Extracellular protease from Pseudomonas marinoglutinosa: some properties and its action on fish actomyosin [Postmortem storage]

ABSTRACT A bacterium isolated from Indian mackerel (Rastrelliger kanagurta) and identified as Pseudomonas marinoglutinosa, was found to produce appreciable amounts of extracellular protease when grown in nutrient medium. This enzyme which degraded several proteins, was found to be most active against mackerel myofibrillar proteins. The optimum temperature and pH range for enzyme activity were 50°C and 7–8 respectively. Treatment of mackerel actomyosin with the protease at 0–2°C for 4 days resulted in degradation of the protein as assessed by release of tyrosine, loss in Mg++‐dependent ATPase activity and changes in SDS‐polyacrylamide gel electrophoretic patterns.