Encyclopedia of Environmental Science and Engineering, Volume I and II

694 MICROBIOLOGY

microbial types, their interactions and their relationships to

higher plants and animals. It is important to note that the

“natural” balance may be undesirable. Thus studied efforts

to change these bal ances would be quite desirable. The

most important precaution to observe relates to the ancillary

consequences of these changes, i.e. do the changes produce

side effects which may be as unappetizing as the original

condition.

The development of techniques which form the bases for

studying microbial ecology comprise an important chapter in

Bacteriochlorophyll+

light

cytochrome c

cytochrome b

Ubiquinone

Ferredoxin

Intermediate

ADP + Pi

AT P

• e

'E 0

(REDOX POTENTIAL)

+0.6

+0.4

+0.2

0

• 0.2


• 0.4


• 0.6


• 0.8

FIGURE 9 Electron flow in bacterial photosynthesis.

cytochrome f

cytochrome b

ADP + Pi

ADP + Pi

AT P

AT P

• e
  
  
  • e
  
  
  
  

e–

photosystem I

photosystem II

Plastoquinone

light 400–500 nm

light, 700 nm

chlorophyll+

chlorophyll+

intermediate

oxidant

intermediate

reductant

reduced ferrodoxin

NADP

NADPH

H 2 O 2H+1/2 O 2

+0.6

+0.8

+1.0

+0.4

+0.2

0

–0.2

–0.4

–0.6

–0.8

–1.0

FIGURE 10 Electron flow in algal and higher plant photo-synthesis.

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