Microbial Metabolism and Production Complete Summary
15 views 1 purchase
Module
Metabolism and Bioengineering (MCB2022S)
Institution
University Of Cape Town (UCT)
Content covered includes:
- Microbial metabolsim including respiration and fermentation as well as metabolic pathways
- glutamic acid production
- lysine production
- citric acid production
• Macroelements = CHNOPS K, Ca, Mg, Fe
• Microelements = Mn, Mo, Zn, Cu, Co, Ni, V, B, Cl, Na, Se, Si, W
• Water!! à can measure required water amt via water activity
o Bacteria have high water activity levels
• Plants vs other orgs
o Photosynthetic production = linked to organic compound
mineralization
o Photosynthesis à use sun energy to liberate e- from H2O to power
oxidation and reduction of glucose
*large amounts of flexibility in use of C sources amongst microorganisms
• Prototrophs = microorganism requiring nutrients as most of the naturally
occurring members of its species
• Auxotroph = mutation in a prototroph that causes it to no longer be able to
synthesize a necessary growth factor (will require it to be supplied as a
nutrient)
• Nutrients in addition to C + energy sources, macroelements, microelements
= growth factors
1. Amino acids
2. Purines and pyrimidines
3. Vitamins (enzyme cofactors)
Nutritional Types
• Microorganisms require:
o Carbon source
§ Autotrophs = microorganisms using CO2 as sole carbon source
§ Heterotrophs = microorganisms that use reduced preformed
organic mols as C source
o Energy source
§ Light (phototrophs)
§ Chemical (chemotrophs)
• Derived from oxidation of organic/inorganic molecules
o Hydrogen ions
o Electrons
§ Organotrophs à obtain e- from oxidation of organic comps
§ Lithotrophs à oxidize inorganic compounds to obtain e-
• Eg. Methanogens (archaea)
*mixotrophs = chemolithotroph autotrophs (use an organic C source and obtain
energy from inorganic molecules
,Major nutritional types Sources of energy, Microorganisms
hydrogen/e-, carbon
Photolithotrophic Light energy Algae
autrotphy Inorganic hydrogen/e- Purple and green sulfur
donor bacteria
CO2 Cyanobacteria
Photoorganotrophic Light energy Purple and green non sulfur
heterotrophy Organic H/e- donor bacteria
Organic carbon source
Chemolithotrophic Chemical energy Sulfur oxidizing bacteria
autotrophy Inorganic H/e- donor Nitrifying bacteria
CO2 Hydrogen bacteria
Iron oxidizing bacteria
Chemoorganotrophic Chemical energy Protozoa
heterotrophy Organic H/e- donor Fungi
Organic carbon source Most nonphotosynthetic
bacteria (pathogens)
Energy
• Spontaneity is determined by whether ∆G<0
o ∆G<0 à free energy decreases, exergonic, energy is released
o ∆G>0 à energy requiring, endergonic
o ∆G=0 is at equilbiirum
• ∆Gº = standard state
o 1M concentration of H but that equates to a very LOW pH
• ∆Gº’ à determined at standard biological conditions so that pH = 7
Oxidation and Reduction (OIL RIG)
= those rxns in which e- are transferred from a donor to an acceptor (reducing agent
to oxidizing agent)
• Oxidation = loss of electrons
• Reduction = gain of electrons
Metabolism
= ordered transformation of molecules in the cell
à total of all chemical reactions occurring in the cell
o Energy conserving reactions (catabolism) and energy expending
reactions (anabolism)
• Nutrients acquired from the environment serve as energy sources for
metabolism
• Nutrients are transformed in a series of successive reactions via specific
metabolic pathways
• Enzyme catalyzed reactions
o Except for proline synthesis
• Function = provide precursors for synthesis of cellular components + provide
energy for biosynthetic and other energy requiring processes
• 3 major phases=
1. Catabolism à oxidative + exergonic
2. Synthesis of building blocks (monomers)
, 3. Synthesis of polymers
2 + 3 = anabolic, reductive + energy requiring (require electrons as a source of
reducing power à anabolism = reductive)
Funneling of nutrients
• Microorganisms can channel a wide variety of molecules into essential
processes
o à require unique uptake methods or:
§ Proteins
§ Polysaccharides
§ Lipids
• Default state of e- carriers = oxidized
o Catabolism = oxidative!
, Laws of thermodynamics
1. Energy cannot be created or destroyed
2. Entropy of the universe (system + surroundings) always increases in a
spontaneous reaction
Coupling of energy production and energy use
• ATP = mediator of anabolism and catabolism
• ATP generated via catabolism as nutrients are broken down
• ATP used in anabolism where precursors are made into products
o ATP has a very large –‘ve energy of hydrolysis to drive anabolic
reactions
o Does NOT mean that there is a significant amount of energy stored in
a bond
o Has high phosphate group transfer potential
Lecture 2
Standard half reaction = 2H+ + 2e- à H2 (Eº = 0)
• Assigned a standard [potential of 0V
For a spontaneous reaction: Eº>0
Eº à Eº’
• Standard reduction potential at pH 7.0 (biological pH)
• Overall reaction in e- transport in aerobic respiration à e- transport =
exergonic (spontaneous)
∆𝐺º! = −𝑛. 𝐹. 𝐸º!
Where n = number of e- transferred and F = 96400 J/V/mol
Unit for Gº’ = kj/mol
• Redox couples with more –‘ve reduction potentials donate e- to couples with
more +’ve potentials (greater affinity for e-)
• -‘ve electrode potential = better e- donor
• -”ve electrode potential = better e- acceptor
Breakdown of Carbohydrates
• Carbohydrates = main products of plant photosynthesis
o General nutrients for microorganisms
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller erinsnotes. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £4.71. You're not tied to anything after your purchase.
