dweibel

Bacterial Biochemistry and Engineering Our laboratory studies microbial biochemistry with an emphasis on understanding the molecular mechanisms that give rise to phenotypes in bacteria. Although our current understanding of the complexity of a bacterium is still emerging, it is becoming clear that the genetic and biochemical mechanisms that govern cellular homeostasis are far more sophisticated than we had imagined. Our approach to the study of bacteria is driven by the development of new capabilities for studying single cells or small groups of cells and the application of these techniques to dissect the molecular choreography within the cell. This research is interdisciplinary and is based on a fusion of techniques from biology, physics, engineering, and chemistry. The top-level goal of our research is to understand how the behavior and physiology of bacteria is encoded at the molecular level. The results of these projects drive the application phase of our research, which is aimed at using bacterial cells to produce new materials. We summarize several areas we are working on below.

Behavior: Bacterial swarming.
 Some strains of bacteria can swim in liquid; others can ‘swim’ on surfaces.  To migrate on solids, bacteria differentiate into long, hyperflagellated cells that move collectively and colonize surfaces in search of new resources.  We are studying the chemical and physical communication between swarmer cells to better understand how cooperativity and the transduction of signals plays a role in this phenotype.  Our work aims to shed light on the connection between swarming motility and pathogenesis.

Evolution: Size and shape of bacterial cells. To understand evolutionary pathways that bacteria have followed, we are studying the evolution of the size and shape of cells by combining biochemistry with mathematical models and data mining.  The approach makes it possible for us to explore how phenotypes evolved in parallel with changes in cell morphology.  This work allows us to systematically study how much of cell morphology 'phase space' bacteria have explored as their shape and volume fluctuated.

Growth: Accelerating microbial culture. It is widely believed that >99% of the microorganisms in the biosphere resist isolation and culture using the techniques currently available to microbiologists.  We are designing, fabricating, and studying polymer structures that mimic the natural environment of differentbacterial genera and will be used to culture and isolate `uncultivatable’ organisms.  The long-range goal of this project is to expand our foundation of the mechanisms of sensory transduction between the cell and its environment.

Physiology: Developmental cycles in populations of bacteria. Microbes are programmed to conserve their genotype.  Strains of bacteria handle this task using different mechanisms.  We are interested in strains of bacteria that undergo developmental cycles consisting of cellular differentiation and dedifferentiation that is critical for the survival of the colony.  We are studying how these cycles are initiated, coordinated, and terminated in monoclonal populations of bacteria.

Structure: Control of cell shape. Cells of bacteria have a defined shape and volume. The shape of a cell arises from the spatial and temporal organization of molecules in the cell that we are only beginning to understand.  We are studying the role and dynamics of homologs of eukaryotic cytoskeletal proteins in bacteria using new biophysical approaches that makes it possible for us to manipulate and image structures at unparalleled resolution.