Antimicrobial effect of cleaning formulations of industrial interest on free-living cells and biofilms

Biofilms are a challenging source of contamination due to their resistance to conventional cleaning and hygiene procedures. In this work, we assessed the antimicrobial properties at room temperature of surfactants of industrial interest in detergent formulation. The adhesion abilities of the yeast Yarrowia lipolytica and the mould Aspergillus niger to polyurethane foam and glass surfaces and their ability to develop as biofilm was firstly studied under different culture conditions. The most stable biofilms were then treated at room temperature with a mixture of an alkylpolyglucoside and an ethoxylated fatty alcohol, and with an ether carboxylate. Experimental results illustrated that surface-attached cells were more resistant to disinfectant treatment than cells of the same microorganism grown in suspension. Although the assayed surfactant solutionshardly removed attached biofilms, they showed a greatinhibitory effect on free-living cells. What is more, biofilmsdid not grow during treatments. Therefore, the good antimicrobial effects of these ecological surfactants at roomtemperature could provide them a potential interest inlow-temperature cleaning in place procedures.