Day 1 :
Kaposvar University, Hungary
Keynote: Comparative studies on diverse Propolis samples in order to reveal their antimicrobial feature by means of a novel in vitro human intestinal model
Time : 10:00-10:45
Propolis is a natural product deriving from plant resins collected by honeybees. Propolis has been applied in the traditional medicine since ancient times, and at present gains growing popularity in healthy foods owing to its beneficial composition and plausible antimicrobial character. In this paper the antimicrobial properties of four different Hungarian propolis samples and their extracts were examined. We investigated the effects of various Hungarian propolis samples on a model microbiota of the large intestine. Until recently, only very few data was published about the impact of propolis on intestinal bacteria.
Agar diffusion test was applied to assess the inhibition zones in order to evaluate the impact of propolis samples on various bacteria strains. Influence of digestion on the antimicrobial activity was assessed by means of an improved in vitro model system simulating the digestion process by a three-step procedure.
Most of the investigated propolis samples exhibited inhibitory activity against the tested bacteria subsequent to the simulated digestion procedure, so digestion appears to have no decisive influence on the antibacterial properties of propolis. Some specific bacterial strains did not prove to be susceptible to propolis in certain concentrations.
Depending on the propolis concentration, the tested bacterial strains proved to be sensitive against the propolis samples of different geographical origin, except for E. coli. The largest inhibition zones were noticed for propolis denoted as “Z” and “B”, followed by “D” and “E” samples. Additionally the Gram negative Bacteroides fragilis showed susceptibility against bee glue. The soluble part of digested propolis samples did not inhibit the growth of E. coli strain, but at the same time it showed activity against all the other tested bacteria. Enterococcus faecium and E. coli displayed resistance against the insoluble part of the digested propolis, whereas the other investigated 10 bacteria exhibited sensitivity.
Based on our results it might be stated that the actual biological impact of propolis samples of diverse origin can just be accurately estimated if well-tailored model studies are performed on representative human intestinal bacteria. On the basis of the current knowledge, in this paper we pointed out the prospects of applicability of selected propolis samples for manufacturing functional foodstuffs of beneficial physiological features in the future.
United Arab Emirates University, UAE
Time : 11:00-11:45
Dr. Mutamed Ayyash is an Assistant Professor of Food Microbiology and Safety in the Department of food Science at UAE University. Before joining UAEU, Dr. Ayyash completed his PhD in Food Science at Victoria University – Melbourne, Australia. Dr. Ayyash worked hardly on foodborne pathogens area with a research group at the food science department. His research focuses on lactic acid bacteria with potential probiotics characterization. Dr. Ayyash is also interested with functional foods produced by novel probiotics. the antimicrobial activities of probiotics against popular foodborne pathogens.
Objective: The objectives of this study were to isolate LAB from fish products in UAE and investigate their probiotic characteristics. This study aimed also to characterize the isolated LABs which possessed a bio-preservative (bacteriocin) properties.
Method: Physiological properties, cell surface properties (hydrophobicity, autoaggregation, co-aggregation), acid and bile tolerance, bile salt hydrolysis, cholesterol removing, exopolysaccharide (EPS) production, haemolytic, resistance toward lysozyme and six antibiotics were examined. The rRNA sequencing was carried out to identify the LAB isolates and to acquire Genbank accession numbers. The antimicrobial activity of the neutralized cell-free supernatant (NCFS) of 39 LAB isolates was tested according to referred method. Selected LABs were employed to product fermented fish sausages (FFS). The health-promoting benefits (antioxidant, antihypertensive and cytotoxicity) of the FFS were examined.
Results: A 39 LABs were isolated and identified as Enterococci, Lactobacilli and Streptococci. Virulence genes for Enterococci were tested and found safe. In general, all identified LAB (Lactococcus lactis KX881768, Lactobacillus plantarum KX881772, Lactococcus lactis KX881782 and Lactobacillus plantarum) showed auto-aggregation ability, high cholesterol removal ability, high co-aggregation, strong antimicrobial activity and EPS production. Among the isolates, Lactococcus lactis KX881768, Lactobacillus plantarum KX881772, Lactococcus lactis KX881782 and Lactobacillus plantarum KX881779 exhibited remarkable cholesterol removal abilities. Similarly, Lactobacillus plantarum KX881779, and Lactococcus lactis KX881782 showed very promising fermentation profiles. Enterococcus spp showed good probiotic activities and remarkable antimicrobial properties. The health-promoting benefits of FFS fermented by Enterococcus species were greater than Lactobacillus ones.
Conclusions: Selected isolates from camel milk exhibited outstanding probiotic characteristics. Results of this study showed that LABs isolated from traditional fish products in UAE had great potential to be used in food industry. Further studies are required to explore the health benefit of these isolates of fermented foods made by these isolates.
HNM Foundation, Switzerland
Time : 11:45-12:30
Dr. Ing. R. te Biesebeke is PhD from the Wageningen University (NL) with a record of achievements in Microbial Biotechnology, Food technology, Fermentation, Nutrition, Enzymes, Probiotics, Fibers, Antibiotics and Gastro-intestinal Microbiology. He is Manufacturing, Technology & Science Officer at HNM Engineering, Valais, Switzerland and Chairman of HNM foundation, Valais, Switzerland.
Lactobacillus reuteri DSM17938 is the first genetically modified probiotic strain that is used in large-scale production for Infant Nutrition. Now that this formula is several years in the global market, it may have proven value that the product can be considered safe for consumption. The use of this strain is a landmark for genetically manipulation of probiotics in order to change functional properties of a probiotic species to change its efficacy, quality or safety.
The Food and Agriculture Organization of the United Nations and the World Health Organization provide guidelines for probiotics:
1. Proper identification to the level of strain of all probiotics in the product, with deposit of all strains in an international culture collection.
2. Characterization of each strain for traits important to its safety and function.
3. Validation of health benefits in human studies, including identification of the quantity of the microorganism required to provide the benefit.
4. Truthful and not misleading labeling of efficacy claims and content through the end of shelf life.
Consumed probiotics encounter the microbiome, which is (majorly) the microbiological ecosystem in the gastro-intestinal tract that lives in close harmony with its host. The microbiome of any living organism catalyzes biochemical reactions influencing the bioavailability and metabolism of bioactive molecules like nutraceuticals, pharmaceuticals, feed and/or food (additives). Consumption of food, (bioactive) components or genetically modified probiotics changes the Microbiome so that the growth of certain microbial species will be (dis) favored. New developments in microbial biotechnology, food technology & nutrition enable a targeted approach to prevent or treat medical conditions through engineering the Microbiome. As we learn from approaches that have been applied, careful evaluation should be made when genetically modified micro-organisms are used in food or nutrition products for general or specific purpose in human and animal nutrition.