Dr. M. Robert Belas
Ph.D., Microbiology University of Maryland at College Park, 1981
The goal of our research is to discover the molecular mechanisms underlying the transmission of external stimuli into cells – called signal transduction – and to understand how that information is used to control gene expression and thus enhance survival. Much of our research is focused on bacterial flagella and biofilm formation.
Most, if not all, bacteria are able to live either as independent planktonic cells or as members of organized surface-anchored communities called biofilms. Biofilm formation is thought to be a developmental process that begins when a motile bacterium (the ‘swim’ stage) attaches to a surface (the ‘stick’ phase). Many bacterial processes are involved in biofilm formation. One such process is flagellum-mediated motility, which facilitates attachment to and colonization of surfaces. Both motile and sessile lifestyles confer specific advantages and liabilities, therefore choosing the right one in any particular environment is crucial for bacterial adaptation and survival. What are the molecular mechanisms that control the swim-or-stick lifestyle switch in bacteria?
We use two bacterial species as model systems to answer these questions. The first bacterium, Proteus mirabilis, is an excellent experimental model cell used to ask questions about how bacteria sense and respond to surfaces, while the second model bacterium, Silicibacter sp. TM1040, is used to understand the molecular mechanisms (including biofilm formation) involved in marine bacterial symbioses with phytoplankton and algae. The tools and techniques used to answer these questions include microbiology, biochemistry, classical and molecular bacterial genetics, molecular biology, genomics, transcriptomics, proteomics, and microscopy.
Knowledge gained from our research has a major impact in the fields of molecular microbiology, sensing and signal transduction, and gene expression and regulation. Our research improves understanding of how organisms take physical signals and cues from their environment and transform them into the molecular signals necessary to regulate gene function and the physiology of the organism. Results from our research have transformed our concepts concerning flagellum function and signal transduction in prokaryotes and may shed light on similar mechanisms in higher organisms.