Identification of major operating factors for an optimal torularhodin production by yeast and its enzymatic modifying based on kinetic studies

• Main Author: Alves da Costa Cardoso, Ligia
• Other Authors: Laboratoire des Sciences du Génie Chimique (LSGC), Institut National Polytechnique de Lorraine (INPL)-Centre National de la Recherche Scientifique (CNRS), Institut National Polytechnique de Lorraine, Ivan Marc, Isabelle Chevalot
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2008
• Subjects: Torularhodin; Novozym; Bixin; Raw glycerol; Carotenoids; Sporobolomyces ruberrimus; Batch bioreactor; Oleic acid; Enzymatic acylation; Lysine; Torularhodine; Glycérol technique; Caroténoïdes; Bioréacteur discontinu; Acide oléique; Plan d'expériences multicritère; Acylation enzymatique; Bixine; Multiobjective optimization; Carotènes; Acides carboxyliques; [SDV.AEN]Life Sciences [q-bio]/Food and Nutrition; [SPI.OTHER]Engineering Sciences [physics]/Other; Antarc*; Antarctica
• Online Access: https://hal.univ-lorraine.fr/tel-01753061; https://hal.univ-lorraine.fr/tel-01753061/document; https://hal.univ-lorraine.fr/tel-01753061/file/2008_ALVES_DA_COSTA_CARDOSO_L.pdf

The aim of this work was to determine the optimum of an original carotenoid, the torularhodin, produced by Sporobolomyces ruberrimus, in batch culture. A very interesting characteristic of this strain is its ability to consume raw glycerol as a carbon and energy source for microbial growth and carotenoid production. In the fist part of this study, the identification of operating parameters that have an influence on the optimum torularhodin production, was achieved. Experimental assays reinforced by a statistical study allowed to identify temperature, dissolved oxygen pressure and oleic acid supplementation, as the major parameters of influence, and then the integration of these data was performed for the construction of a multiobjective optimization based on a multicriteria experimental design. The establishment of a mathematical model of a second degree polynomial type was developed for the prediction of the values of µmax and of the torularhodin concentration reported to biomass. In the last part, considering that torularhodin has an important antioxidant property and it exhibits a free carboxyl acid function which can be used as acyl agent, a study of its structure modifying by an enzymatic way as a stabilization pattern was started. The experimental conditions of lysine acylation by the lipase B of Candida antarctica were determined using a model carotenoid, the bixin. The resulting product of the synthesis of bixin derivative was purified and showed an antiradical activity of 2.5 times higher than that of bixin. This result showed the ability of the acylation reaction of peptides with this kind of carotenoids Ce travail a eu pour objectif de déterminer les conditions optimales de production d'un caroténoïde original, la torularhodine, par Sporobolomyces ruberrimus, cultivée en réacteur discontinu. Cette souche est capable d'utiliser le glycérol technique comme source de carbone et d'énergie pour sa croissance et pour la production de caroténoïdes. D'abord, il s'agit didentifier les facteurs opératoires ...