Purification and characterization of an extracellular chitinase from the antifungal biocontrol agent Streptomyces halstedii

摘要

An extracellular chitinase from Streptomyces halstedii AJ-7,a broad spectrum antifungal biocontrol agent,was characterized and purified.The apparent molecular weight of the purified protein was 55 kDa,K_m value and V(max)of the protein for colloidal chitin were 3.2 mg ml~(-1)and 118 mumol h~(-1),respectively.The growth and chitinase activity of S.halstedii AJ-7 were enhanced by adding of 0.1% killed mycelium of Fusarium oxysporium in a medium containing 0.2% colloidal chitin.