Notes:
1) Biogeochemical cycles is which mechanisms by which recycling nutrient occur.
2) The characteristics of biogeochemical cycles are transformed and cycled through oxidation-reduction reactions and all cycles are linked.
3) Carbon cycle
- The final product of aerobic respiration in carbon cycle is oxidized products: H20, NO3-, SO42- and carbon dioxide.
- The final product of anaerobic respiration in carbon cycle is reduced products: NH4+, H2S. H2 and CH4.
4) Nitogen cycle
- Nitrification
- Nitrification carry out in aerobic condition where ammonium ion (NH4+) undergo oxidation to form Nitrite (NO2-), followed by oxidation of nitrite (NO2-) to form Nitrate (NO3-).
- The example of microorganisms that oxidized ammonium (Nh4+) to nitrite (NO2-) is Nitrosomonas and Nitrococcus. The example of microorganisms that oxidized nitrite (NO2-) to nitrate (NO3-) is Nitrobacter.
- Denitrification
- Denitrification carry out in anaerobic condition where nitrate (NO3-) is reduced to nitrite (NO2-), nitrogen gas (N2) or nitrous oxide (N2O).
- Dissimilatory process (use nitrate NO3- as the electron acceptor to produce ATP)
- Nitrate (NO3-) as oxidant.
- The example of microorganisms is Pseudomonas.
- Nitrate (NO3-) can reduced to ammonia (NH3) by Geobacter, Desulfovibrio and Clostridium.
- Nitrogen fixation
- Nitrogen fixation is a process in which nitrogen (N2) in the atmosphere is converted into ammonium (NH4+) or nitrogen dioxide (NO2).
- Reductive processes
- Ammonia is the product
- must occur in anaerobic condition even in aerobic microorganisms
- Anammox process: anaerobic oxidation of NH4+ and reduction of NO2- to produce nitrogen gas by some microorganisms.
5) Sulfur cycle
- Sulfur Oxidation
- Sulfur is oxidized to sulfate (SO42-) by using Sulfide (H2S) as electron acceptor.
- The example of microorganisms are Thiothrix, Beggiatoa and Thiobacillus.
- Sulfur Reduction
-Sulfur is reduced to sulfide (H2S) .
- Sulfate Reduction (Dissimilatory process)
- Sulfate (SO42-) is reduced to sulfide (H2S) by Desulfovibrio and Desulfuromonas.
- Sulfite (SO32-) is reduced to sulfide (H2S) by Alteromonas, Clostridium, Desulfovibrio and Desulfotomaculum.
- Sulfate Reduction (Assimilatory process)
- Sulfate (SO42-) is reduced to organic sulfur for use in amino acid and protein biosynthesis.
- Mineralization is the process where the sulfhydryl (-SH) groups in protein of dead animals converted to sulfide (H2S).
6) Iron cycle
- Ferrous ion (Fe2+) is oxidized to Ferric ion (Fe3+) in aerobic condition. The example of microorganisms are Thiobacillus ferrooxidans, Gallionella,Sulfolobus.
- Ferric ion (Fe3+) is reduced to Ferroous ion (Fe2+) in anaerobic condition. The example of microorganisms are Geobacter, Ferribacterium and Shewanella.
7) Manganase cycle
- Manganase ion ( Mn2+) is oxidized to manganic ion (Mn4+) in aerobic condition. the examples of microorganisms are Leptothrix, Arthrobacter and Pedomicrobium.
- Manganic ion (Mn4+) is reduced to Managnase ion (Mn2+)in anaerobic condition. The examples of Shewanella and Geobacter,
8) The function of microorganisms in microbial ecology:
- Microorganisms as pollutants - Food borne and water borne pathogens, massive growth of pathogens causes eutrophication
- Microorganisms as cause of pollution - Mercury will combine with the organic methyl group that found in aerobic microorganisms and form Methyt mercury. Methyl mercury will totally absorbed by body and retained in the body longer than elemental mercury.
- Microorganisms as an indicator of pollution - colliform group of bactera and biofilm can test for pollution
- Microorganisms may reduce pollution - Biodegradation and Bioremediation
9) Biodegradation is the natural decomposition or breakdown of molecules by microorganisms. All natural organic compounds are degradable. Recalcitrant are non-biodegradable because they are synthetic molecules.
10) The example of biodegradation:
- Biodegradation of oil spills
- Slow because low nutrients and low population. We can improve by using bioremediation and genetic engeneering. Nutrient sprayed to encourage microbial growth.
- Microorganisms in Landfills
- The microorganisms found in landfills are mostly anaerobic and they are methanogens and cellulose digesters. The major product of fermentation is carbon dioxide, methanem organic acids and alcohols. The products will leached out from landfills so landfills have to far from water source.
- Microbial application as pesticides
-Bt protein that produced naturally by Bacillus thuringiensis used to spray on plants. Bt protein won't harm plants but will attack specific stages of insects only and solve the problem of pesticides.
11) Bioremediation is the use of living organisms to promote the degradation of environmental pollutants cartificiallyby increase the growth of naturally occuring microorganisms. Bioremediation only carry out when biodegradation processes not at a desired rate. Microorganisms use the contaminant as nutrient for reproduction and converts contaminant to less harmful form and release to the environment.
12) Cometabolism is defined as the simultaneous degradation of two compounds, in which the degradation of the second compound (the secondary substrate) depends on the presence of the first compound (the primary substrate). For example: trichloroethylene (TCE) is groundwater pollutant. Methane and oxygen is added to encourage methanotrophs. TCE not a substrate for methanotrophs but methanotrophs produce methane monooxygenase to degrade TCE.
