Environmental Microbiology

Key points: Microbes give us access to nutrients Nitrogen fixation Microbes rarely live alone Biofilms Some microbes can do some far out chemistry Mining bacteria

Nature of ecosystems Energy flow 3 3

Rule of 10 4

Microbes Recycle Key Elements 5

Biogeochemical Cycles — Water 6 6

Biogeochemical Cycles — Carbon 7 7

Biogeochemical Cycles — Nitrogen 8 8

Nitrogen Fixing Bacteria Nitrifying Bacteria(Nitrosomonas, Nitrosococcus, Nitrobacter, Nitrococcus) NH4+ --> NO3- Denitrifying Bacteria include Thiobacillus denitrificans, Micrococcus denitrificans Paraoccus denitrificans and Pseudomonas NO3 --> N2 9 9

Nitrogen fixation Nodules N2 + 6 H+ 6 e- --> 2 NH3 Reaction is oxygen sensitive Cyanobacteria Azotobacteraceae Rhizobia (Rhizobium meliloti) Bradyrhizobia Frankia

Sulfur Cycles Sulfate Reduction SO4-2 --> SO3-2-->S Desulfobacterales Desulfovibrionales Syntrophobacterales Sulfate Reduction SO4-2 --> SO3-2-->S Sulfur Reduction S -->H2S Sulfur Oxidation S -> SO4-2 Desulfuromonas, Proteus Beggiatoa, Paracoccus 11 11

Sulfur Cycles 12 12

Phosphorous cycle 13 13

Air as an Environment Determining Microbial Counts Controlling Microbial counts 14 14

Soil as an Environment Components Microbes 15 15

Microbes Are Everywhere! In the soil 16

Soil Influential Factors Soil Pathogens 17 17

Water as an Environment Freshwater 18 18

Microbes Live Together In biofilms in pipes 19

Biofilms Your shower …………. Dental plaque …………. almost any moist surface …………... There are five stages of biofilm development . initial attachment irreversible attachment maturation I maturation II dispersion

More biofilms Catheter Staph aureus biofilm

Water Environments Marine 22 22

Deep Ocean Vents 23 23

Water Purification Procedures 24 24

Coliform Tests Membrane Test MUG Test 25 25

We Use Existing Microbes To treat sewage 26

Sewage Treatment 27 27

Sewage Treatment Plant 28

Other Microbial Treatments Septic Tanks 29 29

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We Use Existing Microbes To clean up oil spills 31

We Use Existing Microbes To leach ores 32

Thiobacillus ferrooxidans A tiny rod-shaped bacterium known as Thiobacillus ferrooxidans gets energy by oxidizing some inorganic materials such as sulfide-containing minerals. As the bacteria metabolize, they release acid and an oxidizing solution of ferric ions, which can wash metals right out of ore. The copper and gold industry quickly and enthusiastically put this discovery to work.

We Modify Microbes To protect plants from pests Bacillus thuringensis Delta endotoxin protein 34

We Modify Microbes To clean up toxic waste = bioremediation TNT, plastics PCBs 35

Bioremediation 36 36