Just as the Twilight saga is coming to an end, another group of
light-loving vampires has been found out for what they truly are. The
algae, Chlamydomonas reinhardtii, normally lives a quiet life,
transforming sunlight and carbon dioxide into energy, like a good
plant should. But biologist Olaf Kruse of Bielefeld University
discovered that the algae can also be vegetation vampires.
When carbon dioxide levels get low, the algae’s darker side
takes over and it makes a salad of its neighbors. The unicellular
algae sucks the life from other plants by devouring their cellulose,
the long, tough chains of sugars that make up much of its victims’
durable structures. These vampire algae are
no strangers to the sun and dine on the cellulose when bathed in sunlight.
Kruse’s study, published in Nature Communications, found that the
algae excretes an enzyme to break down cellulose into shorter sugars
that the fiendish foliage can digest. Prior to this study, the only
other organisms know to dine upon cellulose were some fungi, bacteria
and a few other species, but no cannibal carnations or zombie zinnias
were known to stalk celery.
The algae’s taste for cellulose may have applications in the
production of biofuel. Cellulose is abundant and cheap, since even
hardy plants that grow in poor quality soil contain the chemical.
However, the cellulose is not a sugar to give up its energy easily.
Converting cellulose to ethanol by conventional means requires adding
enzymes to break down the cellulose into simpler sugars that can be
converted into ethanol by yeast. Those enzymes are usually extracted
from another organism, which increases the cost of production.
Kruse suggests that Chlamydomonas reinhardtii‘s taste for
cellulose could be used to streamline the process of cellulosic
ethanol production. The algae could be fed plant material in a low
carbon dioxide environment with abundant sunlight and thereby break
down cellulose cheaply.
A statue outside the Monkey Forest Temple in Ubud, Bali, Indonesia. (Shawn Allen, Wikimedia Commons)