Glycerol effect on Beta-galactosidase

[ScienceRob]

So I recently performed Lac operon lab in my Biology course. During this we put TMG and the Ecoli into one flask, TMG and Glucose in another, and TMG and Glycerol in yet another. We took various samplings of the flasks at standard intervals from a shaker bath.

After we sorted the samples we put them into a spectrometer and read their diffraction. From the charts generated, the solution with TMG had the correct effect of producing B-galactosidase. The glucose solution expectantly produced nothing. Glycerol+TMG however produced the enzyme for around 30 minutes(if I remember the results) and then the amount of Galactosidase decreased rapidly. I am trying to find a reason for this but don't quite understand the results I gave. I am assuming that Glycerol which has the OH groups. As you increase the glycerol in a substance it start to decrease the pH of the solution. I am taking a stab that galactosidase prefers a higher pH than the pH of the solution that changes due to glycerol. I've been looking in scientific literature for some verification on this but I haven't had any luck so far. I'm going to continue my search but I thought I'd swing by for some assistance.

Thank you in advance.

[JackBean]

will you share, what does TMG mean, with us?

You put E.coli only into the first flask?

Glycerol is not acidic (at least not at physiological pH), also, it would decrease the pH immediately, not in 30 min

[billcosby]

Umm...not sure where you are going with this...If I were I would approach the problem from the perspective of biochemical pathways and not focus too much on the organic chemistry portion. I can't give an answer to the glycerol portion, but there are numerous articles out there on E.coli and this experiment in particular.

[Francol]

Glycerol represses the β-galactosidase biosynthesis...