Microbial Technology: Microalgae


Juan Roberto Benavente-Valdés*, María Elena Velázquez-Arellano, Israel Hernández-López, Diederich Enrique Aguilar-Machado, Lourdes Morales-Oyervides, José Eduardo García-Martínez, and Julio César Montañez-Sáenz.

The algae are varied aquatic organisms that can be found as unicellular and multicellular
organisms that form large, extensive, and showy colonies. The algae make
one of the most significant contributions of oxygen to the planet. It is estimated that
they participate with close to 50 % of global photosynthesis; 30,000 species are
described, but it is believed there are more than 50,000 species. Microalgae represent
an important source of valuable compounds, including lipids, proteins, carbohydrates,
and a variety of pigments. Therefore, these microorganisms denote a
potential ecological and economical option for applications in various industries.
Microalgal cultivation requires strict control of growth conditions (nutrients, pH,
temperature, gas exchanged, and light regimen). Optimal culture conditions will
allow high yields of biomass or the desired metabolite of interest. The cultivation of
microalgae is commonly done in two varieties of systems, open and closed. Closed
systems are also known as photobioreactors, which although more expensive, offer
higher productivities than open systems. In recent years, microalgae have been used
in different industries such as food, feed, or biofuel production and as a source of
ingredients for cosmetic and pharmaceutical products. In this chapter, the main characteristics
of microalgae, their classification, the factors that influence their growth,
the types of cultivation, the different cultivation systems, and the potential applications
of these photosynthetic microorganisms will be described.