Nikki,

Are you trying to look at live bacteria?  If so they may not like the lysine.  If you are fixing them then, the poly-L-Lysine will work and you don't have to spin. We usually coat coverslips with 0.01 % poly-L-lysine for 5 min, rinse with D-H2O for 5 min, drain and apply live sample to coated coverslips for 5-10 min (bacteria may take longer to attach).  Then we add fixative to the chamber.

Good Luck.