title: Development of a Laboratory Model of a Phototroph-Heterotroph Mixed-Species Biofilm at the Stone/Air Interface.
abstract: Recent scientific investigations have shed light on the ecological importance and physiological complexity of subaerial biofilms (SABs) inhabiting lithic surfaces. In the field of sustainable cultural heritage (CH) preservation, mechanistic approaches aimed at investigation of the spatiotemporal patterns of interactions between the biofilm, the stone, and the atmosphere are of outstanding importance. However, these interactions have proven difficult to explore with field experiments due to the inaccessibility of samples, the complexity of the ecosystem under investigation and the temporal resolution of the experiments. To overcome these limitations, we aimed at developing a unifying methodology to reproduce a fast-growing, phototroph-heterotroph mixed species biofilm at the stone/air interface. Our experiments underscore the ability of the dual-species SAB model to capture functional traits characteristic of biofilms inhabiting lithic substrate such as: (i) microcolonies of aggregated bacteria; (ii) network like structure following surface topography; (iii) cooperation between phototrophs and heterotrophs and cross feeding processes; (iv) ability to change the chemical parameters that characterize the microhabitats; (v) survival under desiccation and (vi) biocide tolerance. With its advantages in control, replication, range of different experimental scenarios and matches with the real ecosystem, the developed model system is a powerful tool to advance our mechanistic understanding of the stone-biofilm-atmosphere interplay in different environments.
authors.affiliation: Center for Biofilm Engineering, Montana State University, Bozeman MT, USA ; Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente, Università degli Studi di Milano Milano, Italy.
authors.forename: Federica
authors.initials: F
authors.lastname: Villa
authors.affiliation: Center for Biofilm Engineering, Montana State University, Bozeman MT, USA.
authors.forename: Betsey
authors.initials: B
authors.lastname: Pitts
authors.affiliation: Center for Biofilm Engineering, Montana State University, Bozeman MT, USA.
authors.forename: Ellen
authors.initials: E
authors.lastname: Lauchnor
authors.affiliation: Dipartimento di Scienze per gli Alimenti, la Nutrizione e l'Ambiente, Università degli Studi di Milano Milano, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Cappitelli
authors.affiliation: Center for Biofilm Engineering, Montana State University, Bozeman MT, USA.
authors.forename: Philip S
authors.initials: PS
authors.lastname: Stewart
keywords: Lab-scale system; dual-species subaerial biofilm; phototroph-heterotroph interactions; stone monuments; subaerial biofilms