Adhesion of<i>bacillus</i>spores to inanimate materials: Effects of substratum and spore hydrophobicity^a^b

Abstract

The adhesion of bacterial spores to substrata such as packaging materials used in food and pharmaceutical industries can lead to product contamination and spoilage. This study was conducted to determine the influence of substrata and spore surface properties on the adhesion of Bacillus spores to food contact materials. Contact angle measurements were used to describe the hydrophobic character of the test materials. The number of Bacillus subtilis ATCC 6633 spores adhering to different test materials was quantified by scanning electron microscopy, phase‐contrast microscopy, and a 14C‐labelled spore assay. The three methods yielded comparable results. Generally, the number of attached spores increased with increasing substrata surface hydrophobicity. The relatively low hydrophobicity of Bacillus subtilis A spores, compared to B, subtilis ATCC 6633 spores, contributed to a decrease in the adhesion of B. subtilis A spores to all materials tested.