string: However, a short-term antibacterial action of free nisin has previously been observed to contribute to the development of nisin tolerance (Chi-Zhang, Yam, & Chikindas, 2004), or else a loss of apparent activity from an insufficient concentration and/or proteolytic degradation of nisin (Huang et al., 2009; da Silva Malheiros, Daroit, da Silveira, & Brandelli, 2010).