Environmental Engineering Reference
In-Depth Information
Table 12.1
Major distinctions between the Oömycota in the Chromista and the true fungi (Chytridiomycota,
Glomeromycota, Zygomycota, Ascomycota and Basidiomycota)
Characters
Oömycota
True fungi
Sexual reproduction
Heterogametangia. Fertilization
of oöspheres by nuclei from
antheridia-forming oöspores
Oospores not produced; sexual
reproduction results in zygospores,
ascospores or basidiospores
Nuclear state of vegetative mycelium
Diploid
Haploid or dikaryotic
Cell wall composition
Beta glucans, cellulose
Chitin. Cellulose rarely present
Type of fl agella on zoospores,
if produced
Heterokont of two types: one whiplash
and directed posteriorly and the other
fi brous, ciliated and directed anteriorly
If fl agellum produced, usually of
only one type: posterior, whiplash
Mitochondria
With tubular cristae
With fl attened cristae
After Rossman and Palm (
2006
)
Fig. 12.1
The Stramenopiles
Bolidophytes
Diatoms
Pelagophytes
Dictyophytes
Pinguiophytes
Chrysomerophytes
Phaeophytes (brown algae)
Phaeothamniophyceae
Xanthophytes
Raphidophytes
Chrysophytes
Synurophytes
Eustigmatophytes
Oomycetes
Hypochytridiomycetes
Developayella
Labyrinthulomycetes
Opalinids
Blastocystis
Bicosoecids
accepted as a class of heterotrophic organisms,
probably derived from heterokont algal ancestry
(Bessey
1950
; Copeland
1956
). Manton (
1952
,
1965
), on the basis of his studies on the fi ne
structure of fl agella, confi rmed the algal ancestry,
and Vogel (
1960
), too, confi rmed it on the basis
of modes of lysine synthesis. The chemical
composition of the hyphal wall (Novaes-Ledieu
et al.
1967
) and an assessment of the signifi cance
mitochondria (Turian
1962
) have also established
the specifi c identity of these fungi.
Later, cellulose containing cell walls, bifl agel-
late (dissimilar) zoospores, diploid life cycle
pattern and its algal affi nities have led to its taxo-
nomic shifting from true fungi to pseudo-fungi
(Table
12.1
) and were kept under Hetero-
kontophyta (Kingdom: Chromalveolata) with
algae - the Stramenopiles (Figs.
12.1
and
12.2
).
The Oömycota were once classifi ed as fungi,
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