The Brazilian Caatinga Biome and Its Biotechnological Potential

Abstract

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.