Effect of temperature on fermentation kinetics of waste sulphite liquor by Saccharomyces cerevisiae

Abstract

The optimum operating temperatures for the maximum production of ethanol and the maximum utilization of substrate in batch fermentations of a waste sulphite liquor (WSL) as well as a synthetic medium using Saccharomyces cerevisiae were determined. The fastest consumption of substrate resulting in the shortest fermentation times of 13 h and 45 h was achieved at 35°C and 30°C for the synthetic medium and the WSL, respectively. The concentrations of ethanol in the two media were also maximum under these conditions: 11.6g dm−3 and 9.4 g dm−3 for the synthetic medium and the WSL, respectively. The productivities of biomass and ethanol increased with the increase of temperature and reached maximum values of 0.89 g dm−3 h−1 and 0.21 g dm−3 h−1 in the synthetic medium and the WSL, respectively. The inhibiting agents in the waste sulphite liquor affected the metabolic rates of microbial activities and prolonged the overall fermentation time while decreasing the productivities of biomass and ethanol. From analysis of the fermentation kinetics a mathematical model based on the Monod model was developed to describe the cellular growth and ethanol production. The model included inhibition terms for ethanol and the inhibiting agents in the waste liquor. The temperature dependence of the model parameters followed the Arrhenius law for temperatures between 15°C and 35°C. The activation energies (E) and the frequency constants (A) of these parameters were also determined.

Optimization of fermentation conditions for producing Indian rock bee (Apis dorsata) mead using response surface methodology

“…But temperature tolerance for growth of yeast and fermentation is strongly strain dependent (Rousseau et al, 1992). In the honey wine fermentation, ethanol production was high at 28ºC upto 6 days.…”

Bioethanol production from rice bran with optimization of parameters by Bacillus cereus strain McR-3

“…Bajpai and Margaritis (1986) also studied the effect of temperature of medium on the ethanol production by the immobilized Zymomonas mobilis cells during continuous fermentation and found maximum ethanol productivity and activity at 37°C. Rousseau et al (1992) explained the effect of temperature on fermentation kinetics of waste sulfite liquor by S. cerevisiae for bioethanol production and found that the fastest consumption of substrate resulting in the shortest fermentation times of 13 and 45 h was achieved at 35 and 30°C for synthetic medium. Cazetta et al (2007) stated the effect of temperature and sugar concentration on ethanol production by molasses and found that the temperature 30°C was the most favorable for production process.…”

Study on the alcohol fermentation technology of D. zingiberensis and D. zingiberensis residue

“…Subsequently, it was fermented under different temperatures for different time duration. Fermentation liquor was taken and the alcoholic concentration was measured (Rousseau et al, 1992). The results are shown in Table 3.…”