The isolates were tested for various enzymatic activities, including catalase, oxidase, and urease. Substrate and hydrolysis tests were performed using media supplemented with specific substrates such as casein, starch, gelatin, and citrate [4 (link),11 (link),13 (link)].
Starch hydrolysis was tested on peptone yeast extract agar, replacing sucrose with 10 g of soluble starch per liter. A clear zone around the colony indicated a positive reaction after flooding with Gram’s iodine solution. Gelatin hydrolysis was tested on tubes containing a solid gelatin medium. A positive result was fluid production due to the bacterial enzyme gelatinase. Casein hydrolysis was tested on peptone yeast extract agar containing 10 g glucose per liter and 25 mL 15% (w/v) skim milk per liter and adjusted to pH 5.6. A positive result was a clear zone around a strip inoculation after flooding with 10% (w/v) HgCl2.
Starch hydrolysis was tested on peptone yeast extract agar, replacing sucrose with 10 g of soluble starch per liter. A clear zone around the colony indicated a positive reaction after flooding with Gram’s iodine solution. Gelatin hydrolysis was tested on tubes containing a solid gelatin medium. A positive result was fluid production due to the bacterial enzyme gelatinase. Casein hydrolysis was tested on peptone yeast extract agar containing 10 g glucose per liter and 25 mL 15% (w/v) skim milk per liter and adjusted to pH 5.6. A positive result was a clear zone around a strip inoculation after flooding with 10% (w/v) HgCl2.
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