Cell recycling during repeated very high gravity bio-ethanol fermentations using the industrial Saccharomyces cerevisiae strain PE-2

• Autor(a) principal: Pereira, Francisco B.
• Data de Publicação: 2012
• Outros Autores: Gomes, Daniel Gonçalves, Guimarães, Pedro M. R., Teixeira, J. A., Domingues, Lucília
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/16657
• topic: Bio-ethanol production; Industrial strain PE-2; Saccharomyces cerevisiae; Repeated-batch system; Very high gravity fermentation; Science & Technology

A very high gravity (VHG) repeatedbatch fermentation system using an industrial strain of Saccharomyces cerevisiae PE-2 (isolated from sugarcane-to-ethanol distillery in Brazil) and mimicking industrially relevant conditions (high inoculation rates and low O2 availability) was successfully operated during fifteen consecutive fermentation cycles, attaining ethanol at 17.1 ± 0.2% (v/v) with a batch productivity of 3.5 ± 0.04 g l-1 h-1. Moreover, this innovative operational strategy (biomass refreshing step) prevented critical decreases on yeast viability levels and promoted high accumulation of intracellular glycerol and trehalose, which can provide an adaptive advantage to yeast cells under harsh industrial environments. This study contributes to the improvement of VHG fermentation processes by exploring an innovative operational strategy that allows attaining very high ethanol titres without a critical decrease of the viability level thus minimizing the production costs due to energy savings during the distillation process.