Transcript Microbes and Food Production

Organism
Nutrition
Locomotion
Cell Wall
Chloroplasts
Cilia or flagella
Saccharomyces
Heterotroph
(extracellular
digestion
Absent
Made of chitin
Absent
Absent
Amoeba
Heterotroph
(intracellular
digestion
Slides using
pseudopodia
Absent
Absent
Absent
Plasmodium
Heterotroph
(intracellular
digestion)
Glides on
substrate
Absent
Absent
Absent
Paramecium
Heterotroph
(intracellular
digestion)
Swimming
Absent
Absent
Cilia
Euglena
Autotroph and
heterotroph
Swimming
Absent
Present
Flagellum
Chlorella
Autotroph
None
Made of
cellulose
Present
Absent
http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/earth_system/nitrogen_cycle_EPA.jpg
Industrial
fixation
Mutualistic
Rhizobium
Pseudomonas
denitrificans
Excretion
and death
Active
Transport
Nitrobacter
Putrefaction
Free-livingAzotobacter
Nitrosomonas
http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/earth_system/nitrogen_cycle_EPA.jpg
Denitrification
Conditions needed for anaerobic
autotrophic bacteria to convert
nitrates to nitrogen gas.
1. No available oxygen
2. High nitrogen input
Industrial
fixation
Pseudomonas
denitrificans
Mutualistic
Rhizobium
Nitrification
Excretion
and death
Active
Transport
Conditions needed for the
aerobic autotrophic bacteria
to convert ammonia to nitrites
Putrefaction
then nitrates:
Nitrobacter
Free-living- 1. Available oxygen
Azotobacter 2. Neutral pH
3. Warm temperatures
Nitrosomonas
http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/earth_system/nitrogen_cycle_EPA.jpg
Denitrification
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Bad for soil
Removes nitrites
Destroys ozone
NO (one product- minor greenhouse gas,
contributes to global warming)
Raw Sewage- Adds pathogens to water
which in some countries may be used for
bathing or drinking (as well as irrigating
crops)
Diseases- E. coli, cholera, typhoid
Nitrate Fertilizer- Leads to
Eutrophication (overgrowth of a lake or
stream due to excess nutrients)
•Nitrates and Phosphates fertilize the algae
in water
•Algal bloom (overgrowth of algae)
•Decomposed by aerobic bacteria which
used up the oxygen. (BOD- Biochemical
Oxygen Demand- the amount of oxygen
needed by organisms over a set period of
time)
•Water is deoxygenated
•Fish (etc. ) die.
Raw Sewage- Adds pathogens to water
which in some countries may be used
for bathing or drinking (as well as
irrigating crops)
Diseases- E. coli, cholera, typhoid
Nitrate Fertilizer- Leads to
Eutrophication (overgrowth of a lake or
stream due to excess nutrients)
•Nitrates and Phosphates fertilize the algae
in water
•Algal bloom (overgrowth of algae)
•Decomposed by aerobic bacteria which
used up the oxygen. (BOD- Biochemical
Oxygen Demand- the amount of oxygen
needed by organisms over a set period of
time)
•Water is deoxygenated
•Fish (etc. ) die.
To prevent contamination by raw
sewage, saprophytic bacteria are
used. These bacteria break down
the organic material in raw sewage.
Trickling Bed Filter•Bacteria adhere to stones
•Cleaner water flows out bottom
•Excess bacteria settle out (in a
second tank) and are removed
•Water is disinfected with chlorine.
Reed Bed•Artificial wetland
•Nutrients from waste promote
growth of reeds.
•Small Scale
From Damon :HL Biology
From Damon :HL Biology
Biomass- Manure and crops, or crop
by-products, can be used to make
methane and ethanol.
To make biogas (60% methane) need
anaerobic digestor.
•No free oxygen.
•Constant temperature of 35 ⁰C
•pH –not too acidic
•Ammonia and phosphate by-products
Methanogenesis
• Acidogenic bacteria convert organic matter to
organic acids and alcohol.
• Acetogenic bacteria make acetate, with carbon
dioxide and hydrogen as by-products from organic
acids and alcohol.
• Methanogenic bacteria create methane from either
the reaction of carbon dioxide and hydrogen or the
breakdown of acetate.
From Damon :HL Biology
Manure
Acidogenic bacteria (produce acids)
alcohol
Organic acids
Acetogenic bacteria
(produce acetate)
Carbon dioxide + hydrogen
acetate
Methanogenic bacteria (produce methane)
methane
CO2 + 4H2
CH4 + 2 H2 O
methane
CH3 COOH
CH4 + CO2
From Damon :HL Biology
Microbes and Food Production
Objective F.4
Saccharomyces cerevisae
• Organism
• Yeast
• Pasteur in 1837 outlined its role in food
production (bread, wine, beer)
• Uses sugar for energy
• Reproduces by budding
users.ugent.be
Process?
