Elisabetta Carraro

Detection of Biogenic Amine Producer Bacteria in a Typical Italian Goat Cheese

The aim of this study was to research decarboxylating bacterial strains and biogenic amine content in a typical Italian goat cheese (Robiola di Roccaverano). The study was performed on fresh and ripened samples of goat cheese manufactured from industrial and artisanal producers. Sixty-seven bacterial strains isolated showed decarboxylating activity, and Enterococcus faecalis was the most widespread decarboxylating species in all artisanal and industrial products. Pediococcus acidilactici and Enterococcus malodoratus were also identified as biogenic amine producers in Robiola di Roccaverano cheese. All the E. faecalis strains isolated in this study were able to decarboxylate tyrosine. Tyramine was the most abundant biogenic amine in cheese samples, while histamine was the most widespread. High amounts of these two biogenic amines were found in ripened samples (up to 2,067 mg/kg for tyramine and 1,786 mg/kg for histamine), whereas 2-phenylethylamine and tryptamine were present in almost all ripened cheeses at low concentrations. The detection of strains producing biogenic amines and the high concentrations of tyramine and histamine found in ripened Robiola di Roccaverano could represent a potential risk to the consumer.

Photocatalytic bacterial inactivation by TiO2-coated surfaces

The aim of this study was the evaluation of the photoactivated antibacterial activity of titanium dioxide (TiO2)-coated surfaces. Bacterial inactivation was evaluated using TiO2-coated Petri dishes. The experimental conditions optimized with Petri dishes were used to test the antibacterial effect of TiO2-coated ceramic tiles. The best antibacterial effect with Petri dishes was observed at 180, 60, 30 and 20 min of exposure for Escherichia coli, Staphylococcus aureus, Pseudomonas putida and Listeria innocua, respectively. The ceramic tiles demonstrated a photoactivated bactericidal effect at the same exposure time. In general, no differences were observed between the antibacterial effect obtained with Petri dishes and tiles. However, the photochemical activity of Petri dishes was greater than the activity of the tiles.Results obtained indicates that the TiO2-coated surfaces showed a photoactivated bactericidal effect with all bacteria tested highlighting that the titania could be used in the ceramic and building industry for the production of coated surfaces to be placed in microbiologically sensitive environments, such as the hospital and food industry.

Evaluation of Legionella pneumophila contamination in Italian hotel water systems by quantitative real-time PCR and culture methods.

Aims:  This study was designed to define the extent of water contamination by Legionella pneumophila of certain Italian hotels and to compare quantitative real‐time PCR with the conventional culture method.

BIOLOGICAL DRINKING WATER TREATMENT PROCESSES, WITH SPECIAL REFERENCE TO MUTAGENICITY

Many researches have demonstrated that the use of biological processes in the production of drinking water has many advantages over conventional alternatives. One possibility is that biological processes will result in lower levels of genotoxic by-products in the drinking water. This possibility was investigated in the present study, which compares the levels of such by-products following either chemical or biological treatments. Water samples, collected at the main steps of the two key stages of both treatments were passed over XAD2/8 resins, to concentrate micropollutants, included by-products, for subsequent analysis using the microsome/Salmonella assay (TA98 and TA100±S9). The results showed that biological treatment, avoiding break-point chlorination, limits by-product formation and associated mutagenic generation. It follows that, in this respect, biological processes seem to have significant advantages over conventional water treatments.

Agricultural Reuse of the Digestate from Anaerobic Co-Digestion of Organic Waste: Microbiological Contamination, Metal Hazards and Fertilizing Performance

The aim of this study was to evaluate the agricultural reuse of the digestate products (DPs) obtained from mesophilic anaerobic co-digestion of different organic wastes (sludge, cattle slurries and organic fraction of municipal solid wastes). At this scope, the content of faecal indicators and pathogens as well as the heavy metal concentration of DPs was monitored. The fertilizing performance of the DPs was also investigated. Co-digestion trials were performed using laboratory-scale (LRs) and pilot-scale reactors (PRs). The microbiological analysis of DPs showed the common presence of Salmonella and an inadequate reduction of indicator organisms during the digestion process, both in the LRs and the PRs. Moreover, the presence of pathogens (e.g. Listeria monocytogenes) in some DP samples highlighted the importance of the microbiological quality evaluation of the DPs to study the possible health risks for consumer. In several samples of DPs, the Cu, Ni and Zn contents exceeded the maximum admissible concentration for fertilizer, as specified by Italian law, suggesting possible environmental contamination if the DPs are used for agricultural purposes. Considering the fertilizing performance, significant differences of growth parameters were observed only for the DPs that were produced by LRs. In conclusion, this work can be considered as a preliminary study to evaluate the possible agricultural reuse of the digestate obtained from different organic wastes.

