Purification of the viridicin produced by Aerococcus viridans

Abstract

A new bacteriocin produced by Aerococcus viridans was purified. Bacteria grown on liquid medium synthesized a bacteriocin, viridicin, which can be extracted from the cells by treatment with 0.86 M NaCl solution. Viridicin production was not induced by ultraviolet irradiation or by treatment with mitomycin C. The bacteriocin was purified by ultrafiltration, gel filtration, and preparative polyacrylamide disc gel electrophoresis. The molecular weight was between 100,000 and 120,000. The purified viridicin was homogeneous on polyacrylamide gel electrophoresis. The viridicin was composed of protein, carbohydrate, and lipid.Bacteriocins are high-molecular-weight bactericidal substances which are synthesized by many bacteria. The specificity of their action and their nature distinguish them from most of the classical antibiotics. It has been well established over the years that various strains of most species of bacteria produce these inhibitory substances (8, 14, 22, 23).Intensive work has been done on the bacteriocins of gram-negative bacteria, the best studied of which are the colicins (8,19,20).A recent review reported the physiochemical properties of some gram-positive bacterial bacteriocins (23).The bacteriocins produced by the gram-positive species are less well known than those of gram-negative species, and many concepts drawn from studies on colicins are not consistent with results obtained with the gram-positive organisms.Recently, we showed that the gram-positive bacterium Aerococcus viridans synthesizes a bacteriocin that we have called viridicin (1).A crude preparation of this macromolecule was not inactived by heating for 1 hour at 50°C and was sensitive to the action of protease, lipase, and catalase. Bacteriocin activity was not suppressed by trypsin, chymotrypsin, lysozyme, a-amylase, phospholipase C, lipase, f-glucuronidase, deoxyribonuclease, and ribonuclease. Growth of a large number of gram-negative and gram-positive bacteria was inhibited by viridicin.MATERIALS AND METHODS Microorganisms. The viridicin-producing strain A. viridans was isolated at

Aerococcus sp. with an antimycobacterial effect

“…Nevertheless, our results corroborate with some studies showing the antagonistic effect of A. viridans 167 on Staphylococcus aureus (Gorbunova et al, 1989;Zhurylo and Drozd, 1999) and also with the authors revealing that A. viridans was able to inhibit the growth of Staphylococcus hyicus, S. aureus and some other gram-positive bacteria, including Streptococcus group A and D Corynebacteria (Allaker et al, 1989;Zaria, 1993), while in Kremenchutskiĭ and Samoĭlenko research, it has been shown that A. viridans inhibited E. coli and B. subtilis by producing hydrogen peroxide (Kremenchutskiĭ and Samoĭlenko, 1987). Our findings agree also with the results obtained from Ballester et al (1980) study showing that the growth of a large number of Gram-negative and Gram-positive bacteria was inhibited by viridicin produced by A. viridans (Ballester et al, 1980). However, other studies have shown Aerococcus sp had effect against either Erwinia chrysanthemi or Mycobacterium sp.…”

“…These findings agree with Ballester et al (1980) study which aimed the purification of the viridicin produced by A. viridans. Indeed, a crude preparation of this macromolecule was sensitive to the action of protease.…”

“…The genus Aercoccus belongs to lactose acid bacteria (Liu, 2003;Stiles and Holzapfel, 1997;Simpson and Taguchi, 1995;Parada et al, 2007;Leroi, 2010) which namely produce bacteriocins, antimicrobial peptides known to be sensitive to most proteases (Ballester et al, 1977(Ballester et al, , 1980Wu et al, 2004;Papagianni and Anastasiadou, 2009) and their antibacterial activity could be affected by high heat treatment (Galvez et al, 2007;Noonpakdee et al, 2003;Jack et al, 1996), hence, the antimycobacterial compounds of Aercoccus sp ZI1 may be a bacteriocin or it can be just another protein such as lactate oxidase of A. viridians possessing antagonistic activity relative to 27 test-cultures of bacteria (Kremenchutskiĭ and Arenkov, 1989). Therefore, further study is required to examine deeply characteristics of antimycobacterial molecules.…”

Harnessing diversity and antagonism within the pig skin microbiota to identify novel mediators of colonization resistance to methicillin-resistant Staphylococcus aureus

“…A. viridans BGCs included a terpene. Prior studies in A. viridans have also identified and isolated a bacteriocin, viridicin, that inhibited Gram-negative and -positive pathogens ( 34 ). R. aerolata contained BGCs predicted to encode a lanthipeptide, a betalactone, and an RRE (ribosomally synthesized post-translationally modified peptide (RiPP) recognition element)-containing cluster though no prior reports were found of its inhibitory properties ( Fig.…”