| Citation | Professor Walsby is a microbiologist who has contributed substantially to knowledge of motility, nitrogen fixation and extracellular products of cyanobacteria and buoyancy control in phytoplankton generally. He was the first to show unequivocally that the buoyancy of certain cyanobacteria and other prokaryotes is regulated by gas vesicles, which are formed or collapsed in response to environmentally induced changes in metabolism, as well as by accumulation or depletion of ballast such as carbohydrate. Using elegant biophysical and biomolecular techniques he has established the nature, structure, properties and formation of gas vesicles and shown the vesicle wall to be a biological membrane of a unique type. His researches, extending from the molecular level to field experiments in freshwater and marine habitats, are notable contributions to microbial physiology and ecology. |