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

摘要

Three proteases, namely chymotrypsin-like protease (CTP), trypsin-like protease (TLP) and metalloprotease (MTP), were identified in cultures of Streptomyces albidoflavus 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.