Growth and the envrionment

Figure 5.2

Figure 5-3 Psychrophilic environment and psychrophiles.

Figure 5-4 Thermophilic environments and thermophiles.

Figure 5.5

Figure 5.6

Figure 5-8 Halophilic salt flats and halophilic bacteria.

Changes in pH

Figure 5.11

Figure 5-15 A soda lake ecosystem.

Figure 5-16 Na+ circulation in alkaliphiles.

Figure 5.17

Oxygen as an Electron Acceptor• Many microorganisms use oxygen as a terminal

electron acceptor in a process called aerobic respiration.

Figure 5.18

Figure 5.19

Oxygen-related growth zones in a standing test tube

• Generation and destruction of reactive oxygen species (ROS)

Figure 5.20

Humans Influence Microbial Ecosystems

• Maximum diversity in an ecosystem is maintained, in part, by the different nutrient-gathering profiles of competing microbes.

Figure 5.23

• Microbes die at a logarithmic rate.

• Decimal reduction time (D value) is the length of time it takes an agent or a condition to kill 90% of the population.

Figure 5.25

• The phenol coefficient test compares the effectiveness of disinfectants.

The Phenol Coefficient

Table 5.3

Figure 5.30

• Antibiotics are chemical compounds synthesized by one microbe that kill or inhibit the growth of other microbial species.

• Penicillin mimics part of the bacterial cell wall.• - Prevents cell wall formation and is bactericidal

Antibiotics

Figure 5.31

Figure 5.32

Effect of ampicillin (a penicillin derivative) on E. coli