Title:
Conversion of Crude Glycerol to Citric Acid by Yarrowia Lipolytica
Author(s):
Giacomobono, R., Albergo, R., Valerio, V., De Bari, I.
Document(s):
Paper
Poster
Abstract:
Citric acid is a key biochemical in the emerging bioeconomy, to date mostly produced through fermentation by A. niger of molasses. One main issue is represented by the replacement of the molasses-based medium with less expensive and more sustainable feedstocks. Crude glycerol, a secondary product from the biodiesel industry was used without any pretreatment as substrate for fermentation by Yarrowia lipolytica DSM 8218 to produce it. The raw glycerol was retrieved from a local biodiesel production plant. The fermentation set-up was first optimized in flasks by using the Response Surface Methodology (RSM). A 3-level Full Factorial Design of Experiment was employed to investigate the impact of crude glycerol concentration and C/N ratio on citric acid yield and two N sources (ammonium sulphate and yeast extract) were alternatively tested. The optimized conditions were subsequently applied to a 2L bioreactor. The best conditions to maximize YCA were found to be: crude glycerol 33 g/L and C/N 141, which resulted in the production of 8 g/L of citric acid and in a metabolic yield of 0,27 g/g. Scale up in bioreactor indicated that the citric acid production like can be controlled and improved by adjusting the concentration of dissolved oxygen.
Keywords:
biodiesel, biological conversion, circular economy, raw glycerol
Topic:
Biomass Conversion Technologies for Energy Carriers, Chemicals and Materials
Subtopic:
Production and application of biobased chemicals
Event:
27th European Biomass Conference and Exhibition
Session:
3DV.4.39
Pages:
1471 - 1474
ISBN:
978-88-89407-19-6
Paper DOI:
10.5071/27thEUBCE2019-3DV.4.39
Price:
FREE
