Selective Promotion of Adhesion of Shewanella oneidensis on Mannose-Decorated Glycopolymer Surfaces

Using glycopolymer surfaces, we have stimulated Shewanella oneidensis bacterial colonization and induced where the bacteria attach on a molecular pattern. When adherent bacteria were rinsed with methyl alpha-D-mannopyranoside, the glycopolymer-functionalized surfaces retained more cells than self-assembled monolayers terminated by a single mannose unit. These results suggest that the three-dimensional multivalency of the glycopolymers both promotes and retains bacterial attachment. When the methyl alpha-D-mannopyranoside competitor was codeposited with the cell culture, however, the mannose-based polymer was not significantly different from bare gold surfaces. The necessity for equilibration between methyl alpha-D-mannopyranoside and the cell culture to remove the enhancement suggests that the retention of cells on glycopolymer surfaces is kinetically controlled and is not a thermodynamic result of the cluster glycoside effect. The MshA lectin appears to facilitate the improved adhesion observed. Our findings that the surfaces studied here can induce stable initial attachment and influence the ratio of bacterial strains on the surface may be applied to harness useful microbial communities.