Term
Differential Media Example |
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Definition
-MacConkey
-Lactose utilization
-Bacteria import lactose (a disaccharide); metabolize glucose using fermentation, producing acid
-Dye shows change in pH, indicating fermentation of lactose |
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Term
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Definition
-Good for growing specific amounts of bacteria and for growing large amounts of bacteria
Types of liquid media (also applies to solid media)
-Complex
-Defined |
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Term
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Definition
Complex : contains uncharacterized mixtures of compounds.
-Usually used for routine growth (cheap, easy to make)
-Defined : uses specific chemicals
-Used for nutritional studies
-Requires knowledge (or trial and error) of requirements of bacteria
Minimal: only has the minimal components for growth of a particular bacterium |
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Term
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Definition
-(short for chemoheterotroph) or ‘Organotroph’ refer to bacteria that use organic C as both energy and C source
-Most pathogenic bacteria fall into this category |
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Term
Basic Growth Requirements for Bacteria |
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Definition
Inorganic
-N, C, O, H
-S
-P
-K, Na (some), Cl (some)
-Mg, Ca (some)
-Trace elements (Fe, Cu, Zn, Mn, etc.)
-Vitamins and growth factors (some bacteria) |
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Term
Environmental Requirements for Bacteria |
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Definition
-Temperature
-pH
-Oxygen
-Salt
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Term
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Definition
Anaerobes
-Obligate (i.e. intestinal bacteria)
-Aerotolerant- does not use oxygen but tolerates it
Utilize fermentative metabolism or ’anaerobic respiration’: use of electron acceptors other than O2
Aerobes
Obligate aerobes
Microaerophiles
-Require low oxygen tensions; harmed by oxygen concentrations that are too high.
Both utilize respiratory metabolism (O2)
Facultatives (aerobic or anaerobic)
Utilize respiratory or fermentative metabolism (respiratory preferred if oxygen present) – ex: E. coli
Aerotolerant anaerobes
Can grow in the presence of oxygen but do not utilize respiratory metabolism (utilize fermentative metabolism under all conditions. ex: Streptococcus pyogenes
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Term
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Definition
Generation Time
-Cells divide by binary fission at a constant rate
-Period between the time that a new cell arises and the time that this cell completes division into two new daughter cells is known as the generation time |
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Term
Catabolism of Carbohydrates |
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Definition
Glycolysis
Followed by
-Fermentation or
Respiration
Goals: ATP generation
Generation of metabolic building blocks
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Term
Basic Facts of Glycolysis |
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Definition
-Substrate level phosphorylation
-Not very efficient
-Lots of C utilized
-Lots of energy remains in the end products
-Different bacteria utilize different glycolytic pathways! |
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Term
Embden-Meyerhof-Parnas Pathway |
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Definition
-Net ATP yield = 2 moles of ATP per mole of glucose fermented
-Not very energy efficient
-Lots of energy remaining
-Need to further metabolize pyruvate
-Fermentation used (see below) |
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Term
HexoseMonophosphateGlycolytic Pathway |
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Definition
-Provides NADPH and pentoses for biosynthesis
-Pathway for utilization of pentoses as C and energy sources
-Makes ribose-5-phosphate, key intermediate for production of nucleotides
-Also called Pentose phosphate pathway (PPP) |
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Term
Entner-Doudoroff (ED) glycolytic pathway |
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Definition
-Replaces the EMP pathway in many pseudomonads.
-Less energy efficient than EMP pathway (1 ATP/mole glucose).
-Usually utilized under aerobic conditions. |
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Term
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Definition
-Used by anaerobic bacteria or by facultatives under anaerobic conditions
-These organic end products are used as electron acceptors to recycle NADH, which is produced during glycolysis, to NAD+
-End product depends on bacterial species
-Identification of bacteria
-Industrial value
-Stinks! |
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Term
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Definition
-Electrons transferred from reduced carbon compound (acetate, fumarate) and NADH (which are oxidized to NAD+) through electron carriers similar to aerobic electron transport chain (but distinct carriers) to various electron sinks (which are reduced)
-ATP generated in the process, but <38 ATP that is seen in aerobic respiration; yields vary
nSO42- H2S Sulfate reductase
nNO3- NO2- Nitrate reductase
nHCO3- CH4 Methyl Co-M reductase |
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Term
Energy Yields
Fermentation vs. Respiration |
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Definition
From Most to Least:
-Glycolysis+TCAcycle+electron transport
38 ATP/mole glucose
-Glycolysis+Anaerobic respiration
Variable ATP yield, but more than fermentation
-Glycolysis+fermentation
-EMP
2 ATP/mole of glucose
-HMP & ED
-1 ATP/mole glucose
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Term
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Definition
-E. coli can synthesize all cellular components from glucose, N, S, P
source, some trace metals, and some salts! |
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