epub 2012 Jan 5.
Glycerol, a co-product of biodiesel production, was evaluated as carbon source for biosurfactant production. For this reason, seven non-pathogenic biosurfactant-producing Bacillus strains, isolated from the tank of chlorination at the Wastewater Treatment Plant at Federal University of Ceara, were screened. The production of biosurfactant was verified by determining the surface tension value, as well as the emulsifying capacity of the free-cell broth against soy oil, kerosene and N-hexadecane. Best results were achieved when using LAMI005 and LAMI009 strains, whose biosurfactant reduced the surface tension of the broth to 28.8 ± 0.0 and 27.1 ± 0.1 mN m(-1), respectively. Additionally, at 72 h of cultivation, 441.06 and 267.56 mg L(-1) of surfactin were produced by LAMI005 and LAMI009, respectively. The biosurfactants were capable of forming stable emulsions with various hydrocarbons, such as soy oil and kerosene. Analyses carried out with high performance liquid chromatography (HPLC) showed that the biosurfactant produced by Bacillus subtilis LAMI009 and LAMI005 was compatible with the commercially available surfactin standard. The values of minimum surface tension and the CMC of the produced biosurfactant indicated that it is feasible to produce biosurfactants from a residual and renewable and low-cost carbon source, such as glycerol.
甘油是生物柴油生产的副产品，被评估为生物表面活性剂生产的碳源。出于这个原因，从联邦大学的废水处理厂氯化罐中分离出的七种非致病性生物表面活性剂产生芽孢杆菌菌株进行了筛选。通过测定表面张力值以及游离细胞发酵液对豆油、煤油和正十六烷的乳化能力来验证生物表面活性剂的产生。使用 LAMI005 和 LAMI009 菌株时效果最佳，其生物表面活性剂将发酵液的表面张力分别降低到 28.8±0.0 和 27.1±0.1 mN m(-1)。此外，在 72 小时的培养过程中，LAMI005 和 LAMI009 分别产生了 441.06 和 267.56 mg L(-1)的表面活性剂。生物表面活性剂能够与各种碳氢化合物（如豆油和煤油）形成稳定的乳液。使用高效液相色谱（HPLC）进行的分析表明，LAMI009 和 LAMI005 产生的生物表面活性剂与市售表面活性剂标准品兼容。所产生的生物表面活性剂的最低表面张力和 CMC 值表明，从甘油等残留的、可再生的和低成本的碳源生产生物表面活性剂是可行的。
