Initial adhesion suppression of biofilm-forming and copper-tolerant bacterium Variovorax sp. on laser microtextured copper surfaces

Abstract

The growth of detrimental biofilms on metal surfaces affects their structural performance and lifespan. Microtopographic texturization has emerged as an approach to suppress biofilm growth by preventing the initial stages of bacterial adhesion. This work studies the effects of linear pattern copper texturization on the initial adhesion steps of the biofilm-forming and copper-resistant bacterium Variovorax sp. Linear patterns with 4.7, 6.8, 14, and 18 μm periodicity were produced by direct laser interference patterning (DLIP) on copper coupons. Surface features were characterized by microscopic and spectroscopic techniques, and bacterial adhesion behavior was characterized by epifluorescence microscopy and functionalization of atomic force microscopy tips. We found a periodicity of 4.7 μm as the most efficient pattern to suppress Variovorax sp. initial adhesion by 31.1 % with respect to the nontextured surface. Preferential settlement in hummocks over hollows was observed for patterns with 14 and 18 μm periodicity, with adhesion events showing higher frequency in these topographies than patterns with periodicities of 4.7 and 6.8 μm. Our results highlight an understanding of the initial bacteria-copper adhesion and settlement behavior, thus contributing to the potential development of innocuous strategies for controlling biofilm growth on copper-based materials.