[en] The influence of three extracellular factors (namely, the methyl oleate dispersion in the broth, the dissolved oxygen variations, and the pH fluctuation) on the lipase production by Y. lipolytica in batch bioreactor has been investigated in different scale-down apparatus. These systems allow to reproduce the hydrodynamic phenomena encountered in large-scale equipments for the three specified factors. The effects of the extracellular factors have been observed at three distinct levels: the microbial growth, the extracellular lipase production, and the induction of the gene LIP2 encoding for the main lipase of Y. lipolytica. Among the set of environmental factors investigated, the dissolved oxygen fluctuations generated in a controlled scale-down reactor (C-SDR) have led to the more pronounced physiological effect by decreasing the LIP2 gene expression level. The other environmental factors observed in a partitioned scale-down reactor, i.e., the methyl oleate dispersion and the pH fluctuations, have led to a less severe stress traduced only by a decrease of the microbial yield and thus of the extracellular lipase specific production rate.
ME Guerzoni R Lanciotti L Vannini F Galgano F Favati F Gardini 2001 Variability of the lipolytic activity in Yarrowia lipolytica and its dependence on environmental conditions Int J Food Microbiol 69 79 89 10.1016/S0168-1605(01) 00575-X
P Fickers P-H Benetti Y Wache A Marty S Mauersberger MS Smit 2005 Hydrophobic substrate utilisation by the yeast Yarrowia lipolytica and its potential applications FEMS Yeast Res 5 527 543 10.1016/j.femsyr.2004.09.004
SO Enfors M Jahic A Rozkov B Xu M Hecker B Jürgen 2001 Physiological responses to mixing in large scale bioreactors J Biotechnol 85 175 185 10.1016/S0168-1656(00)00365-5
P Fickers JM Nicaud C Gaillardin J Destain P Thonart 2004 Carbon and nitrogen sources modulate lipase production in the yeast Yarrowia lipolytica J Appl Microbiol 96 742 749 10.1111/j.1365-2672.2004.02190.x
J Destain D Roblain P Thonart 1997 Improvement of lipase production from Yarrowia lipolytica Biotechnol Lett 19 105 107 10.1023/A:1018339709368
P Fickers J Destain P Thonart 2005 Methyl oleate modulates LIP2 expression in the lipolytic yeast Yarrowia lipolytica Biotechnol Lett 27 1751 1754 10.1007/s10529-005-3547-2
J Destain P Fickers F Weeckers B Moreau P Thonart 2005 Utilization of methyloelate in production of microbial lipase Appl Biochem Biotechnol 121-124 269 278 10.1385/ABAB:121:1-3:0269
J Destain P Fickers F Weekers B Moreau P Thonart 2005 Utilization of methyloleate in production of microbial lipase Appl Biochem Biotechnol 121 269 277 10.1385/ABAB:121:1-3:0269
P Neubauer L Häggström SO Enfors 1995 Influence of substrate oscillations on acetate formation and growth yield in Escherichia coli glucose limited fed-batch cultivations Biotechnol Bioeng 47 139 146 10.1002/bit. 260470204
CJ Hewitt H Onyeaka G Lewis IW Taylor AW Nienow 2007 A comparison of high cell density fed-batch fermentations involving both induced and non-induced recombinant Escherichia coli under well-mixed small-scale and simulated poorly mixed large-scale conditions Biotechnol Bioeng 96 495 505 10.1002/bit.21127
AR Lara E Galindo OT Ramirez LA Palomares 2006 Living with heterogeneities in bioreactors-Understanding the effects of environmental gradients on cells Mol Biotechnol 34 355 381 10.1385/MB:34:3:355
PK Namdev PK Yegneswaran BG Thompson MR Gray 1991 Experimental simulation of large-scale bioreactor environments using a monte carlo method Can J Chem Eng 69 513 519
F Delvigne J Destain P Thonart 2006 A methodology for the design of scale-down bioreactors by the use of mixing and circulation stochastic models Biochem Eng J 28 256 268 10.1016/j.bej.2005.11.009
F Delvigne A Lejeune J Destain P Thonart 2006 Stochastic models to study the impact of mixing on a fed-batch culture of Saccharomyces cerevisiae Biotechnol Prog 22 259 269 10.1021/bp050255 m
J Ruiz-Herrera R Sentandreu 2002 Different effectors of dimorphism in Yarrowia lipolytica Arch Microbiol 178 477 483 10.1007/s00203-002-0478-3
R Szabo V Stofanikova 2002 Presence of organic sources of nitrogen is critical for filament formation and pH-dependent morphogenesis in Yarrowia lipolytica FEMS Microbiol Lett 206 45 50 10.1111/j.1574-6968.2002.tb10984.x