Environmental Biotechnology

• Clean Water
  • Berlin Sewage (Box 6.1)
  • Aerobic
  • Anaerobic
  • One cow = 16 city=dwellers
• Sewage plants
  • Trickling filters (Figure 6.4)
  • Activated sludge (Figure 6.7)
  • Eutrification (from fertilizer runoff)
  • Denitrification (removal of ammonia to nitrogen gas)
  • Phosphorous removal
    • Bacterial
    • Precipitation
  • Methane bacteria - tree of life (Figure 6.14)
• Biogas
  • Will o' the wisp / UFOs
  • Methane hydrates
  • Methanogens (Figure 6.13)
  • Gobar project
  • Potential of 1% of U.S. energy needs
• Biofuels
  • Ethanol
    • Sugarcane
      • Environmental impact
        • Sugar residues
        • 1 liter ethanol = waste for 4 city dwellers
        • Area for fuel = area to supply food for 30 people
• Oil Guzzlers
  • Superbacteria (Figure 6.19) (first patented organism)
  • Exxon Valdez (Figure p. 180)
  • BP
• Sugar and Alcohol from Wood
  • Lignocellulose
    • Cellulose
    • Hemicellulose
    • Lignin
  • Cellulases
  • Lignin degrading microbes (Figure 6.21)
• Chemicals from Biomass
  • 100 chemicals make up 99% of all industrial chemicals
  • Basic chemicals from biomass (Figure 6.24)
    • Ethanol
    • Acetic acid
    • N-Butanol (Clostridium acetobutylicum)
    • Glycerol
    • Citric Acid
• Silent Mining
  • Copper
    • Bioleaching - Thiobacillus ferrooxidans and Thiobacillus thiooxidans (Figure 6.27)
    • Direct leaching -energy from electron transfer to make soluble, oxidized product
    • Indirect leaching - bacteria produce a strong oxidant
  • Uranium
  • Biosorption - removal of products from waste water
• Microbial Enhanced oil Recovery
  • 2/3 of oil in wells remains in ground
  • Bacterial production of gas to increase pressure
  • Biosurfactants (Figure 6.34)
  • Secretion of xanthan polymers
• Bioplastic
  • Pollulan - undigestible glucose polymer - from Pullularia pullulans (Figure 6.35)
    • Bacterially degradable when wet
  • Polyhydroxybutyrate (PHB - similar to polypropylene) = Biopol (Figure 6.38)
    • Biodegradable
  • Spidroins (spider silk) = Biosteel
  • Polylactate (envelope material - from corn) = PLA