Partial Characterization of Proteases From Streptomyces Clavuligerus Using an Inexpensive Medium

Abstract

The partial characterization of extracellular proteases from Streptomyces clavuligerus NRRL 3585 and 644 mutant was investigated. The enzyme production was carried out in batch fermentation using soy bean filtrate as nitrogen source. Maximum activity was obtained after 96h of fermentation with an initial pH of 7.0. The enzyme was partially purified by ammonium sulphate precipitation. Enzymes from the two strains retained 37% of their initial activities at pH 8.0 after 2 h incubation at 25ºC. Enzyme half-life at pH 8.0 and 60ºC was 40.30 and 53.32 min, respectively for both strains (partially purified extract). The optimum pH was obtained at pH 7.0-8.0 and 8.4 for enzymes produced for 3585 and 644 strains (crude extract), respectively, and 8.4 and 8.0 for enzymes from the partially purified extract 3585 and 644 strains, respectively. The optimum temperature for the crude extract was 21ºC for both strains. However, for the partially preparation the optimum temperature was 50ºC and 40°C for S. clavuligerus NRRL 3585 and 644 strains respectively.

Secretion of an alkaline protease from a salt- tolerant and alkaliphilic, Streptomyces clavuligerus strain Mit-1

“…1). This result is in agreement with Bascaran et al, (3) and Moreira et al, (25), who showed that synthesis of protease from Streptomyces clavuligerus starts in the early stationary phase of growth. Similarly, in Streptomyces rimosus, the optimum protease production was recorded at 166 h (36).…”

Milk-clotting protease production by Nocardiopsis sp. in an inexpensive medium

“…The results show that the optimum cultivation periods for milk-clotting enzyme productions were 56 h (M1) and 48 h (M2). These results are in agreement with those of other authors (Porto et al 1996;Moreira et al 2001), which showed that protease synthesis starts in Streptomyces clavuligerus in the post-exponential phase of growth. A higher production of milk-clotting enzymes between 72 and 192 h of growth has been reported for P. oxalicum, M. baciliformis and Mucor miehei (Areces et al 1992;Escobar & Barnett 1993;Hashem 1999).…”

“…The proteolytic activity was determined as described previously (Moreira et al 2001), in cell-free supernatants clarified by centrifugation (12,000 · g) for 5 min at 25°C. Azocasein, 1.0% (w/v) (Sigma Chemical Co., St. Louis, Mo USA) in 0.1 M Tris-HCl, pH 7.6, containing 1 mM CaCl 2 , was used as substrate.…”

Production and Stability of Protease from Candida buinensis

“…The ability to digest casein was demonstrated by the formation of transparent halos on the plates and expressed in millimeter. Positive strains were submitted to the quantitative test described by Moreira et al [8]. The proteolytic activity was determined in the cell-free supernatants obtained by centrifugation (5,500×g) for 5 min at 25°C.…”