Byrsonima intermedia and microbial control in bioethanol production

Abstract

The industrial production of bioethanol takes place through the fermentation process by the action of selected yeasts in a favorable environment generated by the high concentration of sugar in the must. For the process to occur properly, it is essential to minimize the presence and action of microbial contaminants, which enter the process compromising production. With the prospect of a growing increase in bioethanol production, the sugar-energy sector seeks to minimize contamination using antibiotics. This use has been questioned due to environmental concerns and limitation of the dry yeast trade by leaving residues and in this way, the use of plant extracts becomes attractive. In this sense, aqueous and hydroalcoholic extracts of Byrsonima intermedia, a plant from the Brazilian cerrado, were evaluated and revealed the ability to inhibit bacteria isolated from fermentation processes. The hydroalcoholic extract showed MIC ranging from 2.5 to less than 0.156 mg.mL-1, the aqueous extract showed less variation (between 1.25 to 0.312 mg.mL-1) and was used in the fermentation process. In the fermentative process the aqueous extract presented a gain of 10.06% of fermentative efficiency. The results obtained accentuate desirable qualities of the aqueous extract for use in production units and may be an alternative for microbial control in fermentation processes to produce bioethanol.