Yeast Strains Inhabiting an Ethanol Production Process with Cell Recycling: Own Dynamics?

M.G.S. Andrietta, S.R. Andrietta, C. Steckelberg

Alcoholic fermentation, bioethanol, Saccharomyces sensu stricto, Yeast

Yeast cell recycling in ethanol production processes is a recurring practice at industrial units installed in Brazil. Units usually use yeasts selected from other industrial processes to start up the season. These yeasts are acquired in large amounts to guarantee a quick start-up by yeast with good fermentative performance. This work examined yeast population dynamics during an entire season at an industrial unit using a select yeast strain (CAT) as inoculum to start up the process. The unit also artificially introduced, in the course of the season, two other yeasts, one select (FT 858) and the other isolated from its own process in previous seasons. Yeast identification was carried out using the karyotyping technique. The results suggest that none of the select strains was able to remain until the end of the season. Strain SM584, introduced during the final months of operation, was the one that remained at the end of the season. The data suggest that each fermentation process has its own dynamics with regards to the yeast inhabiting the process. Biotic and abiotic factors, translated into facilities associated to the type of yeast naturally inhabiting the feedstock, favor the installation of yeast capable of floculating at the unit studied, since out of the 21 yeasts installed during the process, 18 presented some type of floculating characteristic.

https://doi.org/10.31871/WJRR.14.4.6