of the original volume and subjected to sds 12 5 page followed by western blot analysis proteins were transferred from sds paa gels to ba85 nitrocellulose membranes schleicher and schuell dassel germany as described before 31 u03b1 amylase and u03b2 lactamase antigen was detected with 2000 fold diluted rabbit polyclonal anti ampicillinase antibodies 5 prime u2192 3 prime inc boulder colo and alkaline phosphatase conjugated goat anti rabbit antibodies promega corporation madison wis using the western light chemiluminescent detection system and protocol tropix inc bedford mass acma activity was visualized on u00bdm17 agar plates containing 0 2 autoclaved lyophilized m lysodeikticus cells as halos around colonies after overnight growth at 30 u00b0 c u03b1 amylase activity was detected by spotting 10 u03bcl of an overnight culture onto a u00bdm17 agar plate containing 1 of starch sigma after 18 hours of incubation at 30 u00b0 c halos were visualized by staining with an iodine solution according to the protocol of smith et al 29 a similar method was used for the detection of u03b2 lactamase activity 29 x prolyl dipeptidyl aminopeptidase pepx was measured using the chromogenic substrate ala pro p nitroanilid bachem feinchemicalien ag bubendorf switzerland after two minutes of centrifugation in an eppendorf microcentrifuge 75 u03bcl of a culture supernatant was added to 50 u03bcl substrate 2 mm and 75 u03bcl hepes buffer ph 7 the mixture.