In recent years, the spread of antibiotic-resistant bacteria and efforts to preserve food microbiota have induced renewed interest in phage therapy. Phage cocktails, instead of a single phage, are commonly used as antibacterial agents since the hosts are unlikely to become resistant to several phages simultaneously. While the spectrum of activity might increase with cocktail complexity, excessive phages could produce side effects, such as the horizontal transfer of genes that augment the fitness of host strains, dysbiosis or high manufacturing costs.
View Article and Find Full Text PDFBacteriophages are highly specific predators that drive bacterial diversity through coevolution while striking tradeoffs among preserving host populations for long-term exploitation and increasing their virulence, structural stability, or host range. and other coliform bacteria present in the microbiota of milk and during early ripening of raw milk cheeses have been linked to the production of gas, manifested by the appearance of eyes, and the development of off-flavors; thus, they might cause early blowing and cheese spoilage. Here, we report the characterization of coliphages isolated from manure from small ruminant farms and strains isolated from goat and sheep raw milk cheese.
View Article and Find Full Text PDFThe aim of this study was to identify the main Enterobacteriaceae species responsible for early gas blowing during curdling and the first week of ripening in raw goats' milk cheese. Two batches of raw goats' milk cheese were selected. One of them showed early blowing within the first 24 h of cheese ripening while the other showed no alteration.
View Article and Find Full Text PDFBackground: The presence of coliform bacteria is routinely assessed to establish the microbiological safety of water supplies and raw or processed foods. Coliforms are a group of lactose-fermenting Enterobacteriaceae, which most likely acquired the lacZ gene by horizontal transfer and therefore constitute a polyphyletic group. Among this group of bacteria is Escherichia coli, the pathogen that is most frequently associated with foodborne disease outbreaks and is often identified by β-glucuronidase enzymatic activity or by the redundant detection of uidA by PCR.
View Article and Find Full Text PDFThe effect of different brining treatments on salt uptake and diffusion during the first 30 d of ripening was determined in soft ewe cheese. Additionally, salt influence on surface microorganisms and physicochemical parameters was evaluated. Cheeses were placed into different brine solutions (14, 18 and 24°Bé) at 5 and 10 °C for 1, 2 or 3 h.
View Article and Find Full Text PDFJ Ind Microbiol Biotechnol
March 2011
A low-cost procedure was designed for easy and rapid response-on-demand production of fresh wine yeast for local wine-making. The pilot plant produced fresh yeast culture concentrate with good microbial quality and excellent oenological properties from four selected wine yeasts. The best production yields were obtained using 2% sugar beet molasses and a working culture volume of less than 60% of the fermenter capacity.
View Article and Find Full Text PDFAppl Environ Microbiol
August 2004
We describe a genetic instability found in natural wine yeasts but not in the common laboratory strains of Saccharomyces cerevisiae. Spontaneous cyh2(R)/cyh2(R) mutants resistant to high levels of cycloheximide can be directly isolated from cyh2(S)/cyh2(S) wine yeasts. Heterozygous cyh2(R)/cyh2(S) hybrid clones vary in genetic instability as measured by loss of heterozygosity at cyh2.
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