title: Towards the industrialization of new biosurfactants: Biotechnological opportunities for the lactone esterase gene from Starmerella bombicola.
abstract: Although sophorolipids (SLs) produced by S. bombicola are a real showcase for the industrialization of microbial biosurfactants, some important drawbacks are associated with this efficient biological process, e.g., the simultaneous production of acidic and lactonic SLs. Depending on the application, there is a requirement for the naturally produced mixture to be manipulated to give defined ratios of the components. Recently, the enzyme responsible for the lactonization of SLs was discovered. The discovery of the gene encoding this lactone esterase (sble) enabled the development of promising S. bombicola strains producing either solely lactonic (using a sble overexpression strain described in this paper: oe sble) or solely acidic SLs (using a sble deletion strain, which was recently described, but not characterized yet: Δsble). The new S. bombicola strains were used to investigate the production processes (fermentation and purification) of either lactonic or acidic SLs. The strains maintain the high inherent productivities of the wild-type or even perform slightly better and thus represent a realistic industrial opportunity. 100% acidic SLs with a mixed acetylation pattern were obtained for the Δsble strain, while the inherent capacity to selectively produce lactonic SLs was significantly increased (+42%) for the oe sble strain (99% lactonic SLs). Moreover, the regulatory effect of citrate on lactone SL formation for the wild-type was absent in this new strain, which indicates that it is more robust and better suited for the industrial production of lactonic SLs. Basic parameters were determined for the purified SLs, which confirm that the two new strains produce molecules with distinctive properties of which the application potential can now easily be investigated independently.
authors: Centre for Industrial Biotechnology and Biocatalysis (InBio.be), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium. Sophie.Roelants@ugent.be.|Bio Base Europe Pilot Plant (BBEU), Rodenhuizekaai 1, 9042, Ghent (Desteldonk), Belgium. Sophie.Roelants@ugent.be.
authors: Sophie L K W
authors: SL
authors: Roelants
authors: L-Probe, Department of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium.
authors: Katarzyna
authors: K
authors: Ciesielska
authors: Centre for Industrial Biotechnology and Biocatalysis (InBio.be), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
authors: Sofie L
authors: SL
authors: De Maeseneire
authors: Bio Base Europe Pilot Plant (BBEU), Rodenhuizekaai 1, 9042, Ghent (Desteldonk), Belgium.
authors: Helena
authors: H
authors: Moens
authors: Bio Base Europe Pilot Plant (BBEU), Rodenhuizekaai 1, 9042, Ghent (Desteldonk), Belgium.
authors: Bernd
authors: B
authors: Everaert
authors: Centre for Industrial Biotechnology and Biocatalysis (InBio.be), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
authors: Stijn
authors: S
authors: Verweire
authors: Particle and Interfacial Technology Group, Department of Applied Analytical and Physical Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
authors: Quenten
authors: Q
authors: Denon
authors: Bio Base Europe Pilot Plant (BBEU), Rodenhuizekaai 1, 9042, Ghent (Desteldonk), Belgium.
authors: Brecht
authors: B
authors: Vanlerberghe
authors: Centre for Industrial Biotechnology and Biocatalysis (InBio.be), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
authors: Inge N A
authors: IN
authors: Van Bogaert
authors: Particle and Interfacial Technology Group, Department of Applied Analytical and Physical Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
authors: Paul
authors: P
authors: Van der Meeren
authors: L-Probe, Department of Sciences, Ghent University, K.L. Ledeganckstraat 35, 9000, Ghent, Belgium.
authors: Bart
authors: B
authors: Devreese
authors: Centre for Industrial Biotechnology and Biocatalysis (InBio.be), Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.|Bio Base Europe Pilot Plant (BBEU), Rodenhuizekaai 1, 9042, Ghent (Desteldonk), Belgium.
authors: Wim
authors: W
authors: Soetaert
mesh_terms: D001688:Biological Products / Q000378:metabolism*; D004950:Esterases / Q000235:genetics / Q000378:metabolism*; D017353:Gene Deletion; D015870:Gene Expression; D006017:Glycolipids / Q000378:metabolism*; D007783:Lactones / Q000378:metabolism*; D060847:Metabolic Engineering; D004718:Saccharomycetales / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism*; D013501:Surface-Active Agents / Q000378:metabolism*
chemical_list: D001688:Biological Products; D006017:Glycolipids; D007783:Lactones; D013501:Surface-Active Agents; D004950:Esterases
keywords: biosurfactants; fermentation; genetic engineering; sophorolipids; starmerella bombicola