﴿ ا �� ن م� ح� ر ﴿ ۱ل نر م� ح �� حل � ر� � ر ر� ﴾۲ ﴿ ر ن ر�ا ح� ا� ح� � ر� ر� �ر ﴾۳ ﴿ ر ر�ا �ر حل � �� ر� � ر ر� ﴾٤ ﴾

1. The Most Beneficent (Allah)!

2. Has taught (you mankind) the Qur'an (by His Mercy).

3. He created man.

4. He taught him eloquent speech.

Verse of the day…..Speech

ENERGY RESOURCESLecture-10: Basics of bio-energy

•What are microbes•Types•Composition and metabolism•Growth•Oxidation-reduction potential•Other definitions

OUTLINES

Microbes are single-cell organisms so tiny that millions can fit into the eye of a

needle.

Sylvia and Stephen Sharnoff, University of California, Berkeley and others, MicrobeLibrary.org.

Amoeba proteus [protist]Fog-desert Niebla lichen [mergers]

Lentinula edodes [fungi]

Trypanosoma brucei rhodesiense [bacteria]

Rotavirus [viruses]

What are microbes?

• The ability to reproduce new cells

• The ability to ingest food and metabolize it for energy and growth

• The ability to excrete waste products

Role of microbes

• There are four groups of organic macromolecules found in living things:

1. Carbohydrates (C, H, O)

2. Protein (N, S)

3. Lipids (C, N, O)

4. Nucleic acid (P)

Microbe composition

Types of Microbes (C-based)

Microbes metabolism

Respiration:

A way to catabolize organics to generate energyInorganic molecules as terminal electron acceptors (TEAs)

Aerobic respiration: Oxygen as TEAAnaerobic: Other than Oxygen as TEA

Energy production processes

Fermentation: A way to catabolize organics to generate energy, when inorganic TEAs are unavailable

Should provide with the followings:• e-donors (e.g., glucose)• e-acceptors (e.g., O2)• Carbon sources (e.g., glucose)• Nitrogen sources (e.g., NO3

- and NH4+)

• Phosphorous sources (e.g., PO42+ )

• Sulfur (protein source)• Trace metals (e.d., Fe, Cd, Cu, W, Mo, Co, etc)• Various salts (e.g., Na+, K+, Ca2+ and Mg 2+ )• Vitamins• Growth factors (light, temperature)• pH ranges and pH buffers

Food for microbes

Courtesy of Prof Han Jong-In

• Complex media:– Rich in nutrients– Water soluble extracts of plants or animal tissue plus

carbon and/or e-donor– e.g., Wastewater

Types of media

• Defined media:– Pure ingredients– Known chemical compositions and concentra-

tions, typically minimal– Often used for the microbial isolation– e.g., M9 medium, freshwater medium

• As a material is oxidized, the electrons it loses transfer to another material, which is thereby reduced. Such redox re-actions transfer a lot of energy. Much of the energy liberated by the oxidation of the reducing agent is captured in the re-duction of the oxidizing agent.

Oxidation-reduction

• e- flow (and thus energy production) in microbial redox reaction

• Primary e- donors Terminal e- acceptors

(e.g., organic matters) (e.g., O2)

• Coupling of food (organic matter) oxidation to terminal e- acceptors = Microbial respiration

• Terminal electron acceptors (TEAs):– O2: aerobic respiration

– NO3-: nitrate reduction

– Fe3+ : iron reduction– Mn4+ : manganese reduction– SO4

2- : sulfate reduction

– CO2: methanogenesis

Anaerobic respiration

Energye-

Redox states of atoms in a molecule = the charge of the molecule.

e.g., NH4+, redox state of N = -3

redox state of H = +1x4 +1 e.g., H2O, (+1)x2 + (-2) = 0

In compounds, – O is usually (-2), H = (+1), and Cl = (-1)

Carbon can exist in redox states, +4 to -4Redox states need not to be an integer.

Calculating reduction potential (acquiring

electron)

e--donating

e--accepting

Great tendency to donate e-

So act as an e--donor

Great tendency to accept e-

So act as an e—acceptor

Redox tower

Enzymes are Proteins which enhance the rate of a thermodynamically feasible reaction and are not permanently altered in the process.

Enzymes

Enzymes help to obtain desired biological reactions and work under mild conditions

•Form of digestion•Hydrate = to water•ysis = process of•With the breaking

ofbonds, watermolecules are

addedto each smallermolecule

Hydrolysis