A Comparative Study on Screening Methods for the Detection of Protease Activity Containing Bacteria

Investigations were carried out to detect the proteolytic activity of the bacteria inoculated on substrate agar plates using different screening methods. This article focuses on the three methods for screening protease activity. The first method involves the flooding of bromocresol green reagent (BCG) on casein milk agar plates. Second, a minimum of 0.0015% of BCG reagent was incorporated with casein milk agar plates and third, gelatin clearing zone plates flooded with mercuric chloride solution. As an outcome, the plates screened with BCG reagent showed clear zone with green-blue background was effective in determining protease activity containing bacteria when comparing to the plates that were colorless.