Bacterial Growth Question - (May/01/2014 )

ah I see! When conducting the experiment I did find that when both strains were exposed to UV for 5+ mins there was no growth at all. However, in the case of the k12, exposure for 5 seconds showed only 2 individual colonies, where as with the strain B, even at 2 minutes exposure there was still around 80~ odd colonies. So, I mean, from that it does show that the k12 is more sensitive to UV than the strain B. Or maybe I should say, more sensitive at those particular wavelengths.

But thank you very much for your help, it is very much appreciated.

You should specify the type of UV used (A, B, C) and if possible the wavelength range.

It's UVC, however, with the fish tank I couldn't find out which particular wavelength it emits, so I don't even know if it may be more than one wavelength. During my 6 weeks though I did use a UV spectrophotometer and I was getting results showing a wavelength of 251nm was the optimum and I repeated my experiment and still found it was the best, but when I looked it up, other people were saying it was around 260nm so who knows. Maybe it was an anomaly or I messed up the experiment twice! 

Most UVC lamps emit at 254 nm nominally. I don't know how sharp that peak is, but likely quite sharp, since it is a mercury emission line.

Oh really? thank you, that's helps a lot to know that since that is close to the 251nm which I was using on the spec. and it will give a good comparison.