Fugate, a waste product from biogas production, regularly used in agriculture as a fertiliser, may contain bacterial pathogens that cause zoonoses. Anaerobic digestion (AD) can inactivate viable pathogens, including parasites, viruses, and pathogens containing antibiotic resistance genes. This study aimed to compare the numbers of pathogenic bacteria and diversity of potential bacterial pathogens in the fugate using three different types of slurry: cattle, swine, and poultry manure. The swine fugate showed higher numbers of Clostridium perfringens and Campylobacter sp. than the poultry and cattle fugate. In the cattle fugate, the lowest total number of pathogenic bacteria and a low number of coliforms were detected after the AD. The use of cattle manure in biogas plants presents a lower potential for soil contamination with pathogens. The fugate produced using poultry or swine manure can be used carefully to avoid possibility of contamination of aquifers or surface waters. Also fugate produced from manure of cows suffering from chronic botulism can be used only with carefulness because of the presence of Clostridium botulinum spores in biogas waste of diseased cows.

• Keywords
• anaerobic digestion, animal slurry, bacterial pathogens, fugate,
• Publication type
• Journal Article MeSH

Biogas plants have been considered as a source for possible amplification and distribution of pathogenic bacteria capable of causing severe infections in humans and animals. Manure and biogas wastes could be sources for spore-forming bacteria such as Clostridium botulinum. In the present study, 24 liquid manure and 84 biogas waste samples from dairies where the majority of the cows suffered from chronic botulism were investigated for the presence of botulinum neurotoxins (BoNT) and C. botulinum spores. The prevalence of BoNT/A, B, C, D, and E in biogas wastes was 16.6, 8.3, 10.7, 7.1, and 10.8 %, respectively, while in manure, the prevalence was 0.0, 0.0, 0.0, 8.3, and 4.1 %, respectively. After enrichment of samples in reinforced cultural medium, they were tested for C. botulinum BoNT/A, B, C, D, and E using ELISA (indirect C. botulinum detection). The prevalence of C. botulinum type A, B, C, D, and E samples in biogas wastes was 20.2, 15.5, 19, 10.7, and 34.8 %, respectively, while the prevalence in liquid manure was 0.0, 0.0, 0.0, 8.3, and 12.5 %, respectively. In conclusion, the occurrence of BoNT and C. botulinum spores in biogas waste of diseased animals indicates an increased and underestimated hygienic risk. Application of digestates from biogas fermentations as fertilizers could lead to an accumulation of long lifespan spores in the environment and could be a possible health hazard.

• MeSH
• Biofuels analysis   microbiology   MeSH
• Botulism microbiology   veterinary   MeSH
• Botulinum Toxins analysis   metabolism   MeSH
• Clostridium botulinum chemistry   genetics   isolation & purification   metabolism   MeSH
• Feces microbiology   MeSH
• Manure analysis   microbiology   MeSH
• Cattle Diseases microbiology   MeSH
• Waste Products analysis   MeSH
• Plants microbiology   MeSH
• Cattle MeSH
• Animals MeSH
• Check Tag
• Cattle MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Biofuels MeSH
• Botulinum Toxins MeSH
• Manure MeSH
• Waste Products MeSH