Title:
Comparative Study of the Fermentation of Arabinose and Xylose by Hansenula Polymorpha
Author(s):
Olivares, M.I., Martínez, M.L., Moya, A.J., Sánchez, S.
Document(s):
Paper
Poster
Abstract:
The use of lignocellulose materials for the production by biochemical processes of chemical products of high value is promising, because these represent an abundant and renewable source of carbohydrates. The hemicellulose fraction from these lignocellulose materials can produce hydrolysates rich in pentoses (D-xylose, D-arabinose, and L-arabinose). On the other hand, Hansenula polymorpha is a non-conventional methylotrophic yeast, particularly suitable for bioalcohols production in fermentation process at high temperatures (over 30ºC) due to its thermotolerant nature and enable to ferment these pentoses to xylitol and arabitol. In this work, the fermentation of D-arabinose, L-arabinose and D-xylose has been carried out by H. polymorpha (ATCC 34438) at 30, 40 and 50ºC, modifying pH of the culture (3.5, 4.5 and 5.5) and aeration conditions. The xylitol, arabitol and ethanol production has been studied. Fermenting the three pentoses (D-xylose, D-arabinose and L-arabinose) with H. polymorpha, under the operation conditions that were tested, has showed that xylitol production is favored vs generation of ethanol. This yeast is able to ferment L-arabinose to arabitol, but it has difficulties fermenting D-arabinose. In both cases, the yields in arabitol are very low. The best results were obtained at 40ºC, pH=4.5 and agitation of 100 rpm, with an initial concentration of 25 kg dm-3 of D-xylose, reaching a maximum specific growth rate of 0.097 h-1 and a biomass volumetric productivity of 0.024 kg m-3 h-1. The best results were obtained to temperature of 40ºC, pH=4.5 and agitation 100 rpm, with an initial concentration of 25 kg dm-3 of D-arabinose, reaching a maximum specific growth rate of 0.11 h-1 and a biomass volumetric productivity of 0.013 kg m-3 h-1. The best results were obtained to temperature of 40ºC, pH=4.5 and agitation 100 rpm, with an initial concentration of 25 kg dm-3 of L-arabinose, reaching a maximum specific growth rate of 0.12 h-1 and a biomass volumetric productivity of 0.014 kg m-3 h-1. Higher value of xylitol yield was reached at process time (t) of 69 h, Yxy/s = 0.22 g xylitol (g D-xylose)-1, at 50ºC and pH=4.5. The best value of arabitol yield was reached at process time of 190 h in D-arabinose fermentation, YAr/s = 0.12 g arabitol (g D-arabinose)-1, at 50ºC and pH=4.5. However, when substrate was L-arabinose, the best value of YAr/s was reached at process time of 31.50 h, YAr/s = 0.25 g arabitol (g L-arabinose)-1, at 45ºC and pH=3.5. Higher value of qAr was 0.01 g g-1 h-1 at t = 45.5 h, and 0.073 g g-1 h-1 at t = 3 h for D-arabinose and L-arabinose at 40ºC and pH=4.5.
Keywords:
D-xylose, xylitol, D-arabinose, Hansenula polymorpha, L-arabinose, arabitol
Topic:
Biomass Conversion Technologies for Liquid and Gaseous Fuels, Chemicals and Materials
Subtopic:
Biorefineries and chemicals production
Event:
23rd European Biomass Conference and Exhibition
Session:
3AV.3.56
Pages:
1140 - 1145
ISBN:
978-88-89407-516
Paper DOI:
10.5071/23rdEUBCE2015-3AV.3.56
Price:
FREE
