Biofilme de Bacillus cereus em superfície de aço inoxidável: ação bactericida e esporicida de óleos essenciais

Abstract

Microbial adhesion and subsequent biofilm formation are major problems with which the food industry is currently faced, seeing as such phenomena are a major source of product contamination. Among the involved microorganisms, endospore producing bacteria B. cereus stands out, due to its broad distribution in nature, adhesion and survival capabilities under the form of endospores, toxin production, and to its potential to deteriorate certain food products. B. cereus elimination requires sanitizing products with both bactericidal and sporicidal properties. However, such sanitizers are rare, and such rarity can only be remedied through the development of new vegetative cell and endospore cleansing alternatives. This study has sought to characterize AISI 304#4 stainless steel surfaces, relating B. cereus vegetative cell and endospore adhesion to it; assess the planktonic and sessile cells´ sensibility, as well as that of free and adhered endospores, to the essential oils of Elettaria cardamomum and C. citratus, both individually and combined; determine the chemical compositions, as well as superficial tensions, of such essential oils; evaluate, through scanning electron microscopy, the mature biofilm´s morphological aspect, as well as that of the adhered endospores, and the changes induced in them by the essential oils.