1. Environmental Microbiology
Chapter 27, part A
Environmental Microbiology

2. Metabolic Diversity
Microbes live a variety of habitats because of their abilities:
To use a variety of carbon & energy sources
To grow under different physical conditions
Extremophiles live in extreme pH
Temperature
Salinity

3. Mycorrhizae Fungi living in close association with plant roots
Extend surface area of roots
Figure 27.1

4. Commercial Uses of Mycorrhizae
Figure 27.2

5. Biogeochemical Cycles
Recycling (oxidation and reduction) of chemical elements

6. The Carbon Cycle
Figure 27.3

7. The Nitrogen Cycle
Figure 27.4

8. Nitrogen Cycle Proteins and waste products Amino acids
Microbial decomposition
Proteins and waste products
Amino acids
Microbial ammonification
Amino acids (–NH2)
Ammonia (NH3)
Nitrosomonas
Ammonium ion (NH4+)
Nitrite ion (NO2- )
Nitrobacter
Nitrite ion (NO2-)
Nitrate ion (NO3- )
Pseudmonas
Nitrate ion (NO3-) N2
Nitrogen - fixation N2
Ammonia (NH3)

9. Formation of a Root Nodule
Figure 27.5

10. The Sulfur Cycle
Figure 27.7

11. Sulfur Cycle Proteins and waste products Amino acids Amino acids (–SH)
Microbial decomposition
Proteins and waste products
Amino acids
Microbial dissimilation
Amino acids (–SH)
H2S
Thiobacillus
H2S
SO42– (for energy)
Microbial & plant assimilation
SO42–
Amino acids

12. Life Without Sunshine
Primary producers in most ecosystems are photoautotrophs
Primary producers in deep ocean and endolithic communities are chemoautotrophic bacteria
H2S
SO42–
Provides energy for bacteria which may be used to fix CO2
Calvin Cycle
CO2
Sugars
Provides carbon for cell growth

13. The Phosphorous Cycle

14. Degradation of Synthetic Chemicals
Natural organic matter is easily degraded by microbes
Xenobiotics are resistant to degradation

15. Decomposition by Microbes
Figure 27.8

16. Decomposition by Microbes
Bioremediation
Use of microbes to detoxify or degrade pollutants; enhanced by nitrogen and phosphorus fertilizer
Bioaugmentation
Addition of specific microbes to degrade of pollutant
Composting
Arranging organic waste to promote microbial degradation
Figure 27.9

17. Decomposition by Microbes
Figure 27.10