... were taken at different intervals for absorbance readings at 600 nm and b-galactosidase activity determinations To assay b-galactosidase activity, a semiautomated method was developed, using a MultiPROBEÒIIex ... blotting, authentic AmyQ and AmyQ-Leu were secreted into the growth medium, whereas no mature AmyQ-Ala was secreted (Fig 1A) In fact, all AmyQ-Ala detectable in the cells was present in the precursor ... Experimental procedures Plasmids, bacterial strains, and media Table lists the plasmids and bacterial strains used Luria Bertani medium contained Bacto tryptone (1%), Bacto yeast extract (0.5%), and NaCl...