Environmental Biology
for Engineers and Scientists
D.A. Vaccari, P.F. Strom, and J.E. Alleman
© John Wiley & Sons, 2005
Chapter 11 –
Quantifying Microorganisms
Figure 11-1. Elemental Distribution of Microbial Biomass Relative to the
Hydrosphere, Lithosphere, and Atmosphere
Figure 11-2. Modern Compound Light Microscope. This model includes a
fluorescence attachment and a camera
Figure 11-3. Bright-Field Microscopy. Original image viewed against a
light/bright background
Figure 11-4. Dark-Field Microscopy. Bright reflected image is viewed against a
darkened/black background
Figure 11-5. Phase-Contrast
Microscopy. Object a), with high
refractive index (n), bends and
retards the light more; after further
retardation at the edges of the
phase plate, the recombined light
(retarded and unretarded) creates
destructive interference, leading to
a darker appearance. Object b),
with a low n, does not bend or
retard the light, creating no
interference, and thus appears
bright. Thus contrast was created
between the two nearly
transparent objects that was not
otherwise visible. A special
condenser (not shown) with a
phase ring is also required
Figure 11-6. Fluorescence Microscopy. Fluorescent image is viewed against a
darkened/black background.
Figure 11-7. Stage micrometer used to calibrate dimensions under microscope
Figure 11-8. Resolution with Various Microscopes. Electron microscopes include
scanning (SEM), transmission (TEM), and scanning tunneling (ST) or scanning
probe (SP)
Figure 11-9. Petroff-Hauser Counting Cell
Figure 11-10. Filling a Sedgewick-Rafter Cell
Figure 11-11. Spread Plating
Figure 11-12. Membrane Filtration
Figure 11-13. MPN Method Schematic. Positive tubes shown as dark after
Figure 11-14. Bacteriophage Plaques
Figure 11-15 Example of Respirometry Data. Oxygen uptake with various
grades (reagent, technical, lean and rich) of monoethanol amine (MEA).
Figure 11-16 Biometer flasks
Figure 11-17. Example of System for Anaerobic Gas Production Measurement
Figure 11-18. Theoretical Microbial Growth Schematic
Figure 11-19. Representative Microbial Generation Times under Optimal
Figure 11-20. Theoretical Stair-Stepped Batch Bacterial Growth Curve
Figure 11-21. Semi-log Plot of Exponential Growth
Figure 11-22. Typical Batch Bacterial Growth Curve
Figure 11-23. Monod Kinetics
Figure 11-24. Batch Growth Curve Using Equation 11-11, with mmax = 10/day, Ks
= 5 mg/L, Y = 0.6 (explained below), b = 0.1/day, and the starting values of S
and X = 120 and 5 mg/L, respectively
Figure 11-25. Schematic of a Continuous Culture System
Figure 11-26. Schematic of a Chemostat
Figure 11-27. Substrate Minimum and Washout in a Chemostat
Figure 11-28. Example Theoretical Plots of S~ and X~ vs. D in a Chemostat.
Values used in Equations 11-28 and 11-29 were mmax = 10/day, Ks = 5 mg/L, b
= 0.05/day, Y = 0.5, and Si = 200 mg/L
Figure 11-29. Lineweaver-Burk Plot. In a) the same coefficients are used as in
Figure 11-28 to generate the theoretical curves. In b) the value of b = 0.15,
showing its effect on the non-linearity of the 1/D plot
Figure 11-30. Example of Determining Y and b. The same coefficients were
used to generate the plot as in Figure 11-28, except b = 0.15
Figure 11-31. Dependence of Microbial Growth on Temperature for a
Hypothetical Mesophile
Figure 11-32. Example of Andrews Model of Substrate Inhibited Growth