Download Microorganisms in Biotechnology Biotechnology: the use of LIVING

Microorganisms in Biotechnology
Biotechnology:
the use of LIVING things like bacteria and moulds in industrial
or manufacturing applications
ex. using Penicillium to make penicillin
Genetic engineering: also called bioengineering
This involves altering DNA outside an organism to code for a
different function, then reinserting the new DNA into a host so the new product will
be formed.
Two processes:
1. Recombinant DNA technology
2. Gene therapy using Viral vectors
A. RECOMBINANT DNA TECHNOLOGY
Definition:
inserting DNA from other organisms (ex. humans) into bacteria
- the bacteria multiply exponentially (very quickly) to make millions
of copies and thus become factories for the desired product
ex.
- the gene (piece of DNA) that codes for the production of INSULIN
is inserted into a bacteria
- the bacteria with the altered DNA grows exponentially
- these bacteria now form insulin which is collected and purified
v Process of making insulin, see book page 145
1. Human gene for making insulin is isolated from a normal, healthy
PANCREATIC cell
2. RESTRICTION ENZYMES (chemical scissors) then cut this piece of
DNA at specific locations
3. A suitable bacterium (ex. E.coli) has its PLASMID (single
chromosome) cut also using restriction enzymes
4. The human insulin gene is ADDED to the plasmid between cut ends
and sealed
- the plasmid now contains the human insulin gene
5. Bacteria are grown in sterile, correct conditions
6. Insulin is removed from the bacterial factory and purified
Recombinant DNA technology used to make:
· Human growth hormone
· Blood factors for haemophilia patients (help blood clot)
· Hepatitis B vaccine
· Interferons for cancer treatments
B. VIRAL VECTORS AND GENE THERAPY
Viral vectors use viruses to carry altered DNA into cells
Creating a viral vector:
1. remove some genes from a virus
2. replace with desired gene (DNA)
3. add vector (virus) to growing cells (tissue culture) – in vitro – lab, outside body
4. vector enters cells and deposits NEW GENE into cells
5. normal cell reproduces passing on desired gene
see book, pg. 147, fig. 5
This method may try to correct certain HUMAN GENETIC DISORDERS.
Neurological problems like Parkinson’s disease or Alzheimer’s disease cannot
be treated this way yet because the cells (brain and spinal cord) affected are
not multiplying.
However, this method is being used to develop solutions in fighting AIDS or
cancer. In these situations, the body is not making either the correct
chemicals or the proper amounts. By adding the desired gene using viral
vectors the body may once again begin producing the right chemical causing
the disorder to disappear.
This method is still in the in vitro stage. Viral vectors have not been
inserted into live human subjects yet.
WEBSITES:
http://www.ornl.gov/sci/techresources/Human_Genome/publicat/primer/primer.pdf
http://www3.iptv.org/exploremore/ge/what/recombinant.cfm
http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/R/RecombinantDNA.html
http://www.accessexcellence.org/RC/AB/BA/aapost/firstcommerce.html
http://www.biochemistry.org/education/pdfs/basc/10/BASC10_chap3.pdf
Comparing Recombinant DNA therapy and Viral Vector Gene Therapy
Similarity
Differences
Recombinant DNA
therapy
- involve the removal and
insertion of genes.
- involve the use of
microorganisms.
Viral Vectors in Gene
Therapy
- involve the removal and
insertion of genes.
- involve the use of
microorganisms
Restriction enzymes cut a
gene sequence from a
bacterial plasmid and replace
it with genes that will produce
the desired product.
The bacterial host produces
the new product (e.g., human
insulin) and it is harvested for
use.
Restriction enzymes cut a
gene sequence from the
nucleic acid (RNA or DNA) of
a virus and replace it with
genes that will produce the
desired effect when the
altered virus is inserted into a
human T-cell lymphocyte
(e.g., a new ADA gene is
incorporated into the
chromosome of the human
T-cell lymphocyte; the altered
DNA is replicated when the
lymphocyte divides and all
new generations will carry
the altered gene sequence).
Summary – Microorganisms
VIRUS
EUBACTERIA
Nonliving
Prokaryotic
• Protein capsid,
nucleic acid core
• Reproduce by
lytic and lysogenic
cycles
• Size: 20–400 nm
diameter
• Transmitted by
airborne particles,
body fluids
• Viral vectors used
in gene therapy
• Diseases caused
by DNA viruses:
infectious
mononucleosis,
smallpox,
chickenpox
• Diseases caused
by RNA viruses:
polio, infectious
hepatitis,
common cold,
measles, mumps,
rabies, influenza,
AIDS, some
cance rs
• Reproduce by
binary fission,
conjugation
• Structure: nuclear
region w ith single
chromosome and
plasm ids, ce ll wa ll,
cell membrane,
cytoplasm,
ribosomes; may
have capsule,
pili, flagella
• Shape: spherical
(coccus—found
singly, in pairs, or
chains); rod
(bacillus—found
singly or in chains);
or spiral (always
found
singly)
• Size: 0.4 :m in
diameter to several
:m in length
• Motility: use
flagella, moist
environment
• Useful role:
recyclers, pollution
control, probiotics,
industrial and
medicinal use
• Many diseasecausing
orga nism s, due to
toxin release
ARCHAEBACTERIAI PROTISTA
A
Prokaryotic
Eukaryotic
• Thermophiles,
methanogens,
halophiles; thrive under
extreme conditions
• Cell wall does not
contain peptidoglycan;
share other features of
eubacte ria
• Useful role:
bioremediation,
industrial, and
medicinal use
• Do not cause disease
• Size varies: 2 :m
length to 5 cm
diameter
• Most unicellular;
som e form
colonies of
identic al cells
(slime m ould); a
few are
multicellular
but do not form
tissues (algae)
• Thrive in moist
habitats or very
damp terrestrial
env ironm ents
• Widely varied
shapes
• Structure varies
from simple to
complex
• Motility varies:
flagella or cilia,
free floating, or
parasitic
• Useful role: food,
oxygen, petroleum
resources,
production
of fertilizers,
con sum er produ cts
• Path ogenic
protozoans cause
human disease
FUNGI
Eukaryotic
• Nonmotile
• Structure:
vegetative
(mycelium) and
reproductive
(button, stalk, cap,
gills, sporangium
with spores)
• Wide variety of
sizes, shapes,
colours
• Asexual/sexual
life cycle: spore
formation
• Us eful role:
decom poser,
bioremediation,
symbiotic
relationships
(mycorrhizae,
lichen), production
of antibiotics
• Responsible for
skin infections
such as athlete ’s
foot and
ringworm
(Microsporum)
• The Am anita
genus produces
neurotoxins that
can be fatal if
ingested