Introduction: Pseudomonas putida is well known as a potential cell factory for many different biochemicals. Biofilm-based production can be advantageous for possibly toxic products due to increased chemical tolerance and robustness. Biofilm cells frequently differentiate, which challenges the benefits of biofilm-based production, and knowledge about factors driving the heterogeneity is therefore of importance.Methods: Biofilm flow chamber systems connected to confocal laser scanning microscopy were used to study biofilm structures of P. putida KT2440 at different carbon conditions. Subsequent plating of mature biofilm allowed for variant selection followed by pheno- and genotypic analysis.Results: Structure and cell differentiation in mature P. putida KT2440 biofilms were highly dependent on the type of carbon source utilised. Low glucose concentrations (0.3 mM – 10 mM) did not alter biofilm structures nor motility, biofilm capability nor growth rate. However, increasing the glucose concentration (15 - 30 mM) introduced filamentous cell structures, as well as variations in colony morphology. Filamentous structures were also observed when using citrate (1 mM – 50 mM), and different morphotypes appeared. These morphotypes showed a large variation in swimming motility, biofilm formation and growth rate, and whole genome sequencing revealed alterations in cyclic-di-GMP-related genes involved in biofilm development.Conclusions: Low concentrations of glucose seem to allow a more homogenous P. putida KT2440 biofilm. In contrast, citrate as a carbon source induces cell differentiation and seems associated with an apparent selection for mutations of genes involved in cyclic-di-GMP-mediated global regulation.
|Title of host publication||The Danish Microbiological Society Annual Congress 2015 : Programme & Abstracts|
|Place of Publication||Copenhagen|
|Publication status||Published - 2015|
|Event||The Danish Microbiological Society Annual Congress 2015 - Eigtved's Pakhus, Copenhagen, Denmark|
Duration: 9 Nov 2015 → 9 Nov 2015
|Conference||The Danish Microbiological Society Annual Congress 2015|
|Period||09/11/2015 → 09/11/2015|