4^th World Congress and Expo on Applied Microbiology November 29-30, 2017 Madrid, Spain

Derya Önal Darilmaz has completed her PhD from Gazi University. She is working as Associate Professor, Doctor in Aksaray University. Her areas of expertise are probiotics, food microbiology and microbial biotechnology. She has published more than 15 papers in reputed journals and serving as an Editorial Board Member and Referee in different reputed journals.\r\n\r\n\r\n

Enterococci belong to the lactic acid bacteria (LAB) and they are of importance in foods due to their involvement in food spoilage and fermentations, as well as their utilization as probiotics in humans and slaughter animals. The purpose of this study was to evaluate the probiotic properties of Enterococcus faecium RI 41, RI 56, RT 81 strains isolated from traditional naturally fermented cheese produced in different regions of Iran and Turkey. The ability to autoaggregation and coaggregation are desirable properties for probiotics in health-promoting foods. Therefore, in the current study, we assessed the effect of exopolysaccharides (EPSs) produced by E. faecium strains on the aggregation and hydrophobicity properties. All E. faecium strains tested showed autoaggregation (38.80-53.50%) and coaggregation ability (18.55-35.25%) with Escherichia coli ATCC 11230, but the results were strain specific and dependent on exopolysaccharides production (129-185 mg/L). In addition, enterococci strains tested were showed affinity to all solvents (chloroform, p-xylene, toluene and ethyl-acetate), suggesting a high complexity of the cell surface. Our results indicate that the ability to autoaggregation, together with cell-surface hydrophobicity and coaggregation abilities with E. coli strain can be used for preliminary screening in order to identify potentially probiotic bacteria suitable for human or animal use.\r\n\r\n\r\n

Derya Önal Darilmaz has completed her PhD from Gazi University. She is working as Associate Professor, Doctor in Aksaray University. Her areas of expertise are probiotics, food microbiology and microbial biotechnology. She has published more than 15 papers in reputed journals and serving as an Editorial Board Member and Referee in different reputed journals.

Hypercalciuria and hyperoxaluria are among the most important pathophysiologic causes of kidney stone formation. An increased intestinal absorption of oxalate is known to lead to hyperoxaluria with a significantly enhanced risk of urinary stone formation. In the present study, five strains of Propionibacterium were examined for their abilities to survive at 10 and 20 mM oxalate concentrations, and exopolysaccharide (EPS) production in these conditions as well as oxalate degrading activities. To determine the toxic effect of oxalate on EPS production ability and viability, EPS production of Propionibacterium strains was determined in yeast extract-lactate (YEL), 10 and 20 mM YEL-ox media. All strains grew in the presence of 10 and 20 mM sodium oxalates illustrating that oxalate at these concentrations are not toxic to Propionibacterium strains. No major loss of viability was observed at YEL-ox media. A high variability in the oxalate-degrading capacity was found in the different species and oxalate concentrations. The high EPS-producing P. jensenii BDP6 and P. freudenreichii subsp. freudenreichii DO8 strains showed high oxalate degrading activity, whereas the low EPS-producing P. jensenii DO6 showed low oxalate degrading activity in both oxalate concentrations. A better understanding of the mechanisms related to EPS production and oxalate degrading activity can be used for preliminary screening in order to determine potentially probiotic bacteria applications for human or animal use.

Marina has completed her Master and PhD in Physical Chemistry from the University of Salamanca. She was awarded with the Prize for Excellent Doctoral Thesis. She has published more than 20 papers in peer reviewed journals. Since 2013,she is working as Post-doctoral researcher in the HERCULES laboratory at the Évora University where she is focused on the development of a rapid and accessible tool for analyzing the microorganisms involved in biodeterioration of Cultural Heritage. In 2014 awarded with a Post-doctoral Fellowship and since 2016, PI of the MICROTECH-ART project, both focused on reaching this goal and funded by FCT (Fundação para a Ciencia e a Tecnologia).

