Uso de Baccharis dracunculifolia DC. no controle de contaminação microbiana em fermentação industrial

Abstract

Scientifically known as Baccharis dracunculifolia DC., a “vassourinha”, or “alecrim do campo”, is a plant of the Asteraceae family, present in South America and in several regions of Brazil. Its contrast is due to the presence of secondary metabolites, as the plant's own defense mechanism against external agents. The search for sugar-energy industries to improve the production of alcohol through fermentation is constant, because bacterial contamination in the fermentation process can cause damage, such as: yeast flocculation; inhibition and drop in yeast viability due to toxins and liquids excreted in the medium; reduction in productivity and fermentation yield. Methods for the treatment of the wort where the objective is to control the microbial load are being studied as an alternative to the use of antibiotics. The objective of this work was to search, through the aqueous extract of the leaves of Baccharis dracunculifolia, an alternative to control contamination against bacteria from plants using plant extracts. The extract was prepared by cold and hot extraction. As Gram positive bacteria, Staphylococcus aureus (ATCC 25923) and Bacillus sp. (B. cereus group) isolated from Usina São Fernando by the Center for Research and Technology in Natural Resources, State University of Mato Grosso do Sul; and a Gram negative bacterium Escherichia coli (ATCC 25922). The yeast used was Saccharomyces cerevisiae (PE 2). In the disk diffusion test were used such as 0.1 mgxmL-1 , 0.25 mgxmL-1, and 0.5 mgxmL-1 procedures to assess antimicrobial activity. The results showed that the extract of Baccharis dracunculifolia at a concentration of 0.5 mgxmL-1 did not inhibit yeast activity, and was effective in inhibiting the bacteria.