Production of extracellular enzymes by Brevibacterium linens in fermenter and preparation of enzyme powder

Two strains of Brevibacterium linens (B. linens FLK61 and B, linens DSM20425) were grown separately in a fermenter at 25 degreesC. Growth and extracellular proteinase production were analysed during fermentation. The rate of growth was higher for DSM compared to FLK strain. Extracellular proteinase activity was slightly higher in culture of DSM after 19 h of fermentation. Cells were removed from the cultures by filtration at the end of 26 and 21 h of fermentation for FLK and DSM strains, respectively. Cell free filtrates were concentrated 5fold by ultrafiltration (UF) and diafiltration. The retention of proteinase activity was 57.7 and 65.3% in UF and 48.0 and 51.4% in diafiltrated retentate for the enzymes from FLK and DSM strains, respectively. The yields of activity in lyophilised enzyme powders were 54.7 and 62.5% from UF and 47.1 and 51.2% from diafiltrated retentates of FLK and DSM strains, respectively. After 5 months of storage at -19 degreesC the loss in proteinase activity in the powder of ultrafiltrated enzymes from FLK and DSM strains amounted to 2.3 and 7.3%, respectively. For both enzymes the loss in activity during storage was lower in powder prepared from diafiltrated than ultrafiltrated retentate.