Microbiology

disease caused by invisible living creatures

Spontaneous generation: organisms arise de novo from nonliving sources

imbalance between 4 humours (blood, phlegm, yellow bile, black bile) caused disease

invisible organisms ("germs") caused disease such as syphillis

"Father of Microbiology"; Drew and described bacteria and protozoa; described in royal society of London transactions

Published first drawing of microorganism in Micrographia

silkworm disease caused by fungus

• Mice from Wheat 
• Pro Spontaneous Generation

• "Vital force" from infusions
• Pro Spontaneous Generation

Pro Spontaneous Generation

• Found microbes in hay infusions; described protozoa
• Con Spontaneous Generation

• Maggots do not arise spontaneously
• Con Spontaneous Generation

• filtered air
• Con Spontaneous Generation

• Discovered yeast were living cells, and fermentation a biological process
• Con Spontaneous Generation

• with Schwann proposed the Cell Theory
• Con Spontaneous Generation

• heated air
• Con Spontaneous Generation

• Air may carry germs; described bacterial binary fission
• Con Spontaneous Generation

• Air contains oxygen; not enough oxygen in closed flask to support microbes
• Con Spontaneous Generation

• Final refutation of spontaneous generation; also worked with anthrax
• Con Spontaneous Generation

hand washing prevents puerperal fever; used chlorine as antiseptic

Sterilization of instruments with heat; use of phenol as antiseptic

Found spore-like bodies in Bacillus anthracis; developed postulates relating causative agent to disease; developed methods of growing pure cultures of bacteria 

used agar to solidify media

developed container to hold solidified media

Heat-resistant life forms present; Dust does carry microbes

Named heat-resistant forms of bacteria "endospores"

Described lithotrophy; used model ecosystem

Use of enrichment cultures; described nitrogen fixation

modern methods of microbial ecology; involved with Deepwater Horizon oil spill

Worked with Vibrios; marine microbiology; coined "viable but nonculturable bacteria"

Endosymbiont hypothesis; parasitic bacteria in eukaryotes gave rise to mitochondria and chloroplasts

Discovered archaeons

Sequenced thermophiles

Described archaeons; used 16s rRNA to characterize species; developed "domains"

First to sequence bacterial genomes (Haemophilus influenzae)

Sequenced bacterial genomes with venter

showed lateral gene transfer from archaeons to bacteria; sequenced Thermotoga maritima

for co-discovery of restriction enzymes; First to sequence bacterial genomes (Haemophilus influenzae) in 1994-95 with venter

Work with Deepwater Horizon Oil spill

work with deepwater Horizon Oil Spill; work with vibrios

discovered nuclein (nucleic acid)

Transformation; suggested that DNA might be genetic material

Used ascomycete Neurospora crassa to formulate One gene, one enzyme/polypeptide hypothesis

discovered “jumping genes” (transposons) in maize

“Transforming agent” was DNA

[A]=[T] and [G]=[C], but [A+T]ǂ[G+C]

Bacteriophage and blender expt. suggested DNA as genetic material

X-ray diffraction of DNA

molecular model of DNA as double helix

discover polynucleotide phosphorylase, which adds bases to RNA

discovered ribosomes

describe translation

DNA replicates semi-conservatively

Discover DNA polymerase III as enzyme involved in DNA replication

coined “Central dogma”

propose life started with RNA and evolved to DNA

describe triplet genetic code

describe regulation of genes involved in degradation of lactose

Assigned triplet codons to individual amino acids

independently discover viral  RNA-dependent DNA polymerase (reverse transcriptase)

define ribosomal binding site

discover autocatalytic processes in RNA

takes first electron micrograph photograph of DNA strands

• 1. Microorganism present in every case of disease
• 2. Microorganism must be grown in pure culture
• 3. Same disease when second host inoculated with pure culture
• 4. The microorganism must be isolated from the infected host

• 1. Virulence trait seen with pathogenic strains, not nonpathogenic strains.
• 2. Inactivation of gene(s) associated with virulence decrease(s) pathogenicity
• 3. Replacement of the mutated gene with wild-type gene restores pathogenicity.
• 4. Gene should be expressed some time during infection & disease process
• 5. Antibodies/immune system cells directed against gene products protect host.