Reducing bacterial pathogen contamination not only improves overall global public health but also diminishes food waste and loss. The use of lytic bacteriophages (phages) that infect and kill bacteria could be a beneficial tool for suppressing bacterial growth during dairy products storage time. Four Enterobacter cloacae (E. cloacae) complex isolates which were previously isolated from contaminated dairy products were used to identify lytic phages in wastewater. Phages specific to multi-drug resistant (MDR) E. cloacae complex 6AS1 were isolated from local sewage. Two novel phages vB_EclM-EP1 and vB_EclM-EP2 were identified as myoviral particles and have double-stranded DNA genome. Their host range and lytic capabilities were detected using spot test and efficiency of plating (EOP) against several bacterial isolates. The phages had a latent period of 30 min, and a large burst size of about 100 and 142 PFU/cell for vB_EclM-EP1 and vB_EclM-EP2, respectively. Both phages were viable at pH ranging 5-9 and stable at 70 °C for 60 min. The individual phages and their cocktail preparations (vB_EclM-EP1 and vB_EclM-EP2) reduced and inhibited the growth of E. cloacae complex 6AS1 during challenge test in milk and yogurt samples. These results indicate that the E. cloacae complex-specific phages (vB_EclM-EP1 and vB_EclM-EP2) have a potential application as microbicidal agents in packaged milk and milk derivatives during storage time. In addition, our environment is a rich sources of lytic phages which have potential use in eliminating multidrug-resistant isolates in food industry as well as in biocontrol.
- MeSH
- bakteriofágy * genetika MeSH
- Enterobacter cloacae MeSH
- jogurt MeSH
- mléko mikrobiologie MeSH
- odpadky - odstraňování * MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
This study was undertaken to investigate the starter and probiotic potential of lactic acid bacteria isolated from dromedarian camel's milk using both culture-dependent and -independent approaches and metataxonomic analysis. Strains of lactic acid bacteria recovered were examined in vitro for tolerance to gastric acidity, bile, and lysozyme. Bile salt hydrolysis, serum cholesterol-lowering, oxalate degradation, proteolytic activity, exopolysaccharide production, and cell surface characteristics necessary for colonizing intestinal mucosa were also evaluated. A single strain of the species, Lactobacillus fermentum named NPL280, was selected through multivariate analysis as it harbored potential probiotic advantages and fulfilled safety criteria. The strain assimilated cholesterol, degraded oxalate, produced exopolysaccharides, and proved to be a proficient alternate yogurt starter with good viability in stored bio-yogurt. A sensorial analysis of the prepared bio-yogurt was also found to be exemplary. We conclude that the indigenous L. fermentum strain NPL280 has the desired traits of a starter and adjunct probiotic culture for dairy products.
- MeSH
- jogurt mikrobiologie MeSH
- Limosilactobacillus fermentum * metabolismus MeSH
- mikrobiota fyziologie MeSH
- mléko * mikrobiologie MeSH
- probiotika * klasifikace izolace a purifikace metabolismus MeSH
- velbloudi MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Pákistán MeSH
- MeSH
- jogurt využití MeSH
- kaseiny MeSH
- kozy * MeSH
- laktosa MeSH
- lidé MeSH
- mateřské mléko MeSH
- mléčné bílkoviny MeSH
- mléčné výrobky * analýza klasifikace využití MeSH
- mléko * chemie metabolismus využití MeSH
- nesnášenlivost laktózy MeSH
- savci MeSH
- skot MeSH
- statistika jako téma MeSH
- sýr využití MeSH
- syrovátkové proteiny MeSH
- Check Tag
- lidé MeSH
- skot MeSH
The effect of three different amounts of acacia honey (1, 3 and 5 %) on the survival of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus, and on the chemical and sensory properties of yogurts was tested. Analyses were carried out shortly after manufacture, 7 and 14 days of storage. The obtained values were compared with the those for yogurt without any addition of the acacia honey. During storage of yoghurts the count of bacteria decreased. The smallest changes in the numbers of bacteria have been found during storage of yoghurt with the highest addition of honey. This type of yogurt reached the highest antioxidant activity and the highest score in sensory evaluation.
Within this study, a new method enabling monitoring of various estrogenic substances potentially occurring in milk and dairy products was proposed. Groups of compounds fairly differing in physico-chemical properties and biological activity were analyzed: four natural estrogens, four synthetic estrogens, five mycoestrogens, and nine phytoestrogens. Since they may pass into milk mainly in glucuronated and sulfated forms, an enzymatic hydrolysis was involved prior to the extraction based on the QuEChERS methodology. For the purification of the organic extract, a dispersive solid-phase extraction (d-SPE) with sorbent C18 was applied. The final analysis was performed by ultra-high-performance liquid chromatography (UHPLC) coupled with triple quadrupole tandem mass spectrometry (MS/MS). Method recovery ranged from 70 to 120% with a relative standard deviation (RSD) value lower than 20% and limits of quantification (LOQs) in the range of 0.02-0.60 μg/L (0.2-6.0 μg/kg dry weight) and 0.02-0.90 μg/kg (0.2-6.0 μg/kg dry weight) for milk and yogurt, respectively. The new procedure was applied for the investigation of estrogenic compounds in 11 milk samples and 13 yogurt samples from a Czech retail market. Mainly phytoestrogens were found in the studied samples. The most abundant compounds were equol and enterolactone representing 40-90% of all estrogens. The total content of phytoestrogens (free and bound) was in the range of 149-3870 μg/kg dry weight. This amount is approximately 20 times higher compared to non-bound estrogens.
- MeSH
- estrogeny chemie MeSH
- fytoestrogeny chemie MeSH
- houby MeSH
- jogurt analýza MeSH
- mléko chemie MeSH
- reprodukovatelnost výsledků MeSH
- steroidy chemie MeSH
- tandemová hmotnostní spektrometrie MeSH
- vysokoúčinná kapalinová chromatografie metody MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- Bifidobacterium růst a vývoj MeSH
- fermentace MeSH
- funkční potraviny MeSH
- geneticky modifikované potraviny * škodlivé účinky využití MeSH
- jogurt * mikrobiologie MeSH
- lidé MeSH
- probiotika klasifikace terapeutické užití MeSH
- škrob analýza aplikace a dávkování škodlivé účinky MeSH
- Check Tag
- lidé MeSH
