Putting population models to experimental tests
Influenced by the population research of Pearl, Lotka and Volterra, Gause combined mathematical models with controlled microbial experiments. The Struggle for Existence, published in the United States in 1934, presented this programme.
Simple culture systems reduced some environmental complexity, allowing changes in abundance to be compared with predictions. They tested interactions under defined conditions rather than reproducing an entire natural community.
Paramecium experiments and competitive exclusion
Gause compared two Paramecium species grown alone and together and investigated Paramecium prey interacting with Didinium predators. Monocultures, competitive mixtures and predator–prey systems became comparable experimental cases.
This work helped develop competitive exclusion: complete competitors cannot coexist stably under the relevant model assumptions. Differences in resource use or refuges can alter outcomes, so the principle does not mean that any two similar organisms are unable to coexist.
Gramicidin S in 1942
Gause and Maria Brazhnikova investigated soil bacteria in 1942 and isolated a strain producing an antibacterial substance. Their 1944 Nature report described a crystallizable product named gramicidin S, distinguishing it from previously investigated gramicidin and related products.
The research extended microbial interaction studies into the isolation and characterization of antibacterial compounds. Their joint authorship records the collaborative nature of the discovery.
References: [4]
Organizing antibiotics research
A new antibiotics institute was established in 1953 from an antibiotics laboratory of the USSR Academy of Medical Sciences. Gause helped organize this research system and directed the institute from 1960 to 1986.
His career connected mathematical and experimental ecology with microbiology and drug research. These programmes asked different questions while sharing an interest in microbial interactions and products.