To obtain selective media, ampicillin (50 mg/l), was added as antibiotic
to the liquid media after autoclavation and cooling to 50psy176 C.
Ampicillin
(6-[D-(-)- 
-amino- phenylacetamido]-penicillanic
acid) is
a derivative of penicillin
that kills growing cells by interfering with a terminal reaction in bacterial
cellular synthesis.
