2.4. Biochemical tests
A commercial biochemical test kit (API 50 CH strips and CHB
medium, BioMerieux, Inc., Durham, NC) was used to characterize
the carbohydrates fermentation pattern of the new isolate. The
biochemical tests included catalase, nitrate reduction, formation of
indole, deamination of phenylalanine, utilization of citrate and
hydrolysis of starch and casein. The wells containing substrates
were inoculated with the new isolate at appropriate density and
were incubated at 30 _C for 24e48 h. Results were recorded and
identificationwas done by referring to the database provided by the
manufacturer.