Bacteria are widely studied as self-propelled organisms with collective behaviors in the context of active colloids. We study bacteria at oil-water interfaces; bacteria become trapped at fluid interfaces, where they form Films of Bacteria at Interfaces (FBI) with rich behaviors that depend subtly on microbial features and genetic makeup. FBI can contain bacteria that remain active as they colonize the interface, allowing studies analogous to those in quasi-2D systems to be performed. Alternatively, over time, FBI can contain bacteria in complex, elastic structures comprising secretions like exopolysaccharides, surfactants, living and dead bacteria, akin to those formed in biofilms. Recent observations for different strains of Pseudomonas bacteria are discussed with an emphasis on FBI mechanics, colloidal probe- bacterium interactions, and the role of cellular features including flagella, pili, and the ability to produce certain polysaccharides. Transcriptional profiles of interface-trapped bacteria indicate that microbial gene expression is altered at the interface; a particular metabolism enzyme is implicated in the ability to form elastic versus active FBI. Such insights could lead to new strategies to promote or avoid elastic FBI formation.

Films of bacteria at interfaces

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.