The production strain could not be detected in a test volume of 1 g of three independent liquid batches
tested in triplicate by liquid culturing in non-selective medium for 4 days (for resuscitation) followed
by growth on selective solid agar plates for 4 days at a suitable temperature favouring the growth of
the production strain. No recombinant DNA was detected starting with 1 g of three samples of the
concentrated product before formulation obtained from three independent production batches and
tested in triplicate. Analysis was performed by PCR, amplifying a 1 076 bp recombinant fragment
spanning the deletion of an endogenous gene specific for the strain lineage, introduced in the first
genetic modification step of the parental strain.