Attachment of Asaia lannensis to materials commonly used in beverage industry

The aim of the study was to evaluate the adhesion abilities of Asaia ssp. to materials commonly used in food and beverage industry, namely glass, polyethylene tereftalate and polypropylene. These materials are certified by the Polish National Institute of Public Health and approved for contact with food. In this study, the strain of Asaia lannensis isolated from spoiled strawberry-flavored bottled mineral water was used. The hydrophobicity and adhesive abilities of Asaia ssp. in minimal and enriched culture media supplemented with a carbon source of glucose or sucrose, were determined using a MATH test and luminometry respectively. The experiments were also conducted in commercially available strawberry-flavored mineral water, and the viability of the adhered and planktonic bacterial cells was controlled using the plate count method. On this basis the relative adhesion coefficients were calculated. The hydrophilic cells of A. lannensis were characterized by the formation of more hydrophobic flocks and by strong adhesion properties, which were dependent on the availability of nutrients, the carbon source and the type of surface. Adhesion to the glass surface was highest in the minimal medium with sucrose. In the strawberry-flavored mineral water with sucrose, the highest relative adhesion coefficient was noted for polyethylene tereftalate.

► Adhesion abilities of Asaia lannensis were environmentally-dependent.
► The highest level of adhesion was noted in culture media supplemented with sucrose.
► Pleomorphism of bacterial cells was observed in minimal media.