E.coli "gene knockout": help

[Giuseppe Borsani]

Does anybody have any suggestion on how to create a "gene knockout" in the
E.coli genome when no selectable phenotype is available for the gene to
inactivate?
Probably it's something obvious for people with experience in bacterial
genetics.  References and protocols are welcome.

Thanks


 / }
{ /  Giuseppe Borsani
 X   Tigem - Telethon Institute for Genetics and Medicine
{ \  Via Olgettina 58
 \ } 20132 Milano
  X  Italy
 / }
{ /  e-mail: borsang at dibit.hsr.it
 X   tel     39-2-21560203
{ \  fax     39-2-21560220
 \ }