Monitoring air pollution effects on children for supporting public health policy: the protocol of the prospective cohort MAPEC study

Introduction Genotoxic biomarkers have been studied largely in adult population, but few studies so far have investigated them in children exposed to air pollution. Children are a high-risk group as regards the health effects of air pollution and some studies suggest that early exposure during childhood can play an important role in the development of chronic diseases in adulthood. The objective of the project is to evaluate the associations between the concentration of urban air pollutants and biomarkers of early biological effect in children, and to propose a model for estimating the global risk of early biological effects due to air pollutants and other factors in children. Methods and analysis Two biomarkers of early biological effects, DNA damage by the comet assay and the micronuclei (MN) test, will be investigated in oral mucosa cells of 6–8-year-old children. Concurrently, some toxic airborne pollutants (polycyclic aromatic hydrocarbon (PAH) and nitro-PAH) and in vitro air mutagenicity and toxicity in ultra-fine air particulates (PM0.5) will be evaluated. Furthermore, demographic and socioeconomic variables, other sources of exposures to air pollutants and lifestyle variables will be assessed by a structured questionnaire. The associations between sociodemographic, environmental and other exposure variables and biomarkers of early biological effect using univariate and multivariate models will be analysed. A tentative model for calculating the global absolute risk of having early biological effects caused by air pollution and other variables will be proposed. Ethics and dissemination The project has been approved by the Ethics Committees of the local Health Authorities. The results will be communicated to local Public Health Agencies, for supporting educational programmes and health policy strategies. LIFE+2012 Environment Policy and Governance. LIFE12 ENV/IT/000614.

Application of semipermeable membrane device (SPMD) to assess air genotoxicity in an occupational environment.

Semipermeable membrane device (SPMD) is a passive sampler that sequesters lipophilic contaminants, mimicking the bioconcentration in the fatty tissue of organisms. This study was designed to assess the use of SPMD and biological tests (Comet assay and Ames test) for air monitoring. For this purpose an occupational environment with expected polycyclic aromatic hydrocarbons (PAHs) contamination (coke plant) was selected for a case study. The SPMDs were deployed in five occupational contaminated sites and in a control site. The SPMD dialysates were chemically analysed and examined for in vitro DNA-damaging activity in human cells (Jurkat) by Comet assay and for mutagenicity with the Ames test (TA98 strain, w/o S9). Total suspended particulates were also collected and analysed (GC-MS). No biological effect of SPMD extract was revealed in the control site. On the other hand, air samples collected with SPMDs within the coke plant showed variable degrees of genotoxic and mutagenic activity. The highest effects were associated with the highest PAH level recovered in the SPMDs extracts and in particulate samples. Results obtained support the sensitivity of biological tests associated to SPMD sampling for evaluating the health risk of potentially contaminated work environments highlighting the usefulness of SPMDs for environmental air quality monitoring.

PM10 in a background urban site: Chemical characteristics and biological effects

PM10 was sampled in a background urban site in Torino, a northern Italian city. PM10 extracts were tested with THP-1 and A-549 cells to evaluate their effects on cell proliferation, LDH activity, TNFα, IL8 and CYP1A1 expression, and genotoxic damage induction (Comet assay). Through Principal Component Analysis (PCA), it was observed that (1) the aqueous extracts induced the inhibition of cell proliferation in the warm season that clustered together to total ions, (2) organic extracts determined a winter cell viability reduction and (3) there was a genotoxic effect associated with PAH and metal concentrations. The analysed low PAH levels were unable to induce significant CYP1A1 expression. The results obtained confirmed that PM composition and seasonality play an important role in particle-induced toxicity. The presence of PM10-induced biological effects at a low polluted site suggested that a reduction of PM10 mass did not seem to be sufficient to reduce its toxicity.

Environmental Advances Due to the Integration of Food Industries and Anaerobic Digestion for Biogas Production: Perspectives of the Italian Milk and Dairy Product Sector

Anaerobic digestion (AD) is a biotechnology that is able to produce an energy vector from waste organic materials. Its inclusion in the food industries, especially if farming activities are present, represents an interesting perspective. This work reviews the main aspects of the inclusion of AD in milk and dairy production. It includes an analysis of the sector characteristics in terms of diffusion, a discussion of waste production and disposal concerning milk and dairy production, a description of the biological and technological aspects of AD, a discussion regarding the application of AD for milk by-products, a description of environmental and legislative aspects, and the suggestion of an integrated model that includes the anaerobic co-digestion of whey and cattle slurry in the milk and dairy production industries. Both environmental and economic impacts of such integration promise to pay for the preliminary investment in AD plant installation and the development of additional expertise.

Microbiological and chemical characterization of a typical Italian cheese: Robiola di Roccaverano

Robiola di Roccaverano is a traditional Italian goats milk cheese carrying a Protected Designation of Origin (PDO). The present work studied both cheese microflora and cheese physicochemical characteristics to obtain a more accurate description of this PDO product. Multivariate statistical analysis (PCA) was performed to evaluate the influence of cheesemaking (artisanal and industrial), ripening time, and season of production on cheese characteristics. Multiplex PCR and fatty acid methyl esters (FAMEs) were used to identify the kind of milk employed by Robiola di Roccaverano producers. The results obtained highlight some product differences between the artisanal and industrial products. These differences were most evident in the microbiological data. The use of PCA allowed cheese samples to cluster on the basis of their age (fresh or ripened), the origin of production (artisanal and industrial), and even the season of production. Gross composition, microbiological parameters, and gas chromatographic analyses of FAMEs provided the most important parameters for Robiola di Roccaverano cheese characterization.