|
Discovery of Marine Algae Picobiliphytes
Scientific Journal of Science, Volume 316
'Picobiliphytes: A
marine picoplanktonic new algal group.
An international group of researchers has
succeeded in identifying a previously
unknown group of algae. As currently
reported in the scientific journal Science,
the newly discovered algae are found among
the smallest members of photosynthetic
plankton - the picoplankton ('Picobiliphytes:
A marine picoplanktonic algal group with
unknown affinities to other Eukaroytes"
Science, Vol. 316'). On account of the
minute size of the organisms (no more than a
few thousandth of a millimetre) and the
appearance of phycobili-proteins,
researchers have termed the new group
Picobiliphyta.
Approximately 50 percent of global
photosynthesis is conducted in the world's
oceans where it is dominated by microscopic
algae, the so-called phytoplankton.
Scientists estimate that up to 90 percent of
phytoplanktonic species are currently
unidentified. In the present study,
scientists used molecular techniques to
investigate the smallest members of the
plankton, the picoplankton. Because
picoplankton algae are so extremely small,
they are almost impossible to study by means
of microscopy.
Researchers investigated gene sequences
of the 18S gene, common to all cells. The
identity of new organisms can be deduced
from a comparison of familiar and unfamiliar
gene sequences. "The gene sequences found in
these algae could not be associated with any
previously known group of organisms",
explain Dr Klaus Valentin and Dr. Linda
Medlin, co-authors of the study and
molecularbiologists at the Alfred Wegener
Institute in Bremerhaven. The algae in this
study were found in plankton samples
originating from various regions of the
North Atlantic and the Mediterranean. The
scientists have discovered a group of
organisms which, despite being completely
new to science, have a wide distribution.
"This is a good indication for how much
there is still to discover in the oceans,
especially using molecular tools", says Valentin. Apart from the unfamiliar gene
sequences, the researchers also extracted
phycobili-proteins from the algae. In red
algae, for example, these proteins occur as
colour pigments. However, in the newly
discovered algal group, the phycobili-proteins
are found at the sites for photosynthesis,
i.e. in the plastids. This location of
pigment proteins represents a novelty in
that it has not been reported for any other
algal species. Hence, it provides a clear
indication that the researchers are dealing
with a previously unidentified species of
algae. Referring to their small size and the
presence of phycobili proteins, the
researchers named the new group
Picobiliphytes.
|
