Transcript Microbial Biotechnology

Lab 2
Reem Alsharief
Microbes (or microorganism): are organisms that are too
small to be seen by the unaided eye they include bacteria,
fungi, protozoa, microalgae and viruses.
•They live in familiar settings such as soil, water, food,
animal intestines, rocks, hot springs and deep sea vents.
•The wide variety of microbial habitats reflects an enormous
diversity of biochemical & metabolic traits that have arisen
by genetic variation.
Is the totality of genetic material in the DNA of a
particular organism.
Genomes differ greatly in size & sequence across
different organisms. Obtaining the complete genome
sequence of a microbe provides crucial information
about its biology, but is the only first step toward
understanding a microbe’s biological capabilities and
modifying them, if needed, for agriculture purposes
The mapping of microbial genomes is a key technology
to understanding microorganisms and devising ways
to improve their use in agriculture production, food
safety & security, Biotechnology, human nutrition,
functional foods, plant& animal protection and biobased chemicals
1-The Light Microscope: a type of microscope which uses
visible light and a system of lenses to magnify images of
small samples
2-Autoclave: is an instrument used to sterilize equipment
& supplies by subjecting them to high pressure saturated
steam at 121̊ C for around 15-20 minutes depending on the
size and the load and the content.
3-Incubator: is a device used to grow and maintain
microbiological cultures on cell cultures.
4- Hot Air Oven: are electrical devices used in
sterilization, it uses dry heat to sterilize articles, operated
from 50-300 ̊ C
5-Water Bath: is a tool used to maintain a very stable
temperature .
6- PH meter: an electronic instrument used for
measuring the PH of liquid.
7- colony counter: used to count colonies of bacteria or
other microorganism growing on agar plate.
8-Delicate Scales: it is used to scale some cultures&
chemical objects in high tech.
9-Bunsen burner: it produces a single open flame
which is used for heating, sterilization and
combustion>
10-Magnetic Stirrer: a device that employs a rotating
magnetic field to cause a stir bar immersed in a liquid to
spin very quickly.
11- Hot Plate: are generally used to heat glassware or its
contents.
12-Vortex Mixer: a simple device used commonly in
laboratories to mix small vial and liquids
13- Centrifuge: it puts an object in rotation around a
fixed axis applying a force perpendicular to the axis.
14- Spectrophotometer: is the quantitative
measurement of the reflection or transmission
properties of material as function of wave length.
15-Biosafety cabinet: is an enclosed, ventilated
laboratory workspace for safety working with materials
contaminated with pathogens requiring a defined
biosafety level.
Petri dish
Glass Pipettes
Microscopically slides
Cover slide
Inoculating Loop
Inoculating Needle
Culture Tubes
Cork Borer
Holder
Forceps
filter Paper
Conical flask
Cylinder
Beaker
Cotton Swab
Funnel
spatula
Glass Rod
Staining dishes
Pipette Pump
Dropper
Lab thermometer
Petri dish sterilizing box
Sterilization (or sterilisation) is the elimination of all
transmissible agents (such as bacteria, prions and viruses)
from a surface or piece of equipment. This is different from
disinfection, where only organisms that can cause disease
are removed by a disinfectant.
Sterilization Methods:
First: Heat Sterilization:
Probably the most widely used method for sterilization.
heat methods include using dry heat, moist heat,
flaming and incineration
•
A-flaming: is done to loops and straight-wires, Leaving
the loop in a Bunsen burner until it glows red, ensures
that any infectious agent gets oxidized completely into
small molecules. Heating small metal or glass objects is
really the extent to which this method is used.
•B-Incineration will also burn any organism to ash It
obviously is only used to sanitize unwanted medical and
other waste before its ash goes to the tip
•C-Dry heat can be used to sterilize glassware,
fixed oils
and Thermo table powder, but as the heat takes much
longer to be transferred to the organism, both the time,
and the temperature required, must be increased. The
standard setting for a hot air oven is at least two hours at
160°C. A rapid method heats air to 190°C for 6–12 hours.
