Moulds (sometimes
spelled molds) are microscopic fungi whose spores are everywhere.
These spores can germinate quickly and colonize new food
substrates (e.g., bread, cheese, peaches) very quickly.
They may be white, pink, green, blue, grey or black, and
often look like spreading fuzzy spots. They usually grow
only where it is damp.
There are two
major kinds of mould, which belong to two very different
groups of fungi.
(1) The first
and most numerous group are the Hyphomycetes, mostly asexual
phases of a Class called Ascomycetes.
There are many thousands of different moulds in the Hyphomycetes.
(2) The second
group often grow very fast, and are asexual phases of the
Class Zygomycetes
. There are several hundred of these moulds, and most
can grow only in very damp places.
Both kinds specialize
in producing very large numbers of spores with minimum expenditure
of energy, since the spore bearing structures are always
microscopic.
The structure
of the two groups is rather different, and it is not hard
to tell them apart, as you will find if you browse the two
pages linked above.
Much more detailed
accounts can be found in 11 chapters of the book and CD-ROM.
