ISOLATION AND CHARACTERIZATION OF PROTEASE WITH COLLAGENOLYTIC ACTIVITY PRODUCED BY BACTERIA FROM DIFFERENT SOURCES FOUND IN PHRA NAKHON SI AYUTTHAYA PROVINCES. SUWANNAPHANAbstract Collagen is generally extracted by non-environmentally friendly chemical methods, with occurrence restricted to several proteases due to its complex structure with hydrogen bond binding. Discovery of an enzyme with the potential to extract collagen would be beneficial. This research isolated and characterized 52 proteases with bacterial collagenolytic activity, which produced a clear zone surrounding colonies on Basal medium skim milk agar and Davis minimal gelatin agar. Two potential isolates as BS25 and BS44 showed maximum protease production in Basal medium gelatin broth, with specific activities of 158.30 and 167.25 Umg-1, respectively. They were identified as Chryseobacterium sp. BS25 and Pseudomonas aeruginosa BS44. The optimum pH of crude enzyme from BS25 and BS44 isolates was 7.0, while optimum temperatures were 50 and 60 ºC, respectively. The BS25 enzyme was stable in pH range 5.5 to 8.0, whereas the BS44 enzyme showed higher stability in a wider pH range (5.5 to 11.0). The BS25 enzyme was stable at 30 ºC, while the BS44 enzyme retained activity over a wider range of 30 to 50 ºC. Both the BS25 and BS44 isolates showed high potential to produce protease with collagenolytic activity and enabled efficient extraction of collagen from protein waste or crocodile cartilage for commercial production. |