Properties of nisin Z and distribution of its gene, nisZ, in Lactococcus lactis

Abstract

Two natural variants of the lantibiotic nisin that are produced by Lactococcus lactis are known. They have a similar structure but differ in a single amino acid residue at position 27: histidine in nisin A and asparagine in nisin Z (J. W. M. Mulders, I. J. Boerrigter, H. S. Rollema, R. J. Siezen, and W. M. de Vos, Eur. J. Biochem. 201:581-584, 1991). The nisin variants were purified to apparent homogeneity, and their biological activities were compared. Identical MICs of nisin A and nisin Z were found with all tested indicator strains of six different species of gram-positive bacteria. However, at concentrations above the MICs, with nisin Z the inhibition zones obtained in agar diffusion assays were invariably larger than those obtained with nisin A. This was observed with all tested indicator strains. These results suggest that nisin Z has better diffusion properties than nisin A in agar. The distribution of the nisin variants in various lactococcal strains was determined by amplification of the nisin structural gene by polymerase chain reaction followed by direct sequencing of the amplification product. In this way, it was established that the nisZ gene for nisin Z production is widely distributed, having been found in 14 of the 26 L. lactis strains analyzed.

Anti-Listeria effect of enterocin A, produced by cheese-isolated Enterococcus faecium EFM01, relative to other bacteriocins from lactic acid bacteria

“…The results were in accordance with a previous report (Maisnier-Patin et al 1996) in which it was hypothesized that the rate of cell destruction would be inversely proportional to the molecular weight of three bacteriocins (nisin, 3·5 kDa; pediocin AcH, 4·6 kDa; and enterococcin, 6·9 kDa), i.e., the higher the molecular weight, the longer the time necessary to achieve MVL. In addition to the three bacteriocins, the present study included enterocin A (4·8 kDa) and sakacin A (4·3 kDa), showing that this suggestion could be valid even for bacteriocins with strong sequence similarities as in those of class IIa (enterocin A, pediocin AcH and sakacin A); this limits the possible role of the nature and sequence of residues in the peptides, as suggested by other investigators (Liu and Hansen 1990;de Vos et al 1993;Kuipers et al 1993).…”

Modified agar diffusion bioassay for better quantification of Nisaplin®

“…This modified agar diffusion assay can be used for the quantification of nisin in solutions and monitoring the rate of nisin production during fermentation. Study has shown that nisin A and nisin Z have significantly different diffusion behaviour in agar (De Vos et al 1993). Our study is specific to the quantification of nisin A, and its application to other nisin variants (nisin Z, F, Q and U) needs to be tested.…”

Biomedical applications of nisin

“…2; Table 1) (Mulders et al 1991). Nisin A and Z share similar properties as antimicrobials, but nisin Z has a superior rate of diffusion and solubility under neutral pH conditions (De Vos et al 1993). Nisin F was isolated from Lc.…”