micro ch 15

  1. Beijerinck
    • opinion of atmospheric nitrogen essential for plant growth;
    • bacteria from nodules
  2. importance of nitrogen metabolism
    N - essential element of organic compounds, including amino acids
  3. nitrogen fixation
    trapping of nitrogen gas from atmosphere and its incorporation in organic compounds
  4. two types of microbes accomplishes nitrogen fixation.
    • -free-living microbes
    • -symbiotic microbes
  5. free living nitrogen fixers includes these species.
    Azotobacter, Beijerinckia, & Clostridum and cyanobacteria (Nostoc & Anabaena)
  6. symbiotic nitrogen-fixers includes these species.
    • Rhizobium and Bradyrhizobium
    • -live in nodules on roots of legume plants
  7. symbiotic relationship between microbes and plants...
    • complex; involves chemical attraction between bacterium and cells of plant root, binding to plant root, curling and branching of rootlets, and entry of bacteria into root hairs
    • -infection thread develops and tumorlike growth (nodule) and bacter aumme distorted forms (bacteriods)
  8. bacteroids
    bacteria that's distorted form in the nodules
  9. Bacteria that started a symbiotic relationship...
    cannot live independently
  10. nitrification
    ammonia deposited in soil and converted to valuable nitrate ions thru this process
  11. steps of nitrification
    • 1. bacter, Nitrosomonas, convert ammonia to nitrite ions
    • 2. nitrite ions converted by Nitrobacter to nitrate ions, which are relished by plants for making their organic materials
  12. nitrification occurs under ..
    aerobic conditions and used by microbes as energy-yielding process
  13. denitrification
    some species of microbes break down nitrate ions and produce nitrogen gas, giving atmosphere
  14. ruminants
    grazing animals
  15. Cheese manufactured from milk in 3 steps.
    • 1. curd formation
    • 2. curd treatment
    • 3. curd ripening
  16. Bacillus thuringiensis
    a bacterial insecticides
  17. baculovirus
    • type of virus having high affinity for insect tissues.
    • -gene cloned from cells of scorpion which have toxin that paralyzes larvae of moths.
Card Set
micro ch 15
exam 2