Isolation and Identification of

Industrially Important Microbes

.

Presented To: Dr. Shahjahan

Presented By: Amina

Hussain

PhD Biotechnology

1st Semester

University of Punjab , Lahore

POINTS TO BE DISCUSS

Economic and

industrial

importance

of microbes

Identification of

microbes

Isolation of microbes

Introduction

Industrial microbiology and biotechnologyassociates with the commercial exploitation ofmicrobes for the benefit of mankind.

Microorganisms are used to create a widevariety of products and to assist inmaintaining and improving the environment

These microbial products may have direct orindirect impact on the economics,environment and social parameters of thesociety.

Commercially

Environmental Economically

Microbes are

important

industrially

Microbes have wide scope in different

areas. Some of them are, starter cultures in commercial food

and beverage production.

Products of alcoholic fermentation.

Production of Enzymes and other industrial products.

Production of Pharmaceuticals, like antimicrobials, recombinant

hormones, and other cell regulators.

Pesticides and agricultural products

Biosensors and bioreporters.

ISOLATION OF INDUSTRIALLY IMPORTANT MICROBES

Isolation is having mainly 2 strategies

1) From the environment by collecting samples of free living microorganism from natural habitats.

2) By sampling of microbes with desired characteristics from specific sites such as found among the natural micro flora.

The site for isolation of microbes is decided by the type of microbe one is interested in.

Methods of isolation of microbes (isolation of pure culture

from mixed culture)

• Streak Plate Method

• Spread Plate Method

• Pour Plate Method (Serial Dilution Method)

Plating Techniques (Classical Methods)

• Laser Tweezers

Microscopic Tool (New

Technology)

Streak plate method

Sterilize the wire loop.

Cool the loop

Dip the loop into culture

containing the mixture of bacteria.

Drag the loop over the top

one-third of the plate back and forth in a "zig-zag" formation.

It is one of the commonly used isolation techniques

In this way a number of microbes are spread out over the surface of the

agar.

Sterilize the loop in the flame.

Turn the plate 90 degree and repeat the streaking

procedure

Sterilize the loop in the flame.

Turn the plate again at 90 degree

Repeat the procedure 3rd time for t streak method and for quadrant streak method repeat for one

more time.

Be very careful not to touch any of the areas previously streaked.

Incubate the plate for 24 hours.

If streaking is correctly, you will see isolated colonies in the third

sector.

The heaviest growth will be in the first sector. There will be less

growth and some isolated colonies in the second sector.

The third area should have the least growth with isolated colonies.

Original sample is diluted several times to thin out the population sufficiently.

Most diluted samples are then mixed with warm agar and poured into petri dishes.

Isolated cells grow into colonies on the surface or subsurface.

Used to establish Pure Culture.

Pour plate method

The pour-plate technique also will yield isolated colonies and has

been extensively used.

Spread plate method

Useful for isolating slow growing bacteria & organisms

present in less number.

Cell is isolated from microscopic field & moved away from mixture of cells.

Consists of an inverted light microscope

equipped with infrared laser &

micromanipulation device.

THE LASER TWEEZERS

Mixed Sample in Capillary tube

Focus laser beam

Traps a single cell & drags down the optically

trapped cell.

Cell moves away from contaminants

Capillary is severed

Cell is flushed into a tube of sterile medium

IDENTIFICATION OF INDUSTRIALLY IMPORTANT MICROBES

After the isolation of bacteria, it is important to identify the specified bacteria.

Identification is mostly done with the help of following characteristics

Morphology Selective and diagnostic

media,Cultural

characteristics

Additional recognized

biochemical tests,

Profile of microbial

stains, and

It is the science dealing with the structures and

forms of organisms.It includes

MorphologyShape

length and breadth,

body arrangeme

nt

Motility

formsspores

capsule

It specifically favour thegrowth of particularmicroorganisms.

Eg. MacConkey’s agarmedium for E. coli.

Differential media, Enrichmentmedia, and Characteristicmedia are types ofidentification techniques.

Selective and differential media

These tests are extensively used for identification

purpose. These tests are,

Carbohydrate (Sugar)

Fermentation

Litmus Milk,Indole Production

Methyl Red Test [MR-Test]

Voges-Proskauer Test [VP-Test]

Citrate Utilization, etc.

ADDITIONAL RECOGNIZED BIOCHEMICAL TESTS

Microbes are extremely small in size, hence to visualize them,

staining is takes place, in which either cell interior or exterior part

stains in color.

Different Staining technique includes, Differential staining, Capsule staining ; Endospore staining ; Flagellar staining.

Profile of microbial stains

These characteristics are,

Shape, Size, Elevation Margins,

Surface, Edges,Colour , Structure,

Consistency, etc.

Cultural characteristics