This document defines and describes various types of microorganisms. It explains that microorganisms include bacteria, fungi, protozoa, viruses, and other microscopic organisms. While some microorganisms are harmful and can cause disease, others play important roles in industries like food production, waste decomposition, and more. The document also provides details on the characteristics, structures and uses of specific microorganisms like bacteria, algae, fungi and protozoa.

2. Microorganism
• Micro means tiny.
• Organisms means living things.
• There are many types of microorganisms. Types
of microorgaanism can be categoried as
Bacteria
Fungi, Moulds and Yeast
Protozoa
Virus
Rickettsias
Mycoplasmas

3. • We cannot see some of them with our naked
eyes, because they are so tiny.
• So we need to use microscope.
Bacteria
• Bacteria are a large group of unicellular
microorganisms.
• Have a wide range of shapes, ranging from
spheres to rods and spirals.
• Most kind of bacteria are harmless and many
even helpful.
• Its causes diseases such as diarrhea, sore throat.

4. Microbes in our lives
• Some are pathogenic (disease-causing)
• Decompose organic waste
• Produces through photosynthesis (e.g.Purple sulphur bacteria
must fix CO2 to live)
• Play role in industry (e.g. fermentation to produce ethanol and
acetone)
• Produce fermented food (vinegar, cheese & bread)
• Produce products used in manufacturing (cellulase) and
treatment (insulin)

5. Microbes in our lives
Food
• Lactococci
• Ferment milk
Water treatment
Such as certain bacteria belonging to the Bacillus species
1. Digest a wide variety of organic material that are present in wastes.
2. Digest waste quickly and completely, without producing significant odors of noxious gas.
3. Non-pathogenic.
4. Grow and reproduce quickly and readily in the environmental conditions found in waste disposal systems.
Energy
• Produce methane
Science- laboratories
Warfare -anthrax

6. Microbes and agriculture
• Nitrogen fixation
• Rumen microbes help digest grass and hay in cows,
sheep etc
• Cycles nutrients (C, N and S)
• Causes disease to animals and plants

7. Microorganism and Food
• Microorganism and food
1) Prevent spoilage (tempeh, salted fish)
2) Assist in manufacturing of food
• Microorganisms and energy
1) Natural gas (methane)
2) Ethanol (biofuel)
3) Bioremediation
• Microbes and the future
1)Genetic engineering

8. Microbes and diseases

9. • Bacteria are unicellular and are among the smallest organisms.
• In favourable conditions, bacteria will reproduce rapidly by binary
fission, an asexual process whereby one bacteria can split into
two every 10-15 minutes.
• In unfavourable conditions, bacteria may survive by becoming
dormant. They form spores with a thick, protective coat around
them, which will split open in favourable conditions.
• Endospores are spores created by a small group of bacteria. They
are specialized to withstand unfavourable conditions. They can
survive for thousands of years and can cause diseases such as
tetanus and anthrax.

10. • Bacteria vary in shape and can be
classified accordingly:
– Spherical bacteria are called cocci
– Rod-shaped bacteria are called bacilli
– Spiral shaped bacteria are called spirilla
– Comma-shaped bacteria are called
vibrios.
• Can occur singly, in chains
(streptococcus) or in clumps
(staphylococcus).

11. Morphologic arrangements of
bacteria.

13. • Bacteria are unicellular and are made up of simple cells, but can
carry out all the functions of living organisms.
• Have a rigid cell wall which consists of large peptidoglycan*
molecules.
• They have a plasma membrane, which serves as a mitochondrion,
endoplasmic reticulum and sometimes a chloroplast. Also controls
exit and entry of materials.
• As prokaryotes, they do not have a true nucleus. This is because
they do not have a true nuclear membrane and the DNA isn’t
combined with the protein found in eukaryotes.
• Single chromosome of DNA – closed loop.
• Pathogenic bacteria have a waxy capsule.
• Some bacteria have flagella to enable them to move around.

