Effect of Surface Roughness on the Adhesion of Escherichia Coli in Stainless Steel Surface

Abstract

Bacterial adhesion and biofilm formation in metal containers are the major concerns in food and pharmaceutical industries. The surface roughness of containers is a factor plausibly affecting the amount of bacterial attachment. However, the relationship between the surface roughness and bacterial adhesion has not clearly been understood yet. Thus, this study aimed to examine the role of surface roughness on the bacterial adhesion in the food grade AISI 316L stainless steel surface. Escherichia coli was selected to be the bacteria tested in this study as it is a sanitization indicator in the food and pharmaceutical manufacturing. The average surface roughness ranging from 0.054 to 0.386 μm were prepared on the flat steel surface by mechanical polishing process with the different grit numbers of sandpapers. All samples were incubated for two hours with E. coli, and the results demonstrated that the adhesion of E. coli was found to increase with the increased surface roughness. The average number of E. coli was 3.17 x 102 cfu/cm2 when the surface roughness of stainless steel was 0.054 μm. The implication of this finding could enable an essential guideline for the selection and control of surface roughness of the metal with the minimum adhesion of E. coli or other similar bacteria.