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http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/earth_system/nitrogen_cycle_EPA.jpg. Industrial fixation. Pseudomonas denitrificans. Excretion and death. Active Transport. Mutualistic Rhizobium. Nitrobacter. Putrefaction. Free-living- Azotobacte r. Nitrosomonas.
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http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/earth_system/nitrogen_cycle_EPA.jpghttp://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/earth_system/nitrogen_cycle_EPA.jpg
Industrial fixation Pseudomonas denitrificans Excretion and death Active Transport Mutualistic Rhizobium Nitrobacter Putrefaction Free-living- Azotobacter 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. • No available oxygen • High nitrogen input Industrial fixation Pseudomonas denitrificans Nitrification Conditions needed for the aerobic autotrophic bacteria to convert ammonia to nitrites then nitrates: 1. Available oxygen 2. Neutral pH 3. Warm temperatures Excretion and death Active Transport Mutualistic Rhizobium Nitrobacter Putrefaction Free-living- Azotobacter Nitrosomonas http://www.uwsp.edu/geo/faculty/ritter/geog101/textbook/earth_system/nitrogen_cycle_EPA.jpg
Denitrification • 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.
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 • 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. 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) Organic acids alcohol Acetogenic bacteria (produce acetate) Carbon dioxide + hydrogen acetate Methanogenic bacteria (produce methane) methane methane CO2 + 4H2 CH4 + 2 H2 O 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.ca/catalog/product_info HOPS www.botanical.com/botanical/mgmh/h/hops--32.html
More on beer • 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 • Filtered, pasteurized (heated to 82⁰) to kill the yeast. • Product contains 2-6 % alcohol http://www.hgca.com/images/upload/barley.jpg
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 • 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 www.kitchenproject.com/history/sourdough.htm terander.wordpress.com
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.
Soy Sauce “ A fine product since 3000 BC” • Soy beans are fermented • Different fungus Aspergillus oryzae gryphonscry.wordpress.com http://www.yellowman.dk/images/medium/food/n8715035110106_MED.jpg www.bio.nite.go.jp/ngac/e/rib40-e.html
Soy SauceGet some soy beans… • Soak, boil, drain • Mash and mix with toasted wheat. • Add fungus Aspergillus oryzae • Leave for 3 days at 30⁰ C • 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 www.virginiagrains.com/Wheat%20Information.htm
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! pickle-recipes.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/salmonella/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