  We study the Klein-Gordon equation in a non-commutative space-time as applied
to the Hydrogen atom to extract the energy levels, by considering the
second-order corrections in the non-commutativity paramete and by comparing to
the 2S - 1S transition accuracy we get a bound on the parameter of
noncommutativity. Phenomenologically we show that non-commutativity is the
source of lamb shift corrections and spin electron.
