The interaction of the bacteria Azospirillum spp. with photosynthetic, single cell microalgae that are co-immobilized in alginate beads provides a significant shortcut for understanding the interaction of this plant growth-promoting bacteria (PGPB) with plants in general. This interaction is currently relevant for studying physiological, physical, biochemical, and molecular aspects. As an independent subfi eld of Azospirillum research, this interaction has some signifi cant potential biotechnological applications, such as wastewater treatment, production of biofuel (ethanol and biodiesel), increased fertility of eroded soils combined with promoting growth of higher plants, production of pigments, and production of biomass. All of these applications have yet to be scaled up and evaluated for their true practical potential.
The Logic Behind Using This Interaction as a Model for Plant-Bacteria InteractionA major obstacle in the study of interactions between Azospirillum spp. and plants is the complexity of the plant. Studies of basic plant-bacterium interactions of Azospirillum spp., done mainly with roots, are diffi cult because there are manyDedication : This chapter is dedicated to the memory of the German/Spanish mycorrhizae researcher Dr. Horst Vierheilig (1964 of CSIC in Spain.