Amylase Producing Potentials of Bacteria Isolated from Selected Dumpsites in Benin Metropolis, Edo State, Nigeria

Amylase enzyme has extensive usage in different industries and can be obtained from microorganisms (e.g., bacteria) before purification and usage. In the current study, the amylase-producing potential of bacteria isolated from selected dumpsites in Benin City, Edo State, Nigeria, was investigated. A total of 54 soil samples were obtained from three different dumpsites (Ikhueniro, Eyaen, and Uhumarioge) between August and October 2023. The pour plate method was used to quantify the total number of heterotrophic bacteria, and starch hydrolysis agar was used to assess the organisms' starch-hydrolyzing capacity. The bacterial isolates' capacity to produce amylase was assessed qualitatively using starch agar and quantitatively using colorimetric (3,5-dinitrosalicyclic acid reagent) techniques, while optimal pH and temperature for amylase production were done by spectrophotometric technique. The bacterial isolates were further identified by their cultural, morphological, biochemical, and 16S rRNA characteristics. A total of 23 different bacterial isolates were identified from the soil samples, out of which 8 were found to hydrolyze starch. Achromobacter anxifer, Providencia alcalifaciens, and Proteus mirabilis were further reported as the highest producer of amylase enzyme, with optimum temperature and pH being 35°C and 6, respectively. The study of amylase-producing bacteria from the soil of waste dump sites reveals a complex and dynamic microbial ecosystem with profound ecological, industrial, and scientific significance. Efforts must, therefore, be made to obtain this enzyme in sufficient amounts and ensure its usage in different industries.