Morphological diversity of actinobacteria isolated from oil palm compost (Elaeis guineensis).

Composting is a natural process of decomposition of organic matter that occurs by the action of microorganisms such as fungi, bacteria, and actinobacteria. The actinobacteria are present throughout the process due to their resistance to different environmental conditions. They are Gram-positive, filamentous bacteria with a high capacity for producing secondary metabolites of biotechnological importance. Thus, the objective of this work was to isolate and characterize actinobacteria from industrial composting soil of oil palm (Elaeis guineensis) in the municipality of Igarapé-Açu, Pará. Ten samples of the material were collected and seeded on soy tryptone agar, Reasoner's 2A agar, and Columbia agar, using the serial dilution technique. For morphological characterization of the strains, Gram staining and microculture were performed, and for biochemical characterization, the motility, triple sugar iron, Simmons citrate, maltose, phenylalanine, catalase, and DNAse tests were performed. It was observed that compost actinobacteria have a great diversity in morphological and metabolic production, which may be associated with the substrate and cultivation conditions. Therefore, palm oil compost material represents a rich source of bacterial biodiversity, bringing new perspectives for the bioprospecting of actinobacteria of biotechnological importance in little explored environments.