Characterisation of a modified rotating disk reactor for the cultivation of Staphylococcus epidermidis biofilm

Aims:  The purpose of this study was to develop a system that would allow biofilms to be cultivated under strictly defined conditions in terms of dissolved oxygen, fluid shear and to assess whether the method was suitable for the detection of respiratory activity stratification in biofilm samples. Methods:  The system is a modified version a commercially available laboratory biofilm reactor and incorporates a number of features such as the provision of defined levels of dissolved oxygen, constant average shear, enhanced gas–liquid mass transfer, aseptic operation and the ability to remove biofilm for ex situ analysis during or after continuous cultivation. Conclusions:  The system was shown to be effective for the characterization of the effects of dissolved oxygen on a pure culture of Staphylococcus epidermidis. The versatility of the system offers the potential for cultivating pure culture biofilm in defined, controlled conditions and facilitates a range of analyses that can be performed ex situ. Significance and Impact of the Study:  The ability to provide strict regulation of environmental conditions and enhanced transfer of oxygen to the biofilm during cultivation are important, first because oxygen is known to regulate biofilm development in several micro-organisms and second because many conventional biofilm cultivation systems may not provide adequate oxygen supply to the biofilm.