Microbiology and Immunology

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ZIEHL-NEELSEN STAIN•seeLABORATORY TECH-

NIQUES IN MICROBIOLOGY

ZZoBell, Claude EphraimOBELL, CLAUDEEPHRAIM(1904-1989)

American microbiologist and marine biologist

Claude Ephraim ZoBell’s research confirmed several behav-

ioral characteristics of water and ocean-borne bacteria. ZoBell

researched the special adhesive properties of organisms to sur-

faces, and experimented with mean of controlling such popu-

lations. 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 biochemistryof

various bacteria and developed his interest in marine biology.

ZoBell’s first position was as Instructor of Marine

Microbiologyat 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 con-

ducted 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 organ-

isms in a specific environment. Also, he quickly found that he,

as well as other marine scientists, were frustrated by difficul-

ties in reproducing marine conditions and organism behavior

and growth in the lab.

ZoBell and his colleagues devised a number of techni-

cal 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 cultureor 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 mul-

titude of culture media in the lab. This microscopic observa-

tion 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, permit-

ted 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 speci-

mens, 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 alsoBiofilm formation and dynamic behavior

ZZoonosesOONOSES

Zoonoses are diseases of microbiological origin that can be

transmitted from animals to people. The causes of the diseases

can be bacteria, viruses, parasites, and fungi.

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