CH. 5PROKARYOTIC GROWTH

TBL05_01: Some microbial record holders

Figure 05.01: Atacama Desert

© Photodisc/age fotostock

Figure 05.02a: Binary fisson of bacteria

Figure 05.02b: A false color TEM of a cell of Bacillus licheniformis undergoing binary fission

© Lee Simon/Photo Researchers, Inc.

Figure 05.03: A skyrocketing bacterial population

Growth curve plotted in logs and arithmatically

Figure 05.04: Bacterial growth curve

Figure 05.05a: Bacterial colony on blood agar

Courtesy of Dr. J. J. Farmer/CDC

Figure 05.05b: Salmonella typhi culture

Courtesy of CDC

Note the slimy colonies of Salmonella typhi, denoting

capsules

Figure 05.06b: Bacillus anthracis spore

© Scott Camazine/Alamy Images

Figure 05.06c: Germinating spore

Courtesy of Janice Carr/CDC

Figure 05.07: The formation of a bacterial spore

BACTERIAL GROWTH IS AFFECTED BY MANY

FACTORS

TBL05_01: Some microbial record holders

Oxygen can support or hinder growth

Figure 05.09abc: Bacterial cultivation in different gas environments

© Scott Coutts/Alamy Images

Figure 05.10: The effect of oxygen on prokaryotic growth

Hyperbaric chamber

Most bacteria like to grow at a neutral pH

• Optimal pH for growth

Figure 05.12a-e: The streak plate isolation method

Courtesy of James Gathany/CDC

Population growth can be measured in several ways

• Turbidity• Direct measurements• Indirect methods

Counting Bacteria by MPN (most probable number)

Figure 05.13: Direct counting procedure using the Petroff-Hausser counting chamber

Counting bacteria by filtration

Counting bacteria by measuring turbidity in a broth culture

Figure 05.14: The standard plate count

© R.A. Longuehaye/Photo Researchers, Inc.

BACTERIAL DEATH

Bacteria die at a constant rate

Death Curve