Download Microbiology: Organisms in Industry

Microbiology and
Organisms in Industry
Essential Idea: Microorganisms
can be used and modified to
perform industrial processes.
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TOK

Alexander Fleming
discovered penicillin in
England in 1928 on a
discarded petri dish.
To what extent was Dr.
Fleming’s discovery a
lucky observation, or
do we only perceive
what we are open to?
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Metabolic Diversity of
Microbes

Microorganisms have a very diverse set of
metabolisms.
› Photoautotrophs
› Chemoautotrophs
› Photoheterotrophs
› Chemoheterotrophs
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Metabolic Diversity of
Microbes

Microbes also show diversity in the way
they use oxygen.
› Aerobes
› Anaerobes
› Facultative
› Obligate
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Metabolic Diversity of
Microbes
Photoautotrophs are photosynthetic
microorganisms.
 They use light as an energy source and
inorganic carbon (CO2) as their carbon
source.

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Metabolic Diversity of
Microbes

Photoheterotrophs use
light as their energy
source and any of a
variety of organic
compounds as a
carbon source, such as:
› Carbohydrates
› Lipids
› Amino acids
http://textbookofbacteriology.net/procaryotes_2.html
Purple, non-sulfur
Heliobacteria
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Metabolic Diversity of
Microbes
Chemotrophs obtain energy by oxidizing
electron donors from within the
environment.
 These donors can be organic or inorganic
molecules that become oxidized when
they deliver their electrons.

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Metabolic Diversity of
Microbes

These electrons then flow through various
transport chains and synthesize
compounds needed for survival.
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Metabolic Diversity of
Microbes

Most chemotrophs
are bacteria that
live in hostile
environments such
as deep sea
hydrothermal
vents.
http://www.photolib.noaa.gov/htmls/nur04506.htm
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Metabolic Diversity of
Microbes
Chemoautotrophs use inorganic
chemicals as their source of energy and
CO2 as their carbon source.
 They derive their energy from the redox
reactions that transfer electrons to the
various electron transport chains within
these organisms.

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Metabolic Diversity of
Microbes
Chemoautotrophs use the energy from
inorganic compounds involving sulfur,
iron, manganese or nitrogen to provide
electrons for redox reactions.
 They also use CO2 to synthesize organic
compounds they need for survival.

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Most chemoautotrophs live in hostile environments.
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Metabolic Diversity of
Microbes
Chemoheterotrophs use organic compounds
as an energy source and as a carbon source.
 The oxidation-reduction reactions of the
organic compounds provide both the energy
and building blocks needed for survival.

http://classes.midlandstech.edu/carterp/Courses/bio225/chap12/lecture1.htm
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Common Microbes: Summary
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Microorganisms in Industry
Microorganisms are used in industry
because they are diverse, small, and
have a very fast growth rate.
 They are used industrially to produce
metabolites of interest.

› Citric acid
› Insulin
› Penicillin
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Pathway Engineering

Pathway engineering is used in industry to
optimize genetic and regulatory
processes within microorganisms to
maximize the production of metabolites
of interest.
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Pathway Engineering

Pathway engineering seeks to redesign
microorganisms (bacteria and fungi) to
efficiently produce metabolites of
interest.
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Fermenters (Bioreactors)

Once organisms of interest have been
identified or redesigned, the process of
culturing them has to be worked out.
› Largely due to the microorganisms becoming
limited by their own waste products.

Fermenters (bioreactors) are used to
allow for large-scale production of these
metabolites.
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Fermenters (Bioreactors)
People using fermenters have to monitor
the conditions within them using various
probes.
 These probes measure things like pH,
temperature, salinity, waste build-up, etc.
 Optimal conditions need to be
maintained to ensure optimal growth
and maximal production of product.

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Optimal Conditions
Most microorganisms grow optimally
between a pH of 6 and 8, and a
temperature of 20-40°C.
 Extremophiles grow in conditions much
different from these.

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Batch or Continuous Culture
Fermentation/growth can be carried out
by Batch Culture or Continuous Culture.
 Batch Culture is where microorganisms
are grown within a nutrient medium in a
closed fermenter (bioreactor).
 At the end of the growth cycle, the
desired product is separated out.

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Batch or Continuous Culture
In Continuous Culture, a sterile, nutrient
solution is continuously added to the
fermenter at the same time as an
equivalent amount of nutrient solution
with microorganism is removed.
 Steady growth is maintained by ensuring
enough nutrient medium is added to
maintain a maximum growth rate.
 This ensures maximum yield of product.

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Deep-Tank Batch
Fermentation
Deep tank fermentation isn’t really
fermentation.
 Yeast and bacteria ferment. Aspergillus
and Penicillium are fungi, and like nearly
all funguses, they require oxygen.
 Many of these reactions produce gas as
a biproduct, and this biogas must be
bled off to prevent explosions.

