Microbial Ecology • Microbes in their Environment • Microbe-Microbe Interactions • Biogeochemistry (Cycling of Elements) • Microbe-Higher Organism Interactions • Environmental Pollution Control
Ant-Fungi Mutualism Actinomycete amensalism of parasitic fungi Fungal-Fungal Parasitism
SOIL • Oxygen supply limited by mineral particle size, organic matter content and water content. • Plant roots may also add oxygen to deeper soils or anaerobic soils. • Water saturation leads to anaerobic conditions and increased denitrification. • Distribution of microbes depends on organic matter supply and source (humus and root exudates)
Soil Close-Up Geosmin = “earthy smell” = Cyanobacteria = Actinomycetes
Mycorrhizae Fungi Ectomycorrhizal association between Douglas Fir (Pseuditsuga menziesii) and a boletus-like mushroom (Suillus caerulescens).
Bovine Rumen It’s a 100+ liter cellulose-degrading methane-producing microbial incubation.
There are only a few manned submersibles in the world that can explore hydrothermal vent communities (e.g. Alvin)
Control Point SourcesWastewater Treatment • Raw Sewage (99.9% water to 0.1% waste) • Pollutants in sewage are: • Debris and grit • Particulate organic material • Colloidal and dissolved organic material • Dissolved inorganic material • Human Pathogens • Toxic Chemicals • Pharmaceuticals
Wastewater Treatment • Preliminary (physical screening) • Primary (physically settle solids) • Secondary (biological) • Remove organics aerobicaly (lower BOD) • Solids production (separate water and “sludge”) • Sludge Treatment (solids reduced) • Tertiary (biological or chemical “polishing”) • Biological nutrient removal systems • Pathogen removal by chlorine or ozone • Chemical nutrient removal (costly)
Secondary Treatment: Activated Sludge (aerobic) Trickle Filters (aerobic) Anaerobic Sludge Digesters
What da Floc? • Bacterial growth in activated sludge digested (aerobic) will aggregate (floc). • Dissolved organics aggregate with bacterial growth and removed from the water. • Imbalances may cause growth of filamentous bacteria or fungi; prevents settling; called “bulking”.
Anaerobic Sludge Digester (Methane Production)