In plate tests, you should see a cleaning zone where microbial cultures grow. The Red Starch is depolymerised by alpha-amylase and will diffuse throughout the plate giving a zone of lighter colour. A concentration of 0.1% is correct. You may try even lower. Ensure that the pH of the Agar is in line with enzyme requirements, i.e. pH 4.5-5.5 for fungal and 6.0-7.0 for bacterial alpha-amylases.
What is the procedure for using Red Starch (S-RSTAR) on agar pates to detect microbial colonies that are known to produce alpha-amylase? What should positive results look like?
Modified on: Thu, 23 Sep, 2021 at 4:00 PM
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