Surface physical roughness correlating to biofilm attachment on galvanized aluminum surfaces by bacteria

Microbial biofilm formation on surfaces of materials is important information to better understand the adhesion mechanisms and to prevent bacterial colonization. Atomic force microscopy is a useful tool for examining bacterial biofilms formed on metal surfaces. The objectives of the present study were to evaluate the metal surface properties including roughness for attachment of the bacterium Janthinobacterium lividum  isolated from drinking-water catridge and to establish the relationship between surface modification through galvanization and susceptibility to biofilm formation. Four metal coupons used in this study were Al Galvanic 0.3%, 5%, 55% and a pure zinc plate. The results showed that several roughness parameters including autocovariance, Z -range, mean roughness, and maximum height increased with bacterial attachment on the selective metal type surfaces. There was a strong positive correlation between different roughness parameters and the number of bacteria attached on the specific metal types. The highest population number of bacteria was observed on Al Galvanized 55% coupon, which was also the roughest surface among the test coupons with different galvanization treatments. Our data suggest that prevention of bacterial attachment on metal surfaces can be achieved by surface treatment to obtain better morphological characteristics.