Hi,
for a work on bacteriocin production from lactic acid bacteria, I use the
deferred antagonism assay with good results. Many isolated strains (116 out
of 1000) inhibit the target bacteria (Listeria) on solid media (BHI, TSA-YE,
APT).
However, I cannot succeed to stop the inhibition by adding several
proteolytic enzymes commonly used for this purpose.
The enzymes (protease, trypsine, proteinase K) are solubilized in PBS 0.01M
at 10mg/mL, and a few ug are deposed on spots of lactic cultures on solid
media, and an overlay is added containing Listeria. But the inhibition zones
are still present. Obviously, maybe there are no bacteriocin-producing
strains, but what can cause the inbition (clues: no peroxyde because
anaerobiosis; no bacteriophages detected; no acidification because of the
no-glucose TSA-YE) ? Is this enzyme methodology inadequate ?
Thank you for help !
Mike Dew
Center for aquatic innovation
_____________________________________________________________________________________
Get more from the Web. FREE MSN Explorer download : http://explorer.msn.com
---