ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Continuous production of citric acid from raw glycerol by Yarrowia lipolytica in cell recycle cultivation
Anita Rywińska and Waldemar Rymowicz
Department of Biotechnology and Food Microbiology, Faculty of Food Science, Wroclaw University of Environmental and Life Sciences, PL 50-375 Wroclaw, Poland
Abstract: The kinetics of continuous citric acid (CA) fermentation, using two acetate-negative mutants of Yarrowia lipolytica (Wratislavia AWG7 and Wratislavia 1.31) with long-term cell recycle, were investigated at a dilution rate (D) of 0.011 h−1. The capacity of the mutants to produce CA from raw glycerol under steady state conditions was compared. The process involving
the Wratislavia AWG7 strain showed that this strain was a better producer of CA than the Wratislavia 1.31 strain in this regime.
In steady state, the concentration of CA in the effluent was constant and amounted to 116 g dm−3. This corresponded to a volumetric CA production rate of 1.3 g dm−3 h−1. A stable high-level production of CA was maintained for over 400 h of operation. The Wratislavia AWG7 strain employed remained
highly stable throughout the experiment and demonstrated good viability, high genetic and phenotypic stability over the long-term
continuous fermentation process.
Keywords: cell recycle – citric acid – raw glycerol – Yarrowia lipolytica
Full paper is available at www.springerlink.com.
Chemical Papers 65 (2) 119–123 (2011)