A dumpsite-isolated Bacillus safensis Z1 with protease yield for potential industrial use

Abstract

Proteases, particularly those derived from microbial sources, have become indispensable in various industries due to their cost-effectiveness, versatility, and sustainability. They provide a more efficient and environmentally friendly alternative to traditional animal- and plant-based enzymes. In this regard, water samples collected from the Sidon dump site were screened for their ability to produce protease. The isolates showed positive results on skim milk agar and were therefore selected as protease-producing strains. The isolates were tested on skim milk agar plates. Of the 6 isolated strains, the most potent isolate was identified as Bacillus safensis Z1. Optimized parameters (time, pH, temperature) for maximum protease activity and microbial growth of B. safensis Z1 include 48 h, pH 7, at 40 °C. The enzyme was homogeneously purified by salt precipitation. SDS-PAGE confirmed that the isolated enzyme had a molecular weight of approximately 50 kDa. It was significantly inhibited by PMSF, indicating that it belongs to serine protease family. The enzyme’s tolerance with surfactants and commercial detergents indicates its potential application in the detergent industry. Furthermore, the partially purified enzyme demonstrated stain removal and feather disintegration capabilities.