Sugar esters lipase mediated synthesis from vegetable oils

Scientific conference (2005, September 19)

Formulation solide de la lipase de Yarrowia lipolytica

Poster (2005, March 05)

THE TWO-PHASE BIOREACTOR WATER / SILICON - OIL : PROSPECTS IN THE OFF- GAS TREATMENT

in Applied Biochemistry and Biotechnology (2005), 122(1-3), 707-719

ABSTRACT: A research was carried out to develop a biphasic biological reactor able to clean the gas effluents polluted by volatile organic compounds (V.O.C). Initially, Rhodococcus erythropolis T 902.1 ... [more ▼]

ABSTRACT: A research was carried out to develop a biphasic biological reactor able to clean the gas effluents polluted by volatile organic compounds (V.O.C). Initially, Rhodococcus erythropolis T 902.1 had been selected on the basis of its capacity to degrade isopropyl-benzene (IPB). The effect of gas flow and IPB concentration on the biodegadation of IPB was evaluated. The results show that the use of silicon-oil allows large quantities of IPB to be absorbed within the medium of biological abatement. On the other hand, the biodegradation rate is directly correlated to the inlet flow of IPB. Thus, the reactor presents interesting opportunities in the biological treatment of gas effluents. [less ▲]

Selection of new over-producing derivatives for the improvement of extracellular lipase production by the non-conventional yeast Yarrowia lipolytica

in Journal of Biotechnology (2005), 115(4), 379-386

The non-conventional yeast Yarrowia lipolytica produces an extracellular lipase encoded by the LIP2 gene. Mutant strains with enhanced productivity were previously obtained either by chemical mutagenesis ... [more ▼]

The non-conventional yeast Yarrowia lipolytica produces an extracellular lipase encoded by the LIP2 gene. Mutant strains with enhanced productivity were previously obtained either by chemical mutagenesis or genetic engineering. In this work, we used one of these mutants, named LgX64.81 to select new overproducing strains following by amplification of the LIP2 gene. We also developed a process for lipase production in bioreactors and compared lipase production levels in batch and fed-batch cultures. Batch culture led to a lipase production of 26 450 U ml(-1) in a media containing olive oil and tryptone as carbon and nitrogen sources. Feeding of a combination of tryptone and olive oil at the end of the exponential growth phase yielded to lipase activity of 158 246 U ml(-1) after 80 h of cultivation. In addition this production system developed for the extracellular lipase could also be applied for other heterologous protein production since we have demonstrated that LgX64.81 is an interesting alternative host strain. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

Study of catalase production by an Aspergillus phoenicis mutant strain in date flour extract submerged cultures

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2005), 9(3), 173-178

The production of extracellular catalase in date flour submerged medium by a selected mutant Aspergillus phoenicis K30 (member of the Aspergillus niger group) was investigated. The strain was tested in ... [more ▼]

The production of extracellular catalase in date flour submerged medium by a selected mutant Aspergillus phoenicis K30 (member of the Aspergillus niger group) was investigated. The strain was tested in 500 ml shake-flasks and in a 20 l bioreactor with date powder as a single carbon source. Extracellular catalase production reached 59 U ml-1 in both cases. This value is much greater than that of a wild-type strain (9.5 U ml-1). Microscopic examination showed that the extracellular catalase production was correlated with the ramified hyphals morphology in the external layer of the pellets. [less ▲]

Structured mixing model for stirred bioreactors : an extension to the stochastic approach

in Chemical Engineering Journal (2005)

Bioreactor hydrodynamic effect on Escherichia coli physiology: experimental results and stochastic simulations.

in Bioprocess and Biosystems Engineering (2005), 28(2), 131-7

A microorganism circulating in a bioreactor can be submitted to hydrodynamic conditions inducing a significant effect on its physiology. The mixing time exhibited by the stirred bioreactor and the ... [more ▼]

A microorganism circulating in a bioreactor can be submitted to hydrodynamic conditions inducing a significant effect on its physiology. The mixing time exhibited by the stirred bioreactor and the circulation of microorganisms are both involved in this reacting system. The mixing component determines the intensity of the concentration gradient and the circulation component determines the way in which the microorganism is exposed to this gradient. These two components linked to the experimental evaluation of microbial physiology can be analysed by a structured stochastic model in the case of a partitioned or "scale-down" reactor (SDR). A stochastic model indeed enables to simulate the mixing process as well as the circulation of microorganisms in SDRs. The superimposition of mixing and circulation processes determines the concentration profile experienced by a microorganism in the reactor. In the present case, the glucose concentration experienced by Escherichia coli has been modelled during a fed-batch culture. In this context, the use of a stochastic hydrodynamic model has permitted to point out an interesting feed pulse retardant effect in the SDRs. Nevertheless, the metabolic response of E. coli is not easy to interpret because of the possible simultaneous developments of overflow metabolism and mixed acid fermentation induced by the strong glucose concentration in the reactor. [less ▲]

Utilization of methyloleate in production of microbial lipase

in Applied Biochemistry and Biotechnology (2005), 121(Spring), 269-277

In this article, we report the development and optimization of an industrial culture medium for the production of extracellular lipase in the yeast Yarrowia lipolytica. Until now olive oil in combination ... [more ▼]

In this article, we report the development and optimization of an industrial culture medium for the production of extracellular lipase in the yeast Yarrowia lipolytica. Until now olive oil in combination with glucose was used as the carbon source and inducer for the production of lipase. Our results demonstrate that methyloleate, a cheap hydrophobic compound, could efficiently substitute olive oil as the inducer and carbon source for lipase production. A new process of lipase production was developed yielding a twofold increase in the level of production compared with the levels in previous reports. [less ▲]

Immobilisation and adsorption techniques enhance the efficiency of an antilisterial strain of Lactobacillus curvatus THT 030550 in cold-smoked salmon.

Poster (2004, December 17)

Utilization of methyloleate in the production of Yarrowia lipolytica.

Poster (2004, May)