How the acetate and propionate accumulation impact anaerobic syntrophy during methane formation is not well understood. To investigate such effect, continuous acetate (35 g/L), propionate (11.25 g/L) and bicarbonate (30 g/L) supplementation were used during mesophilic anaerobic digestion. The high throughput sequencing (16S rRNA and mcrA), Real-Time quantitative PCR, and stable carbon isotope fingerprinting were applied to investigate the structure and activity of microbial community members. The results demonstrated that the abundance of syntrophic acetate oxidizing bacteria exhibited a gradual decrease coupled with heavier stable carbon isotopic signature of methane (δ 13CH4) in the three reagents impacted reactors. The increased acetate and propionate concentrations exerted negative influence on biogas production but the relatively stable hydrogenotrophic methanogens together with syntrophic acetate/propionate oxidizing bacteria kept the stable methane formation facing acetate and propionate accumulation. The functional genes copy number of the hydrogenotrophic Methanocellaceae and Methanomicrobiaceae correlated significantly with δ 13CH4 (R2 > 0.74), but only the abundance of Methanocellaceae fitted well with δ 13CH4 (p < 0.05). The δ 13CH4 signatures can predict methanogenesis, as it directly reflects the main methanogenic pathway; yet, further investigation of isotope fractionation in acetate/propionate coupled with δ 13CH4 is needed. Collectively, these results provide deep insight into anaerobic syntrophy and reveal changes of synergistic relationships, both of which may contribute to the stability of biogas reactors.

• MeSH
• acetáty MeSH
• anaerobióza MeSH
• bioreaktory * MeSH
• methan MeSH
• propionáty * MeSH
• RNA ribozomální 16S genetika   MeSH
• Publikační typ
• časopisecké články MeSH

The residual antibiotics in the environment have lately caused widespread concerns. However, little information is available on the antibiotic bioaccumulation and its health risk in drinking water resources of South China. Therefore, the occurrence, distribution, and health risk of four quinolone antibiotics including ofloxacin (OFX), norfloxacin (NOR), ciprofloxacin (CIP), and enrofloxacin (ENR) in the Qingshitan reservoir using high-performance liquid chromatography were investigated. Results revealed that the concentrations in water, sediment, and edible fish ranged from 3.49-660.13 ng/L, 1.03-722.18 μg/kg, and 6.73-968.66 μg/kg, respectively. The ecological risk assessment via the risk quotient (RQ) method showed that the values in sediment were all greater than 1, posing a high risk to the environment. The health risk index of water samples was at the maximum acceptable level, with OFX at the top while the rest were at the medium risk level. The main edible fish kinds of the reservoir had high dietary safety and the highest contaminations were found in carnivorous feeding habits and demersal habitat fishes with OFX as the highest magnitude. Source identification and correlation analysis using SPSS showed significant relationships between NOR with pH and turbidity (in water), as well as total phosphor (TP) and total organic carbon (TOC) in sediment. NOR was the highest in sediment which mostly sourced from livestock wastewater, croplands irrigation drain water, and stormwater. Correlations between CIP and ENR with TP were significant, while OFX was positively associated with total nitrogen (TN) which mainly originated from urban sewage as well as directly dosed drugs in fish farms. In conclusion, our results are of great significance for ensuring the safety of drinking water and aquatic products in this region.

• MeSH
• antibakteriální látky škodlivé účinky   analýza   MeSH
• chemické látky znečišťující vodu škodlivé účinky   analýza   MeSH
• chinolony škodlivé účinky   analýza   MeSH
• geologické sedimenty chemie   MeSH
• hodnocení rizik * MeSH
• monitorování životního prostředí * MeSH
• řeky chemie   MeSH
• řízení kvality MeSH
• ryby * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Čína MeSH

Temperature regulations (mesophilic/thermophilic) and digesting modes (mono-/co-digestion) play key roles in the biomethane potential of anaerobic digestion, but limited research focus on the synergetic effects on microbial interconnections of the biomethane process. In this study, the pineapple and maize residues under different operations were monitored by batch biogas assays and 16S high-throughput sequencing to explore: 1) biomethane potential regarding different operations, 2) microbial communities in different treated reactors, and 3) significant factors determine microbial distribution. Results showed that the co-digestion had higher methanogenic abundance and biomethane production (~3300 mLn) versus mono-digestion under mesophilic condition. To the thermophilic condition, the co-digestion had less methanogenic abundance but more biomethane production (~5000 mLn). Statistical evidence uncovered that the Clostridiaceae and Thermoanaerobacteraceae dominated pathways linked closely with methanogenesis which may contribute the more biomethane production in the thermophilic condition. This study demonstrated the temperature regulations drove rare taxa as major contributors for biomethane production.

