TEXTO:
New glowing mushrooms found in Brazil
Like a black light poster come to life, a group of
bioluminescent fungi collected from Ribeira Valley Tourist
State Park near São Paulo, Brazil, emanates a soft green
glow when the lights go out. The mushrooms are part of
5 the genus Mycena, a group that includes about 500
species worldwide. Of these only 33 are known to be
bioluminescent — capable of producing light through a
chemical reaction.
Since 2002, Cassius Stevani, professor of Chemistry
10 at the University of São Paulo, Dennis Desjardin,
professor of mycology at San Francisco State University
in California, and Marina Capelari of Brazil’s Institute of
Botany have discovered 10 more bioluminescent fungi
species — four of which are new to science — in Brazil’s
15 tropical forests. The work, Stevani says, has increased
the number of glowers known since the 1970s by 30
percent.
In addition to mushrooms, a variety of marine
animals, select species of bacteria, insects, and annelids
20 (earthworms) are known to be bioluminescent.
Bioluminescence creates “cold” light — emissions with
low thermal radiation. An enzyme called luciferase
triggers a pigment called luciferin to oxidize, and the
reaction emits light. But why the fungi evolved to glow
25 this way remains a mystery, Stevani says. To get the
green glow of the new specimens of bioluminescent
mushrooms, Dr Desjardin and Dr Stevani had to go out
on new moon nights and stumble around in the forest,
running into trees, while keeping an eye out for poisonous
30 snakes and prowling jaguars.
Besides helping researchers decipher how and why
mushrooms glow, Stevani is studying the bioluminescent
fungi’s ability to signal the presence of toxins in the soil.
In the lab, his team has developed a procedure that
35 shows that fungi emit less light when exposed to several
metals and organic pollutants. “In a near future we can
use it to evaluate the toxicity of environmental samples
of soil and sediments,” Stevani said in an email to
National Geographic News. The researcher also says
40 that the fungi could serve as a tool for bioremediation
(cleanup using living organisms) of contaminated soil.
New glowing mushrooms found in Brazil. Disponível em: . Acesso em:
“the fungi could serve as a tool for bioremediation [...] of contaminated soil.” (l. 40-41)
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