this is a view slides that you can easily know the nutrition of bacteria.....

1. Bacterial nutrition

2. Nutrient requirements
 Microorganisms require about ten elements in
large quantities, because they are used to
construct carbohydrates, lipids, proteins, and
nucleic acids.
 Several other elements are needed in very small
amounts and are parts of enzymes and cofactors.

3. Macronutrients
• 95% or more of cell dry weight is made up
of a few major elements: carbon, oxygen,
hydrogen, nitrogen, sulfur, phosphorus,
potassium, calcium, magnesium and iron.
• The first six ( C, H, O, N, P and S) are
components of carbohydrates, lipids,
proteins and nucleic acids

4. Trace Elements
 Microbes require very small amounts of
other mineral elements, such as iron, copper,
molybdenum, and zinc; these are referred to
as trace elements. Most are essential for
activity of certain enzymes, usually as
cofactors.

5. Growth Factors
(1)Amino acids
(2) Purines and pyrimidines,
(3) Vitamins
 Amino acids for protein synthesis
 Purines and pyrimidines for nucleic acid synthesis.
 Vitamins are small organic molecules that usually
make up all or part enzyme cofactors, and only
very small amounts are required for growth.

6.  The growth of microorganisms depends on
adequate supply of suitable nutrients,pH,
oxygen and temperature.
 All bacteria have three major nutritional needs
for growth:
 A source of carbon for making cellular
constituents.

7.  A source of nitrogen for making protein.
 A source of energy (ATP) in order to
synthesize macromolecules.
 Smaller amounts of molecules such as
phosphate for nucleic acids and ions for
enzymatic activity.

8.  Bacteria are divided according to their nutrition
needs:
1. autotrophs: they can utilize very simple
inorganic compounds like carbon dioxide as
carbon source and ammonium salts as nitrogen
source .
 Also known as lithotrophs
 Obtained energy either photosynthetically
(phototrophs) or by oxidation of inorganic
compound (chemolithotroph).

9. 2. hetrotrophs:
 Bacteria are unable to synthesis their own
metabolites.
 And depend on performed organic compounds
are known as heterotrophs.
 They require an organic source of carbon such
as glucose, and obtain energy by oxidizing or
fermenting organic substances.

10.  The same substances is used as both the
carbon source and energy source.
 All bacteria inhabit the human body fall into
the heterotrophic.

11. Culture media
 The original media used by Louis Pasteur were
liquid like meat broth .
 Ropert Koch first used the solid media
 Culture media are needed to grow
microorganisms in the laboratory and to carry
out specialized procedures like microbial
identification, water and food analysis, and the
isolation of particular microorganisms.
 A wide variety of media is available for these
and other purposes.

12. Types of culture media
 Base media
 Enriched media
 Selective media
 Differential media or indicator media
 Transport media

14. Environmental factors influencing
growth
 Oxidation reduction:
bacteria are divided into two groups:
1. Aerobes: require oxygen for their growth.
They may be obligate aerobes like
Pseudomonas which grow only in the
presence of oxygen and facultative
anaerobes grow in present or absence of
oxygen.
2. Anaerobes: they don’t required oxygen for
their growth.

15.  They may be obligate anaerobes like
Clostridium tetani and microaerophilic like
C.perfringenes.

16. Carbon dioxide
 Some organisms like Brucella abortus
required extra CO2 in the air .
 Others like pneumococci and gonococci
grow better in air supplemented with 5-
10% CO2 (capnophilic).

17. Temperature
 Pathogenic bacteria the optimum temperature
for their growth is 37 C (our body temperature)
which called as mesophiles.
 Organism with optimum temperature less than
20 C called psychophiles .
 Other with an optimum 55-80 are known as
thermophiles .

18. pH
 most of medical important bacteria grow at
neutral or slightly alkaline pH (7.2-7.6).
 Some bacteria like lactobacilli grow at acidic
pH while vibrio grow at alkaline pH .