Isolation and characterisation of Bacillus amyloliquefaciens H2 glutamyl endopeptidase that is secreted in stationary phase of culture growth

The culture broth of Bacillus amyloliquefaciens H2 was used for isolation by chromatography on CM-cellulose and MonoS columns of proteinase that are secreted in early and late stationary phases of culture growth. Based on their inhibition by specific serine proteinase inhibitors and their action on specific chromogenic substrates and on oxidised B-chain of insulin, the enzymes were classified as glutamyl endopeptidases. The molecular weight of secreted enzyme is 26.5 kDa. We show that although the enzyme is secreted in different phases of culture growth, both enzyme fractions have similar enzymatic properties and amino acid content, but they were distinguished in