Alcoholic fermentation with flocculant Saccharomyces cerevisiae in fed-batch process.
Studies have been conducted on selecting yeast strains for use in fermentation for ethanol production to improve the performance of industrial plants and decrease production costs. In this paper, we study alcoholic fermentation in a fed-batch process using a Saccharomyces cerevisiae yeast strain with flocculant characteristics. Central composite design (CCD) was used to determine the optimal combination of the variables involved, with the sucrose concentration of 170 g/L, a cellular concentration in the inoculum of 40% (v/v), and a filling time of 6 h, which resulted in a 92.20% yield relative to the theoretical maximum yield, a productivity of 6.01 g/L h and a residual sucrose concentration of 44.33 g/L. With some changes in the process such as recirculation of medium during the fermentation process and increase in cellular concentration in the inoculum after use of the CCD was possible to reduce the residual sucrose concentration to 2.8 g/L in 9 h of fermentation and increase yield and productivity for 92.75% and 9.26 g/L h, respectively. A model was developed to describe the inhibition of alcoholic fermentation kinetics by the substrate and the product. The maximum specific growth rate was 0.103 h(-1), with K(I) and K(s) values of 109.86 and 30.24 g/L, respectively. The experimental results from the fed-batch reactor show a good fit with the proposed model, resulting in a maximum growth rate of 0.080 h(-1).
Faculty of Chemical Engineering, Uberlândia Federal University, P.O. Box 593, Av. João Naves de Ávila, 2121, Campus Santa Mônica-Bloco 1K, 38400-902, Uberlândia, MG, Brazil.
Carla Zanella
CZ
Guidini
Líbia Diniz Santos
LD
Marquez
Helisângela
H
de Almeida Silva
Miriam Maria
MM
de Resende
Vicelma Luiz
VL
Cardoso
Eloízio Júlio
EJ
Ribeiro
D061249:Batch Cell Culture Techniques; D019149:Bioreactors; D000431:Ethanol / Q000138:chemical synthesis* / Q000737:chemistry; D005285:Fermentation; D005427:Flocculation; D007218:Industrial Microbiology / Q000379:methods; D007700:Kinetics; D012441:Saccharomyces cerevisiae / Q000737:chemistry
D000431:Ethanol