EFFECTS OF BIOCIDES ON LACTIC ACID AND ACETIC ACID BACTERIA, POLLUTANTS IN THE PRODUCTION OF FUEL ALCOHOL.

Abstract

Within the group of biofuels of plant origin, fuel alcohol from sugar cane stands out. It is used as a source of sugars, producing byproducts such as honey A, which is extracted from 75% of the recoverable sugar, honey B when it completes 86 % crystallization and molasses. During the production of ethanol by fermentation with Saccharomyces cerevisiae, bacterial contamination on the raw material must be kept controlled, because the bacteria reduce the availability of carbon sources for the yeast to carry out its fermentation process, therefore, The most common contaminants are Lactic Acid Bacteria (LAB) and Acetic Acid Bacteria (BAA), due to this the biocide effect on the contaminating bacteria BAL and BAA was evaluated as a control measure in the fermentative stage of fuel alcohol production. The ideal concentration of the biocide PROQUAT BC 50 and the exposure time of PROCIDE BIOQ were found, the effect of which was to reduce the contaminant load produced by BAL and BAA in the fuel alcohol production process, at the selected points (fermenter and vinasse), likewise, the interaction between yeast-bacteria and yeast-yeast, as well as the effect on the performance of S. cerevisiae with the previous selection of bacteria and the classification of yeast-bacteria interactions, developing interaction studies in two different fermentation media, in a first stage of study, the interactions were analyzed in MRS and WL medium; means used to evaluate the behavior of interactions.