Definition

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Biotechnology

• Introduction
• Definition
• Bio is Greek for life
• teuchos means tool
• Logos is Greek for word, study of or
  essence
• Impact
• Biotechnology and society
• Development
• Milestones
• Application

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The Five Kingdoms
monera
protista
fungi
plantae
animalia

• There are estimated to be over 100,000 different
  fungi, most of which form only tiny threads
  (Hypha) that can only be seen through a
  microscope.
• 20,000 are considered to be high fungi or macro
  fungi, i.e. those that produce visible fruiting
  bodies (Ascomycotina and Basidiomycotina).

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Background information

• Old biotechnology
• Whole organism level
• genes mixing (planned crosses or mating)
• within species
• selection based on resulted phenotypes
• breeding program (years)
• New biotechnology
• Molecular level
• Recombinant DNA technology
• gene transfer (precise)
• selection can be monitor at genotypic level
• Quick results are expected
• Old and new biotechnology are used in
  complementary fashion

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Hieroglyphics suggest that that ancient Egyptians
were using yeast and the process of fermentation
to produce alcoholic beverages and to leaven
bread over 5,000 years ago.
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It was not until the invention of the microscope
followed by the pioneering  scientific work of
Louis Pasteur in the late 1860s that yeast was
identified as a living organism and the agent
responsible for alcoholic fermentation and dough
leavening.
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Yeasts are single-celled fungi. As fungi, they
are related to the other fungi that people are
more familiar with. These include edible
mushrooms available at the supermarket, common
bakers yeast used to leaven bread, molds that
ripen blue cheese and the molds that produce
antibiotics for medical and veterinary use. Many
consider edible yeast and fungi to be as natural
as fruits and vegetables.        Over 600
different species of yeast are known and they are
widely distributed in nature.
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Bakers yeast is used to leaven bread throughout
the world and it is the type of yeast that people
are most familiar with. Bakers yeast is produced
from the genus and species of yeast called
Saccharomyces cerevisiae. The scientific name of
the genus of bakers yeast, Saccharomyces, refers
to saccharo meaning sugar and myces meaning
fungus. The species name, cerevisiae, is derived
from the name Ceres, the Roman goddess of
agriculture. Bakers yeast products are made from
strains of this yeast selected for their special
qualities relating to the needs of the baking
industry. The typical yeast cell is approximately
equal in size to a human red blood cell and is
spherical to ellipsoidal in shape. Because of its
small size, it takes about seven billion yeast
cells to make up to one gram of compressed
bakers yeast. Yeast reproduce vegetatively by
budding, a process during which a new bud grows
from the side of the existing cell wall. This bud
eventually breaks away from the mother cell to
form a separate daughter cell. Each yeast cell,
on average, undergoes this budding process 12 to
15 times before it is no longer capable of
reproducing. During commercial production, yeast
is grown under carefully controlled conditions on
a sugar containing media typically composed of
beet and cane molasses. Under ideal growth
conditions a yeast cell reproduces every two to
three hours. Yeast is the essential ingredient
in many bakery products. It is responsible for
leavening the dough and imparting a delicious
yeast fermentation flavor to the product. It is
used in rather small amounts in most bakery
products, but having good yeast and using the
yeast properly often makes the difference between
success and something less than success in a
bakery operation.
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Production of carbon dioxide Carbon dioxide is
generated by the yeast as a result of the
breakdown of fermentable sugars in the dough. The
evolution of carbon dioxide causes expansion of
the dough as it is trapped within the protein
matrix of the dough. Causes dough maturation
This is accomplished by the chemical reaction of
yeast produced alcohols and acids on protein of
the flour and by the physical stretching of the
protein by carbon dioxide gas. This results in
the light, airy physical structure associated
with yeast leavened products. Development of
fermentation flavorYeast imparts the
characteristic flavor of bread and other yeast
leavened products. During dough fermentation,
yeast produce many secondary metabolites such as
ketones, higher alcohols, organic acids,
aldehydes and esters. Some of these, alcohols for
example, escape during baking. Others react with
each other and with other compounds found in the
dough to form new and more complex flavor
compounds. These reactions occur primarily in the
crust and the resultant flavor diffuses into the
crumb of the baked bread.
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The bakers yeast production process flow chart
can be divided into four basic steps. In order
these steps are, molasses and other raw material
preparation, culture or seed yeast preparation,
fermentation and harvesting and filtration and
packaging. The process outlined in the flow chart
takes approximately five days from start to
finish.
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                            Yeasts can grow in
the presence or absence of air. Anaerobic growth,
