Physiological diversity and trehalose accumulation in schizosaccharomyces pombe strains isolated from spontaneous fermentations during the production of artesanal Brazilian cachaca.

Abstract

Twenty-seven schizosaccharomyces pombe isolates from seven cachaca distilleries were tested for maximum temperature of growth and fermentation, osmotolerance, ethanol resitance, invertase production, and trehalose accumulation. Two isolates were selected for studies of trehalose accumulation under heat shock and ethanol stress. The S. pombe isolates were also characterized by RAPD-PCR. The isolates were able to grow and ferment at 41§C, resited concentrations of 10 percent ethanol, and grew on 50 percent glucose medium. The S. pombe isolates were able to accumulate trehalose during stationary phase. Two isolates, strains UFMG-A533 and UFMG-A1000, submitted to a 15 min heat shock, were able to accumulate high trehalose levels. Strain UFMG-A533 had a marked reduction in viability during heat shock, but strain UFMG-A1000 preserved a viability rate of almost 20 percent after min at 48oC. No clear correlation was observed between trehalose accumulation and cell survival during ethanol stress. Strain UFMG-A1000 had higher trehalose accumulation levels than strain UFMG-A533 under conditions of combined heat treatment and ethanol stress. Molecular analysis showed that some strains are maintained during the whole cahaça production period; using the RAPD-PCR profiles, it was possible to group the isolates according to their isolation sites.