The halocin activity was determined using serial twofold
critical end point dilutions to extinction (Meseguer et al.,
1986) and expressed as arbitrary units (AU), which are defined
as the reciprocal of the first dilution at which all traces of
inhibitory activity disappears (Cheung et al., 1997). The two
fold dilution ratio of halocin follows a geometric progression
where the halocin activity can be calculated by