Biofertilizer production from microalgae

Abstract

Biofertilizers of microalgae extracts are a sustainable alternative in the improvement, production and protection of agricultural crops, being one of the most promising fields of biotechnology and bioengineering to be explored. Microalgae are multifunctional microorganisms that have photosynthetic efficiency, ability to supply nitrogen in available forms for plants, also improve the development of crops through phytohormones (auxins, gibberellins and cytokines) and macro and micronutrients, essential for plants. These photosynthetic microorganisms need standard conditions for their fast growth that resemble those of plants: light, temperature (18-28ºC), pH (6-9) and nutrients that can come from different organic sources (biol, compost, manure poultry) as inorganic (agrochemicals). Besides, they can be cultue for large-scale production in open atmosphere systems and closed systems under controlled conditions, as in photobioreactors. In the present review, we compare the different types of biofertilizers, microalgae cultures and their large-scale production, we present a perspective of biofertilizers in the world and an analysis of the main challenges to overcome, such as: the cost of production, selection and optimization of strains isolation techniques, bioreactors design, etc