Dear Rania, the best medium to determine lipolytic bacteria is Tributyrin Agar. We have previously face with some dispersion problems when using olive oil.
I suppose that you can replace tributyrin with olive oil or other fats and oil. Should you have problems with dispersion, you can employ some nonionic surface active compound.
As Mert has pointed out, tributyrine-agar is a very good medium for identifying lipolytic bacteria. Check always that the medium is working fine by including a positive control (i.e.: Pseudomonas fluorescens) and a negative control (i.e.: Escherichia coli). Not only the diameter of the halos, but also their transparency, will give you information about the lipolytic activity of your strains.