The Brazilian Caatinga Biome and Its Biotechnological Potential

The Caatinga biome is a unique Brazilian biome predominant in the Northeast of Brazil and situated in
the Semiarid Region. The rhizosphere comprises the narrow zone of soil that is directly influenced by
the roots of plants and associated soil microorganisms. It is a dynamic environment with maximum
microbial activity due to the presence of root exudates and radicular secretions representing the major
carbon source readily available to microorganisms. The typical rhizospheric community in the
Caatinga biome comprises microorganisms with different types of metabolism and adaptive
responses to changes depending on soil temperature, plant species, nutritional status, age, stress,
illness, and other factors. Assays for a variety of soil enzymes give an indication of the functional
diversity assumed by the microbes present. A useful characteristic of the rhizosphere isolates is the
ability of the rhizobacteria to excrete enzymes such as cellulases and L-asparaginases. Among the
important species found in the Caatinga biome is Poincianella pyramidalis, which is common in the
Northeast of Brazil and is popularly known as “catingueira”. This plant species is heavily exploited by
the local population as a source of firewood, charcoal, fodder and for medicinal purposes. This review
will consider the structure of the Caatinga biome in terms of its biotechnological potential, with special
emphasis on such components as the rhizosphere and enzymes associated with P. pyramidalis.