Anthony Walsby is a microbiologist who uncovered the curious method by which many aquatic microorganisms control their buoyancy. He showed that photosynthesising bacteria form and collapse gas vesicles to maintain their position in the water or reach regions with more sunlight. Anthony also discovered the first saltwater microbe with square-shaped cells.
Cyanobacteria, also known as blue–green algae, are photosynthetic. Anthony showed that these, and many other single-celled aquatic organisms, use gas vesicles to provide their buoyancy. He described the unique protein membrane of the vesicles, now exploited as the target for ultrasonic treatment of troublesome algal blooms in bodies of water.
Anthony discovered the first Haloquadratum archeon in a coastal brine pool on the Sinai Peninsula in Egypt. Named after him, Haloquadratum walsbyi proliferates in salt-rich water and, unusually, has cells shaped like flat, square boxes. Anthony now continues his research as Emeritus Professor of Microbiology at the School of Biological Sciences of the University of Bristol.