IMMUNODOT DETECTION OF NISIN-Z IN MILK AND WHEY USING ENHANCED CHEMILUMINESCENCE

A highly specific antisera was produced in New Zealand white rabbits a gainst nisin Z, a 3400 Da bacteriocin produced by Lactococcus lactis s sp. lactis biovar. diacetylactis UL 719. A dot immunoblot assay was th en developed to detect nisin Z in milk and whey. As few as 1.5 10(-1) international units per ml (IU ml(-1)), corresponding to 0.003 mu g ml (-1) of pure nisin Z, were detected in carbonate-bicarbonate buffer wi thin 6h using chemiluminescence. When mill; and whey samples sere test ed, approximately 0.155 mu g ml(-1) (7.9 IU ml(-1)) of nisin Z was det ected. The detection limit obtained was lower than that of traditional methods including microtitration and agar diffusion.