13) Source of microorganisms is contaminated sites, culture collection and genetically engineered "superbug". Unfortunately, superbug are less effective due to the attractiveness of laboratory-grown microorganisms as the food source for predators, inability to contact the compounds to be degraded and failure to survive and compete with indigenous microorganisms.
14) In general, bioremediation is the addition of microorganisms to accelerate the growth of indigenous microorganisms.
15) Phytoremediation is the use of plant to stimulate the degradation, transformation or removal of compounds, either directly or in conjunction with microorganisms.
16) The advantages of plants with microorganisms in bioremediation are extensive root system, higher ability for storage and easy to harvest.
17) The types of phytoremediation are phytoextraction, phytodegradation, rhizofiltration, phytostabilization and phytovolatilization.
Activity:
No other activity except for teaching....^^
My own Explorace:
1) In nature, nitrogen not only fixed by microorganisms but also by lighting.
2) Fritz Haber undertook the work on the fixation of nitrogen from the air for which he was given the Nobel Prize in Chemistry for 1918 (awarded in 1919).
3) In biology, the opposite of assimilation in the process of metabolism, consisting in the decomposition of organic compounds and conversion of protein, nucleic acids, fats, and carbohydrates (including those ingested) into simple substances.
4) The definition of biotechnology is the use of living organisms and biomolecular process to develop, make or modify product to improve our human lives.
5) Blue baby syndrome occurs when newborn babies have cyanotic heart defects. Th reason cause blue baby is methemoglobinemia. Methemoglobinema is caused by nitrate contamination in groundwater resulting in decreased oxygen carrying capacity of hemoglobin in babies leading to death.
6) Endotoxin only released when the cells or microorganisms are lysed and exotoxin is more pathogenic compared to endotoxin because exotoxin can released without the lysis of cells.
7) Superbugs are strains of bacteria that are resistant to several types of antibiotics.
Reflection:
Today is the last class of Microbiology 2 . The things we learnt getting harder and harder. I felt that the use of Bt protein as pesticides is a great discovery. This really help farmer to solve their problem. To avoid blue baby, the landfill sites need to far away from water source. The biogeochemical cycle made me confused but Dr Wan said we gonna learn more detail about biogeochemical cycle during physiology miicrobiology. @.@
Dr Wan, thanks for teaching us this semester~~~ See You~~~ ^^
11) Bioremediation is the use of living organisms to promote the degradation of environmental pollutants cartificiallyby increase the growth of naturally occuring microorganisms. Bioremediation only carry out when biodegradation processes not at a desired rate. Microorganisms use the contaminant as nutrient for reproduction and converts contaminant to less harmful form and release to the environment.
12) Cometabolism is defined as the simultaneous degradation of two compounds, in which the degradation of the second compound (the secondary substrate) depends on the presence of the first compound (the primary substrate). For example: trichloroethylene (TCE) is groundwater pollutant. Methane and oxygen is added to encourage methanotrophs. TCE not a substrate for methanotrophs but methanotrophs produce methane monooxygenase to degrade TCE.
13) Source of microorganisms is contaminated sites, culture collection and genetically engineered "superbug". Unfortunately, superbug are less effective due to the attractiveness of laboratory-grown microorganisms as the food source for predators, inability to contact the compounds to be degraded and failure to survive and compete with indigenous microorganisms.
14) In general, bioremediation is the addition of microorganisms to accelerate the growth of indigenous microorganisms.
15) Phytoremediation is the use of plant to stimulate the degradation, transformation or removal of compounds, either directly or in conjunction with microorganisms.
16) The advantages of plants with microorganisms in bioremediation are extensive root system, higher ability for storage and easy to harvest.
17) The types of phytoremediation are phytoextraction, phytodegradation, rhizofiltration, phytostabilization and phytovolatilization.
Activity:
No other activity except for teaching....^^
My own Explorace:
1) In nature, nitrogen not only fixed by microorganisms but also by lighting.
2) Fritz Haber undertook the work on the fixation of nitrogen from the air for which he was given the Nobel Prize in Chemistry for 1918 (awarded in 1919).
3) In biology, the opposite of assimilation in the process of metabolism, consisting in the decomposition of organic compounds and conversion of protein, nucleic acids, fats, and carbohydrates (including those ingested) into simple substances.
4) The definition of biotechnology is the use of living organisms and biomolecular process to develop, make or modify product to improve our human lives.
5) Blue baby syndrome occurs when newborn babies have cyanotic heart defects. Th reason cause blue baby is methemoglobinemia. Methemoglobinema is caused by nitrate contamination in groundwater resulting in decreased oxygen carrying capacity of hemoglobin in babies leading to death.
6) Endotoxin only released when the cells or microorganisms are lysed and exotoxin is more pathogenic compared to endotoxin because exotoxin can released without the lysis of cells.
7) Superbugs are strains of bacteria that are resistant to several types of antibiotics.
Reflection:
Today is the last class of Microbiology 2 . The things we learnt getting harder and harder. I felt that the use of Bt protein as pesticides is a great discovery. This really help farmer to solve their problem. To avoid blue baby, the landfill sites need to far away from water source. The biogeochemical cycle made me confused but Dr Wan said we gonna learn more detail about biogeochemical cycle during physiology miicrobiology. @.@
Dr Wan, thanks for teaching us this semester~~~ See You~~~ ^^