14. Structure

15. Structure of bacterial cell:
1) Capsule: Cell surrounded by gelatinous or slimy material forming a protective
covering layer or envelop.
• It consists of polysaccharide or polypeptide. It protects the organism against
environmental changes.
2) Cell wall: It is a rigid structure that renders the cell capable of survival even when
there are great differences of osmotic pressure between cell and environment. It is
made up of protein and polypeptide with mucin, polysaccharide or phospholipids
components. It encloses cytoplasm and cytoplasmic membrane. It gives shape to
the cell.
3) Cytoplasmic membrane: It is a semi permeable membrane beneath the cell wall. It
is composed of phospholipids and proteins. It controls the passage of nutrients
and waste products into and out of the cell.
4) Nucleus: Nucleus is not well defined but nuclear material is present near the Centre
of the cell. The total nuclear material called nucleoid, consist if a single circular
chromosome and it contains genetic material such as RNA and DNA
5) Cytoplasm: It consists of about 80% water along with nucleic acids, proteins
carbohydrates, lipids, inorganic ions, many low molecular weight compounds and
particles with various functions.
6) Ribosomes: Ribosomes are present in cytoplasm and are sites of protein synthesis.
7) Flagella: Thin hair like filament that extends from cytoplasmic membrane and
through the cell wall. It is an organ of locomotion.

16. – Eukaryotic (have a true nucleus)
– All live in moist environments as they have no means of preventing
themselves from drying out.
However, there is a lot of variety in this group. The following
characteristics are variable:
– Can be unicellular or multicellular
– Can be microscopic or over 100 metres long
– Can be heterotrophs or autotrophs.
The Protista Kingdom is grouped into the following subcategories:
– Plant-like protista
– Animal-like protista

17. Plant-like Protista are known as algae.
• Algae are simple, aquatic eukaryotes (have true nuclei)
• Contain chlorophyll. They photosynthesis, thus they are autotrophic.
• Release large chains of oxygen during photosynthesis.
• Mostly free-floating but some, e.g. kelp, are attached.
• Can be unicellular: e.g. diatoms, or multicellular: e.g. seaweeds.
• Usually reproduce asexually and sometimes sexually.
• Grouped into: green algae, brown algae, red algae, yellow-green,
orange, olive, diatoms and dinoflagellates.

18. Algae can be divided into the following groups:
• Green algae
– e.g. spirogyra (slime found in fresh water) and green seaweeds (found
in shallow water – for photosynthesis)
• Brown algae,
– e.g. kelp (found in deep water)
• Red algae,
– e.g. red seaweeds (found in deep water)
• Diatoms
– microscopic, unicellular algae whose cell walls contain silica.
• Dinoflagellates
– microscopic, unicellular algae with flagella. Found in surface waters.

19. Uses
• Human food-because rich in carbohydrates and
vitamins
• Food for fishes and other animals
• Source of iodine- eg. Sea weeds
• As laxative and manufacturing of pills and ointments-
agar-agar from gelidium and gracilariya
• As a culture medium- agar
• To increase fertility of soil and improve growth of
plant- blue-green algae
Some algae are nuisance to water reservoirs.

20. Fungi
• Fungus is a eukaryotic organism that is a member of the
kingdom protists and sub group thallophyata.
• Fungi . Some of them can look with naked eyes, but some of
them can not.
• Example yeast is one of the useful microorganism that we
need to use microscope to look them.
• Yeast can help people to produce delicious bread and cake.

21. • PROTOZOA
• Protozoa are microorganisms classified as unicellular
eukaryotes.
• Can be harmless and harmful.
• Malaria is one diseases cause by a kind of protozoa.

22. • Microbiology is the study of microscopic organisms It is derived from three greek
words ‐mikros
• ("small"), bios ("life") and logos (science") .
• There is close association of microbes with the health and welfare of human beings.
Some of
• them are beneficial while the others are harmful to mankind. The microbes which
are beneficial to us are involved in the formation of curd, wine, alcohol, in the
production of antibiotics like penicillins, streptomycin. They are also involved in
processing and recycling of domestic and industrial wastes, and help in cleaning up
of the environment.
• The harmful microbes cause serious diseases to humans, animals, plants. They also
cause deterioration of food and other materials. Because of this association,
microbiology has emerged as one of the most important branches of life sciences.

23. • Virus• A virus is a microscopic infectious agent that can only
reproduce inside a host cell.
• Can infect human, plants and animal.
• Virus are responsible for many serious diseases and sometime
deadly such as AIDS.
USAGE OF MICORORGANISM : Making curd and Bread
Medicinal use of Microorganism : Increasing Soil Fertility,
Cleaning the Environment, Vaccine Production of alcohol and
wine