Butanol production from renewable biomass by clostridia Review Butanol production from renewable biomass by clostridia Yu-Sin Jang a,1, Alok Malaviya a,1, Changhee Cho a, Joungmin Lee a, Sang Yup Lee a,b,⇑ a Metabolic and Biomolecular Engineering National Research Laboratory, Department of Chemical and Biomolecular Engineering (BK21 Program), BioProcess Engineering Research Center, Center for Systems and Synthetic Biotechnology, Institute for the BioCentury, KAIST, Republic of Korea b Department of Bio and Brain Engineering and Bioinformatics Research Center, KAIST, Republic of Korea h i g h l i g h t s " Butanol is an important industrial chemical as well as an advanced biofuel. " We review the use of various carbon sources on fermentation performance. " We review advanced fermentation and recovery processes for butanol production. g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 12 May 2012 Received in revised form 25 July 2012 Accepted 26 July 2012 Available online 7 August 2012 Keywords: Biomass Butanol Clostridium Fermentation Recovery a b s t r a c t Global energy crisis and limited supply of petroleum fuels have rekindled the worldwide focus towards development of a sustainable technology for alternative fuel production. Utilization of abundant renew- able biomass offers an excellent opportunity for the development of an economical biofuel production process at a scale sufficiently large to have an impact on sustainability and security objectives. Addition- ally, several environmental benefits have also been linked with the utilization of renewable biomass. Butanol is considered to be superior to ethanol due to its higher energy content and less hygroscopy. This has led to an increased research interest in butanol production from renewable biomass in recent years. In this paper, we review the various aspects of utilizing renewable biomass for clostridial butanol produc- tion. Focus is given on various alternative substrates that have been used for butanol production and on fermentation strategies recently reported to improve butanol production. � 2012 Elsevier Ltd. All rights reserved. 1. Introduction Butanol is an important industrial chemical and is also consid- ered as a superior liquid fuel with a potential to replace gasoline (Dürre, 2007; Lee et al., 2008; Papoutsakis, 2008). Research effort towards the efficient production of butanol from sustainable and renewable carbon sources has steadily been progressing. Based on advances in biotechnology and process engineering, new fer- mentation processes are being developed for converting the abun- dantly available biomass to butanol (Dürre, 2007; Lee et al., 2008; Papoutsakis, 2008). Butanol has traditionally been produced by anaerobic fermentation of sugar substrates using various species of solventogenic clostridia (Jones and Woods, 1986). Except for the solventogenic clostridia, it is believed that no genus among the bacteria, archea and eucarya is efficient enough to naturally produce butanol (Qureshi et al., 2008). Treatment of biomass for the extraction of fermentable sugars results in a mixture of sugar substrates, mainly pentoses, hexoses, and disaccharide. Clostridium sp. are known to have the capability of utilizing simple and complex sugars, including both pentose and 0960-8524/$ - see front matter � 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.biortech.2012.07.104 ⇑ Corresponding author at: Department of Chemical and Biomolecular Engineer- ing, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 305–701, Republic of Korea. Fax: +82 42 350 3910. E-mail address: leesy@kaist.ac.kr (S.Y. Lee). 1 These authors contributed equally to this work. Bioresource Technology 123 (2012) 653–663 Contents lists available at SciVerse ScienceDirect Bioresource Technology j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / b i o r t e c h http://dx.doi.org/10.1016/j.biortech.2012.07.104 mailto:leesy@kaist.ac.kr http://dx.doi.org/10.1016/j.biortech.2012.07.104 http://www.sciencedirect.com/science/journal/09608524 http://www.elsevier.com/locate/biortech