Characteristics of New Contact Plate Prepared with Native Gellan Gum

Abstract

The contact plate is a medium for simple microbial testing in which microbes are sampled by directly contacting its surface with the test surface. In general, sampling may be difficult when the conventional agar-based contact plate is used for sampling from uneven test surfaces. Additionally, a wet trace of nutrient components may be left on the test surface after sampling. In order to solve these problems, we prepared contact plates by the combined use of native gellan gum and agar as solidifiers. Compared to the conventional agar-based medium, the gellan gum and agar-mixed contact plate exhibited better performance of sampling from uneven test surfaces, owing to its relatively softer and more deformable medium gel. These results indicate that media prepared with native gellan gum and agar are suitable for contact plates.