• Glucose broken into two ethanol
• Two molecules of CO2 are by-products
www.bio.miami.edu
Beer
• Glucose-from grain (like barley)
• The grain is wetted to germinate
• Germination breaks down
starches into sugars.
• Maltose is an early sugar “malt”
• More water added “wort”
• Hops are added- bitter
• Wort and hops are boiled
www.vancouverseedbank.c
a/catalog/product_info
HOPS
www.botanical.com/botanical/
mgmh/h/hops--32.html
More on beer
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Yeast is added
Yeast uses the maltose for food
Maltose is a disaccharide
Broken into 2 glucose molecules
When all the sugar is used up
– Ethanol and carbon dioxide
http://www.hgca.com/images/upload/barl
ey.jpg
• Filtered, pasteurized (heated to 82⁰) to kill the
yeast.
• Product contains 2-6 % alcohol
Wine
• There are many different strains of
saccharomyces cerevisiae.
• Alcohol kills yeast.
• Wine strains can survive a
higher alcohol content.
• Wine is not boiled
flavourofwines.com
Wine
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Crush grapes
Add yeast (saccharomyces cerevisiae)
Place in fermentation tank
Let carbon dioxide escape
Ethanol stays in tank
http://www.bath.ac.uk/bio-sci/research/profiles/wheals-a.html
Bread
• This time we care about the carbon dioxide!
• Sugar in the dough is utilized by
saccharomyces.
• CO2 makes bread rise
• Baking kills the yeast,
• evaporates the ethanol
terander.wordpress.com
www.kitchenproject.com/history/sour
dough.htm
• Recipe for sourdough starter
•
• 1. Boil potatoes with the jackets on until they fall apart.
2.lift out the skins and mash potatoes in the water making a puree. cool
and save 2 cups of the puree adding it to 2 cups of flour and 2 Tbs. of
sugar.
Beat it smooth, then leave loosely covered in a warm place to start
fermentation. Usually there is a good effervescent action within a week.
To replenish your starter, add flour, water and a pinch of sugar. Leave it to
work.
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Soy Sauce
“ A fine product since 3000 BC”
• Soy beans are fermented
• Different fungus Aspergillus oryzae
gryphonscry.wordpress.com
http://www.yellowman.d
k/images/medium/food/
n8715035110106_MED
.jpg
www.bio.nite.go.jp/ngac/e/rib40-e.html
Soy Sauce
Get some soy beans…
• Soak, boil, drain
• Mash and mix with toasted
wheat.
• Add fungus Aspergillus oryzae
www.virginiagrains.com/Wh
• Leave for 3 days at 30⁰ C
eat%20Information.htm
• Add salt and water, ferment for 6-8 months
• Carbohydrates are broken down to glucose and ultimately
lactic acid and alcohol.
• Proteins are broken down to peptides and amino acids
• Filter and pasteurize.
• Sprinkle on your favorite food 
Sugar or salt preservation
• Increased sugar or salt dehydrates
– Salts-meat
– Sugar-fruit
• Reduces bacteria, yeast and molds
• Lets review hypotonic, hypertonic, and isotonic
• The contaminating cells are dehydrated also due to
the high osmotic pressure
blogs.kqed.org
To make jam…
• Boil fruit with sugar. Kills microorganisms,
dissolves sugar.
• Add pectin for jelling
• Seal in hot sterile jars
• Shelf life good without refrigeration
Preserving with Acid
(lowers intracellular pH of microorganisms/prevents growth)
• Pickles-preserved in vinegar (acetic acid) with
spices
• To make:
– Place vegetable in brine. Strain and rinse.
– Pour hot vinegar and spices over them.
– Place lids, Process in a hot water bath to make a
vacuum preventing fungi growth.
• Salt and acid!
picklerecipes.itsallgud.com
Lye (sodium hydroxide)
• Can raise intracellular pH of microroganisms.
• Prevents their growth
• E.g. hominy and lutefisk
Food Poisoning
• Salmonella is a bacterium that commonly causes food
poisoning.
• Occurs 12-72 hours after infection
– Diarrhea
– Fever
– Abdominal cramps
– Rarely- Reiter’s syndrome
• Last for years, arthritis, irritation of the eyes, painful
urination.
• May move to the bloodstream and cause death
http://omino.com/pixelblog/content/2007/salm
onella/salmonella.jpg
Salmonella transmission
• Lives in animal intestines
– Ineffective hand washing
– Contaminated food
– Reptile handling
– Cutting boards
– Irrigation
– Raw eggs
– Unpasteurized dairy
falloutofline.wordpress.com/2008/12/26/041-eggs
Treatment
• Treat dehydration
– Water, maybe with a
little sugar and salt
– IV fluids if needed
• Antibiotics if in
bloodstream
http://www.krider.com/MPj03211260000%5B1%5D.jpg