Abstract
The Very High Gravity (VHG) fermentation is a technology that can lead to a reduction in waste generation, a reduction in energy consumption and GHG emissions and several technical, economic, and environmental advantages. Having, as a limiting factor, yeast tolerance to the most diverse stressors in the fermentation medium. To overcome this limitation, the aim of the work was to verify the potential protective effect of silica (+A) on Saccharomyces cerevisiae (Ethanol Red®) submitted to VHG fermentation. Initially, an adaptive test to VHG fermentation was carried out, with 5 cell recycles in musts from sugar cane syrup. Each recycle was subjected to the treatments, in quadruplicate: T1C (control) - Wort without silica supplementation; T2S100- Wort with supplementation of 100 mg L-1 of silica and T3S300- Wort with supplementation of 300 mg L -1 of silica. As a result, the T3S300 treatment in the adaptive test, showed viability of 77.5 to 81.55%; biomass production from 8.1 to 10.0 g L-1; yield from 90.0 to 95.3% and productivity from 7.3 to 10.9 mL L-1h-1. In conclusion, the treatment of the wort with silica (+A) (100 and 300 mg L-1) has an effect protector on yeast and may present positive responses in VHG fermentations.
Keywords:
Cell recycling; Ethanol; Supplementation; Tolerance; Yeast strain.
HIGHLIGHTS
Saccharomyces cerevisiae yeast can gradually adapt to very high gravity fermentation.
Supplementation of the medium with silica (+A) improves fermentative parameters.
Silica (+A) has a protective effect on the yeasts Saccharomyces cerevisiae.
Silica (+ A) maintains the capacity to produce cellular biomass during fermentation.