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| Coprophilous fungi are
species from certain genera that grow nowhere else but in
faeces. Yes, these lowly organisms live in a stinky world but
who knows, one day they may save lives. |
Story by PONGPET MEKLOY Pictures
by SAYANH SOMRITHIPOL
Forget all the recent global
tumult for a moment _ small-scale changes like the strange
relationship between fungi and faeces are interesting, too, at
least for one scientist.
Sayanh Somrithipol, a mycologist at the National Centre for
Genetic Engineering and Biotechnology (Biotec), has spent recent
months observing the succession of fungi to appear on droppings of
elephants and other herbivorous wildlife.
``You rarely find a decomposer like fungi in the high-protein dung
of meat-eating animals, which will have just bacteria and some
insects,'' says Sayanh. ``In the dung of plant-eaters, much of the
content is cellulose which bacteria can't tackle efficiently. They
need the help of fungi.''
Despite their ability to multiply quickly, bacteria can only break
down waste matter from the outside in. Fungi, on the other hand,
produce ``feeding threads'' that penetrate through the cellulose
and work from the inside out.
``What's really important to us humans is the fact that
Coprophilous (dung-loving) fungi are able to thrive and flourish
in such bacteria-infested conditions,'' said the scientist. ``It
hints that these fungi must have some kind of protection that
keeps them from being harmed by the bacteria.''
Asked how the Coprophilous fungi get themselves into faeces,
Sayanh says that while there may be some ``contaminant'' fungi
that fall and grow on old dung, Coprophilous species come mixed
with the waste matter from the start.
``Their spores are attached to the leaves and other plant matters
that herbivores feed on. When the dung is unloaded onto the
ground, the fungi grow, usually one species after another. They
produce the fruiting bodies (the visible structures that contain
spores) and then release their spores onto nearby plants,'' he
explains. ``When those plants are eaten the life cycle of the
fungi is repeated.''
Coprophilous fungi do not grow on other things, not even on leaves
their spores land on. The spore's growth mechanism is not
activated unless it passes through the animals' digestive system
first.
Sayanh collected fresh faeces of herbivores from Khao Yai and
Kaeng Krachan national parks as well as from Huay Kha Khaeng
Wildlife Sanctuary. He brought them to the lab at Biotec to
monitor fungal succession over periods ranging from a few days to
one full month.
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| An unidentified species of
mushroom grows on an old dung specimen in the lab at Biotec. |
The mycologist found 10 species or so of
fungi in each specimen of deer droppings, but more in the elephant
droppings.
``Also, the species that appear in deer faeces are pretty
predictable. But you never know what you'll get in the case of
elephants. Diversity is high. The species combination varies
hugely in different droppings.''
The succession of fungi that grow on the dung seem to occur in a
particular order. Sayanh found that species of Genus Pilobolus
develop fruiting bodies within only three to five days, while
others, like the Ascobolus, tend to wait until the earlier species
have wilted and begun rotting away. (See graphic.)
There are a number of possible explanations.
``Fresh droppings contain more sugar than old ones. So it's
possible that the species that grow first are better at consuming
the available sugar; the species that follow may have different
food requirements,'' says Sayanh.
``Then again, since the spores of all Coprophilous fungi are all
already there from the start, it's also possible that the reason
is nothing but the fact that different species require different
amount of time to develop.''
Or, he adds, there may be some kind of competition among the fungi
that regulates the order of succession.
Sayanh's work is only at the beginning stage. He plans to conduct
similar studies in the fields, where moisture and other conditions
are very different from the controlled environment of a
laboratory.
His work also includes isolating and cultivating fungi from which
he tries to find bioactive compounds and useful enzymes.
It is hoped that one day the scientist might discover something
from the dung-dwelling fungi that could help humans in our
unending war against harmful bacteria.
