Columbia Encyclopedia

Search results

227 results found

Dujardin, Félix

(Encyclopedia)Dujardin, Félix fālēksˈ düzhärdăNˈ [key], 1801–60, French zoologist. He did valuable research on bacteria and on the Infusoria. In 1835 he described protoplasm in unicellular animals, naming...

cystitis

(Encyclopedia)cystitis sĭstīˈtĭs [key], common acute or chronic inflammation of the urinary bladder. The disease occurs primarily in young women and frequently results from bacterial invasion of the urethra fro...

probiotic

(Encyclopedia)probiotic, live microorganism administered to a host with the intention of providing a health benefit, or a food, supplement, or treatment containing such microorganisms. Many of the microbes found in...

nitrogen cycle

(Encyclopedia)CE5 Nitrogen cycle nitrogen cycle, the continuous flow of nitrogen through the biosphere by the processes of nitrogen fixation, ammonification (decay), nitrification, and denitrification. Nitrogen...

chloramphenicol

(Encyclopedia)chloramphenicol klōrˌămfĕnˈəkŏlˌ [key], antibiotic effective against a wide range of gram-negative and gram-positive bacteria (see Gram's stain). It was originally isolated from a species of S...

sore throat, streptococcal

(Encyclopedia)sore throat, streptococcal strĕpˌtəkŏkˈəl [key], infection and inflammation of the pharynx caused by certain streptococcal bacteria. These organisms are known as hemolytic streptococci because t...

sewerage

(Encyclopedia)sewerage, system for the removal and disposal of chiefly liquid wastes and of rainwater, which are collectively called sewage. The average person in the industrialized world produces between 60 and 14...

biotechnology

(Encyclopedia)biotechnology, the use of biological processes, as through the exploitation and manipulation of living organisms or biological systems, in the development or manufacture of a product or in the technol...

Protista

(Encyclopedia)Protista prōˌtŏktĭsˈtə [key], in the five-kingdom system of classification, a kingdom comprising a variety of unicellular and some simple multinuclear and multicellular eukaryotic organisms. Pro...

decay of organic matter

(Encyclopedia)decay of organic matter or putrefaction, process whereby heterotrophic organisms, including some bacteria, fungi, saprophytic plants, and lower animals, utilize the remains of once-living tissue as a ...