› Some gases can be used as an energy
source (CH4).
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Biogas
Biogas is generally a mixture of CH4 and
CO2, and may have some H2S.
 Thus, biogas is often used as a fuel.

http://highacreslandfill.wm.com/facility/landfill-gas.jsp
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Biogas
Typical Composition of Biogas
Biogases are
produced by the
anaerobic
breakdown of
organic matter.
 Common sources
of biogas are
farming and land
fills.

Molecular
Formula
Percentage
Methane
CH4
50-75%
Carbon
Dioxide
CO2
25-50%
Nitrogen
N2
0-10%
Hydrogen
H2
0-1%
Hydrogen
Sulfide
H2S
0-3%
Oxygen
O2
0%
Compound
http://www.sierrainstruments.com/blog/?biogas-flow-meter-measurementthe-problem
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Biogas
Capturing biogas is beneficial to both
society and to the environment.
 Methane and other compounds are 20300 times more potent greenhouse gases
than CO2.
 Capturing the gas for sale allows it to be
used for generating electricity, heat, and
powering vehicles.
 It is a very important renewable energy.

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Biogas
Biogas can also be
produced using fermenters.
 Using anaerobic digesters,
biodegradable material
can be fed into the tanks.
 Microorganisms (bacteria
and archeans) transform
the waste into biogas and
the gases are collected.

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http://eng3060.pbworks.com/w/page/18918910/Insert%20a%20landfill%20gas%20extraction%20system
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http://en.wikipedia.org/wiki/Anaerobic_digestion#/media/File:Anaerobic_digesters_overhead_view.jpg
http://en.wikipedia.org/wiki/Anaerobic_digestion#/media/File:Haase_Lubeck_MBT.JPG
Biogas

Leftover digestate
can be spread on
fields to condition
the soil, providing
nutrients and
moisture holding
properties.
http://en.wikipedia.org/wiki/Digestate#/media/File:Anaerobic_digestate.JPG
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Deep-Tank Batch
Fermentation

Deep tank fermentation is performed in a
bioreactor.
› These can be HUGE! 40K liter!
They started off as small, one-liter tanks
that were modified and then were scaled
up.
 Just like with individual cells, tanks need
to take surface area to volume into
account.

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Deep-Tank Batch
Fermentation
These tanks are deep
and include a lot of
fluid.
 The fluid is continuously
mixed at all levels within
the tank and aerated
with sterile air to prevent
contamination--one of
the main obstacles in
deep-tank fermentation.

http://en.wikipedia.org/wiki/Bioreactor#/media/File:Bioreactor_principle.svg
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Deep-Tank Batch
Fermentation

Here’s an example of
a small-scale
bioreactor.
http://en.wikipedia.org/wiki/Bioreactor#/media/File:Autoclavable_benchtop_laboratory_bioreactor_%26_fermenter,_Lambda_MINIFOR.jpg
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Aspergillus niger
A. niger is used to produce citric acid.
 Citric acid is used as a preservative and
flavoring in the food industry.
 It is also used as an acid to descale
coffee machines!

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Aspergillus niger
The production of citric acid by A. niger is
achieved in a continuous fermenter.
 In this process, the growth of A. niger is
held in the stationary phase (as the citric
acid cycle produces the desired
product) and while nutrients are added
and an equivalent amount of liquid and
micoorganisms are taken out.

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Citric Acid
As the liquid is draw out of the fermenter,
the A. niger is filtered out and the citric
acid is precipitated with Ca(OH)2 to yield
calcium citrate salt.
 Treatment of this salt with sulfuric acid
yields citric acid.

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Penicillium
chrysogenum/notatum
Penicillin production has a very storied
history.
 A lot of time elapsed from when
Alexander Flemming discovered its
antibiotic properties to when it was
produced on an industrial scale.
 It was used exclusively during wartime
(WWII) before being used publicly.

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http://www.nationalww2museum.org/learn/education/for-teachers/lesson-plans/pdfs/penicillin-fact-sheet.pdf
Penicillium
chrysogenum/notatum
P. chrysogenum is the fungus used to
produce mass quantities of penicillin.
 Like A. niger, the production of penicillin
makes use of a continuous fermenter.

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Penicillium
chrysogenum/notatum
During the production of the penicillin, P.
chrysogenum/notatum is cultured with
sugar, nutrients and a nitrogen source.
 Penicillin is a secondary metabolite, and
is usually produced when the organisms
enter the stationary phase of growth.
 Secondary metabolites help organisms,
but are not immediately necessary for
growth.

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Penicillium
chrysogenum/notatum

Here you can
see the
stationary phase
of growth as well
as the
production of
secondary
metabolite.
http://nopr.niscair.res.in/bitstream/123456789/4242/1/IJMS%2038(1)%2038-44.pdf
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Penicillium
chrysogenum/notatum
As the culture is in the stationary phase,
waste is removed and nutrients are
added.
 The desired product is also removed and
purified using a variety of techniques.
 The product is then ready for use.

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