Biomedical Engineering Reference
In-Depth Information
1
Introduction
Taurai Mutanda
Institute for Water and Wastewater Technology
Durban University of Technology
Durban, South Africa
CONTENTS
1.1 General Overview ............................................................................................. 1
Acknowledgments ...................................................................................................... 4
References .................................................................................................................. 4
1.1 GENERAL OVERVIEW
Microalgae are single-celled, ubiquitous, prokaryotic and eukaryotic primary
photosynthetic microorganisms that are taxonomically and phylogenetically diverse.
The advanced plant life of today is thought to have evolved from these simple
microscopic plant-like entities. In general, the algae are a heterogeneous group of
polyphyletic photosynthetic organisms with an estimated 350,000 known species
(Brodie and Zuccarella, 2007). There are predominantly two prokaryotic divisions
(Cyanophyta and Prochlorophyta) and nine eukaryotic divisions (Glaucophyta,
Rhodophyta, Heterokontophyta, Haptophyta, Cryptophyta, Dinophyta, Euglenophyta,
Chlorarachniophyta, and Chlorophyta). The biology of microalgae is interesting, and
their enigma is due to their wide diversity as well as their plethora of habitats. The
biology of microalgae is discussed extensively in Chapter 2 of this topic.
Interest in microalgal cultivation is currently blossoming globally for a number
of reasons. Microalgae are not extremely fastidious microorganisms but are found
in diverse aquatic habitats. Microalgae can be found almost anywhere on Earth, in
freshwater, marine, and hyper-saline environments (Williams and Laurens, 2010).
The nutritional requirements of a wide array of microalgal strains are known, and
the technology for microalgal cultivation is developing at a fast pace. The advent of
genetic engineering protocols has brought new vistas to algal molecular systemat-
ics. Recently, the general study of microalgae using genomics and molecular biol-
ogy tools has attained phenomenal dimensions. The sheer number of microalgal
strains from extreme environments that are yet to be discovered and identified
is enormous (Brodie and Lewis, 2007). However, microalgal culture collection
banks have been established as repository centers for these microorganisms (e.g.,
UTEX at The University of Texas at Austin).
The importance of microalgae in day-to-day life cannot be overemphasized.
As the main primary producers, microalgal biomass is used for food and feed
supplements (Lewis et al., 2000). Microalgae are important sources of commercial
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