Zobell, Claude Ephraim (1904-1989)

American microbiologist and marine biologist

Claude Ephraim ZoBell's research confirmed several behavioral characteristics of water and ocean-borne bacteria . ZoBell researched the special adhesive properties of organisms to surfaces, and experimented with mean of controlling such populations. He also was one of the pioneering scientists to study marine pollution. His work continues to be utilized by marine biologists, petroleum engineers, and the shipping industry.

ZoBell was born in Provo, Utah, but his family moved to Rigby, Idaho, when he was young. He pursued studies in biology and bacteriology at the University of California at Berkeley. By the time he was awarded his Ph.D. in 1931, he had already conducted several studies on the biochemistry of various bacteria and developed his interest in marine biology.

ZoBell's first position was as Instructor of Marine Microbiology at the Scripps Institute of Oceanography. He was made a full professor in 1948 after conducting research in environmental biology. While at the Scripps Institute, ZoBell left his research in medical microbiology in favor of pursuing his interests in marine life. Thus, ZoBell was among the first generations of modern marine biologists.

Most of ZoBell's career defining research was conducted while at Scripps. ZoBell noted that most of the research done at the institute focused on relationships between various groups of organisms, instead of trying to isolate various organisms in a specific environment. Also, he quickly found that he, as well as other marine scientists, were frustrated by difficulties in reproducing marine conditions and organism behavior and growth in the lab.

ZoBell and his colleagues devised a number of technical innovations and methodological procedures that help to overcome such obstacles to their research. For example, ZoBell designed a slide carrier that could be lowered into the water to study the attachment of organisms to surfaces, thus eliminating the need to culture or breed organisms in the lab. Organisms that colonized the slide carrier were removed from the water and instantly processed for microscopic observation. The device proved successful, eliminating the need for a multitude of culture media in the lab. This microscopic observation of cultured slides became known as biofilm microbiology.

ZoBell and his colleagues also conducted experiments on bacteria and organism levels in seawater. The scientists lowered a series of sterile glass bottles into the water, permitted water to flow in and out of the bottles for several days, and then raised the bottles. ZoBell found that bacterial levels were higher on the glass than in the liquid. Thus, ZoBell devised that certain organisms have a certain "sticking power" and prefer to colonize surfaces rather than remain free-floating. The experiment was repeated in the lab using seawater specimens, with similar results. The exact nature of this sticking power, be it with barnacles or bacteria, remains alusive.

After receiving several rewards for his research at the Scripps Institute for Oceanography, ZoBell briefly researched and taught at Princeton University, in Europe, and spent time at several other oceanographic research institutes. He returned to the Scripps Institute and turned his attention to the effects of pollution and petroleum drilling on marine environments. He remained a passionate advocate for marine preservation and research until his death.

See also Biofilm formation and dynamic behavior