  We study the properties of X-ray galaxy clusters in four cold dark matter
models with different baryon fraction $\Omega_{BM}$ ranging from 5 to 20 per
cent. By using an original three-dimensional hydrodynamic code based on the
piecewise parabolic method, we run simulations on a box with size $64 h^{-1}$
Mpc and we identify the clusters by selecting the peaks in the X-ray luminosity
field. We analyse these mock catalogues by computing the mass function, the
luminosity function, the temperature distribution and the
luminosity-temperature relation. By comparing the predictions of the different
models to a series of recent observational results, we find that only the
models with low baryonic content agree with the data, while models with larger
baryon fraction are well outside the 1-$\sigma$ errorbars. In particular, the
analysis of the luminosity functions, both bolometric and in the energy band
[0.5--2] keV, requires $\Omega_{BM}\mincir 0.05$ when we fix the values $h=0.5$
and $n=0.8$ for the Hubble parameter and the primordial spectral index,
respectively. Moreover we find that, independently of the cosmological
scenario, all the considered quantities have a very little redshift evolution,
particularly between $z=0.5$ and $z=0$.
