Improvement of Hydrolysis and Fermentation of Sugarcane Bagasse by Soaking in Aqueous Ammonia and Methanolic Ammonia

• Published in: Bioscience, biotechnology, and biochemistry biotechnology, and biochemistry, 2013, Vol.77 (7), p.1379-1383
• Main Authors: HEDAYATKHAH, Abolghasem, MOTAMEDI, Hossein, NAJAFZADEH VARZI, Hossein, GHEZELBASH, Gholamreza, AMOPOUR BAHNAMIRY, Mostafa, KARIMI, Keikhosro
• Format: Article
• Language: English
• Subjects: Ammonia - chemistry; bagasse; Cellulose - chemistry; Cellulose - metabolism; ethanol; Fermentation; Hydrolysis; Immersion; Methanol - chemistry; Saccharomyces cerevisiae; Saccharum - chemistry; Water - chemistry
• ISSN: 0916-8451; 1347-6947
• DOI: 10.1271/bbb.120867

Sugarcane bagasse was pretreated by soaking it in aqueous ammonia (SAA) and methanolic aqueous ammonia (SMAA) at 70 °C for 12 h. Then the pretreated as well as untreated bagasse was subjected to enzymatic hydrolysis at 50 °C for 72 h by 15 FPU cellulase and 30 CBU cellobiase per g of substrate. The hydrolysis of SAA-pretreated bagasse with a solid to liquid (S:L) ratio of 1:10 resulted in 95.9% of the maximum theoretical yield. The production yield for SMAA at an S:L ratio of 1:6 with 15% methanol was 88.6%, while it was only 21.3% for the untreated bagasse. Ethanol production by simultaneous saccharification and fermentation was conducted at 37 °C for 72 h. The results revealed that the ethanol production yield was improved from 12.7% for the untreated bagasse to 92.45% and 90.8% for the SAA and the SMAA pretreated bagasse, respectively. The compositional and chemical structural analysis suggested that lignin removal and crystallinity reduction were responsible for the hydrolysis and SSF improvements.