Anaerobic digestates derived from agricultural mesophilic biogas plants are mainly used as organic fertilizers. However, animal derived pathogens could persist in the anaerobic digestates (ADs) posing an epidemiological risk. The present study investigated whether storage of ADs could reduce Salmonella Typhimurium, Listeria monocytogenes, and ESBL carrying Escherichia coli and whether reduction rates are dependent on temperature and substrate. Quantified bacterial suspensions were used to inoculate ADs derived from five biogas plants using different input materials to investigate the substrate dependence of the pathogen reduction. ADs were stored over six months with four different temperature profiles each representing six consecutive months, and, thus, the four seasons. Pathogen reduction during storage was shown to be strongly dependent on the temperature but also on the type of AD. This influence was higher at low temperatures. At higher temperatures (spring and summer profiles), a 5-log reduction was achieved after twelve weeks for S. Typhimurium, after twenty weeks for E. coli (ESBL) and after twenty-four weeks for L. monocytogenes in all ADs, respectively. In contrast at lower temperatures (autumn and winter profiles), a 5-log reduction was reached after twenty-four weeks for S. Typhimurium and not reached for ESBL-E. coli and L. monocytogenes. In conclusion, storing the ADs after the biogas process improves the hygienic quality and reduce the risk of introducing pathogens to the environment, but each case should be evaluated individually considering the composition of the ADs and the storage temperatures.

Recycling of organic waste material from biogas plants in agriculture is always connected with an epidemiological risk. This risk is connected with the microbiological quality of the recycled substrates as well as the disinfection potency of the used biotechnological processes. Therefore, it is necessary to evaluate these parameters on the individual basis as the spreading of human and animal pathogens cannot be excluded. This article shall give an overview on possible ways for pathogens to get in slurry or products from biogas plants but also on possibilities and efficiency of hygienic treatment by anaerobic digestion.

Organic fertilizers and organic wastes contribute significantly to humus reproduction in soil and to plant nutrient recycling. As regards their generation and usage, two opposing trends have appeared over the past few years. On the one hand, there has been a marked regional increase in the volume of organic fertilizers produced and used in agriculture, on the other, the non-agricultural demand for biomass previously used as a humus substitute has risen significantly.This article intends to estimate the national and regional demand for nitrogen, phosphates and potassium as well as for organic carbon for humus substitution and to compare it to the national and regional volume of these substances that arises with organic fertilizers and organic wastes. This includes an assessment of organic fertilizers and organic wastes in terms of their nutrient content and nutrient availability, pollutant content, nutrient and pollutant load and any health risks associated with their use in agriculture. Based on the estimated demand, the available amount and the assessment of risks and benefits, recommendations for use are derived for the agricultural, administrative, political and legislative sectors.

Organische Dunger und organische Reststoffe leisten einen entscheidenden Beitrag fur die Humusreproduktion von Boden und das Recycling von Pflanzennahrstoffen. Im Hinblick auf deren Anfall und Nutzung sind in den vergangenen Jahren zwei gegenlaufige Trends festzustellen. Einerseits hat das Volumen der in der Landwirtschaft anfallenden und der in die Landwirtschaft eingetragenen organischen Dunger regional stark zugenommen, andererseits hat sich gleichzeitig eine starke auserlandwirtschaftliche Nachfrage nach bisher fur den Humusersatz genutzter Biomasse entwickelt. Ziel dieser Stellungnahme ist es, den nationalen und regionalen Bedarf von Stickstoff, Phosphat und Kalium sowie von organischem Kohlenstoff fur den Humusersatz abzuschatzen und dem nationalen und regionalen Anfall dieser Stoffe mit organischen Dungern und organischen Reststoffen gegenuberzustellen. Dabei soll eine Bewertung der organischen Dunger und organischen Reststoffe im Hinblick auf Nahrstoffgehalte und Nahrstoffverfugbarkeit, Schadstoffgehalte, Nahr- und Schadstofffrachten sowie hygienische Risiken bei der landwirtschaftlichen Verwertung vorgenommen werden. Auf der Basis des geschatzten Bedarfs, des Anfalls und der Bewertung von Nutzen und Risiken sollen Nutzungsempfehlungen fur Landwirtschaft, Verwaltung, Politik und Rechtsetzung abgeleitet werden. Use of organic fertilizers and organic wastes in agriculture Organic fertilizers and organic wastes contribute significantly to humus reproduction in soil and to plant nutrient recycling. As regards their generation and usage, two opposing trends have appeared over the past few years. On the one hand, there has been a marked regional increase in the volume of organic fertilizers produced and used in agriculture, on the other, the non-agricultural demand for biomass previously used as a humus substitute has risen significantly. This article intends to estimate the national and regional demand for nitrogen, phosphates and potassium as well as for organic carbon for humus substitution and to compare it to the national and regional volume of these substances that arises with organic fertilizers and organic wastes. This includes an assessment of organic fertilizers and organic wastes in terms of their nutrient content and nutrient availability, pollutant content, nutrient and pollutant load and any health risks associated with their use in agriculture. Based on the estimated demand, the available amount and the assessment of risks and benefits, recommendations for use are derived for the agricultural, administrative, political and legislative sectors. L’utilisation d’engrais et de dechets organiques dans l’agriculture Les engrais et les dechets organiques contribuent de maniere significative a l’humification des sols et au recyclage des substances nutritives pour les plantes. Quant a leur production et leur utilisation, deux tendances opposees se sont manifestees au cours des dernieres annees. D’une part, le volume des engrais organiques produits et utilises dans l’agriculture a fortement augmente au niveau regional; d’autre part, la demande extra-agricole de biomasse, jusqu’alors utilisee pour remplacer l’humus, a fortement augmente. L’objectif de la presente contribution est d’estimer les besoins nationaux et regionaux en azote, en phosphate, en potassium et en carbone organique pour remplacer l’humus et de comparer la production nationale et regionale de ces substances avec les engrais et dechets organiques. A cet effet, il convient d’evaluer la teneur en nutriments et leur disponibilite, la teneur en polluants, les charges de nutriments et de polluants, ainsi que les risques hygieniques lors de la valorisation agricole. Sur la base de l’estimation des besoins et de la production ainsi que de l’evaluation des benefices et des risques, il convient de deduire des recommandations d’utilisation pour les secteurs agricole, administratif, politique et legislatif.