• MeSH
• anaerobióza MeSH
• biopaliva MeSH
• bioreaktory * MeSH
• Euryarchaeota * MeSH
• methan MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH

Feedstock type influences bacterial and methanogenic communities in anaerobic digestion. These two communities work tightly to maintain the stability of anaerobic digestion. How to quick report the changes of microbial community structure especially methanogenesis is the key issue for optimizing anaerobic digestion process. In this study, 13C isotope fractionations of CH4 and CO2 in biogas and microbial community composition were analyzed in 5 different feedstocks. Our results showed that grass silage, maize silage and swine manure fed reactors had similar δ 13C values and methanogenic community composition, dominated by Methanosarcinaceae. The lowest δ 13CH4 values were detected in straw and chicken manure fed reactors, reflecting reduced microbial degradation of material or the presence of toxic components in these feedstocks. The straw fed bioreactor lead to low δ 13CH4 values, probably reflecting relatively high levels of the syntrophic acetate oxidizing bacteria, Synergistaceae and Syntrophaceae, which might work collectively with hydrogenotrophic methanogens, resulting in the low δ 13CH4 values in this bioreactor. Significantly, all core microbes in the 5 different feedstock fed bioreactors were either Clostridia species or related to the Synergistaceae (syntrophic acetate oxidizing bacteria).

• MeSH
• anaerobióza MeSH
• biopaliva * MeSH
• bioreaktory MeSH
• hnůj MeSH
• izotopy MeSH
• methan MeSH
• mikrobiota * MeSH
• prasata MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Process fluctuation caused by temperature modification of anaerobic digestion is routinely monitored via operational parameters, such as pH and gas production, but these parameters are lagging on microbial community performance. In this study, 13C isotope fractionation in CH4 and CO2 of biogas together with microbial community dynamics were applied to evaluate process stability in response to temperature increment. Results showed that the weakening correlated links between Firmicutes affiliated families and Methanomicrobiaceae were found regarding temperature increase. In contrast, Methanosarcinaceae and Methanobacteriaceae strengthened their links with multiple bacterial groups. This suggests that the 13C isotope fractionation in CH4 can predict the collapse of certain microbial interconnections and process instability, the new reinforced microbial links directly reflect the microbial community redundancy for maintaining function of syntrophic populations.

• MeSH
• anaerobióza MeSH
• Bacteria MeSH
• bioreaktory * MeSH
• Euryarchaeota * MeSH
• methan MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH

The aim of this study was to investigate how the microbial community structure adapts during the start-up phase and how the 13C fractionation of biogas reflects the microbial population dynamics in two parallel swine manure-fed anaerobic digesters. Two swine manure-fed reactors for the start-up of continuously stirred tank reactors at mesophilic condition were evaluated. Changes in community structure were monitored using 16S rRNA high-throughput sequencing to measure the abundance of fermenting bacteria and methanogens. Digesters with relatively stable Methanosarcinaceae started up successfully and contained high gas production and low levels of propionate. In contrast, the digester that experienced a difficult start-up period had reduced Methanosarcinaceae along with accumulated propionate and low gas production. Specific gas production, specific methane production, and 13C fractionation of biogas were influenced significantly by Methanosarcinaceae, Methanobacteriaceae, and Clostridiaceae, indicating that the 13C fractionation of biogas had significant potential to reflect microbial population changes and digester performance during the start-up period.

• MeSH
• anaerobióza MeSH
• Bacteria MeSH
• biopaliva MeSH
• bioreaktory mikrobiologie   MeSH
• chemická frakcionace MeSH
• fermentace MeSH
• hnůj mikrobiologie   MeSH
• prasata MeSH
• RNA ribozomální 16S genetika   MeSH
• uhlík chemie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH