Cultural factors affecting biosurfactant production by Gordonia

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• 作者：Andrea Franzetti ; Paolo Caredda ; Paolo La Colla ; Manuela Pintus ; Elena Tamburini ; Maddalena Papacchini ; Giuseppina Bestetti
• 关键词：Surface-active compound ; Biosurfactant ; Gordonia ; Design of experiments
• 刊名：International Biodeterioration and Biodegradation
• 出版年：2009
• 出版时间：October 2009
• 年：2009
• 卷：63
• 期：7
• 页码：943-947
• 全文大小：158 K

文摘

Gordonia sp. BS29 is a hydrocarbon-degrading bacterium isolated from a site chronically contaminated by diesel. The strain produces extracellular bioemulsifiers, able to produce stable emulsions, and cell-bound glycolipid biosurfactants, able to reduce surface tension. The aims of this work were to investigate the cultural factors affecting the production of the cell-bound biosurfactants by Gordonia sp. BS29 and to find the optimal composition of growth medium for the production. The cultural factors which have a significant influence on surfactant biosynthesis, identified by a two level 2^(8-2) Fractional Factorial Design, were the type and concentration of the carbon source, the concentrations of phosphates and sodium chloride, and the interactions among these factors. On these factors, a flask-scale optimisation of cultural conditions was carried out. Then, a steepest ascent procedure and a Central Composite Design were applied to obtain a second order polynomial function fitting the experimental data near the optimum. In the optimised cultural condition we obtained a 5-fold increase in the biosurfactant concentration compared to the un-optimised medium (26.00), reaching a Critical Micelle Dilution value (129.43) among the highest in literature. The optimisation procedure did not change the number and type of the glycolipid biosurfactants produced by Gordonia sp. BS29.