This paper studied bioethanol production at very high gravity (VHG) conditions using flocculent Saccharomyces cerevisiae, evaluating the response yield, ethanol concentration, productivity, and residual sugar through a central composite design (CCD). This CCD was evaluated at 12 and 24 h fermentation times. In the CCD evaluated for 12 h of fermentation, the best condition for alcoholic fermentation was 27 °C, 260 g/L substrate concentration and a 30% v/v cell concentration; a maximum overall desirability of 0.937 was achieved. For CCD at 24 h of fermentation, the best condition was 27 °C, 300 g/L substrate concentration, and a 26% v/v cell concentration. The desirability achieved was 0.811. These conditions allowed us to verify, experimentally, that the CCD models described the fermentation behavior well. VHG alcoholic fermentation in fed-batch with the reuse of cells without chemical treatment was performed using the optimum conditions obtained from the desirability function (27 °C, 300 g/L, 26% v/v). This resulted in favorable alcohol content 132.90 g/L in comparison to the conventional fermentation process.

Batch Fermentation Ethanol VHG Fermentation Flocculating Yeast

Bertrand E, et al., Green fuels technology: Biofuels in first generation bioethanol, eBook (2016).
UNICA, Unica returns China with positive balance, https://www.unica.com.br/noticias/unica-retorna-da-china-com-saldopositivo (2019).
Deesuth O, Laopaiboon P, Klanrit P, Laopaiboon L, Ind. Crop. Prod., 74, 102 (2015)
Rivera EC, Yamakawa CK, Saad MBW, Atala DIP, Ambrosio WB, Bonomi A, Junior J, Rossell CEV, Biochem. Eng. J., 119, 42 (2017)
Laluce C, Tognolli JO, de Oliveira KF, Souza CS, Morais MR, Appl. Microbiol. Biotechnol., 83(4), 627 (2009)
Cruz ML, de Resende MM, Ribeiro EJ, Chem. Eng. Commun., 205(6), 846 (2018)
Hidzir NS, Som A, Abdullah Z, A review in International Conference on Global Sustainability and Chemical Engineering (ICGSE) (2014).
Rokem JS, Greenblatt CL, JSM Microbiol., 3, 1023 (2015)
Vasconcelos Y, uso de novas linhagens de levedura pode reduzir custo de producao das usinas de acucar e alcool in revista Fapesp, 135 (2007).
Choi GW, Um HJ, Kang HW, Kim Y, Kim M, Kim YH, Biomass Bioenerg., 34(8), 1232 (2010)
Pacheco TF, de Morais WG, Guidini CZ, Marquez LDS, Cardoso VL, Resende MM, Ribeiro EJ, Chem. Eng. Technol., 38(2), 345 (2015)
Lima UA, Aquarone E, Borzani W, Schimidell W, Biotecnologia industrial, Edgard Blucher, Sao Paulo (2001).
Pimenta CD, Silva MB, Salomon VAP, Penteado RB, Gomes FM, Production., 25, 598 (2015)
Jones P, Pamment RP, Greenfield N, Biochemistry, 16, 42 (1981)
Guidini CZ, Marquez LDS, Silva HD, de Resende MM, Cardoso VL, Ribeiro EJ, Appl. Biochem. Biotechnol., 172(3), 1623 (2014)
Santos LD, Sousa MD, Guidini CZ, de Resende MM, Cardoso VL, Ribeiro EJ, Process Biochem., 50(11), 1725 (2015)
Wheals AE, Basso LC, Alves DMG, Amorim HV, Trends Biotechnol., 17, 482 (1999)
Santos J, Sousa MJ, Cardoso H, Inacio J, Silva S, Spencer-Martins I, Leao C, Microbiology, 154, 422 (2008)
Gonzalez FJT, Narvaez-Zapata JA, Lopez-y-Lopez VE, Corona CPL, LWT - Food Sci. Technol., 67, 1 (2016)
Phukoetphim N, Khongsay N, Laopaiboon P, Laopaiboon L, Chin. J. Chem. Eng., 27(7), 1651 (2019)
Monteiro B, Ferraz P, Barroca M, Cruz SH, Collins T, Lucas C, Biotechnol. Biofuels, 18, 251 (2018)
Yamakawa CK, Atala DIP, Ambrosio WB, Junior JN, Rossell CEV, Zuckerindustrie, 4, 212 (2017)