Willenbacher Judit, Rau Jens-Tilman, Rogalla Jonas, Syldatk Christoph, Hausmann Rudolf
Institute of Process Engineering in Life Sciences, Section II: Technical Biology, Karlsruhe Institute of Technology (KIT), Engler-Bunte-Ring 1, 76131, Karlsruhe, Germany.
Institute of Food Science and Biotechnology (150), Section Bioprocess Engineering (150 k), University of Hohenheim, Garbenstr. 25, 70599 Stuttgart, Germany.
AMB Express. 2015 Mar 17;5:21. doi: 10.1186/s13568-015-0107-6. eCollection 2015.
Surfactin is one of the most popular biosurfactants due to its numerous potential applications. The usually aerobic production via fermentation of Bacillus subtilis is accompanied by vigorous foaming which leads to complex constructions and great expense. Therefore it is reasonable to search for alternative foam-free production processes. The current study introduces a novel approach to produce Surfactin in a foam-free process applying a strictly anaerobic bioreactor cultivation. The process was performed several times with different glucose concentrations in mineral salt medium. The fermentations were analyzed regarding specific (qSurfactin, vol. qSurfactin) and overall product yields (YP/X, YP/S) as well as substrate utilization (YX/S). Fermentations in which 2.5 g/L glucose were employed proofed to be the most effective, reaching product yields of YP/X = 0.278 g/g. Most interesting, the product yields exceeded classical aerobic fermentations, in which foam fractionation was applied. Additionally, values for specific production rate qSurfactin (0.005 g/(g∙h)) and product yield per consumed substrate (YP/S = 0.033 g/g) surpass results of comparable foam-free processes. The current study introduces an alternative to produce a biosurfactant that overcomes the challenges of severe foaming and need for additional constructions.
由于其众多潜在应用，表面活性素是最受欢迎的生物表面活性剂之一。通过枯草芽孢杆菌发酵进行的通常需氧生产伴随着剧烈起泡，这导致结构复杂且成本高昂。因此，寻找替代的无泡沫生产工艺是合理的。当前的研究引入了一种新方法，即在严格厌氧生物反应器培养的无泡沫工艺中生产表面活性素。该工艺在矿物盐培养基中使用不同葡萄糖浓度进行了多次。对发酵过程进行了分析，涉及特定（q表面活性素，体积q表面活性素）和总产物产率（YP/X，YP/S）以及底物利用（YX/S）。使用2.5 g/L葡萄糖的发酵被证明是最有效的，产物产率达到YP/X = 0.278 g/g。最有趣的是，这些产物产率超过了应用泡沫分离的经典需氧发酵。此外，特定生产率q表面活性素的值（0.005 g/(g∙h)）和每消耗底物的产物产率（YP/S = 0.033 g/g）超过了可比的无泡沫工艺的结果。当前的研究引入了一种生产生物表面活性剂的替代方法，该方法克服了严重起泡和需要额外结构的挑战。
