Potencial Biotecnológico do Isolado Priestia megaterium cepa E1

Abstract

The increasing production of petroleum-derived plastics and their improper disposal have led to severe environmental impacts. In this context, biopolymers synthesized by bacteria, such as polyhydroxyalkanoates (PHAs), emerge as a promising solution for the development of bioproducts with a wide range of industrial applications. Therefore, the aim of the present study was to evaluate the PHA production and enzymatic potential of the bacterium Priestia megaterium strain E1, previously isolated from agricultural soil in the municipality of Dourados, MS, Brazil. For this purpose, qualitative tests were conducted for PHA detection using lipophilic dyes, specifically Sudan Black B and Nile Red. The evaluation of enzymatic potential was performed using the Cup Plate technique with solid minimal medium supplemented with Skim Milk for proteolytic activity and soluble starch for amylolytic activity. Plates were incubated in a BOD incubator at 30 °C and analyzed after 24, 48, and 72 hours. The enzymatic index (EI) was calculated based on the ratio between the degradation halo diameter and the colony diameter. Data were analyzed through mean, standard deviation, and analysis of variance followed by Tukey’s test (p > 0.05) in triplicates. PHA production was confirmed by the intense blue coloration with Sudan Black B and by fluorescence under ultraviolet light after cultivation in a medium containing Nile Red. Regarding enzymatic activity, the strain exhibited significantly higher performance in protease production, reaching an average EI of 2.97 after 72 hours. For amylase, no degradation halos were observed within the first 24 hours; however, from 48 hours onwards, the average EI was 1.5 mm, indicating amylolytic potential. The results demonstrate that Priestia megaterium strain E1 possesses relevant characteristics for microorganisms of biotechnological interest. Its sustainable potential makes it an essential candidate in the transition toward cleaner production processes, contributing to the reduction of environmental impact.