The selection of an adequate method for investigating the microorganisms that are deteriorating a work of art is of utmost importance for selecting adequate remediation, inhibition prevention and safeguard strategies. RNA-Fluorescence In Situ Hybridization (RNA-FISH) seems to be a powerful alternative for signalizing the artwork’s biodeterioration agents. The technique is based on specific and sensitive fluorescent staining of the target microorganisms. Since the materials commonly used in the production of works of art usually show autofluorescence, for improving the permorfance of the technique it is crucial to minimize/avoid this interference. Thus, investigation of materials autofluorescence and adequate fluorophores’ selection is of utmost importance for unequivocal detection/identification of the microorganisms of interest. In this way, this work was focused on: i) the investigation of the autofluorescence of various materials that are found forming part of Cultural Heritage objects (parchment, paper, wood, fabric, rock, mortar and plastic among others) by epifluorescence microscopy using fluorescence filter sets targeted at commonly used fluorophores (TRITC/CY5/6-FAM); ii) the detection of RNA-FISH stained microbial cells on the selected materials or in the presence of residual particles. High orange and green fluorescence were observed for most of the materials tested. The results revealed that the use of red fluorescent dyes, in contrast to green and orange fluorophores, for staining the cells by RNA-FISH allow unequivocal detection/identification of the stained cells in the presence of most of the materials tested. It represents an important step forward in the application of RNA-FISH for detecting/identifying microorganisms causing deterioration in artworks.

P Branco has completed her Master’s in Molecular Biology from the Institute of Health Science Egas Moniz, Monte da Caparica, Portugal and PhD in Food Engineering from the Higher Institute of Agronomy, University of Lisbon, Portugal. She has published seven papers in peer reviewed journals. Since May 2017, she is working as Researcher in the Hercules Laboratory at the Évora University where she is focused on the development of new RNA-FISH probes for identification and detection of microorganisms involved in biodeterioration of cultural heritage in MICROTECH-ART project funded by FCT (Fundação para a Ciencia e a Tecnologia).

RNA-fluorescence in situ hybridization (FISH) technique is based on the hybridization of fluorescently-labelled oligonucleotide probes targeting to specific regions of the ribosomal RNA. Its use has exponentially increased in the last decades for microbial identification. However, one of the main limitations of this technique is the reduced number of specific RNA-FISH probes available. One of the key issues is the design of probes with the desired level of specificity and high hybridization efficiency. Specificity of probe binding to the target site depends on the stringency conditions, commonly adjust using formamide. Thus, in silico and empirical formamide denaturation curves are commonly used searching for the optimal conditions for ensuring specificity. Therefore, this work was focused on the design of an RNA-FISH probe target to a yeast specie (Dekkera bruxellensis) and on the evaluation of its suitability in silico and experimentally. The probe was designed in silico by using DECIPHER program. It was analyzed with mathFISH program and blast nucleotide to calculate hybridization efficiency and specificity/coverage, respectively. Experimental evaluation was done by constructing the fluorescence-signal response/formamide concentration curve for the target and a nontarget yeast (Candida krusei). A previously described FISH procedure was applied, and fluorescence intensity was measured by flow cytometry. Excellent performance of the probe was observed with high maximal theoretical in silico hybridization efficiency (99.89%) and specificity. The experimental evaluation revealed that the probe has high specificity with 5% of formamide showing its maximal fluorescence signal response for the target and none for the non-target yeast. \r\n\r\n

Ilana Racowski has a background in Food Engineering, with Masters and PhD degree in Food Microbiology and Genetics at the University of São Paulo (USP). She has been working as a Professor and Researcher in this area for 17 years, with publications in the area of natural antimicrobials for both bacteria and fungi, where her research area is also concentrated. Today, she is a professor of food microbiology and a researcher at the Termomecanica Technology College (FTT) in the Food Engineering course. In addition to the Microbiology Area, she has a degree in Administration, where she also has Lacto Senso and MBA postgraduate courses.\r\n\r\n

Evaluation of the antimicrobial activity of oregano essential oil in different concentrations against microorganisms present by natural contamination of sliced mozzarella cheese: Increasingly, natural substances that can act on microorganisms are being studied, delaying their development in order to replace or reduce the use of synthetic preservatives, since some of these substances can be aggressive to humans and the environment. In this way, the present work had the objective to evaluate the antimicrobial power of the essential oil of oregano, in front of deteriorating fungi of the genus Aspergillus sp. (A) and Penicillium sp. (B) isolated by sowing technique on surface of apparent contamination of sliced mozzarella cheese. To verify the analysis of the antimicrobial power of oregano oil at concentrations of 1:10; 1: 100; 1: 1000; 1: 10000; 1: 100000 and pure the agar diffusion methodology was used using PDA (Potato Dextrose Agar) as the culture medium in the Petri dishes and as the growth control the addition of sterile distilled water. With the result it was possible to notice that for the microorganisms A and B the pure oil and its dilution of 1:10 exert antimicrobial power obtaining a final PGI (Percent of Growth Inhibition) of 100% of Growth Inhibition and 77,23% respectively for the microorganism B the PGI values were 100% and 70.69%.