  We examine the phenomenological consequences of a supersymmetric bulk in the
scenario of large extra dimensions. We assume supersymmetry is realized in the
bulk and study the interactions of the resulting bulk gravitino Kaluza-Klein
(KK) tower of states, with supersymmetry breaking on the brane inducing a light
mass for the zero-mode gravitino. We derive the 4-d effective theory, including
the couplings of the bulk gravitino KK states to fermions and their scalar
superpartners. The virtual exchange of the gravitino KK states in selectron
pair production in polarized \epem collisions is then examined. We find that
the leading order operator for this exchange is dimension six, in contrast to
that of bulk graviton KK exchange which induces a dimension eight operator at
lowest order. The resulting kinematic distributions for selectron production
are dramatically altered from those in D=4 supersymmetric scenarios, and can
lead to a enormous sensitivity to the fundamental higher dimensional Planck
scale, of order $20-25\times \sqrt s$.
