Enzyme Production by Rhizobium meliloti

In an attempt to discover the control mechanism(s) of three enzymes (β-glucosidase, β-galactosidase and β-fucosidase) in Rhizobium meliloti, large numbers of mutants were geneerated by transposon mutagenesis. Mutants that appeared either dark blue,ligt blue, or white on chromogenic substrates were chosen as possible overproducers or underproducers of these enzymes.\nAfter potential mutant enzyme producers were selected due to differences in enzyme production they were restreaked and then re-grown on the chromogenic substrates. After this elimination procedure, the strains were then assayed to determine their amounts of enzyme production.\nAt the time of this thesis there are three undoubtedly dramatic mutants: 203, 93, and 164. It now appears that 203 and 93 are nearly identical in their production of the three enzymes to 131 (a mutant discovered earlier by Dr. Daniel Wacks). Mutant 164 appears to be nearly identical in its enzyme production to another of Dr. Wacks's mutants, 381. Due to the results we have obtained so far, it seems very likely that he three activities are carried out by one protein.