Bovicin HC5 reduces thermal resistance of Alicyclobacillus acidoterrestris in acidic mango pulp

Abstract

Aims: To test the effect of bovicin HC5 against vegetative cells and endospores of Alicyclobacillus acidoterrestris DSMZ 2498 in synthetic media and in acidic mango pulp. Methods and Results: Alicyclobacillus acidoterrestris was grown in synthetic medium at 40°C and pH 4·0. The effect on vegetative cells was assayed by adding bovicin HC5 to synthetic medium (40–160 AU ml−1) or to mango pulp (100 AU ml−1) at various pH values and determining the effect on growth (OD600nm) and viable cell number, respectively. The effect of bovicin HC5 on spore germination and thermal sensitivity of A. acidoterrestris was tested in mango pulp (pH 4·0) containing 80 AU ml−1 of bovicin HC5. Bovicin HC5 was bactericidal against vegetative cells of A. acidoterrestris at different pH values and showed sporicidal activity against endospores of this bacterium. When spores of A. acidoterrestris were heat treated in the presence of bovicin HC5, D‐values decreased 77% to 95% compared to untreated controls at temperatures ranging from 80 to 95°C. Conclusion: Bovicin HC5 was bactericidal and sporicidal against A. acidoterrestrsi DSMZ 2498. Significance and Impact of the Study: These results indicated that bovicin HC5 has potential to prevent spoilage of acidic fruit juices by thermocidophilic spore‐forming bacteria.

Modeling the effects of temperature and pH on the resistance of Alicyclobacillus acidoterrestris in conventional heat-treated fruit beverages through a meta-analysis approach

“…For the special case of the model category within the fruit moderating variable, the "clarified" class was assigned because of the low viscosity and the absence of particles in suspension in a buffer (Table 1). On the other hand, the study of de Carvalho et al (2008), which focused on mango concentrate, did not specify Table 1 Meta-analytical data of D-values of Alicyclobacillus acidoterrestris in beverages at different temperature and pH, with extracted study characteristics of fruit, type (single strength or concentrate), clarification (0 ¼ no, 1 ¼ yes), bacteriocins (0 ¼ no, 1 ¼ yes) and sample size N used to estimate a single D-value. whether the concentrate was clarified or not.…”

“…However, as the main objective of such a study was to assess the effect of bovicin on the resistance of Alicyclobacilus in mango pulp, a logical conclusion was that the mango pulp, which was two-fold diluted for their experiments (i.e., concentrate), was not clarified. The fourth study characteristic was "presence of bacteriocins", which was conceived because two of the primary studies investigated the effect of nisin (Komitopoulou et al, 1999;Peña et al, 2009) on the thermal resistance of Alicyclobacillus; and one study the effect of bovicin HC5 e a bacteriocin from Streptococcus bovis (de Carvalho et al, 2008). Thus, this categorical variable was coded to take up the value of 0 for absence of bacteriocins and the value of 1 for added bacteriocins.…”

“…Also, as a major target for fruit juice pasteurization (Tribst et al, 2009), numerous studies are found that report thermal inactivation parameters of Alicyclobacillus, i.e., the D value (time at a determined temperature required to cause one-log cycle decrease in the population of a target bacterium) and the z value (temperature increase required to result in one-log cycle decrease of Dvalue) (Splittstoesser et al, 1994;Komitopoulou et al, 1999;Bahçeci and Acar, 2007;Walls, 1997;Silva et al, 1999;Maldonado et al, 2008;de Carvalho et al, 2008;L opez et al, 2011;Alberice et al, 2012, Peña et al, 2009McKnight et al, 2010). As known, D-and z-values of Alicyclobacillus are affected by the particular conditions or study characteristics (protocols, fruit and variety, Brix, pH, temperature, heating medium, culture medium, inactivation method, strains, etc.)…”

Inhibition of Listeria and Staphylococcus aureus by Bovicin HC5 and Nisin Combination in Milk

“…L. monocytogenes causes disease in high-risk groups, including pregnant women, neonates, and immunocompromised adults, and has a high mortality rate (Arques, Rodriguez, Nunez, & Medina,Bovicin HC5, a bacteriocin produced by Streptococcus bovis HC5, has a broad spectrum of activity (Mantovani, Hu, Worobo, & Russell, 2002). Previous works demonstrated the ability of bovicin HC5 to inhibit L. monocytogenes (Mantovani & Russell, 2003), and prevent the growth and spore germination of strains of Bacillus cereus and Bacillus thuringiensis (de Carvalho, Costa, Mantovani, & Vanetti, 2007), Clostridium tyrobutyricum , and Alicyclobacillus acidoterrestris (de Carvalho, Vanetti, & Mantovani, 2008). Since bacteria that can readily become resistant to nisin did not become significantly more resistant to bovicin HC5 after they were repeatedly transferred with sublethal doses, it appeared that bovicin HC5 had important characteristics (Mantovani & Russell, 2003).…”

Morphological changes in Salmonella Typhimurium caused by the lantibiotic bovicin HC5 in association with EDTA

“…The ability of this bacteriocin to inhibit several Grampositive bacteria, such as Listeria monocytogenes (Mantovani and Russell 2003), Bacillus cereus, Bacillus thuringiensis (de Carvalho et al 2007a), Clostridium t y ro b ut y r i c u m ( d e C a r va l ho e t a l . 2 0 07 b ) and Alicyclobacillus acidoterrestris (de Carvalho et al 2008) has already been demonstrated. Activity on Gramnegative bacteria was also recently demonstrated (Prudêncio et al 2014(Prudêncio et al , 2015a.…”