Factorial supersymmetric Schur functions and super Capelli identities

A factorial analogue of the supersymmetric Schur functions is introduced. It is shown that factorial versions of the Jacobi--Trudi and Sergeev--Pragacz formulae hold. The results are applied to construct a linear basis in the center of the universal enveloping algebra for the Lie superalgebra gl(m|n) and to obtain super-analogues of the higher Capelli identities.