Encyclopedia of Environmental Science and Engineering, Volume I and II

MICROBIOLOGY 697

Soil

Coarse sintered

glass

Sample to be tested

for microbial

population

Water plus pesticide

To

Reservoir

Sampling pipette

Aqueous layer

Areas of microbial

Growth

Soil sample

Aerobic: bacteria spp.,

blue-green+eukaryotic

algae, protozoa

Microae rophilic: bacteria

Anaerobic

purple sulfur bacteria

green sulfur bacteria

facultative hetero-

tropic bacteria

PONDWATER

Pond bottom=

MUD, GYPSUM

ROTTED PLANTS

AEROBIC

A B

C D

E

FIGURE 11 The Winogradsky column. A laboratory model for microbial population development in natural environments.

C013_004_r03.indd 697C013_004_r03.indd 697 11/18/2005 10:42:01 AM11/18/2005 10:42:01 AM