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Aims:  To investigate the bacterial dynamics of a Caciotta cheese traditionally manufactured in the Montefeltro area (Central Italy) with raw cow’s milk and an aqueous extract of dried flowers from Cynara cardunculus as a coagulating agent. Methods and Results:  Conventional methods and a combined PCR‐DGGE approach, relying on culture‐dependent and ‐independent analyses, were used to investigate the cheese bacterial community, with a special focus on lactic acid bacteria. A heterogeneous population, including enterococci, lactococci, lactobacilli, food spoilage and other banal micro‐organisms, was found. Significance and Impact of the Study:  The study contributed to highlighting the influence of different technological parameters on bacterial dynamics of a raw milk Caciotta cheese coagulated with vegetable rennet. Conclusions:  None of the species found in the vegetable rennet became dominant during the cheese‐making and a prevailing role of the adventitions microbita coming from the raw milk and the dairy environment was highlighted.

A variety of foods have been implicated in symptoms of patients with Irritable Bowel Syndrome (IBS) but wheat products are most frequently cited by patients as a trigger. Our aim was to investigate the effects of breads, which were fermented for different lengths of time, on the colonic microbiota using in vitro batch culture experiments. A set of in vitro anaerobic culture systems were run over a period of 24 h using faeces from 3 different IBS donors (Rome Criteria–mainly constipated) and 3 healthy donors. Changes in gut microbiota during a time course were identified by fluorescence in situ hybridisation (FISH), whilst the small -molecular weight metabolomic profile was determined by NMR analysis. Gas production was separately investigated in non pH-controlled, 36 h batch culture experiments. Numbers of bifidobacteria were higher in healthy subjects compared to IBS donors. In addition, the healthy donors showed a significant increase in bifidobacteria (P<0.005) after 8 h of fermentation of a bread produced using a sourdough process (type C) compared to breads produced with commercial yeasted dough (type B) and no time fermentation (Chorleywood Breadmaking process) (type A). A significant decrease of δ-Proteobacteria and most Gemmatimonadetes species was observed after 24 h fermentation of type C bread in both IBS and healthy donors. In general, IBS donors showed higher rates of gas production compared to healthy donors. Rates of gas production for type A and conventional long fermentation (type B) breads were almost identical in IBS and healthy donors. Sourdough bread produced significantly lower cumulative gas after 15 h fermentation as compared to type A and B breads in IBS donors but not in the healthy controls. In conclusion, breads fermented by the traditional long fermentation and sourdough are less likely to lead to IBS symptoms compared to bread made using the Chorleywood Breadmaking Process.

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Aims:  Identification and biotyping of lactic acid bacteria (LAB) isolated from raw‐milk Pecorino cheese manufactured in the Marche region (central Italy) for selection of suitable starter cultures or adjuncts. Methods and Results:  Preliminary characterization with morphological and biochemical assays were undertaken for 112 Gram‐positive and catalase‐negative isolates. Unequivocal identification of the isolates was obtained through restriction analysis of the amplified 16S rRNA gene and sequencing of 360–380 bp amplicons. Fifty‐nine isolates belonging to LAB species generally recognized as safe and potentially utilized as starters or flavour‐producing adjuncts were preselected and tested for their acidifying, proteolitic and autolytic activities. Fifty‐five of these isolates were also subject to RAPD (randomly amplified polymorphic DNA) fingerprinting and unweighted pair‐group method with arithmetic averages (UPGMA) cluster analysis for the estimation of genotypic intra‐species variation. As a result, in Pecorino cheese, a heterogeneous lactic acid bacteria population, which includes strains with metabolic characteristics of technological interest, was characterized. Conclusions:  The polyphasic approach proposed allows the bacterial ecology of Pecorino cheese to be investigated and allows to assess the potential role of autochthonous LAB strains for the dairy industry. Significance and Impact of the Study:  The great economic importance of Pecorino cheese encouraged a deeper knowledge of its microbiota, which is known to influence the peculiar sensory properties of this cheese, also in view of its exploitation.