This document discusses primary and secondary metabolites produced by microorganisms. It notes that primary metabolites are essential compounds for cell growth produced during balanced growth, while secondary metabolites are non-essential compounds produced after exponential growth. Some examples of primary metabolites include vitamins, amino acids, and fermentation end products like ethanol or lactic acid. Secondary metabolites are specifically produced by certain microorganisms and can have unknown beneficial functions. The document also provides an overview of techniques for isolating microorganisms from soil and screening isolates for desirable compound production.

1. PRESENTED BY
L.SUKANYAGANDHI
II-MSC FOOD SCIENCE AND NUTRITION

2. INTRODUCTION
 The microorganisms posses tremendous
capacity to produce a wide range of products that
have commercial value.
 The primary and secondary metabolisms and
bioconversions of microorganisms with special
reference of their importance for the formation of
biotechnologically important products.

3. PRIMARY METABOLITES:
 Primary metabolites also referred to as
trophophase is characterized by balanced growth of
microorganisms. It occurs when all the nutrients
needed by the organisms are provided in the
medium.
 In the trophophase, the cells posses optimal
concentrations of almost the macromolecules
(protein DNA, RNA etc.)

4.  It is during the period of trophophase, an
exponential of microorganisms occurs.
 several metabolites, products are produced in
trophophase(I,e during the period of growth).
The primary metabolites are divided into two groups.
 primary essential metabolites
 primary metabolic end products

5. 1.PRIMARY ESSENCIAL METAMALITES:
These are the compounds produced in adequate quantities
to sustain cell growth e.g. vitamins, amino acids,
nucleosides.
2.PRIMARY METAMOLIC END PRODUCTS:
 These are the normal and traditional end product of
fermentation process of primary metabolism.
 The end products may or may not have any significant
function to perform in the microorganisms, although they
have many other industrial application.
E.g ethanol, acetone, lactic acid.

6. As the exponential growth of the microorganisms
ceases (i.e. as the trophophases ends) they
enter idiophase.
 Idiophase is characterized by secondary
metabolism where in the formation of certain
metabolites, referred to as secondary
metabolites (idiolites) occurs.

7. CHARACTERISTICS OF SECONDARY METABOLITES:
 Secondary metabolites are specifically produced by
selected few microorganisms.
 They are not essential for the growth and reproduction
metabolites.
 The biosynthetic pathways for most secondary metabolites
are not clearly established.
 The regulation of the formation of secondary metabolites
is more complex and differs from that of primary
metabolites.

8. FUNCTIONS:
 As already stated secondary metabolites are not
essential for growth and multiplication of cells.
 The secondary metabolites may perform certain
(unknown) functions that are beneficial for the cells to
survive.
 The secondary metabolites have absolutely no function.
Their production alone is important for the cell, whatever
may be the product. (which is considered to be useless).

9.  There are over a million species of microorganisms
widely distributed in nature.
 Less than 1% of the world’s microorganisms have
been studied.
 In fact only a few hundred species are important for
industrial use.

10. MICROORGANISMS PRODUCTS
ALGAE:
Chlorella sorokiniana
Spirulina maxima
Single-cell protein
Single-cell protein
BACTERIA:
Acetobacter acetic
Bacillus subtitis
Acetic acid.
Bacitracin.
ACTINOMYCETES:
Streplomyces aureoraciens
Micromonospera purpurea
Tetracycline
Gentamycine.
FUNGAI:
Aspergillums' Niger
Candida lipolytica
Citric acid
lipase

11.  The good sources for the isolation of microorganisms are soils,
lakes and river mud's.
 It is estimated that a gram of soil contains 10-10 bacteria, 10-10
acitomycete spores and 10-10fungal spore.
The common techniques employed the isolation or microorganisms are
given below.
1. Direct sponge of the soil.
2. Soil dilution.
3. Gradient plate method

12. 4. Aerosol Dilution
5. Flotation
6. centrifugation.
 The general scheme adopted for isolating microorganism from
soil or water source is given below.
 The sample is diluted with sterile water to which on emulsifying
agent is added.
 Sample is thoroughly mixed and allowed to stand at room
temperature.

13.  Supernatant is diluted 10-1 to 10-1
 Various culture media are inoculated with diluted samples and
incubated.
 Colonies from the plates are isolated & identified.
 The required pure stains are maintained and preserved.

14.  Screening is the next important step in bio processing, where the
isolates are investigated for producing the desired product .
Screening BASICALLY OF TWO TYPES:
 Primary screening
 Secondary screening
Primary screening is checking the quality of microbes. most cases
of primary screening are done on agar plates.

15. Secondary screening is checking of isolates for their quantitative
production in liquid media.
PRIMARY SCREENING:
 Primary screening for enzyme is done by culturing the isolates in
agar plates incorporated with specific substrate.
 The production of a specific enzyme can be detected in two
ways: by observing the substrate utilization zone around the
colonies of isolates or by adding reagents to the end product of
the reaction, which shows the utilization zone.

16.  Secondary screening deals with production in liquid and
quantification of products.
 The product can be evaluated with agar plates and other
appropriate methods.
 Secondary screening of enzymes is done through well-method
in agar plates.
 The agar plates are incorporated with specific
substrates and wells are made in therm.

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