HM Flashcards
an English mathematician and natural historian, was also an excellent microscopist
Robert Hooke (1635–1703)
the first book devoted to microscopic observations
Micrographia (1665)
In 1684, van Leeuwenhoek, who was well aware of the work of Hooke, used extremely simple microscopes of his own construction to examine the microbial content of natural substances.
Antoni van Leeuwenhoek (1632–1723)
The first person to see bacteria in 1676
Antoni van Leeuwenhoek (1632–1723)
was born in Breslau (now in Poland)
trained as a botanist and became an excellent microscopist.
Ferdinand Cohn (1828–1898)
Studied unicellular algae and bacteria particularly interested in heat resistance in bacteria
Ferdinand Cohn (1828–1898)
led to his discovery that some bacteria form endospores.
Ferdinand Cohn (1828–1898)
described the life cycle of the endospore-forming bacterium Bacillus (vegetative cell endospore vegetative cell) and showed that vegetative cells but not endospores were killed by boiling.
Ferdinand Cohn (1828–1898)
laid the groundwork for a system of bacterial classification, including an early attempt to define a bacterial species, an issue still unresolved today, and founded a major scientific journal of plant and microbial biology.
Ferdinand Cohn (1828–1898)
the Defeat of Spontaneous Generation
Louis Pasteur (1822–1895)
is an obsolete body of thought on the ordinary formation of living organisms without descent from similar organisms.
Spontaneous generation or anomalous generation
microbial life can be destroyed by heat
Aseptic techniques
Pasteurization
Techniques that prevent contamination by unwanted microorganisms
Aseptic techniques
In his early work Koch studied anthrax, a disease of cattle and occassionally of humans.
Robert Koch (1843–1910)
a disease of cattle and occassionally of humans.
anthrax
Anthrax is caused by an endospore forming bacterium called
Bacillus anthracis
Koch established that the bacteria were always present in the blood of an animal that was succumbing to the disease.
By careful microscopy and by using special stains
was the first to grow bacteria on solid culture media.
Robert Koch
Robert Koch was the first to grow bacteria on solid culture media
- potato slices
- gelatin
- agar
Not all bacteria can grow, and slices frequently overgrown with molds.
Potato slices
as solidifying agent for various nutrient fluids.
- nutrient-supplemented gelatin was a good culture medium for the isolation and study of various bacteria,
but it had several drawbacks,
- it did not remain solid at 37°C, the optimum temperature for growth of most human pathogens.
Gelatin
is a polysaccharide derived from red algae
Agar
associate of Koch, first to use agar in bacterial culture, actual suggestion from his wife Fannie (used agar to solidify fruit jelly).
Walter Hesse
desirable as a gelling agent for microbial culture media.
Agar
a German bacteriologist,
the development of the transparent double-sided dishes that bear his name as modification to Koch’s flat plate technique, the Petri dishes.
Richard Petri (1887)
Formulated Enrichment culture technique
Martinus Beijerinck (1851–1931)
microorganisms are isolated from natural samples using highly selective techniques of adjusting nutrient and incubation conditions to favor a particular metabolic group of organisms.
enrichment cultures
isolated the aerobic nitrogen-fixing bacterium ___________ from soil
Azotobacter
isolated the first pure cultures of many soil and aquatic microorganisms, including sulfate-reducing and sulfur-oxidizing bacteria, nitrogen- fixing root nodule bacteria Lactobacillus species, green algae, various anaerobic bacteria, and many others
Martinus Beijerinck (1851–1931)
studies of tobacco mosaic disease, Beijerinck used ___________ to show that the infectious agent (a virus) was smaller than a bacterium and that it somehow became incorporated into cells of the living host plant.
- in this insightful work, Beijerinck not only described the first virus, but also the basic principles of virology,
selective filtering techniques
Proposed chemolithotrophy
the oxidation of inorganic compounds to yield energy further showed that these organisms, which he called chemolithotrophs, obtained their carbon from CO2.
Sergei Winogradsky (1856–1953)
Winogradsky thus revealed that, like phototrophic organisms, chemolithotrophic bacteria were
autotrophs.
First to isolate of a nitrogen-fixing bacterium, the anaerobe Clostridium pasteurianum,
Sergei Winogradsky (1856–1953)
is an
obsolete body of thought on the
ordinary formation of living
organisms without descent from
similar organisms.
Spontaneous generation or
anomalous generation
