Screening and Optimization of Alkaline Protease Production from Bacteria Isolated from Seawater in The North West of Algeria

Abstract

Bacteria are attracting the interest of worldwide investors; their use is interesting in several industrial fields, this organism produces a wide variety of extracellular enzymes, including proteases. The objective of this study was to evaluate the production of protease by different bacterial strains isolated from local marine samples collected from the Cap Rousseau beach in the Oran city, northwestern Algeria, 44 bacterial isolates were tested for protease production by cultivating them on skim milk agar medium. The proteolytic activities of all strains were tested using skim milk agar and gelatin agar. Among the 14 isolates that showed a significant hydrolysis diameter, two bacterial strains EC23 and EC2S3 demonstrated the highest potential for protease production and they were selected for further studies. In addition, the extracellular protease was examined using the fermentation production medium at 30°C for 48h, with a constant agitation of 150 rpm. The enzyme activity was determined under varying conditions of pH, incubation temperature, and salt concentration, using Sigma's Universal Protease Activity Assay. The enzyme from EC23 strain showed higher activity in all cases than the EC2S3 strain, which indicated that it was the most ideal organism for enzyme production.

Isolation and Molecular Identification of Proteolytic Bacteria from Rusip an Indonesian Fermented Food

“…Casein is a milk protein composed of phosphoproteins and binds to calcium to form casein micelles or white colloids. Rasheed (2022) and Zeyneb et al (2023) explained that the casein content in SMA media was high enough to cause this medium to be yellowish white or bone white. Proteolytic bacteria grown in SMA media will form a clear zone around the colony due to casein hydrolysis by extracellular proteases produced by these bacteria.…”