A Possible Industrial Solution to Ferment Lignocellulosic Hydrolyzate to Ethanol: Continuous Cultivation with Flocculating Yeast

International Journal of Molecular Sciences

Ronny Purwadi²  Tomas Brandberg¹ 

[1] SEKAB, SE-891-26 Örnsköldsvik, Sweden;Dept. of Chemical Engineering, Institut Teknologi Bandung, 40132 Bandung, Indonesia

关键词: Dilute-acid lignocellulosic hydrolysate;    Saccharomyces cerevisiae;    flocculating yeast;    ethanol;    glycerol;    HMF;    furfural;    continuous cultivation;   

DOI  :  10.3390/i8090920

来源: mdpi

【 摘 要 】

The cultivation of toxic lignocellulosic hydrolyzates has become a challenging research topic in recent decades. Although several cultivation methods have been proposed, numerous questions have arisen regarding their industrial applications. The current work deals with a solution to this problem which has a good potential application on an industrial scale. A toxic dilute-acid hydrolyzate was continuously cultivated using a high-cell-density flocculating yeast in a single and serial bioreactor which was equipped with a settler to recycle the cells back to the bioreactors. No prior detoxification was necessary to cultivate the hydrolyzates, as the flocks were able to detoxify it in situ. The experiments were successfully carried out at dilution rates up to 0.52 h⁻¹. The cell concentration inside the bioreactors was between 23 and 35 g-DW/L, while the concentration in the effluent of the settlers was 0.32 ± 0.05 g-DW/L. An ethanol yield of 0.42–0.46 g/g-consumed sugar was achieved, and the residual sugar concentration was less than 6% of the initial fermentable sugar (glucose, galactose and mannose) of 35.2 g/L.

【 授权许可】

Unknown   
© 2007 by MDPI