Doaa E. El-Hadedy^{1, 2,}, Nesreen A. Safwat³, Abir Pertila^{1, 3}, Rafat A. Siddiqui^4,

In the food industry, alkaline protease plays an important role in the formation of value-added products. Alkaline protease also plays a significant role in waste management. In this study, to construct a stable and high-yield alkaline protease producer, we investigated a combined strategy of gamma radiation as an enhancement factor and alkaline protease PGEM-T easy construct. The present study was focused on the isolation of the sprA gene-producing alkaline protease from Streptomyces flavogriseus ADEM7 (AB723783.1). Optimum growth media, fermentation conditions, and proteolytic activity assay were evaluated. The result showed that the free cells preparation produced alkaline protease with a specific activity of 550 U/mg after being exposed to gamma radiation at 10 KGy. The sprA gene was detected using polymerase chain reaction followed by cloning in PGEM-T easy vector, transformation in E. coli JM109, and direct construct sequencing. The sprA gene encoding streptogrisin a (alkaline protease-like activity) was isolated in this study and recorded in the gene bank with accession number AB827411.1. The extracellular protease enzyme was tested for antioxidant and anticancer activities. In future work, we will extract this alkaline protease from the same strain on a larger scale using a fermenter and will characterize its antioxidant activity under in vivo conditions.

Streptomyces flavogriseus, alkaline protease, antioxidant and anticancer, gamma radiation