Bài giảng - Applications of microbes in environment and agriculture

Applications of Microorganisms in Agriculture and Environment Applications of Microorganisms in Environment Bioremediation is the use of microorganism metabolism to remove pollutants We Use Existing Microbes  To clean up oil spills Decomposition by Microbes Components of agent orange Figure 27.8 We Use Existing Microbes  To leach ores In addition to the oxidation of sulfur and sulfur compounds Thiobacillus ferrooxidans is able to oxidize ferrous to ferric iron and so derive its energy from this exergonic reaction 2Fe++ + 2H+ + ½O2  >    2Fe+++ + H20  2Fe+++ + 6H20       >    2Fe(OH)3 + 6H+ 2Fe++ + 5H20 + ½O2   >    2Fe(OH)3 + 4H+  Wastewater treatment Anaerobic Sludge Digester  CO2 + H2  CH4 + H2O  CH3COOH  CH4 + CO2 Figure 27.23 We Use Existing Microbes  To turn trash into soil Applications of Microorganisms in Agriculture Basic Principles of Recombinant DNA Technology Definition The transfer of genetic information from one organism to another  Methods and techniques are known as Recombinant DNA Technology  Steps in Recombinant DNA Technology Cleaving (cutting) the target DNA Ligating the target DNA into a vector Transformation of a host cell with the recombinant DNA (vector DNA with DNA insert) Screening of cells for those harboring the recombinant DNA or producing the appropriating protein product Examples of applications of genetic engineering in agriculture Insect resistant plants Corn borer – pest of corn in North America and Europe – Lepidoptera (moths and butterflies) – Bt-corn for corn borer control What is Bt and how does it work?  Bacterium Bacillus thuringiensis produces protein, delta-endotoxin, that is toxic to insects in orders Lepidoptera, Coleoptera (beetles) - Bt toxin in form of powder used as insecticide spray  applied to leaves where larvae feed on Mode of action: Insect eats Bt crystals ( ) and bacterial spores Bt crystals dissolve at high pH in insect gut Toxin binds to specific receptors in gut and insects stops eating Toxin causes the gut wall to break down, allowing spores and normal gut bacteria to enter the body Insect dies as spores and gut bacteria proliferate in the body Genetic engineering of Bt-resistant corn (Bt-corn)  Clone Bt toxin gene from bacteria and express in plants  Bt-transgenic plants are resistant to insects, no need for spraying insecticide Bt-crops for corn borer control  Currently in crops of corn (control of corn borer) cotton (control of bollworm)  Studies that demonstrate harmful effects of Bt corn on other insects and ecosystems  effect of Bt-transgenic corn on Monarch butterfly larvae feeding on milkweed? Bt corn may harm stream ecosystems Bt corn may harm stream ecosystems Bt corn may harm the caddishfly, which serves as food for fish and amphibians Parts of Bt corn, such as leaves, cobs and pollen, can travel as far as 2000 meters away from source areas-a phenomenon that was not considered when Bt corn was licensed Biofuels – Alternatives to Corn Jatropha curcas - an important feedstock for the production of biofuels - widespread use in India and Egypt - fast growing source of oil-bearing nuts that can be pressed to produce biodiesel - oil for use in generators, sewing machines and small motors - Glycerin, a by product of Jatropha oil, can also be used to produce soap Genetic engineering of freezing tolerance in Canola Control and CBF-canola before freezing Controls CBF-Canola Control and CBF-canola after days @ -6oC Controls CBF-Canola ... recombinant DNA (vector DNA with DNA insert) Screening of cells for those harboring the recombinant DNA or producing the appropriating protein product Examples of applications of genetic engineering... curcas - an important feedstock for the production of biofuels - widespread use in India and Egypt - fast growing source of oil-bearing nuts that can be pressed to produce biodiesel - oil for use in. .. We Use Existing Microbes  To turn trash into soil Applications of Microorganisms in Agriculture Basic Principles of Recombinant DNA Technology Definition The transfer of genetic information