Glycerol bioconversion in unconventional magnetically assisted bioreactor seeking whole cell biocatalyst (intracellular lipase) production

Abstract

A novel technology that consisted of a magnetically assisted bioreactor to produce biomass and intracellular lipase (whole cell) from Yarrowia lipolytica (Y. lipolytica) has been studied. Fermentations were carried out at 1.5; 4.5, and 9.0kA/m in different experimental setup: a) in conventional fermenter inside magnetic field; b) in conventional fermenter with cellular suspension recycled through spiral-shaped tube under external magnetic field; and c) in conventional fermenter with cellular suspension recycled through U-shaped tube system under external magnetic field. Control experiments were also carried out for comparative purpose. Thus, the yeast showed a little change in the cell growth under magnetic field respect to the control, reaching just an increase of 6% at 1.5kA/m, using the U-shaped tube and transversal direction of field lines. However, around 66.8 units activity/g for lipase production were obtained using a transverse orientation of the field lines, at 9.0kA/m and recirculation through the U-shaped tube system, resulting in 30% higher than control experiment. These effects may be attributed to magnetic field action at the vicinity of the cell-substrate interfaces, which are related to both, the intracellular metabolism and the mass transfer from the substrate to the cell walls, explained by micro-level dynamo concept (MLD).