The goal of this study was to develop and validate, a novel robust CDC biofilm reactor that cultivates a representative complex oral biofilm.16S rDNA metagenetic analysis was deployed to examine the bacterial community diversity and abundance of samples from the CDC biofilm reactor.

The human oral cavity allows the colonisation of a highly diverse and unique microbiota. Much of what is known to date about the behaviour of oral species derives from studies of individual organisms or combinations of several cultivated species, situations which likely do not fully reflect the function of organisms within complex microbiota or multispecies biofilms. The number of validated models that allow an examination of the role that biofilm plays during oral cavity colonisation is also limited. The CDC biofilm reactor is a standard method that has been deployed to study complex interactions between members of human microbiotas allowing studies to be completed during an extended period of time under conditions where pH, nutrient availability, and washout of waste products are controlled. The primary objective of this work described here was to develop a robust in vitro biofilm-model system from a pooled saliva inoculum to study the stability, reproducibility, and development of the oral microbiota. By employing deep sequencing of the variable regions of the 16S rRNA gene, we found that the CDC biofilm reactor could be used to efficiently cultivate microbiota containing all 6 major phyla previously identified as the core saliva microbiota. After an initial acclimation period of approximately 5 days, communities in each reactor stabilised. Replicate reactors were predominately populated by shared core microbiota; variation between replicate reactors was primarily driven by shifts in abundance of shared operational taxonomic units (OTUs). From these analyses, we conclude that the CDC biofilm reactor can be used to cultivate communities that recapitulate key features of the human oral cavity and are a useful tool to facilitate studies of the dynamics of these communities.