  We have considered the contribution of fermionic vacuum loop in the effective
potential of Polyakov loop extended Quark Meson Model (PQM) for the two quark
flavour case and explored the phase structure and thermodynamics of the
resulting PQMVT model (Polyakov Quark Meson Model with Vacuum Term) in detail
at non zero as well as zero chemical potential. The temperature variations of
order parameters and their derivatives have been calculated and the phase
diagram together with the location of critical end point (CEP) has been
obtained in $\mu$, and $T$ plane in both the models PQMVT and PQM. The PQMVT
model analysis has been compared with the calculations in PQM model in order to
bring out the effect of fermionic vacuum term on the physical observables. We
notice that the critical end point (CEP) which is located near the temperature
axis at ($\mu=81.0$, $T = 167$ MeV) in the PQM model gets shifted close to the
chemical potential axis at ($\mu_{CEP}=294.7$, $T_{CEP}=84.0$ MeV) in the PQMVT
model calculations of the phase diagram. Since it emerges from a background of
second order transition in the chiral limit of massless quarks, the crossover
occurring at $\mu$ = 0 in PQMVT model for the realistic case of explicitly
broken chiral symmetry, has been identified as quite a soft and smooth
transition. We have presented and compared the results for temperature
variations of thermodynamic observables at zero and different non-zero quark
chemical potentials. It is noticed that the presence of fermionic vacuum term
in the effective potential leads to a smoother and slower temperature variation
of thermodynamic quantities.
