Characterization and evaluation of the antibacterial potential of bacterial microbiota of cultivated soils of Cassava (Manihot esculenta) and Black pepper (Piper nigrum) in the city of Igarapé Açu – Pará, Brazil

Actinobacteria form a heterogeneous group of Gram-positive bacteria that have a great morphological and metabolic variety, are microorganisms with great biotechnological potential for the production of several substances of industrial and pharmaceutical interest, being considered the main source of antibiotics. Due to the increase in the occurrence of bacteria that are multiresistant to antibiotics used in clinical and hospital routine, the need to discover new substances with antibiotic capacity becomes evident. Thus, studies that assess the diversity and variety, composition and properties of metabolites produced by bacterial species present in cultivated soils are important and necessary. This work aimed to investigate the occurrence of actinobacteria in rhizosphere soils of areas cultivated with cassava (Manihot esculenta) and black pepper (Piper nigrum) in the city of Igarapé Açu - Pará, Brazil, to assess their potential as producers of antimicrobial substances. This is an analytical descriptive, experimental study that performs a microbiological analysis of soil samples. With great morphological diversity, 21 different bacteria were isolated, all with characteristics of actinobacteria. As a result, strains of actinobacteria with variable colonial characteristics were isolated, microscopically characterized as isolated and chained Gram-positive bacilli. Among the isolates, 8 strains were able to inhibit the growth of Escherichia coli and Klebsiella pneumoniae compared to in vitro. It emphasizes the need for more research aimed at the microbiology of Amazonian soils, due to the diversity of bacteria of biotechnological importance that can significantly contribute to the production of new antibiotics, thus generating a positive expectation in the fight against infections.