Brecht Vanlerberghe - Academia.edu (original) (raw)
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Papers by Brecht Vanlerberghe
Journal of the American Oil Chemists Society, Mar 1, 2003
Biotechnology and Bioengineering, 2015
Although sophorolipids (SLs) produced by S. bombicola are a real showcase for the industrializati... more 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. Biotechnol. Bioeng. 2015;9999: 1-10. © 2015 Wiley Periodicals, Inc.
Journal of the American Oil Chemists' Society, 2002
Journal of the American Oil Chemists' Society, 2003
International Dairy Journal, 2008
European Journal of Lipid Science and Technology, 2002
ABSTRACT Different amounts of phospholipids (0.00-0.07%) and water (0.00-0.70%) were added to mil... more ABSTRACT Different amounts of phospholipids (0.00-0.07%) and water (0.00-0.70%) were added to milk fat. The mixtures were crystallised under isothermal conditions and the crystallisation was monitored by differential scanning calorimetry and pulsed nuclear magnetic resonance. The crystallisation behaviour was described with the Avrami and Gompertz model which was fitted by non-linear regression. Variance analysis revealed significant effects, whereas especially the induction time was influenced: higher concentrations of water seemed to decrease the induction time, while higher amount of phospholipids delayed the onset of crystallisation. No interaction effects between phospholipids and water were observed. An attempt to explain the effect of phospholipids on the induction time, based on the molecular interactions between phospholipids and triglycerides is proposed. This principle can be applied for sn-1, 2 diglycerides as well.
International Dairy Journal, 2008
Journal of the American Oil Chemists Society, Mar 1, 2003
Biotechnology and Bioengineering, 2015
Although sophorolipids (SLs) produced by S. bombicola are a real showcase for the industrializati... more 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. Biotechnol. Bioeng. 2015;9999: 1-10. © 2015 Wiley Periodicals, Inc.
Journal of the American Oil Chemists' Society, 2002
Journal of the American Oil Chemists' Society, 2003
International Dairy Journal, 2008
European Journal of Lipid Science and Technology, 2002
ABSTRACT Different amounts of phospholipids (0.00-0.07%) and water (0.00-0.70%) were added to mil... more ABSTRACT Different amounts of phospholipids (0.00-0.07%) and water (0.00-0.70%) were added to milk fat. The mixtures were crystallised under isothermal conditions and the crystallisation was monitored by differential scanning calorimetry and pulsed nuclear magnetic resonance. The crystallisation behaviour was described with the Avrami and Gompertz model which was fitted by non-linear regression. Variance analysis revealed significant effects, whereas especially the induction time was influenced: higher concentrations of water seemed to decrease the induction time, while higher amount of phospholipids delayed the onset of crystallisation. No interaction effects between phospholipids and water were observed. An attempt to explain the effect of phospholipids on the induction time, based on the molecular interactions between phospholipids and triglycerides is proposed. This principle can be applied for sn-1, 2 diglycerides as well.
International Dairy Journal, 2008