Biochemical properties and repression studies of an alkaline serine protease from a haloalkaliphilic actinomycete, Nocardiopsis dassonvillei subsp. albirubida OK-14

Abstract

A marine haloalkaliphilic actinomycete identified as Nocar diopsis dassonvillei subsp. albirubida (strain OK-14) was screened for its ability to produce extracellular alkaline protease under various physical conditions pertinent to different applications. The strain utilized amino acids as the sole source of nitrogen, displaying repression and de-repression phenomenon above the threshold levels. The activity of the partially purified alkaline protease was 1421.7 U/ml/min. The enzyme was optimally active at pH 10 and 60 °C. The activity was assessed under various concentrations of NaCl, organic solvents and metal ions. The partially purified alkaline protease was then examined for its suitability in blood de-staining, gelatine degradation and keratinase activity, implicating its relevance in detergent industries, gelatine extraction from X-ray films and degradation of bio-wastes. • Repression and de-repression of protease by different amino acids. • Protease stability in solvents, metal ions and various other agents. • Highly efficient in gelatin deproteinization and silver recovery. • Compatible as detergent supplement.