Hydrolase producing bacteria among the isolates were screened by plate assay on starch, tributyrin and gelatin agar plates for amylase, lipase and protease respectively.
Amylolytic activity of the cultures was screened on starch nutrient agar plates containing gL-1: starch 10.0; peptone 5.0; yeast extract 3.0; agar 30.0; NaCl 100.0. The pH was from 7.0 to 10.0 depending on experimental conditions. After incubation at 30 ºC for 72h, the zone of clearance was determined by flooding the plates with iodine solution. The potential amylase producers were selected based on ratio of zone of clearance diameter to colony diameter.
Proteolytic activity of the isolates was similarly screened on gelatin nutrient agar plates containing 10.0 gL-1 of gelatin. The isolates showing zones of gelatin clearance upon treatment with acidic mercuric chloride were selected and designated as protease producing bacteria.
Lipase activity of the cultures was screened on tributyrin nutrient agar plates containing 1% (v/v) of tributyrin. Isolates that showed clear zones of tributyrin hydrolysis were identified as lipase producing bacteria.
Amylolytic activity of the cultures was screened on starch nutrient agar plates containing gL-1: starch 10.0; peptone 5.0; yeast extract 3.0; agar 30.0; NaCl 100.0. The pH was from 7.0 to 10.0 depending on experimental conditions. After incubation at 30 ºC for 72h, the zone of clearance was determined by flooding the plates with iodine solution. The potential amylase producers were selected based on ratio of zone of clearance diameter to colony diameter.
Proteolytic activity of the isolates was similarly screened on gelatin nutrient agar plates containing 10.0 gL-1 of gelatin. The isolates showing zones of gelatin clearance upon treatment with acidic mercuric chloride were selected and designated as protease producing bacteria.
Lipase activity of the cultures was screened on tributyrin nutrient agar plates containing 1% (v/v) of tributyrin. Isolates that showed clear zones of tributyrin hydrolysis were identified as lipase producing bacteria.
