Transcript Microbial Ecology

Microbial Ecology
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Microbes in their Environment
Microbe-Microbe Interactions
Biogeochemistry (Cycling of Elements)
Microbe-Higher Organism Interactions
Environmental Pollution Control
Positive Population Interactions
Protocooperation
Protocooperative
Consortium
Negative Population Interactions
Predators
Ant-Fungi
Mutualism
Actinomycete
amensalism of
parasitic fungi
Fungal-Fungal
Parasitism
Carbon Biogeochemistry
Aerobic Carbon Use
Anaerobic Carbon Use
(No Oxygen)
Carbon Biogeochemistry
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).
Legume Root
Nodule formed by
Rhizobium spp.
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 Sources
Wastewater Treatment
• Raw Sewage (99.9% water to 0.1% waste)
• Pollutants in sewage are:
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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)
Wastewater Treatment
Secondary Treatment:
Activated Sludge (aerobic)
Trickle Filters (aerobic)
Anaerobic Sludge Digesters
Trickle Filter Biofilms
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)
What’s a coliform?
Why test them?
How can we test for them?