Second Generation Ethanol Production from Brewers’ Spent Grain

Energies

Rossana Liguori²  Carlos Ricardo Soccol¹  Luciana Porto de Souza Vandenberghe¹  Adenise Lorenci Woiciechowski¹  Vincenza Faraco² 

[1] Department of Bioprocess Engineering and Biotechnology, Federal University of Paraná, Coronel Francisco H. dos Santos Avenue, 210, 81531-980 Curitiba, Brazil; E-Mails:;Department of Chemical Sciences, University of Naples “Federico II”, Complesso Universitario Monte S. Angelo, via Cintia, 480126 Naples, Italy; E-Mail:

关键词: brewers’ spent grain;    lignocellulosic conversion;    second generation bioethanol;    enzymatic saccharification;    ethanologenic microorganisms;   

DOI  :  10.3390/en8042575

来源: mdpi

【 摘 要 】

Ethanol production from lignocellulosic biomasses raises a global interest because it represents a good alternative to petroleum-derived energies and reduces the food versus fuel conflict generated by first generation ethanol. In this study, alkaline-acid pretreated brewers’ spent grain (BSG) was evaluated for ethanol production after enzymatic hydrolysis with commercial enzymes. The obtained hydrolysate containing a glucose concentration of 75 g/L was adopted, after dilution up to 50 g/L, for fermentation by the strain Saccharomyces cerevisiae NRRL YB 2293 selected as the best producer among five ethanologenic microorganims. When the hydrolysate was supplemented with yeast extract, 12.79 g/L of ethanol, corresponding to 0.28 g of ethanol per grams of glucose consumed (55% efficiency), was obtained within 24 h, while in the non-supplemented hydrolysate, a similar concentration was reached within 48 h. The volumetric productivity increased from 0.25 g/L·h in the un-supplemented hydrolysate to 0.53 g/L h in the yeast extract supplemented hydrolysate. In conclusion, the strain S. cerevisiae NRRL YB 2293 was shown able to produce ethanol from BSG. Although an equal amount of ethanol was reached in both BSG hydrolysate media, the nitrogen source supplementation reduced the ethanol fermentation time and promoted glucose uptake and cell growth.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.