Enhancement of ethanol production efficiency in repeated-batch fermentation from sweet sorghum stem juice: Effect of initial sugar, nitrogen and aeration
| Autor: | Niphaphat Phukoetphim, Lakkana Laopaiboon, Pattana Laopaiboon, Nilubol Polsokchuak, Khanittha Butkun, Benjaporn Sriputorn |
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| Rok vydání: | 2020 |
| Předmět: |
0106 biological sciences
0301 basic medicine Ethanol productivity Ethanol fermentation lcsh:Biotechnology 01 natural sciences Applied Microbiology and Biotechnology Bio ethanol 03 medical and health sciences chemistry.chemical_compound lcsh:TP248.13-248.65 010608 biotechnology Aeration Ethanol fuel Food science Sugar lcsh:QH301-705.5 Ethanol Ethanol concentration High gravity fermentation Yeast 030104 developmental biology lcsh:Biology (General) chemistry Fermentation Sweet sorghum Biotechnology |
| Zdroj: | Electronic Journal of Biotechnology, Vol 46, Iss, Pp 55-64 (2020) |
| ISSN: | 0717-3458 |
| DOI: | 10.1016/j.ejbt.2020.06.001 |
| Popis: | Background Ethanol concentration (PE), ethanol productivity (QP) and sugar consumption (SC) are important values in industrial ethanol production. In this study, initial sugar and nitrogen (urea) concentrations in sweet sorghum stem juice (SSJ) were optimized for high PE (≥ 10%, v/v), QP, (≥ 2.5 g/L·h) and SC (≥ 90%) by Saccharomyces cerevisiae SSJKKU01. Then, repeated-batch fermentations under normal gravity (NG) and high gravity (HG) conditions were studied. Results The initial sugar at 208 g/L and urea at 2.75 g/L were the optimum values to meet the criteria. At the initial yeast cell concentration of ~ 1 × 108 cells/mL, the PE, QP and SC were 97.06 g/L, 3.24 g/L·h and 95.43%, respectively. Repeated-batch fermentations showed that the ethanol production efficiency of eight successive cycles with and without aeration were not significantly different when the initial sugar of cycles 2 to 8 was under NG conditions (~ 140 g/L). Positive effects of aeration were observed when the initial sugar from cycle 2 was under HG conditions (180–200 g/L). The PE and QP under no aeration were consecutively lower from cycle 1 to cycle 6. Additionally, aeration affected ergosterol formation in yeast cell membrane at high ethanol concentrations, whereas trehalose content under all conditions was not different. Conclusion Initial sugar, sufficient nitrogen and appropriated aeration are necessary for promoting yeast growth and ethanol fermentation. The SSJ was successfully used as an ethanol production medium for a high level of ethanol production. Aeration was not essential for repeated-batch fermentation under NG conditions, but it was beneficial under HG conditions. How to cite: Sriputorn B, Laopaiboon P, Phukoetphim N, et al. Enhancement of ethanol production efficiency in repeated-batch fermentation from sweet sorghum stem juice: Effect of initial sugar, nitrogen and aeration. Electron J Biotechnol 2020;46. https://doi.org/10.1016/j.ejbt.2020.06.001 |
| Databáze: | OpenAIRE |
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