Title:
Study of Tolerance of Saccharomyces Cerevisiae Spp. to Phenols of Lignin and High Level of Sugars
Author(s):
Vázquez, S., Lopretti Correa, M.I.
Document(s):
Paper
Abstract:
Lignocellulosic materials are one of the most important renewable sources for the energy production. Several transformations are crucial for the use of this type of materials. There are several processes that can be use to turn cellulose into sugar, like aerobic conversion by fungi, such as Trichoderma reesei, acid and basic hydrolysis and radiation. By means of these processes a mixture of glucose and xilose is obtained at a concentration of about 10 g/l, which can be use to produce bioethanol. The purpose of this study is to explore the potential for alcohol production from lignocelluloses materials in presence of residual phenols of lignin and higher sugar concentrations. The microorganism under test, Saccharomyces cerevisiae spp, was incubated in YPD broth at different concentrations of lignin (0.02 % and 1%), at different glucose concentrations (10 g/l, 20 g /l, and 40 g/l) and at different ethanol concentrations (10 %v/v, 30% v/v and 50% v/v). All the cultures were inoculated at 1% and were incubated for 40 hours at 37ºC in aerobic conditions. Spectrophotometer determinations were done at 660 nm to determine the cell biomass of the Saccharomyces. Lignin phenols were studied by a spectrophotometer determination from 400 to 700 nm. In presence of residuals phenols at a maximum concentration of 0,1 %, the results show no variations in growth. At higher concentrations growth decreased 20% and 40%. It was possible to increase sugar concentration to 40 g/l and this resulted in a better growth than in cultures that had glucose at a concentration of 20 g/l. N/ No ratio was 1,589 and 2,327 for sugar concentration of 20 g/l and 40 g/l respectively. There was no difference in the results of alcohol tolerance. In conclusion, this strain of Saccharomyces cerevisiae is tolerant to the presence of phenols. Regarding sugar concentration, has the ability to grow a higher concentration then that reported before. Taking all this into account, we believe that it is possible to work simultaneously on sacharification and fermentation. It is though that the kinetic features of enzymatic activity will be studied in the near future.
Keywords:
bioethanol, fermentation, lignocellulosic, phenols tolerance
Topic:
Fuels from biomass
Subtopic:
Technologies and demonstration of second generation biofuels
Event:
18th European Biomass Conference and Exhibition
Session:
VP3.5.20
Pages:
1862 - 1864
ISBN-13:
978-88-89407-56-1
ISBN-10:
88-89407-56-5
Paper DOI:
10.5071/18thEUBCE2010-VP3.5.20
Price:
FREE
