Efficient process for ethanol production from Thai Mission grass (Pennisetum polystachion) Sirirat Prasertwasu, Darin Khumsupan, Tidarat Komolwanich, Thanyalak Chaisuwan, Apanee Luengnaruemitchai, Sujitra Wongkasemjit ⇑ The Petroleum and Petrochemical College and Center of Excellence for Petrochemical and Materials Technology, Chulalongkorn University, Bangkok 10330, Thailand highlights  Thai Mission grass is converted to ethanol successfully.  S. cerevisiae TISTR 5596 is the fastest ethanol producing microorganism.  The maximum ethanol yield at 16 g/L is produced within 24 h. article info Article history: Received 6 February 2014 Received in revised form 11 April 2014 Accepted 12 April 2014 Available online 20 April 2014 Keywords: Bioethanol production Detoxification Overliming Pennisetum polystachion Saccharomyces cerevisiae abstract Mission grass (Pennisetum polystachion) obtained from Tak Province, Thailand, possesses the potential to become a lignocellulosic biomass for bioethanol production. After the grass underwent milling and alka- line pretreatments, it was subjected to acid and enzymatic hydrolysis. The glucose hydrolyzate from the grass was detoxified to remove inhibitory compounds and degradation products such as furfural and 5- hydroxymethylfurfural. Overliming at pH 10 produced the highest ethanol yield. Among various strains of baker’s yeasts, Saccharomyces cerevisiae TISTR 5596 with a yeast concentration of 10% v/v produced the maximum ethanol yield at 16 g/L within 24 h, which is among one of the fastest ethanol producing microorganisms compared to other strains of S. cerevisiae as well as other ethanol-producing microorganisms. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction Ethanol has become the subject of interest due to its potential to substitute energy from fossil fuels. Presently, food crops such as corn, sugarcane, rice, wheat, and sugar beet are the major sources of ethanol production (Balat, 2011). However, continuous utilization of food crops could jeopardize the food demand for the world population; moreover, frequent consecutive cultivation of corn and sugarcane could result in nutrient depletion and soil erosion (Xu et al., 2011). A potential solution to answer the issue is to utilize lignocellulosic materials to produce ethanol. Lignocel- lulosic materials originated from biomass are comprised mainly of cellulose, hemicellulose, and lignin. Some lignocellulosic materials include wood, agricultural residues, grasses, and newspaper (Sun and Cheng, 2002). With a high cellulose and hemicellulose content, Mission grass (Pennisetum polystachion, denoted as MG) is one suitable lignocel- lulosic biomass to produce bioethanol (Tatijarern et al., 2013). In addition to it being ubiquitous in Africa, Asia, and Australia, its ability to seed during dry season, and its low requirement of energy, fertilizers, and soil moisture allow MG to be a good candi- date for bioethanol production. Mission grass can grow to be 3 m in height, and thus a high quantity of cellulose and hemicellulose could be obtained within a small plot. Currently, no paper has reported on the conversion of MG to produce ethanol. This paper presents a novel study of using MG lignocellulosic biomass to produce bioethanol. The production of ethanol from Mission grass could be beneficial to both weed management and bioethanol production (Tatijarern et al., 2013). A variety of microorganisms ranging from fungi, bacteria, and yeasts could be utilized for producing ethanol from grass hydroly- zate. Baker’s yeast, Saccharomyces cerevisiae, is one of the most popular candidates for ethanol fermentation. The yeast S. cerevisiae has produced ethanol as its main fermentation product and also http://dx.doi.org/10.1016/j.biortech.2014.04.043 0960-8524/Ó 2014 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. Tel.: +66 2 2184133; fax: +66 2 2154459. E-mail address: dsujitra@chula.ac.th (S. Wongkasemjit). Bioresource Technology 163 (2014) 152–159 Contents lists available at ScienceDirect Bioresource Technology journal homepage: www.elsevier.com/locate/biortech