Premium
On enhancing productivity of bioethanol with multiple species
Author(s) -
Geng Jun,
Song HyunSeob,
Yuan Jingqi,
Ramkrishna Doraiswami
Publication year - 2012
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.24419
Subject(s) - kluyveromyces marxianus , pichia stipitis , biofuel , fermentation , yeast , biochemical engineering , ethanol fuel , productivity , biology , kluyveromyces , biological system , saccharomyces cerevisiae , microbiology and biotechnology , chemistry , food science , botany , biochemistry , engineering , economics , macroeconomics
The present work is initiated to investigate whether a defined culture comprising a mixture of three yeast species, Kluyveromyces marxianus , Saccharomyces cerevisiae , and Pichia stipitis can ferment a mixture of sugars to produce bioethanol at rates higher than those achieved by pure cultures of the same. For this purpose, we develop models of single species based on the hybrid cybernetic model framework, and simulate fermentations in the mixed culture by combining individual models. An underlying assumption is that the behavior of each species is determined only by the common environment independently of the presence and metabolism of other species. Model performance is thoroughly assessed using the experimental data available in the literature. The dynamic behavior of mixed cultures in mixed culture experiments are accurately predicted by the model reflecting faithfully the simultaneous/sequential uptake patterns of mixed substrates. This model is then used to investigate performance of various possible reactor configurations. With the foregoing species of organisms, mixed culture itself does not lead to a significant increase of bioethanol productivity. Rather, the model shows that substantial improvement is acquired by sequential use of different, properly chosen organisms during fermentation. Thus, the successive use of K. marxianus and P. stipitis is shown to increase bioethanol productivity up to about 58% in comparison to fermentation by single species alone. Biotechnol. Bioeng. 2012; 109:1508–1517. © 2011 Wiley Periodicals, Inc.