Microbial Ecology Exam 1

Microbial

Relating to single-cell organisms

Ecology

Interactions between biota and abiotic factors

Prokaryotes

Bacteria and archaea, less complex

Eukaryotes

Eukarya (plants, animals) algae, protists, fungi, more complex

Antony van Leeuwenhoek

Found first microscope, bacteria, experiment

Louis Pastuer

Found life that didn’t need oxygen

Robert Koch

Found microorganisms can cause disease and first dish

Martinus Beijerinck & Sergei Winogradsky

Found cycling of nitrogen, carbon, sulfur. microorganism autotrophy, enrichment culturing technique

Thomas Brock

Found first thermophilic (thermus aquaticus) which is now used in PCR, opened up extremophile research

Kary Mullis

Invented PCR for DNA copying

Carl Woese

Found archaea causing a rearrangement of life

Prokaryotic # of species of earth

About 1×10^12

Prokaryotes in one ton soil vs one km³ of water

More in soil than water because they like to stick to the structural complexity of soil

Francis Crick, James Watson, Rosalind Franklin

Found the structure of DNA

Continental fixed carbon (10^12 kg/c)

plants: 560, soil/water prokaryote: 26, intraterrestial: 22-215

Oceanic fixed carbon (10^12 kg/c)

plants: 1.8, soil/water prokaryote: 2.2, intraterrestial: 303

Photoautotrophy

energy source: sunlight

carbon: CO2

Photoheterotrophy

energy: sunlight

carbon: organic compounds (sugar)

Chemolithoautotrophy

energy: inorganic compounds (H2)

carbon: CO2

x-oxidizing bacteria

chemolithotrophs are called this because they oxidize compounds to produce energy

Chemoheterotrophy

energy: organic molecules

carbon: organic molecules

Aerobic respirers

use oxygen as terminal electron acceptor, gives the most ATP

Anaerobic respirers

uses other molecules (nitrate) as terminal electron acceptors, less favorable ATP

“x”-reducing bacteria

Referring to anaerobic respirers because they reduce compounds to produce ATP

Fermenters

(always chemoheterotrophs) use organic c and carbon and energy source

Firmicutes

gram positive, found in soil, produce endospores

Actinobacteria

gram positive, found in soil, produce antibiotics

Tenericutes

gram positive, found in plants and animals, lack cells walls and are small cells with small genomes

Chloroflexi

gram negative, non sulfur, performs photosynthesis, photoheterotrophy, chemoheterotrophy

Chlorobi

gram negative, sulfur, performs photosynthesis

Cyanobacteria

gram negative, performs oxygenic photosynthesis, many are N2 fixers

Heterocysts

specialized cells for N2 fixation, not photosyntheic in cyanobacteria

Aquificae

gram negative, most ancient hyperthermophiles, performs aerobic respiration

Thermotagae

gram negative, hyperthermophile with a genome of 20% archaea DNA, sheathed cells

Thermodesulfobacteria

gram negative, sulfur reducing hyperthermophile containing ethers-linked lipids

Bacteroidetes

gram negative, diverse group of chemoheterotrophic polymers found in guts, soil and water

Bacteroidales

(bacteroidetes) gram negative, provides genes for breaking down complex plant polysaccharides

Cytophagales/Flavobacterium/Sphingobacteriales

(bacteroidetes) gram negative, degrade complex polymers, grows as filaments

Acidobacteria

gram negative, common in soil but hard to culture

Nitrospirae

gram negative, performs chemolithotrophy and nitrify.

Cartenoid

mask green color

Proteobacteria

Highly diverse group of phototrophs, chemolithotrophs, chemoheterotrophs

Purple Sulfur Bacteria

Anoxygenic photosynthetic proteobacteria, electron source H2S

Purple Nonsulfur Bacteria

Anoxygenic photosynthetic proteobacteria, metabolically versatile

Archaea

ether-linked lipids in cell membranes, no peptidoglycan, complex RNA polymerases

Euryarchaeota

“wide spread” archaea, methanogens, all phs, halophiles

Methanogens

Archaea that grow with no oxygen

Halophiles

Archaea that grow with 10-30% salt

Thermophiles

Archaea that grow between 45-80C

Hyperthermophiles

Archaea that grow >80C

Acidophiles

Archaea that grow at ph <6

Neutrophiles

Archaea that grow at ph 6-8

Alkaliphiles

Archaea that grow >8

Crenarchaeota

“spring or source” Thermophiles and hyperthermophiles, sulfur oxidizer/reducers, cold-adapted

Thaumarchaeota

“miracle” chemolithotrophic archaea, ammonia oxidizers

Korarchaeota

No pure cultures, chemoorganotrophic

Nanoarchaeota

Smallest cells and genomes