Efficacy of nisin derivatives with improved biochemical characteristics, alone and in combination with endolysin PlyP100 to control Listeria monocytogenes in laboratory-scale Queso Fresco

• Published in: Food microbiology 2021-04, Vol.94, p.103668-103668, Article 103668
• Main Authors: Ibarra-Sánchez, Luis A., Kong, Wentao, Lu, Ting, Miller, Michael J.
• Format: Article
• Language: English
• Subjects: Anti-Bacterial Agents - pharmacology; Cheese - microbiology; Colony Count, Microbial; Endolysin; Endopeptidases - pharmacology; Food Contamination - analysis; Food Contamination - prevention & control; Food Preservation - methods; Food Preservatives - pharmacology; Listeria monocytogenes; Listeria monocytogenes - drug effects; Listeria monocytogenes - growth & development; Nisin - analogs & derivatives; Nisin - pharmacology; Nisin derivatives; PlyP100; Queso fresco
• ISSN: 0740-0020; 1095-9998
• DOI: 10.1016/j.fm.2020.103668

Nisin is an antimicrobial peptide that is commonly used as a food preservative and capable of inhibiting the pathogen Listeria monocytogenes. However, nisin is ineffective in controlling L. monocytogenes in Queso Fresco (QF). To address the challenge, in this work, we used synthetic biology strategies to create a series of nisin A derivatives by substituting residues 27, 30, 31 and 32 with positively charged amino acids (H, K and R). Our results showed that nisin derivatives exhibited reduced antilisterial activity in vitro compared to nisin A; however, they were all more stable under QF-like experimental conditions (pH 7 + 22% milk fat), notably H27/31K. Compared to nisin A, the derivatives H31K and V32K exhibited slight antilisterial improvement in QF and H27/31K was able to reduce the initial population of L. monocytogenes by up to 1.5 Log CFU/g. L. monocytogenes isolates exhibited similar susceptibility to nisin A or H27/31K after 7 or 14 days of nisin exposure in QF. Notably, when combined with endolysin PlyP100, the application of H27/31K resulted in non-enumerable levels of L. monocytogenes after 14 days of cold storage. Our results highlight the potential of bioengineered nisin derivatives for stabilized and enhanced control of L. monocytogenes in QF. •Nisin derivatives had reduced antilisterial activity in vitro compared to nisin A.•Nisin derivatives were more stable under pH 7 + 22% milk fat conditions.•Nisin derivatives H31K, V32K and H27/31K showed antilisterial improvement in QF.•No susceptibility change to nisin A or H27/31K in QF L. monocytogenes isolates.•H27/31K combined with PlyP100 eliminated Listeria monocytogenes in all QF samples.