Dry heat has the advantage that it can be used on
powders and other heat-stable items that are adversely
affected by steam.
•D-Moist Heat: Kills microorganisms by coagulating their
proteins. In general, moist heat is much more effective than
dry heat.
•Boiling: Heat to 100oC . Kills vegetative forms of bacterial
pathogens, almost all viruses, and fungi and their spores
within 10 minutes or less. Endospores and some viruses are
not destroyed this quickly. However brief boiling will kill
most pathogens. Examples:
Hepatitis virus: Can survive up to 30 minutes of boiling.
Endospores: Can survive up to 20 hours or more of boiling
•However, reliable sterilization with moist heat requires
temperatures above that of boiling water so Steam under
Pressure by using the Autoclave is the preferred method
of sterilization where temperature of steam reaches 121oC for
15 min-20 min.The steam and pressure allow sufficient heat
is transferred into the organism to kill them
•
It is a physical removal of microorganisms by adsorption on
the filter medium. Used for heat sensitive materials.
Equipments needed for bacterial filtrations are:
Porcelain filters
Siliceous earth filters
Sintered glass filters
Asbestoses filters
Membrane filters
• Third:
Gasous Sterilization:
Equipment: special oven for admission of gas and humidity and hermetic
Method: humidity of less than 20% RH and the use of Ethylene Oxide
•Forth: Radiations sterilizations:
Equipment: Ultraviolet Lamp-Ionization( Beta Rays, Gamma Rays, X-Rays)
•Fifth: Sterilization by chemicals:
•Bactericides (Germicides): substance that kills vegetative bacteria and
some spores
•Bacteriostat : substance which stops growth and multiplication of bacteria
but does not necessary kill them. Growth usually resumes when
bacteriostat is removed.
•Antiseptic: Substance used to prevent multiplication of microorganism
when applied to living systems.
•Viricide: an agent that inactivate viruses
•Fungicides: an agent that kills fungi
•Some of these chemical substances:
Ethyl Alcohol 2. Chloroform 3. Phenol 4. Cresol 5.Mercuric chloride
Culture is the term given to microorganisms that are
cultivated in
the lab for the purpose of studying them.
Medium is the term given to the combination of
ingredients that will support the growth and cultivation
of microorganisms by providing all the essential
nutrients required for the growth (that is,
multiplication) in order to cultivate these
microorganisms in large numbers to study them
•Among the different kinds of microorganisms the two
groups that can be grown in cultures are bacteria and
fungi.
•Algae and protozoa require many different nutrients
that are difficult to anticipate and prepare in the lab.
•The microorganisms have different nutritional
requirements and thus various kinds of culture media have
been developed.
•Primary ingredients required by all living organisms
include:
a carbon source, water, minerals, and a nitrogen
source.
Since there are different kinds of organisms that can be
grown in culture media with varying needs, culture media
have also been formulated with different ingredients.
Culture media may be classified in physical form as:
1. liquid (called broth)
2. semi-solid
3. solid.
Media are solidified by the addition of solidifying agents
such as
agar (inert compound).
Varying the concentration of agar will yield varying degrees
of solidification.
Culture media may be classified in chemical characteristic as
1.Synthetic media (Defined): A chemically defined
medium is one prepared from purified ingredients and
therefore whose exact composition is known.
2.Complex media (Non-synthetic :medium contains at least
one component that is neither purified nor completely
characterized nor even completely consistent from batch
to batch.
Culture media can also be classified based on the function
they perform in determining various characteristics of
organism that are able to grow on/in them
e.g. Differential, Selective media.
The ingredients in a medium will affect the chemical nature of
the
medium.
This is important because organisms vary in their requirement for
different environments.
One such property is:
pH (which is a measure of the amount of hydrogen ions in a
particular medium).
This has to be monitored during the preparation of media since
this
will influence the kind of organisms that are able to grow in the
medium.
The pH of the medium will thus determine which organisms are
able to grow on the medium.
For example, fungi prefer acidic media for their growth while
bacteria
grow on neutral pH media.
Thank you