Ethanol fermentation of a diluted molasses medium by Saccharomyces cerevisiae immobilized on chrysotile

Abstract

In this work, the catalytic role of chrysotile support on the acceleration of alcoholic fermentation under non-aseptic conditions by Saccharomyces cerevisiae was investigated. The fermentation medium employed consisted only of diluted sugar-cane molasses. In the batch fermentations process with immobilized yeasts, the initial rate of CO 2 production increased roughly 27 % during the first 30 minutes, compared to systems containing no chrysotile. A study of continuous alcoholic fermentation with chrysotile in the reactor bed showed a higher ethanol production rate at the different dilution rates investigated compared to similar fermentations without chrysotile.

Optimization of ethanol, citric acid, and α-amylase production from date wastes by strains of Saccharomyces cerevisiae, Aspergillus niger, and Candida guilliermondii

“…However, strains SDB, SHW, STISB, and SELK were selected as the best producer of ethanol and the production conditions of SDB were optimized. The ethanol content evolves gradually during the fermentation, reaching a maximum of 126.00 ± 1.81 g/l at 72 h. Therefore, the optimum fermentation period for maximum production of ethanol was 72 h. Our finding is in agreement with those obtained by [27,39]. However, [11] obtained optimum ethanol content for 48 h using a strain of Zymomonas mobilis.…”

“…So, the optimal sugar concentration for maximum ethanol production is 180 g/l. These results are similar to those obtained by [11,27]. The sugar concentration (180 g/l) above which both the ethanol production and metabolism yield decrease are due to the combined effect of decreased water activity and plasmolysis of cell [11].…”

“…On the other hand, the obtained results show an improvement of the ethanol content and metabolism yield with increasing ammonium phosphate concentration to stabilize at a maximum of 136.00 ± 0.66 g/l and 78.61 ± 0.75%, respectively, with a concentration greater than or equal to 1.0 g/l. So, the optimum ammonium phosphate concentration is 1.0 g/l, while several authors [8,11,27,39] advocate 2.0-2.5 g/l.…”

Bioethanol Production from Fermentable Sugar Juice

“…In addition, immobilization prevents cell washout in continuous fermentation that avoids separation or recycle of cells in the process [ 85 ]. Several carriers have been reported for cell immobilization including apple pieces [ 83 ], k-carrageenan gel, polyacrylamide, g-alumina [ 86 ], chrysotile [ 87 ], calcium-alginate [ 88 , 89 ], sugarcane pieces [ 56 ], banana leaf sheath [ 90 ], and orange peel [ 91 ]. Immobilization of S. cerevisiae can easily be carried out by enriched cells from culture media and harvested at the log phase of growth followed by entrapping into the carriers [ 88 ].…”

Saccharification of biopretreated paddy straw with indigenous holocellulase and fermentation with Saccharomyces cerevisiae LN1 under optimized conditions

“…In the present investigation, maximum ethanol concentration was achieved at temperature 30°C. Reed (1982) and Sedha and Verma (2002) have also recommended 30°C as optimal temperature for ethanol production. Most of the yeasts capable of producing ethanol are not thermotolerant and their growth and fermentation efficiency decreases at 40°C (Murata et al 2015;Antil et al 2015).…”