Uniformes de trabajo o elementos de protección personal

TREATMENT TECHNOLOGIES

P. Karaolia1, J. Alexander2, T. Schwartz2, D. Fatta-Kassinos1

1_{Nireas-International Water Research Centre, University of Cyprus, Nicosia, Cyprus} 2_{Institute of Functional Interfaces, Karlsruhe Institute of Technology, Karlsruhe,}

Germany Background

The pressure applied onto bacteria in aquatic environments by the extensive use of antibiotics, leads to increased incidence of antibiotic resistance (AR) (Volkmann et al., 2004), increasing the prevalence of nosocomial diseases. There is limited research regarding alternative actions of controlling AR in wastewater treatment plants (WWTPs), i.e. advanced oxidation processes (AOPs) and new biological methods which may remove AR more efficiently (Rizzo et al., 2013).

Objectives

The aspects examined were: i) the prevalence of selected AR genes (ARGs) at different steps of the WWTP process ii) the ARGs removal efficiency (vim, vanA, mecA and lak genes) of a pilot scale Membrane BioReactor (MBR) and of two AOPs (solar photo-Fenton treatment and heterogeneous (TiO2) photocatalysis).

The AOP experiments took place under bench-scale conditions while the MBR had a capacity of 10 m3 _day-1_{. Real-time qPCR assessment followed the filtration and DNA}

extraction of the samples. Conclusions

The highest prevalence of lak and vanA genes was found in solar photo-Fenton effluent. The highest vim prevalence was found in MBR effluent (Table 1), indicating an increase in the examined ARGs after treatment. Further optimization of the examined technologies must occur to ensure safe disposal of treated effluents into aquatic ecosystems.

This work was funded by COST through a Short Term Scientific Mission (STSM) within the COST scientific programme on 'Detecting evolutionary hotspots of antibiotic resistance in Europe (DARE)'. Nireas-IWRC (ΝΕΑ

ΥΠΟΔΟΜΗ/ΣΤΡΑΤΗ/0308/09) is co-financed by the Republic of Cyprus and the European Regional Development Fund through the Cyprus Research Promotion Foundation.

FEMS-2798

Food Microbiology

Proteomics, thermal robustness and germination heterogeneity of Bacillus spores

S. Brul1_{, W. Abhyankar}2_{, R. Pandey}3_{, J. van Beilen}1_{, N. Vischer}4_{, E. Manders}4_,

A. Ter Beek1, L. de Koning5, C.G. de Koster5

1_{Molecular Biology & Microbial Food Safety, Swammerdam Institute for Life Science,}

Amsterdam, Netherlands

2_{Molecular Biology & Microbial Food Safety / Mass Spectrometry of Biomacromolecul}

es, Swammerdam Institute for Life Science, Amsterdam, Netherlands

3_{Molecular Biology & Microbial Food Safety / Van Leeuwenhoek Centre for Advanced}

Microscopy, Swammerdam Institute for Life Science, Amsterdam, Netherlands

4_{Van Leeuwenhoek Centre for Advanced Microscopy,}

Swammerdam Institute for Life Science, Amsterdam, Netherlands

5_{Mass Spectrometry of Biomacromolecules, Swammerdam Institute for Life Science,}

Amsterdam, Netherlands

Bacterial spores are ubiquitous in nature. They are stress resistant entities that can withstand high environmental temperatures, chemical insults and physical stress such as radiation or increased pressure. Spores are a concern to microbiological food stability due to these characteristics as upon survival of a preservation process they may start to germinate and grow out in food causing food spoilage. In addition germinating and outgrowing spores at undesired times and places pose a significant health burden. The challenge is amplified due to the heterogeneous germination and outgrowth behaviour of an isogenic spore population. We set out to analyse effects of thermal stress and the presence of a weak organic acid preservative on Bacillus subtilis spores of different maturation stages. Spore germination and outgrowth was assessed using live-imaging including the monitoring of intracellular pH with

IpHluorin. Significant heterogeneity in spore germination and outgrowth was observed and monitored using the newly developed Sporetracker image analysis tool. Thermal stress clearly enhances heterogeneous germination behaviour. To analyse whether different levels of spore coat cross-linking may be involved in the (heterogeneous) stress response we set out to identify such cross-links by mass- spectrometry analysis of the insoluble coat fraction of B. subtilis spores of different maturation levels. Heat resistance of spores from all samples was also tested. Using our gel-free proteomic approach and LC-FTICR-MS/MS analysis we monitored the efficiency of tryptic digestion of proteins in the coat during spore maturation over a period of 10 days, using metabolically 15N labelled mature spores as a reference. The results showed that during spore maturation the loss of digestion efficiency of outer coat (for instance CotG, CotC, CotU) and crust (CotY, CotZ) proteins

FEMS-2430

Food Microbiology

The sweet secrets of industrial strain improvement A.R. Neves1

1_{Bacterial Physiology & Improvement, Chr. Hansen A/S, Hørsolm, Denmark}

Lactic acid bacteria (LAB) are a functionally related group of Gram-positive bacteria known essentially for their roles in food bioprocessing. The successful

biotechnological application of LAB depends to a great extent on their unique

phenotypic traits, which among others include fast acidification of the medium, texture and flavour forming abilities, bioprotection, and health promoting properties.

However, the highly dynamic food market and ever-changing preferences from end consumers demands constant focus on product development. Fostered by this market push, Chr. Hansen places continuous efforts into the development of new LAB strains and cultures with novel properties and superior performance for the dairy industry. In the 21st _{century, genetic engineering could make such tasks more ease to}

accomplish. However, the tight requirements of regulatory agencies and the negative perception by consumers of genetically modified foods impose the exclusive use of natural strain improvement methodologies. Thus, at Chr. Hansen innovative product development includes combining classical strain improvement techniques such as random mutagenesis, dominant selection, adaptive laboratorial evolution, with the insights gained from the molecular understanding of our model systems. This

approach will be illustrated with relevant example cases of strain improvement for the dairy industry.

FEMS-1218

Food Microbiology

A MOBILE GENETIC ELEMENT IS RESPONSIBLE FOR SUBSTANTIALLY