Environmental Engineering Reference
Fig. 1 Mechanistic steps involved in hemicellulose bioconversion into ethanol, xylitol and
industry. However, several yeast species have the basic ability to carry out these
processes, i.e., Candida shehatae, Pichia stipitis, and Pachysolen tannophilus for
ethanol production; C. utilis , C. intermedia , and C. gulliermondii for xylitol pro-
duction; and Klebsiella oxytoca ATCC 8724, Bacillus subtilis (Ford strain), and
Aeromonas hydrophilia for 2, 3-butanediol production . This chapter presents sig-
nificant advancements in hemicellulose biotechnology, with an emphasis on acidic
and enzymatic hydrolysis and the conversion of hemicellulose hydrolysates into
commercial products like ethanol, xylitol, and 2, 3-BD.
2 Background Research
To reduce the production of greenhouse gases and ensure sustainable global eco-
nomic development, it is important to increase the use of renewable biomass
resources . There have been active movements accelerating the utilization of
lignocellulose-derived products such as bioethanol, xylitol, microbial enzymes, and
2, 3-BD into alternative source of bioenergy [4, 15, 16]. Ethanol has drawn the most
attention due to its rapid consumption and the global price fluctuations of crude
petroleum [15, 17].
Due to developments in industrial biotechnology, the carbohydrate fraction of the
cell wall can be converted into products of industrial significance. However, hemi-
cellulose has been explored less extensively than cellulose due to several factors.
The hemicelluloses in lignocellulosic materials are broken down into fermentable
sugars by either chemical or enzymatic hydrolysis . The latter is a promising
method that breaks down hemicellulosic materials into fermentable sugars without