Immunodot detection of nisin Z in milk and whey using enhancedchemiluminescence

摘要

A highly specific antisera was produced in New Zealand white rabbits against nisin Z, a 3400 Da bacteriocin produced by Lactococcus lactis ssp. lactis biovar. diacetylactis UL 719. A dot immunoblot assay was then 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 within 6h using chemiluminescence. When mill; and whey samples sere tested, approximately 0.155 mu g ml(-1) (7.9 IU ml(-1)) of nisin Z was detected. The detection limit obtained was lower than that of traditional methods including microtitration and agar diffusion.