Serratia marcescens strain 13090-1was adapted to increasing doses of

    acetone ,  when   it  was  grown  in B.H.I  broth  medium;  a  high  acetone

    concentration  affected  Serratia  growth  more and pigment (prodigiosin)

    production was higher.

         When  the  amount  of  acetone  renge  from  5000 to 8000  PPM in B.H.I

    broth at  incubation  temperature  of  28^o c. At  more  than  13000  PPM  of

    acetone, reduction in the number of   serratia cells  occurred   and  larger

    cells,which were not viable were developed at acetone concentration of

    more  than 19000 PPM. The sensitive cells to many antibiotics formed in the

    high  amount  of  acetone  ( 36000 PPM or more ),  and these serratia cells

    cultured  in  B.H.I  medium  without  acetone ,  that  never    converted  to

    prototype one.

         Therefore that is improving the mutant serratia cells were developed or