The Biology of Microalgae - Biotechnological Applications of Microalgae - page 9

value and, hence, any loss in biodiversity is of serious economic concern. This
emphasizes the need and importance of biodiversity conservation. A survey of the
literature on microalgae diversity during the past four decades has revealed that
ecosystems harbor a large number of algae belonging to various groups. Despite
the availability of elaborate monographs on specific groups of algae, any significant
amounts of literature on the taxonomy of several algal species and genera remain
scarce and scattered.
Proper identification of the algal taxa has always been considered “not an easy
task.” Biochemical investigations of, and research into, environmentally important
organisms have diversified phycological research and allowed it to enter a whole new
phase altogether. Discovery of the potential of microalgae for industrial production
of certain chemicals of pharmaceutical value led to the involvement of multifari-
ous types of scientists in understanding the algae. Researchers on the threshold of
algal taxonomic study and nonbotanists who are intrigued to know about the algae
for pursuing research of their own interest are overwhelmed by the huge literature
available. The present work therefore is an attempt to bring together a basic way
of identifying all microalgae belonging to many of the genera of various groups of
algae that occur abundantly and commonly in all ecosystems. Photographs were
prepared for various groups of algae as described here. These photographs con-
tain taxonomic information on the individual groups of organisms, especially the
identification of genera and species. Different species of microalgae were recorded
from water samples. All species of microalgae belonged to two major groups of
algae, namely Bacillariophyceae and Dinophyceae. The Bacillariophyceae mem-
bers were represented by Mastogloia paradoxa Grun., Rhabdonema adriatium Ktz.,
Synedra gruvei Gr unow, Chaetoceros orientalis Schiller, Nitzschia draveillensis
Coste & Ricard, Pleurosigma formosum Wm. Smith, Coscinodiscus janischii var.
arafurensis Grun . , Cocconeis scutellum Ehrenb., Podocystis spathulata (Shadbolt)
Van Heurck, Actinocylus octonarius Ehrenb. , Biddulphia biddulphiana (Smith)
Boyer, Thalassionema nitzshioides Grun., Rhizosolenia setigera Brightwell, and
Thalassiothrix longissima Cleve & Grun. The Dinoflagellates are represented by
Ceratium hirundinella (Muller) Dujardin, Ceratium longipeps (Bailey) Grun.,
Ceratium trichoceros (Ehrenberg) Kofoid, and Gymnodinium sanguineum Hirasaka
(Figures 2.1, 2.2, 2.3, and 2.4; see color insert) (Rajkumar, 2010).
2.3 MOLECULAR IDENTIFICATION
Recent research in microalgal ecology, physiology, systematics, and genomics has
revealed a vast, unexpected diversity. The estimation of microalgal biodiversity has
been hindered by cultivating microalgae for commercial products. Molecular iden-
tification serves as a prominent tool to distinguish inter- and intra-specific morpho-
logically similar species (Olmos et al., 2000) and mixed populations (Olsen et al.,
1986). The developments of modern biotechnological tools, such as polymerase
chain reaction (PCR)- and rDNA-based technologies facilitate in detecting small
numbers of microalgae in complex natural populations and are widely applied to
ascertain the systematic position of species. Sequence analysis has been used to
clarify the taxonomic affinities of a wide range of taxa (McInnery et al., 1995;