This study was undertaken to prepare tailor-made starter culture (TMSC) for Karst ewe’s cheese production. Therefore, basic technological characteristics (growth ability in milk, acid production, and proteolytic activity) and antistaphylococcal potential were assessed for autochthonous enterococci and lactobacilli. Beside good growth in milk with numbers as high as 8 log CFU ml–1, certain enterococci and lactobacilli also reduced pH below 5.0 and showed proteolytic activity. In antistaphylococcal testing, only pure strains of enterococci and lactobacilli were moderately antagonistic, but not in coagulated milks and coagulated milk extracts. Enterococci and lactobacilli with most relevant technological/antistaphylococcal properties were combined and tested as TMSC.
In control (C) cheese-making, milk was inoculated with TMSC, while staphylococci (SC) cheese-making included contamination with staphylococci. In C trials, high logarithmic counts per g of cheese for enterococci (8.07–8.80) and lactobacilli (7.49–9.98) throughout the ripening period were found, and their authenticity was monitored by RAPD method. Furthermore, cheese extracts failed to inhibit pure cultures of staphylococci, while cheese pieces inhibited Staphylococcus sp. ST17. In SC trials, population dynamics of enterococci (7.81–9.04) and lactobacilli (7.98–9.63) corroborated the results in milk and in C trials, with staphylococci still present at the end of the ripening period but at lower counts than in fresh cheese.
Authors:K.C. Hor, L.C Lew, S.B. Choi and M.T. Liong
.N., Bhat, R., Karim, A.A. & Liong, M.T. (2012): Enhanced growth of lactobacilli and bioconversion of isoflavones in biotin-supplemented soymilk upon ultrasound-treatment. Ultrasonics Sonochem. , 19 , 160
. & Oliver, G. (1993): Inhibition of enteropathogens by lactobacilli strains used in fermented milk. J. Fd Prot. , 56 , 773-776.
Inhibition of enteropathogens by lactobacilli strains used in fermented milk
Authors:E. Paszti-Gere, E. Csibrik-Nemeth, K. Szeker, R. Csizinszky, O. Palocz, O. Farkas and P. Galfi
cells after exposure to non-starter lactobacilli. Int. J. Food Microbiol. 112, 266–274 (2006)
Inhibition of Salmonella-induced IL-8 synthesis and expression of Hsp70 in enterocyte-like Caco-2 cells after exposure to
Authors:Š. Tůma, F. Vogensen, M. Plocková and J. Chumchalová
The antifungal activity of 322 lactobacilli strains isolated from Edam cheese at different stages of the ripening process was tested against
M 5689 using a dual overlay spot assay. Approximately 21% of the isolates showed a certain level of inhibitory activity.Seven strains with the strongest antifungal activity were examined by the milk agar plate method with three different mould strains isolated from spoiled dairy products as target microorganisms and were compared with the antifungal effectiveness of standard antifungal strains
DC 1246.The newly isolated lactobacilli strains exhibited the strongest inhibition against
M 5689, followed by
sp. DMF 0006 and
DMF 0801. The level of mould growth inhibition of several new isolates, namely
ST 40 and
ST 41, was comparable to or slightly higher than that of standard strains. By use of both phenotypic and genotypic methods (REP-PCR, 16S rDNA), four out of seven antifungally active isolates were identified, one as
and three as
Lb. fermentum. Lb. paracasei
ST 68 was chosen for further testing as antifungal protective adjunct for Edam cheese production.
Lactobacilli and bifidobacteria are most commonly encountered in the dairy industries, either existing naturally in milk or inoculated as starters in fermented dairy products. Recent research suggests that fermented dairy products are a cocktail of bioactive ingredients. The objective of our study was to evaluate the bioactivity of cell wall fractions of Lactobacillus and Bifidobacterium grown in reconstituted skimmed milk, and the possibility of intra- and extracellular extracts of these bacteria for applications in foods and beyond. Intracellular and extracellular extracts of Lactobacillus and Bifidobacterium showed inhibitory activities against food and dermal pathogens. All strains were able to produce inhibitors, such as organic acids, antimicrobial peptides, diacetyl, and hydrogen peroxide. Most strains showed higher production of extracellular than intracellular inhibitors (P<0.05). Meanwhile, all strains were able to produce hyaluronic acid, lipoteichoic acid, peptidoglycan, neutral sphingomyelinase and acid sphingomyelinase at concentrations applicable for cosmeceutical application. Findings from our study demonstrated that inhibitors and bioactives from lactobacilli and bifidobacteria have the potential to be developed into formulations for food and non-food applications.
Authors:Markus M. Heimesaat, Ursula Grundmann, Marie E. Alutis, André Fischer and Stefan Bereswill
Host immune responses are pivotal for combating enteropathogenic infections. We here assessed the impact of the innate receptor nucleotide oligomerization domain protein 2 (NOD2) in murine Campylobacter jejuni-infection. Conventionally colonized IL-10−/− mice lacking NOD2 and IL-10−/− controls were perorally challenged with C. jejuni strain 81-176 and displayed comparable pathogenic colonization of intestines until day 14 postinfection (p.i.). Whereas overall intestinal microbiota compositions were comparable in naive mice, NOD2−/− IL-10−/− mice exhibited less fecal bifidobacteria and lactobacilli than IL-10−/− counterparts after infection. Interestingly, NOD2−/− IL-10−/− mice were clinically more compromised during the early phase of infection, whereas, conversely, IL-10−/− animals exhibited more frequently bloody feces lateron. While colonic apoptotic cell and T lymphocyte numbers were comparable in either C. jejuni-infected mice, B lymphocytes were lower in the colon of infected NOD2−/− IL-10−/− mice versus controls. At day 14 p.i., colonic TNF and IL-23p19 mRNA levels were upregulated in NOD2−/− IL-10−/− mice only. Translocation rates of intestinal commensals to mesenteric lymphnodes and extra-intestinal compartments including liver and kidney were comparable, whereas viable bacteria were more frequently detected in spleens derived from IL-10−/− as compared to NOD2−/− IL-10−/− mice. In conclusion, NOD2 is involved during C. jejuni infection in conventionally colonized IL-10−/− mice in a time-dependent manner.