  A matter self-interacting model with N=1-supersymmetry in 3D is discussed in
connection with the appearance of a central charge in the algebra of the
supersymmetry generators. The result is extended to include gauge fields with a
Chern-Simons term. The main result is that, for a simple supersymmetry, only
the matter sector contributes to the central charge in contrast to what occurs
in the N=2 case.