growth in the absence of oxygen, is quite slow
and inefficient. For instance, in bread dough,
yeast grow very little. Instead, the sugar that
can sustain either fermentation or growth is used
mainly to produce alcohol and carbon dioxide.
Only a small portion of the sugar is used for
cell maintenance and growth. In contrast, under
aerobic conditions, in the presence of a
sufficient quantity of dissolved oxygen, yeast
grow by using most of the available sugar for
growth and producing only negligible quantities
of alcohol. This means that the baker who is
interested in the leavening action of carbon
dioxide works under conditions that minimize the
presence of dissolved oxygen. On the other hand,
a yeast manufacturer that wants to produce more
yeast cell mass, works under aerobic conditions
by bubbling air through the solution in which the
yeast is grown. The problem posed to the yeast
manufacturer, however, is not as simple as just
adding air during the fermentation process. If
the concentration of sugar in the fermentation
growth media is greater than a very small amount,
the yeast will produce some alcohol even if the
supply of oxygen is adequate or even in
abundance. This problem can be solved by adding
the sugar solution slowly to the yeast throughout
the fermentation process. The rate of addition of
the sugar solution must be such that the yeast
uses the sugar fast enough so that the sugar
concentration at any one time is practically
zero. This type of fermentation is referred to as
a fed-batch
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The quality of bakers yeast is often discussed
in terms of microbiological purity and gas
producing activity.
Typical gassing activity of yeast
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At the beginning stage of the manufacturing
process, strain purity and trueness to type are
carefully controlled. In the laboratory, a pure
culture of the yeast strain being used is
maintained and prepared for inoculation into the
initial fermentation vessel. Strict adherence to
sanitary practices and GMP rules of the Food and
Drug Administration (FDA) are required at all
stages of yeast production to produce products
with acceptable microbiological standards.
Complete microbiological testing is conducted on
all finished yeast product using approved and
published methods. This insures product safety
and lack of potentially harmful organisms. Dakota
Bakers Yeast microbiological standards have
Salmonella sp. specification of negative/375
grams and an E.coli specification of less than
100/gram. Gas production is the major function
of yeast in bread dough. To ensure consistent
gassing performance, each code of Dakota Baker's
Yeast is tested for gassing activity. The test
involves gassing a standardized dough formula at
a constant-temperature in a precision gassing
apparatus that measures the amount of carbon
dioxide produced over a fixed amount of time.
While the test is an excellent predictor of yeast
performance, it is not an exact predictor of
proof times. This is due to the fact that proof
times are related to both gas-production by yeast
and gas-retention by the dough. Factors such as
flour quality, dough strengtheners, and the
amount of mixing are some of the factors that
affect gas retention. Gassing activity numbers
are provided with the certificate of analysis
(COA) accompanying each shipment of Dakota
Baker's Yeast.
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Biotechnology can be abused
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Microbial Biotechnology
The genetics, biochemistry and physiology of
micro-organisms are the sciences fundamental to
the biotechnology industry
thorough understanding of biotechnological
processes and the problems that have to be
overcome to exploit them commercially, through a
series of case studies.
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Comparison between Biotechnology and Computer
(electronics)

• High volume demand
• Mass market
• Advancement fostered by entrepreneurial companies

Abelson, PE (1983) Science
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Environment -microbes bioremediation capability
on toxic chemicals -BiodiversityAgriculture -G
M food -Bioreactor Medicine/Applied Biology
-New drug discovery -Gene therapy -Transplanta
tion (Stem Cell)China, Modern Chinese
Medicine RD
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Benefits to Society

• Agriculture
• Crop and animal improvement
• Industry
• Alternative fuels, solvent and new materials
• Health/medicine
• Novel drugs, diagnostic tools and gene therapy
• Environment
• Reduced pollution and bio-remediation
• Forensic
• DNA finger-printing
• Advancement of Knowledge
• Understand how nature works

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New Drug Discovery
DNA Protein
Drug
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The Cell
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Watson and Crick describe structure of DNA(1953)
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Central DogmaofMolecular Biology
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DNAmRNAProtein
Transcription
Reverse Transcription
Translation
Post-Translation Modification PTM
Protein
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A T(U) G C
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• Three Experiments
• Single cell isolation
• Replica plating
• Total DNA Extraction

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Plating Bacterial Cultures onto LB Agar Plates.
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Streaking plates to obtain single colonies
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Replica Plating