This study presents results of quantitative pathogen detection by real-time PCR (qPCR) and phase-specific serology for complete Q fever diagnostics. For this, samples of 42 goats in total were taken during a Q fever outbreak.In the early phase of the Q-fever infection, 10(4)-10(8) Coxiella (C) burnetii pathogens per vaginal swab and 10(2)-10(6) C burnetii per ml milk were detected using quantitative real-time PCR (qPCR). Pathogen excretion decreased continuously within two months to less than 10(4) (vaginal swab) and 10(2) (milk) C bumetii. At the end of the study there was a shift toward a 10 fold higher excretion of the pathogen via the genital tract and milk.At the start of the study, serological tests showed a dominance of the phase-2 antibody in 76% (22/29) of the goats in the MONA- (Multiple of Normal Activity) ELISA and 79% (23/29) in the IDEXX-ELISA, which was replaced by a phase-1 dominance in 85% (29/34) and 62% (21/34), of the animals respectively at the end of the study. Serum samples from 13 goats before lambing that excreted C. burnetii after lambing showed antibodies against phase 2 of 100% using MONA-ELISA and 77% in the IDEXX-ELISA.The most important diagnostic instrument for Q-fever infection in goats following birth is testing of vaginal swabs using qPCR. Phase-specific serology allows an estimation of possible pathogen excretion even before birth, as well as achieving valuable results for determination of the infection phase. (C) 2013 Elsevier B.V. All rights reserved.

Caseous lymphadenitis (CLA), a disease affecting sheep and goats, is caused by Corynebacterium pseudotuberculosis (Cp). Eradication programs are based on the serological identification of Cp infected animals. However, available diagnostic ELISAs are not similarly suitable for sheep and goats. In the present study the comparison of antigens revealed major species specific differences between sheep and goat derived Cp field isolates as well as between field isolates and the Cp ATCC reference strains. Furthermore, we found species-specific differences in the anti-Cp humoral immune response between sheep and goats. The analysis of band frequency was able to distinguish between immunodominant and non-immunodominant protein bands. The 150 kDa, 74 kDa, 48 kDa, and 30 kDa antigens were immunodominant in both, sheep and goats. Interestingly, the most commonly used diagnostic antigen, i.e. the 30 kDa phospholipase D (PLD), was recognized by 100% of the Cp positive goats but only by 70% of the Cp positive sheep. Furthermore, analysis of field sera revealed that there were a particular percentage of Cp positive sera which reacted negative with the PLD. In conclusion our results clearly showed that (1) the application of a combination of further defined immunodominant Cp antigens - in addition to the PLD antigen - and (2) consideration of species-specific differences in the anti-Cp immune response will substantially contribute to the improvement of Cp serological diagnostics and to effective eradication programs in both sheep and goats.

Pasteurization of sludge after anaerobic digestion resulted under practical conditions in many cases in recontamination of the stored sludge caused by using contaminated tubes for sludge transport or by infections with bird droppings or, possibly, by infected aerosols from the biological treatment processes. In Switzerland the pasteurization plants were closed down for a certain time to find out the reasons for these recontaminations.