Ação de óleos essenciais de Curcuma longa L. e Bixa orellana L. sobre Pseudomonas aeruginosa e Listeria monocytogenes planctônicas e sésseis em polipropileno

Abstract

Biofilm is a community of sessile microorganisms embedded in an extracellular polymeric matrix that they, themselves, produce. The matrix is characterized by cells irreversibly adhered in a substrate or interface, and exhibits phenotypic alteration in relation to the growth and transcription of genes. A large diversity of microorganisms are capable of adhering and form biofilm on surfaces as stainless steel, glass, low density polyethylene, cast iron, rubber, polycarbonate and polypropylene; presenting certain advantages when compared to planktonic cells, including antimicrobial resistance. The eradication usually requires the use of acid, alkaline and/or iodophoric sanitizers, however, some questions have been raised about the safety of synthetic chemicals, especially those applied by the food industry. As a result, the application of natural products, such as essential oils, has been gaining considerable attention. This study aimed to identify and to quantify the chemical components of essential oils of dry leaves of Curcuma longa L. (turmeric) and Bixa orellana L. (annatto); to determine the minimum inhibitory concentration of the essential oils of turmeric, annatto and synergism on Listeria monocytogenes ATCC 19117 and Pseudomonas aeruginosa ATCC 27853; to evaluate the biofilm formation potential of the bacteria Listeria monocytogenes and Pseudomonas aeruginosa on polypropylene surface, when cultivated in TSB; to evaluate the bactericidal potential of the essential oils of turmeric, annatto and synergism, on the mature biofilm and to evaluate, by scanning and transmission electronic microscopy, morphological aspects of the mature biofilm, as well as the action of the essential oils on planktonic cells.