Isolation of Bacillus licheniformis strain Sh-19 from Soil: Identification by 16S rRNA Gene Sequencing and Characterization of α-Amylase Enzyme

Amylase enzyme is regarded as one of the essential microbial enzymes with several industrial applications The objective of this work was to separate, purify, and describe the amylase enzyme acquired from amylolytic bacteria in addition to optimization of the parameters influencing its activity. Several biochemical tests were used to describe soil-isolated amylolytic bacteria, and molecular methods were used to validate their presence. The bacterial 16S rRNA gene was amplified using universal primers. A comparison was made between the amplified 16S rRNA gene sequences and the NCBI sequence database. Bacillus licheniformis isolate Sh-19. Using 16S rRNA sequencing, phylogenetic and molecular evolutionary analyses were carried out. The isolate's 16s rRNA genes showed 98% identity with reference isolates in the Gene Bank according to similarity searches (BLAST, NCBI). The selected strain of Bacillus licheniformis clustered with the nearest members of the phylogenetic tree based on 16S rRNA gene sequences. The bacterial isolate Bacillus licheniformis strain Sh-19 was selected for characterization of α-amylase enzyme as it was the most potent amylolytic strain and showed prominent α-amylase activity. 37°C was discovered to be the ideal temperature for the activity of the α-amylase enzyme. whereas the optimum pH was 7.0. Exposure to different heavy metals as Mg ^2+, K ⁺ , CO ²⁺ , Cu ²⁺ , Fe ²⁺ and EDTA enhanced α-amylase activity, while treatment with Ag ⁺ , urea and Zn ²⁺ was accompanied by the least activity of the enzyme. Results revealed that Bacillus licheniformis strain Sh-19 might present a promising novel bacterial candidate for the production of α-amylase enzyme.