First evidence of production of the lantibiotic nisin P

Abstract

15Nisin P is a natural nisin variant, the genetic determinants for which were previously identified 16 in the genomes of two Streptococcus species, albeit with no confirmed evidence of production. 17 Here we describe Streptococcus agalactiae DPC7040, a human fecal isolate, which exhibits 18 antimicrobial activity against a panel of gut and food isolates by virtue of producing nisin P. 19 Nisin P was purified, and its predicted structure was confirmed by nanoLC-MS/MS, with both 20 the fully modified peptide and a variant without rings B and E being identified. Additionally, 21 we compared its spectrum of inhibition and minimum inhibitory concentration (MIC) with that 22 of nisin A and its antimicrobial effect in a fecal fermentation in comparison with nisin A and 23 H. We found that its antimicrobial activity was less potent than nisin A and H, and we propose 24 a link between this reduced activity and the peptide structure. 25 26 Keywords: nisin, antimicrobial, structure-activity relationship, fecal microbiome, 27 Structurally, nisin is classified as a lantibiotic because it contains lanthionine (Lan), an unusual 36 amino acid formed by two alanine residues linked by a sulphur atom through their β-carbon 4 . 37Other unusual amino acids present in nisin are dehydroalanine (Dha), dehydrobutyrine (Dhb) 38 3 3 and β-methyl-lanthionine 4 . Nisin activity and stability are closely related to its structure and 39 can be altered by pH changes. Increasing pH results in decreasing activity as a consequence of 40 alterations in structure, therefore, nisin is more stable at lower pH. Nisin is heat-stable and also 41 exhibits high stability at low temperatures, which makes it suitable for freeze-storage 7 . 42Nisin has nine reported natural variants ( Figure 1, Table 1). Nisin A is the most studied nisin 43 as it was the first one purified 8 . Nisin Z is considered the first natural variant of nisin A; it 44 differs in the presence of an asparagine amino acid in position 27 instead of a histidine residue 45 9 . This substitution has very little effect on antimicrobial activity, thermal and pH stability 46 compared to nisin A, but affects the solubility of the molecule, with nisin Z being more soluble 47 at neutral pH 10 . A study of its distribution also revealed that nisin Z is more widespread than 48 nisin A 10 . Nisin F, produced by L. lactis isolated from a fish gut, also has asparagine and valine 49 in positions 21 and 30 11 . Nisin Q was identified in an environmental L. lactis isolate and differs 50 from nisin A due to the presence of valine, leucine, asparagine and valine in positions 15, 21, 51 27 and 30, respectively 12 . Nisin U and U2 were the first variants found to be produced by a 52 species other than L. lactis 13 ; they are produced by Streptococcus uberis strain 42, isolated 53 from bovine mammary secretions 14 , and differ to nisin A by nine and ten amino acids, 54 respectively. Nisin H, produced by Streptococcus hyointestinalis was the first variant isolated 55 from a mammalian gastrointestin...

Kunkecin A, a New Nisin Variant Bacteriocin Produced by the Fructophilic Lactic Acid Bacterium, Apilactobacillus kunkeei FF30-6 Isolated From Honey Bees

“…Several natural variants of nisin are produced by strains belonging to Lactococcus lactis , such as nisin A ( Gross and Morell, 1971 ), nisin Z ( Mulders et al, 1991 ), nisin Q ( Zendo et al, 2003 ; Fukao et al, 2008 ), and nisin F ( de Kwaadsteniet et al, 2008 ), in addition to subtilin produced by strains of Bacillus subtilis ( Banerjee and Hansen, 1988 ). Natural nisin variants produced by strains of other genera have recently been reported, such as nisin U ( Wirawan et al, 2006 ), nisin H ( O’Connor et al, 2015 ), nisin O ( Hatziioanou et al, 2017 ), nisin J ( O’Sullivan et al, 2020 ), and nisin P ( Garcia-Gutierrez et al, 2020 ) by Blautia spp., Staphylococcus spp., and Streptococcus spp. All nisin variants share a basal structure consisting of five mono-sulfide bridges (lanthionine rings), and three dehydrated amino acid residues, which result from post-translational modifications but have some amino acid substitutions.…”

Sequence Permutation Generates Peptides with Different Antimicrobial and Antibiofilm Activities

“…In the current APD [ 9 ], 551 AMPs are annotated to be primarily active against Gram-positive bacteria. These include some bacteriocins synthesized and secreted by Gram-positive bacteria to inhibit competitive strains [ 16 , 17 , 18 , 19 ]. In contrast, 316 AMPs in the APD are reported to be active primarily against Gram-negative pathogens [ 9 ].…”

“…The isolation of potent antimicrobials from natural sources is an important approach [ 2 , 3 , 4 , 5 , 6 , 7 ]. Although labor-intensive, this classic approach has the great potential to identify novel candidates, including peptides [ 15 , 16 , 17 , 18 , 19 ]. Recent efforts have extended the search of new antimicrobials to uncultivable bacteria and microbiota [ 18 , 19 ].…”

A natural food preservative peptide nisin can interact with the SARS-CoV-2 spike protein receptor human ACE2

“…It also has multiple applications in biomedicine including bacterial infections, cancer, oral diseases and other veterinary and research field ( Shin et al, 2015 ). Since the discovery of nisin A, eight natural variants of nisin have been discovered which include nisin A, Z, F, Q, H, U, U2 and P ( Garcia-gutierrez et al, 2020 ). Nisin Z producing organisms are very common in nature ( Mitra et al, 2011 ; Vos et al, 1993 ).…”