Biofilms, i.e., surface-associated microbial populations or communities that are encased in a self-produced polymeric matrix, are the most ubiquitous and resilient form of microbial life on Earth. A robust nature in terms of a high structural stability and high tolerance to harsh physiochemical conditions makes biofilms an important workhorse for chemical and environmental applications including biocatalysis, bioremediation and wastewater treatment. Biofilms studies have shown a complex life cycle involving several stages from initial attachment to maturation and dispersion. The development and performance of a biofilm is governed by their intrinsic heterogeneity, the dynamic signaling systems and their interactions with the highly diverse microenvironments. Therefore, biofilm-mediated bioprocesses are difficult to predict and control. Sensing and response to environmental cues and signals have been reported to play an important role in biofilm formation and in regulating the metabolic pathways responsible for biofilm-mediated bioprocesses. Hence, quantitative elucidation of the relationship between biofilm activity and the environmental cues and signals is required to predict and control biofilm-mediated bioprocesses. In our study, through integrating a biofilm growth chamber with a microfluidic gradient generator, we developed a novel fluidic biofilm reactor in which biofilms could be grown under a defined chemical gradient. The fluidic biofilm reactor is compatible with confocal laser scanning microscopy (CLSM), enabling us to monitor the dynamics of biofilm development. The gradient of chemicals (such as communication signals, carbon and nitrogen sources) were simulated and then validated experimentally. We then applied agarose gel in the fluidic biofilm reactor and examined biofilm development in the synthetic matrix in the presence of a gradient of a quorum sensing signal. Furthermore, using Comamonas testosteroni as a model organism in the gradient generator-flow cell system, we investigated the environmental controls of the metabolic pathways in nitrogen metabolism. Taken together, our results demonstrated that the novel fluidic biofilm reactor is a promising tool to understand biofilm development in response to environmental cues and signals as well as environmental controls of biofilm activity.

Microfluidic gradient generator-flow cell system as a novel tool to study biofilm development and control

251st National Meeting (2016)

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