Universidad Complutense de Madrid
E-Prints Complutense

Growth kinetics and physiological behavior of co-cultures ofSaccharomyces cerevisiae and Kluyveromyces lactis,fermenting carobsugars extracted with whey

Impacto

Downloads

Downloads per month over past year

Rodrigues, B. and Lima-Costa, M. E. and Constantino, A. and Raposo, S. and Felizardo, C. and Gonçalves, D. and Fernandes, T. and Dionísio, L. and Martínez Peinado, José (2016) Growth kinetics and physiological behavior of co-cultures ofSaccharomyces cerevisiae and Kluyveromyces lactis,fermenting carobsugars extracted with whey. Enzyme and Microbial Technology, 92 . pp. 41-48. ISSN 0141-0229, ESSN: 1879-0909

[img] PDF
Restringido a Repository staff only

1MB

Official URL: http://www.sciencedirect.com/science/article/pii/S0141022916301144



Abstract

Alcoholic fermentation of carob waste sugars (sucrose, glucose and fructose) extracted with cheese whey, by co-cultures of Saccharomyces cerevisiae and Kluyveromyces lactis has been analyzed. Growth and fermentation of S. cerevisiae in the carob-whey medium showed an inhibition of about 30% in comparison with water-extracted carob. The inhibition of K. lactis on carob-whey was greater (70%) when compared with the whey medium alone, due to osmolarity problems. Oxygen availability was a very important factor for K. lactis, influencing its fermentation performance. When K. lactis was grown alone on carob-whey medium, lactose was always consumed first, and glucose and fructose were consumed afterwards, only at high aeration conditions. In co-culture with S. cerevisiae, K. lactis was completely inhibited and, at low aeration, died after 3 days; at high aeration this culture could survive but growth and lactose fermentation were only recovered after S. cerevisiae became stationary. To overcome the osmolarity and K. lactis’ oxygen problems, the medium had to be diluted and a sequential fermentative process was designed in a STR–3l reactor. K. lactis was inoculated first and, with low aeration (0.13 vvm), consumed all the lactose in 48 h. Then S. cerevisiae was inoculated, consuming the total of the carob sugars, and producing ethanol in a fed-batch regime. The established co-culture with K. lactis increased S. cerevisiae ethanol tolerance. This fermentation process produced ethanol with good efficiency (80 g/l final concentration and a conversion factor of 0.4 g ethanol/g sugar), eliminating all the sugars of the mixed waste. These efficient fermentative results pointed to a new joint treatment of agro-industrial wastes which may be implemented successfully, with economic and environmental sustainability for a bioethanol industrial proposal.


Item Type:Article
Uncontrolled Keywords:Kluyveromyces lactis; Saccharomyces cerevisiae; Carob; Whey Waste treatment Ethanol
Subjects:Medical sciences > Biology > Microbiology
ID Code:42278
Deposited On:21 Apr 2017 11:58
Last Modified:10 Dec 2018 15:30

Origin of downloads

Repository Staff Only: item control page