Microbes are microorganisms which means they cannot be seen with the naked eye and we use a microscope to see and observe them. Types of Metabolism

1. Microbial Metabolism
Presented by:
Noel Shamaun (1008)
Presented to:
Respected Prof.Sadia
Group-8

2. MICROBES
Microbes are microorganisms which means
they cannot be seen with the naked eye and we
use microscope to see and observe them.
Examples:
Bacteria, archaea, and single cell, amoeba or a
paramecium. Sometimes we call viruses
microbes too.

3. Introduction of Microbial Metabolism
The term metabolism denotes all chemical reactions & physical
workings occurring in a cell.
Energy production from metabolism helps a bacterial cell to be
extensive and varied.
 Energy which produces from metabolism system is required for
synthesis of enzymes, nucleic acids, polysaccharides and other
chemical components.
Energy is also required for repair damage of cell.

4. Metabolism
Metabolism is the chemical reaction and it is the use of body cell which breaks food into energy
and then this energy will be used by the body to move and grow and this chemical reaction is
controlled by specific proteins.
There are two types of metabolism:
Metabolism
Anabolism Catabolism

5. Types of Metabolism
Catabolism
A building and bond-making process that forms larger macromolecules from
smaller ones.
Requires the input of energy stored in the bonds of ATP.
Examples;
Catabolic processes are proteins becoming amino acids, glycogen breaking
down into glucose and triglycerides breaking up into fatty acids.
Anabolism
Breaks the bonds of larger molecules into smaller molecules.
Release energy.
Examples;
Include the formation of polypeptides from amino acids, glucose forming
glycogen and fatty acids forming triglycerides.

6. Types of Microbial Metabolism
All microbial metabolisms can be arranged according to:
 Autotrophs:
An autotroph is an organism that can produce its own food using light, water, carbon dioxide, or
other chemicals.
Examples of autotrophs include plants, algae, plankton and bacteria.
 Heterotrophs:
A heterotroph is an organism that eats other plants or animals for energy and nutrients.
Dogs, birds, fish, and humans are all examples of heterotrophs.
 Phototrophs:
An organism, typically a plant, obtaining energy from sunlight as its source of energy to convert
inorganic materials into organic materials for use in cellular functions such as biosynthesis and
respiration.
These organisms are purple non-sulfur bacteria, green non-sulfur bacteria, and heliobacteria

7.  Chemotrophs:
Chemotrophs obtain their energy from chemicals (organic and inorganic compounds).
They include organisms that use chemical reaction to obtain energy.
 Lithotrophs:
Lithotrophs are a diverse group of organisms using an inorganic substrate to obtain
reducing equivalents for use in biosynthesis or energy conservation via aerobic or
anaerobic respiration.
 Organotrophs:
An organotroph is an organism that obtains hydrogen or electrons from organic
substrates.

8. Enzymes
 Enzymes are proteins that act as biological
catalysts.
 Catalysts accelerate chemical reactions.
 The molecules upon which enzymes may act
are called substrates.
 Enzyme converts the substrates into different
molecules known as products
 They have a globular shape.
 A complex 3-D structure.

9. Transfer reaction of enzyme
 Oxidation-reduction reactions:
Transfer of electrons.
 Aminotransferases:
Convert one type of amino acid to another by
transferring an amino group.
 Phosphotransferases:
Transfer phosphate groups, involved in energy
transfer.
 Methyltransferases:
Move methyl groups from one molecule to another.
 Decarboxylases:
Remove carbon dioxide from organic acids.

10. Fermentation
 Fermentation is a specific type of heterotrophic metabolism that uses organic carbon instead of oxygen as
a terminal electron acceptor.
 In the absence of aerobic or anerobic respiration, NADH is not oxidized by the ETC. This is because no
external electron acceptor is available. But to continue the metabolism, NAD must be regenerated. In such
situations, microorganisms do not convert pyruvate into Acetyl - CoA.
 Instead, they use pyruvate or its derivatives as an electron acceptor for reoxidation of NADH.
It also leads to production of ATP.
 The lactic fermentation is a typical example:
 Bacteria produce energy by fermentation.
 Streptococcus lactis.

11. Glycolytic pathway
The pathway is also known as Embden–Meyerhof–Parnas(EMP)
pathway.
 It is the common pathway for glucose degradation to pyruvate
and is found in animals, plants and large number of microorganism.
 This pathway is used by anaerobic as well as aerobic organisms.
 The process takes place in the cytoplasm of prokaryotes and eukaryotes.
 The pathway consists of ten enzyme- catalyzed reactions that
begin with a glucose molecule.
These reactions comprise three stages:
 Conversion of glucose into fructose 1,6 - bisphosphate
 Splitting of the fructose 1-6- bisphosphate into two three- carbon
fragments.
 The formation of pyruvate along with ATP generation.

12. Glycolytic process

13. Glycolytic pathway

14. Krebs's cycle
The Kreb's cycle is named after its discoverer, British scientist
Hans Adolf Krebs (1900–1981).
Kreb's Cycle also called;
 Citric acid cycle
 Tricarboxylic acid cycle (TCA).

15. Kreb's cycle Process
The Krebs cycle takes place in the cytoplasm of bacteria and in the
mitochondrial matrix of eukaryotes:
 Transfers the energy stored in acetyl CoA to NAD+ and FAD by
reducing them (transferring hydrogen ions to them).
 NADH and FADH2 carry electrons to the electron transport chain.
 Two ATPs are produced for each molecule of glucose through
phosphorylation.
 Along the way, acetyl CoA, which joins with oxaloacetic acid, and
then participates in seven other additional transformations.

16. Kreb's cycle Process

17. Nitrogen cycle
 The nitrogen cycle is the process by which nitrogen is converted between its
various chemical forms. This transformation can be carried out through both
biological and physical processes.
 Jules Reiset recognized in 1856
that decaying organic matter releases
nitrogen.
This discovery ultimately provided
the basis for the nitrogen cycle because
it was the first evidence of nitrogen
cycling in the biological sphere.

18. Nitrogen cycle
Nitrogen Cycle Nitrogen cycle consists of the following steps:
 Nitrogen Fixation
 Nitrogen assimilation
 Ammonification
 Nitrification
 Denitrification.