Production dynamics of extracellular proteases accompanying morphological differentiation of Streptomyces albidoflavus SMF301

Abstract

Three proteases, namely chymotrypsin-like protease (CTP), trypsin-like protease (TLP) and metalloprotease (MTP), were identified in cultures of Streptomyces albidoflaws SMF301. The dynamics of protease production were determined and the roles of the proteases in morphological differentiation were deduced to be as follows: CTP is essential for hydrolysing the proteinaceous nitrogen source for mycelium growth; TLP plays a role in the formation of thickened mycelium in submerged culture and of aerial mycelium in solid culture; MTP may participate in the maturation of spores. The unique thickened mycelia in submerged culture are thought to be an intermediate form between mycelium and spores. TLP (molecular mass 32 kDa) and MTP (molecular mass 18 kDa) were purified and their enzymic properties were determined.

Extracellular serine-proteinases isolated from Streptomyces alboniger: Partial characterization and effect of aprotinin on cellular structure

“…are chymotrypsin-, trypsin-and subtilisin-like enzymes (Sidhu et al 1994). The optima pH and temperature values determined for these enzymes are in agreement with previous reports that described neutral to alkaline values of pH and temperatures ranging from 35°C to 75°C for proteinases purified from streptomycetes (Chandrasekaran & Dhar 1987, Kang et al 1995, Kim & Lee 1996, Yeoman & Edwards 1997. When S. alboniger was grown in the presence of aprotinin its growth was partially or completely inhibited depending on the inhibitor concentration.…”

“…These enzymes are involved in the assimilation of proteinaceous nitrogen sources, degradation of aerial mycelium and sporulation processes, as well as in antibiotic production (Ginther 1979, Kitadokoro et al 1994, Kang et al 1995, Kim & Lee 1996.…”

Lapstatin, a new aminopeptidase inhibitor produced by Streptomyces rimosus , inhibits autogenous aminopeptidases

“…This conclusion is supported by the work of Kim and Lee (1995), who have shown that leupeptin, a peptide inhibitor of trypsin-like proteinases, is involved in the regulation of autogenous proteolytic activity in Streptomyces exfoloatus. The presence of inhibitors regulating the autogenous leucine aminopeptidases would be of special interest since Kang et al (1995) have shown that the inhibition of these enzymes by EDTA or amastatin completely suppresses submerged and aerial spore formation in Streptomyces albidoflavus. In the light of this result, it is reasonable to suppose that endogenous inhibitors of leucine aminopeptidase could benefit antibiotic yield by suppressing spore formation.…”

Differentiation and protease production in Micromonospora echinospora (ATCC 15837)

“…In addition to their nutritional role, proteases perform many functions in prokaryotic cells, including cleavage of signal peptides during protein export, activation of pro-proteins, inactivation of regulatory proteins and removal of aberrant proteins (Gottesman 1999). The close association of nitrogen nutrition and the regulation of differentiation in streptomycetes may also indicate a role for proteases in regulation of spore formation (Kang et al 1995;Fernandez and Sanchez 2002). Investigation of growth of Streptomyces albidoflavus, in relation to protease production, indicated that this organism produced proteolytic enzymes essential for the hydrolysis of complex nitrogen sources during development.…”