Using the residue of spirit production and bio-ethanol for protein production by yeasts

Abstract

The residue (vinasse) formed during the distillation of bio-ethanol and cachaça, a traditional rum-type spirit produced from sugar-cane in Brazil, is highly harmful if discharged into the environment due to high values of COD and BOD. One possibility for minimizing the impact of vinasse in soils and waters is to use the residue in the production of microbial biomass for use as an animal feed supplement that will provide high levels on nitrogen (>9% d.m.) and low content of nucleic (610% d.m.) This paper reports the production and quality of biomass produced from fermentation of Saccharomyces cerevisiae and Can- dida parapsilosis in culture media under 12 different culture conditions and the respective effects of each variable (glucose, yeast extract, peptone, potassium phosphate, vinasse, pH and temperature). Of the S. cerevisiae isolates tested, two (VR1 and PE2) originating from fuel alcohol-producing plants were iden- tified as offering the best potential for the industrial production of single cell protein from vinasse due to highest biomass productivity. Our results showed a potential viable and economic use of vinasse.