Encyclopedia of Environmental Science and Engineering, Volume I and II

688 MICROBIOLOGY

include motile, flagellated stages. Both asexual and

sexual reproduction occurs.

2) Euglenophyta differ from the other algae by pos-

sessing a rather flexible cell wall which allows con-

siderable plasticity of form. They are either fresh

water or marine forms. They all have two flagella

but in some genera the second flagellum is often

rudimentary. Many forms are phagotrophic (can

ingest particles). Chloroplastless forms are fairly

common. Multiplication is only by asexual means.

3) Xanthophyta are mostly freshwater forms. They

may be unicellular, colonial, filamentous or

siphonaceous. Some forms have life cycles which

include both asexual and sexual reproduction.

Motile anteriorly flagellated cells are found.

4) Chrysophyta are mainly freshwater forms but

important marine forms are known. Most genera

are unicellular but there are some colonial forms.

Cell walls are often composed of siliceous or cal-

careous plates. Some form siliceous cysts. They

are mainly found in fresh water but some impor-

tant marine forms exist. Reproduction is asexual.

5) Phaeophyta (diatoms) are unicellular or colonial

forms with distinctly patterned siliceous cell walls.

Both asexual and sexual multiplication is found.

Freshwater, marine, soil and aerial forms exist.

6) Pyrrophyta are unicellular flagellates with cel-

lulose cell walls which are sometimes formed in

plates. Reproduction is asexual. Sexual reproduc-

tion is rare.

7) Cryptophyta are unicellular, usually flagellated

forms which produce asexually.

8) Rhodophyta (red algae) are unicellular, filamentous

or leafy forms with complex sexual cycles. Most

are marine but there are a few freshwater forms.

Fungi

The “true” fungi or Eumycota are eukaryotes which are

related to both protozoa and algae. They are divided between

Reserve material (cont.)

b-1,3 glucans Sugars Sugars

alcohols

Division Laminarin Paramylon Chrysolamainarin Floridoside Sucrose Mannitol Lipid

Chlorophyta (green algae) 


Euglenophyta

Xanthophyta 
 


Chrysophyta

Phaeophyta (brown algae) 
 o 



Bacillariophyta (diatoms) 



Pyrrophyta 


Cryptophyta

Rhodophyta (red algae) 

TABLE 3

Divisions and characteristics of the eukaryotic algae

Pigments Reserve material

Chlorophyll Biliproteins Starches (a-1,4-glucans)

a b c d e Phyco-cyanin Phyco-erythrin True

starch

Floridian

starch

Chlorophyta (green algae) 

 


Euglenophyta 

  

Xanthophyta 

  

Chrysophyta 
  

Phaeophyta (brown algae) 

  

Bacillariophyta (diatoms) 

  

Pyrrophyta 

   


Cryptophyta 

 
 
 


Rhodaphyta (red algae) 
? 
 
 

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