Abstract Purple Amerindian Yam (PAY, Dioscorea trifida L.) is an important component of traditional people dietary in Brazilian central amazon rainforest. It is mainly produced by family farmers, using ecologically friendly ways of cultivation. Face to the new Brazilian legislation about brewing adjuncts, its technical viability for use as brewing adjunct was evaluated, besides a sensorial analysis of the resulting beers by trained consumers. Were produced 4 different beers: control group (only barley malt), PAY15, PAY30 and PAY45, using 15%, 30% and 45% of PAY in substitution of barley malt respectively. Along mashing phase, sugar concentration was affected only in PAY45, while soluble protein increased in all assays using adjunct. The kinetic of fermentation was not affected in any assay. In the final products, not significant differences were observed for pH and sugars and proteins concentration. Alcoholic concentration was signiticantly decreased only by the PAY45 assay. EBC scale values increased in assays using PAY, due its purple color. Flavors and aroma's perceptions for hops and ferment were not affected, being the only significant organoleptic difference observed to malt's flavor in PAY45 assay. These results indicate the viability of PAY as brewing adjunct, viable to substitute until 30% of barley malt.

Background: The yeast strain IB09 was isolated from the gut of Calosoma sp. (Carabidae, Coleoptera, Insecta) that were collected in the central Amazon rainforest. First, tolerance of the strain to ethanol and heat was tested. Then, IB09 was cultivated in a medium using sugarcane bagasse hemicellulosic hydrolyzate as a carbon source, and cell growth (OD600), specific growth rate (µMAX, h-1), biomass yield (Y B, g.g-1) and relative sugar consumption (RSC, %) were evaluated. Taxonomic identification was determined by sequencing the ITS1 region of IB09 and comparing it to sequences obtained from the GenBank database (NCBI). Results: IB09 showed both ethanol tolerance and thermotolerance. Relative sugar consumption indicated that IB09 was able to perform saccharification of sugarcane bagasse hemicellulosic hydrolyzate, increasing the total reducing sugar concentration by approximately 50%. The μMAX value obtained was 0,20, indicating that cell growth was slow under the assessed conditions. Biomass yield was 0,701 g per g of consumed sugar, which is relatively high when compared with other findings in the literature. After 120 hrs of cultivation, 80,1% of total reducing sugar had been consumed. Sequencing of the ITS1 region identified IB09 as Trichosporon mycotoxinivorans. Conclusion: This is the first report to document this species in the central Amazon rainforest at this host. Trichosporon mycotoxinivorans has great biotechnological potential for use in the saccharification of sugarcane bagasse hemicellulosic hydrolyzate and for biomass production with this substrate as carbon source.