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Updated: Aug 10, 2026
Determination of Microbial Extracellular Enzyme Activity in Waters, Soils, and Sediments using High Throughput Microplate Assays
Published on: October 1, 2013
Sensitive plate assay for screening and detection of bacterial polyurethanase activity
G T Howard1, J Vicknair, R I MacKie
1Department of Biological Sciences, South-eastern Louisiana University, Hammond, LA 70402, USA.
Aims:
A plate assay to screen and detect bacterial polyurethanase in agar medium containing a colloidal polyester-polyurethane and rhodamine B is presented.
Methods And Results:
Substrate hydrolysis causes the formation of orange fluorescent halos visible upon u.v. irradiation. The logarithm of polyurethanase activity from a purified polyurethanase protein is linearly correlated with the diameter of halos, thereby allowing quantification of polyurethanase activities ranging from 0.81 to 7.29 Units.
Conclusions:
The potential advantages of this system are in identification and recovery of viable polyurethanolytic bacteria and quantification of polyurethanase activity.
Significance And Impact Of The Study:
These advantages are derived largely from the intense fluorescence observed due to the hydrolysis of substrate reacting with rhodamine B allowing for the use of low substrate concentrations and corresponding decrease in time required detecting low levels of enzyme activity.
