Repeated-Batch Ethanol Production from Sweet Sorghum Juice by Saccharomyces cerevisiae Immobilized on Sweet Sorghum Stalks

Energies

Pongthep Ariyajaroenwong¹  Pattana Laopaiboon³  Prasit Jaisil² 

[1] Graduate School, Khon Kaen University, Khon Kaen 40002, Thailand; E-Mail:;Department of Plant Science and Agricultural Resources, Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002, Thailand; E-Mail:;Department of Biotechnology, Faculty of Technology, Khon Kaen University, Khon Kaen 40002, Thailand; E-Mail:

关键词: ethanol fermentation;    immobilization;    repeated-batch;    sweet sorghum;    Saccharomyces cerevisiae;   

DOI  :  10.3390/en5041215

来源: mdpi

【 摘 要 】

Sweet sorghum stalks were used as a low cost carrier for immobilization of Saccharomyces cerevisiae NP 01 to produce ethanol from sweet sorghum juice. The effects on ethanol production of carrier size (6 × 6 × 6 to 20 × 20 × 20 mm³) and initial cell concentrations (5 × 10⁷ to 2 × 10⁸ cells mL⁻¹) for cell immobilization were investigated. The ethanol production medium was the juice containing 230 g L⁻¹ of total sugar without nutrient supplementation. The fermentations were carried out under static conditions in 500-mL air-locked Erlenmeyer flasks at 30 °C. The results showed that the optimum size of sorghum stalk pieces for repeated-batch ethanol production was 6 × 6 × 6 mm³, while the optimum initial cell concentration for the immobilization was 1.0 × 10⁸ cells mL⁻¹. The immobilized yeast under these conditions could be used for at least eight successive batches without any losses of ethanol production efficiencies. The average ethanol concentration, productivity and yield of the eight successive batches were 99.28 ± 3.53 g L⁻¹, 1.36 ± 0.05 g L⁻¹ h⁻¹ and 0.47 ± 0.03 g g⁻¹, respectively.

【 授权许可】

CC BY   
© 2012 by the authors; licensee MDPI, Basel, Switzerland.