Abstract

Proteases constitute an important group of enzymes widely utilised in industrial processes due to their versatility for various applications. These applications range from their use in textiles and detergents to food processing and pharmaceuticals. Recently, bacterial proteases have garnered considerable attention for commercial applications. This interest stems from their ease of cultivation, simplicity in genetic modification, and low production costs, making them highly useful for commercial purposes. The unique conditions of mangrove soils harbour microorganisms that can produce enzymes and metabolites with valuable industrial properties that are less explored. In this study, bacterial strains were isolated from soil samples taken from the Pichavaram mangrove forest, Tamil Nadu, India, and screened for their ability to produce protease. Among those tested, one isolate (C2) showed the highest protease production after 96 h of incubation, achieving 633.14 U/mL crude enzyme (total enzyme activity). The isolate C2 was further characterized using 16S rRNA gene sequencing, which confirmed it as Fictibacillus phosphorivorans. In addition to measuring protease activity, this work assessed the effectiveness of crude enzyme in removing blood stains and its ability to break down keratin, which suggests potential uses in feather degradation and waste management. Mangrove ecosystems harbor highly diverse microorganisms adapted to extreme and fluctuating conditions, such as salinity, tidal changes, and oxygen limitation. The high organic matter content in mangrove sediments promotes the microbial production of extracellular proteases, facilitating nutrient cycling. These environmental pressures drive the evolution of proteases with enhanced stability and unique catalytic properties, making mangroves promising hotspots for novel protease-producing microbes. Overall, this research emphasizes the potential of bacteria found in mangrove environments as sources of important industrial enzymes. It also highlights the need to explore different ecological niches to find new microbial resources for biotechnological advancements.

Key words: Proteases; mangrove forest; Fictibacillus phosphorivorans; keratin.