Monday, 15 Sep 2008
Bacterial physiology and metabolism – 1
microbial nutrition and culture
energy and redox
Chemical Composition of the Bacterial Cell:
Bacterial cells -- water, 80% of mass, inorganic ions (K, Na, Ca, Mg, Fe, etc.), small organic molecules (amino acids, sugars, fatty acids),
molecules (polymers) (protein, nucleic acid, peptidoglycan (especially for bacterial cells), lipid, polysaccharide).
: C (50), O (20), N (14), H (8) P (3), S (1), Na (1), K (1), Ca (0.5), Mg (0.5), Fe (0.2)
(% of dry weight of cell)
Protein, lipid, DNA, RNA, polysaccharides, peptidoglycan: made up of C, O, H, N, S, P
K -- enzyme activity (variety)
Ca -- heat resistance of endospores, stability of the CW (outside of cell membrane holding things in, would be loose without calcium)
Mg -- cofactor for enzymes, stability of membranes
Fe -- part of cytochromes, cofactor for enzymes (electron transfer)
Take this all in
See Table 5.1 for sources of nutrients. (where macronutrients come from)
co2 good source of carbon for auto trophs
but mose we are talking bout are heterotrophs
get a feel for the list but don't MEMORIZE it!
(trace elements) needed as cofactors and parts of enzymes (0.2) (Cu, Zn, Mo, Bo, Se, Cl, Ni, Cr, Co, Wo)
Mn, phosphatases; oxygen-detoxifying enzymes
Zn, structure of enzymes, DNA and RNA polymerases
Co, Vit B
12 (cofactor of viatmin B12)
Cu, certain enzymes of respiration, oxygen-detoxifying enzymes
Mo, enzymes of nitrogen metabolism (especially nitrogen fixing enzymes)
Ni , hydrogenases
Some bacteria require one or more growth factors:
an organic compound that is essential for growth of a cell but that the cell cannot synthesize.
make almost everything but require certain components pre-formed
Must acquire factor intact from the environment, usually required in small amounts, different for different
a) vitamins -- required in small amounts for growth and activity of the cell, but do not serve as carbon or energy sources.
(organic compounds the cell does not catabolize)
b) amino acids, for protein synthesis.
c) purines and pyrmidines, for nucleic acid synthesis
DIRECTED READING STUDY ASSIGNMENT
used the book to find the difference between: