when sos chromotest assays were performed with no bacteria or with s. typhimurium ta100 or hisg46 ( non-lactose fermenting organisms ) in place of e. coli pq37 , it was found that the extracts contained significant levels of endogenous beta-galactosidase and alkaline phosphatase , which , due to their carry-over in the bacterial pellet ( after centrifugation to remove the coloured extract ) gave rise to the positive induction factor obtained with p-npg .
C0004611
bacteria
C0029235
organisms