Simultaneous bioconversion of cellulose and hemicellulose to ethanol
- Indian Inst. of Tech., New Delhi (India). Dept. of Biochemical Engineering and Biotechnology
Lignocellulosic materials containing cellulose, hemicellulose, and lignin as their main constituents are the most abundant renewable organic resource present on Earth. The fermentation of glucose, the main constituent of cellulose hydrolyzate, to ethanol can be carried out efficiently. On the other hand, although bioconversion of xylose, the main pentose sugar obtained on hydrolysis of hemicellulose, to ethanol presents a biochemical challenge, especially if it is present along with glucose, it needs to be fermented to make the biomass-to-ethanol process economical. A lot of attention therefore has been focused on the utilization of both glucose and xylose to ethanol. Accordingly, while describing the advancements that have taken place to get xylose converted efficiently to ethanol by xylose-fermenting organisms, the review deals mainly with the strategies that have been put forward for bioconversion of both the sugars to achieve high ethanol concentration, yield, and productivity. The approaches, which include the use of (1) xylose-fermenting yeasts along, (2) xylose isomerase enzyme as well as yeast, (3) immobilized enzymes and cells, and (4) sequential fermentation and co-culture process are descried with respect to their underlying concepts and major limitations. Genetic improvements in the cultures have been made either to enlarge the range of substrate utilization or to channel metabolic intermediates specifically toward ethanol.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 318614
- Journal Information:
- CRC Critical Reviews in Biotechnology, Journal Name: CRC Critical Reviews in Biotechnology Journal Issue: 4 Vol. 18; ISSN CRBTE5; ISSN 0738-8551
- Country of Publication:
- United States
- Language:
- English
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