bar1_microbiology.ppt

butterbeanscubaBiotechnology

Dec 12, 2012 (4 years and 6 months ago)

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Microbiology in Agriscience
and Production Agriculture

Competency 11.00

What is a virus?


A virus is an organism composed of a
DNA or RNA core surrounded by a
tough protein outer coat.


NOT CLASSIFIED AS A TRUE LIVING
ORGANISM


Cannot reproduce sexually, only through
division in a HOST (viruses are parasitic)


Reproduce quickly, mutate often, and can
survive harsh environmental conditions

Viruses


Responsible for
some of the most
dangerous human
ailments


Can be destroyed
by altering DNA

HIV Virus

Viruses


Often used as a vector to transport
genes into organisms when genetically
modifying organisms.

Types of Viruses


Tobacco Mosaic Virus (TMV)
-
often
used as a vector for genetic engineering
in plants
-
1 long RNA molecule


Bacteriophage
-
DNA packaged tightly in
a protein head
-
often used in genetic
engineering

Types of Viruses


Common viruses


Human Immunodeficiency Virus(HIV)


Influenza


Common Cold


Measles


Norwalk


Hepatitis


Rabies

Measles

Prokaryotic Organisms

What is a prokaryotic
organism?


A single celled
organism that has no
membrane bound
organelles and no
distinct nucleus.


Usually have very
short life spans


Characteristics of Prokaryotic
Organisms


Contain free
-
floating DNA


Can be autotrophic (produce their own
energy) or heterotrophic (consume
other things for energy)


Also reproduce quickly and mutate
often, but are not as tough as viruses

Examples of Prokaryotic
Organisms


Bacteria


Cyanobacteria


Blue
-
green algae

Blue
-
green Algae

Bacteria

Characteristics of Bacteria


Can be beneficial or harmful to humans


Unlike viruses, bacteria are not
PARASITES, and do not need a host


Molds and funguses including yeast are
not bacteria

Beneficial Bacteria


Provide a benefit to human activity
through normal function or manipulation
through biotechnology techniques


Examples:


Nitrobactus alkalikus


Lactobaccillius sp.

Nitrobactus alkalikus


Bacteria occurring naturally in soil on the roots
of legumes, that change nitrogen in the air to a
form useful for plants


Nitrogen fixing

Lactobaccillus sp.


A genus of microorganisms that have
been introduced to foods (often dairy
products) to aid in digestion

Harmful Bacteria


Affect agriscience products and
processes in a negative manner,
affecting both plants and animals


Example:


Eescherichia coli (E. coli)


Clostridium boutlinum


Salmonella enteriditus


Pythium spp.

Destroying Harmful Bacteria


Sterilization
-
kills all living organisms in a
or on a substance


Pasteurization
-
kills most harmful
microorganisms, leaving some
beneficial organisms surviving

Multiform Bacteria


Can either be beneficial or harmful to plants
under different circumstances and conditions


Example:


Agrobacterium tumefaciens
-
naturally occurring
bacteria that penetrates plant cells transmitting its
own DNA to the cells and causing the growth of a
gall (tumor like mass)


Used in genetic engineering to transmit genes

Agriscience Uses of Bacteria


Pharming


Bioremediation


Biocontrol


Biofuels


Example of Pharming


Inclusion of
cholesterol
consuming
bacteria in milk
products to
lower human
cholesterol

Bioremediation


Use of bacteria that consume
contaminants in soil and water


Example
-

bacteria used to “eat” oil from
tanker spills, or excess organic nutrients
from animal waste


Biocontrol


Use of beneficial bacteria in horticulture
to kill harmful bacteria in soil, water and
on plant surfaces.

Biofuels


Very few applications in renewable
energy or biofuels now, but lots of
potential applications

Eukaryotic Cells

What is a Eukaryotic Cell?


Advanced cells characterized by the
presence of membrane bound
organelles and a distinct nucleus.


Usually occur in multicellular organisms,
but also include a few single celled
Protists.

Eukaryotic Cell Structures


Cell membrane


Golgi apparatus


Mitochondria


Nucleus


Ribosomes


Vacuoles

Cell Membrane


Selectively permeable
membrane surrounding all
eukaryotic cells.


Protects the cell and controls
the movement of substances
into and out of the cell.

Golgi Apparatus


Center for the
distribution of proteins,
enzymes, and other
materials through the
cell


Like the post office

Mitochondria


Structures inside the cell that convert
simple sugars to a useful form of
cellular energy through the process of
respiration

Nucleus


A large central segment of the
eukaryotic cell that contains the cell’s
genetic information (DNA)

Ribosomes


Small structures
in the cytoplasm
of the cell that
utilize RNA to
produce proteins
for cell functions


Vacuoles


Specialized
“bubbles” in cells
used for storage,
digestion, and
excretion.


Much larger in
plant cells

Special Plant Cell Structures


Chloroplasts
-
use chlorophyll to capture
light energy for conversion to chemical
energy


Cell wall
-
structure outside the cell
membrane that helps support and
protect cells.


Not semi
-
permeable

Specialized Eukaryotic Cells


Diploid Cells


Haploid Cells


Stem Cells


Diploid Cells


Includes all single celled eukaryotes
and every non
-
reproductive cell in
multicellular eukaryotes (plants and
animals)


Examples: Skin cells, muscle cells, nerve
cells

Haploid Cells


Specialized reproductive cells in
eukaryotes that contain ½ the amount of
genetic material of normal (diploid) cells


Also called gametes or sex cells


Haploid cells combine during sexual
reproduction to create a fertilized egg


4 distinct types


Male
-
sperm or pollen


Female
-
egg or ovum

Stem Cells


Produced from the union
of haploid cells


Special cells that
differentiate into all diploid
cells in the body.

Culturing Bacteria

Ideal Bacterial Environments


Most bacteria prefer warm moist
environments, though specific species
require different culturing conditions


Bacteria thrive in the harshest
environments on earth


Deep sea ocean vents with no sunlight and
little useable oxygen

Bacteria Testing Methods


Swabbing
-
method used to test surfaces
for bacteria


A sterile cotton swab is dipped in a dilution
solution and rubbed across the surface to
be tested.


The end of the swab is cut and dropped
into the solution


The infested solution is swirled at .1 ml
extracted for plating

Plating


The process of physically spreading
bacteria on an agar based culture
media


Plating Process


To produce agar plates, heat a clear solution
in a water bath. Next, proceed to pour the
solution into Petri dishes and immediately
seal.


Bacteria can be spread using an inoculating
loop or glass “hockey stick”


Plates should be sealed and incubated at 30
degrees Celsius to avoid the growth of most
bacteria harmful to humans (35
-
37 degrees
for Salmonella)

Identifying/Counting Bacteria


Different agar mixes can be used to
culture specific types of bacteria.


Gram staining is used to broadly identify
certain types of bacteria.


Identifying individual strains is much
more difficult.

Cleanup After Culture of
Biological Labs

Cleanup of Labs


Cultures should be placed in a
biohazard bag for sterilization in an
autoclave set at 121 degrees Celsius
and 15 pounds per square inch (psi) for
15 minutes.


Agar should be disposed of according to
lab protocol
-
not poured down sinks, as
liquid agar can quickly solidify and clog
drains.

Cleanup of Labs


Individuals should always wear latex
gloves and immediately dispose of them
after use.


This is due to the hands being the most
common point of contact.