scholarly journals Did Application of Digested Sewage Sludge as Soil Amendment Alter the Abundances of Antibiotic Resistance Genes and Microbial Communities in Soil and Earthworm Gut?

2020 ◽  
Author(s):  
Zheng-Hao Li ◽  
Li Yuan ◽  
Wei Shao ◽  
Guo-Ping Sheng
Keyword(s):  
Microbial Community ◽  
Sewage Sludge ◽  
Microbial Communities ◽  
Soil Amendment ◽  
Antibiotic Resistance Genes ◽  
Digested Sludge ◽  
Earthworm Gut ◽  
The Impact ◽  
Digested Sewage Sludge ◽  
Amended Soil

Abstract Background Digested sewage sludge has been widely applied as soil amendment for enhanced crop production. However, given that digested sludge is abundant with antibiotic resistance genes (ARGs) and antibiotic resistant bacteria, the impact of digested sludge amendment on the abundances of ARGs and microbial communities in soil and soil fauna (e.g., earthworms) remains largely unknown. In this study, the patterns of ARGs and microbial communities in soil and gut of earthworms after 80-days cultivation with digested sewage sludge amendment were investigated to gain insights into this impact. Results The results show that the digested sludge amendment increased the initial abundances of ARGs (e.g., tetA, tetQ, and sulII) in soil. However, after 80-days cultivation, the absolute abundances of target ARGs decreased by 62.3–95.4%. The reduction in ARGs absolute abundances was further enhanced by 31.4–84.7% in the presence of earthworms. In contrast, the relative abundances of some ARGs (e.g., tetA, sulI, and blaTEM−1) in the gut of earthworms increased by 41–130 folds. The microbial community structure of soil was greatly altered because of the introduction of digested sewage sludge at initial, but it recovered to its original pattern after 80-days cultivation. This could be attributed to the gradual attenuation of anaerobic microorganisms under aerobic conditions in soil. In particular, the presence of earthworms further enhanced this phenomenon. The reduction of ARGs in the amended soils was likely attributed to microbial community shift based on redundancy analysis. Several bacterial families (e.g., Saprospiraceae, Chitinophagaceae, and Rhodanobacteraceae) were significantly correlated with the target ARGs. Conclusions Our results reveal that the enrichment of ARGs in soil caused by digested sludge-amendment would recover to their original levels before amendment, highlighting the contribution of earthworms to reducing the ARG abundances in amended soil via shifting the microbial community. However, we also found that the amended soil could increase ARGs abundance in the earthworm gut, which may enhance the potential risk of ARGs spread via food chain. These results may provide a new sight on the control of ARGs occurrence and dissemination in sludge-amended soil ecosystem with consideration of the impact of earthworms.

scholarly journals Agricultural Soils Amended With Thermally-Dried Anaerobically-Digested Sewage Sludge Showed Increased Risk of Antibiotic Resistance Dissemination

2021 ◽  
Vol 12 ◽  
Author(s):  
Leire Jauregi ◽  
Lur Epelde ◽  
Itziar Alkorta ◽  
Carlos Garbisu
Keyword(s):  
Antibiotic Resistance ◽  
Sewage Sludge ◽  
Relative Abundance ◽  
Agricultural Soils ◽  
Antibiotic Resistance Genes ◽  
Exchange Capacity ◽  
Amended Soils ◽  
Α Diversity ◽  
Increased Risk ◽  
Digested Sewage Sludge

The application of sewage sludge (SS) to agricultural soil can help meet crop nutrient requirements and enhance soil properties, while reusing an organic by-product. However, SS can be a source of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs), resulting in an increased risk of antibiotic resistance dissemination. We studied the effect of the application of thermally-dried anaerobically-digested SS on (i) soil physicochemical and microbial properties, and (ii) the relative abundance of 85 ARGs and 10 MGE-genes in soil. Soil samples were taken from a variety of SS-amended agricultural fields differing in three factors: dose of application, dosage of application, and elapsed time after the last application. The relative abundance of both ARGs and MGE-genes was higher in SS-amended soils, compared to non-amended soils, particularly in those with a more recent SS application. Some physicochemical parameters (i.e., cation exchange capacity, copper concentration, phosphorus content) were positively correlated with the relative abundance of ARGs and MGE-genes. Sewage sludge application was the key factor to explain the distribution pattern of ARGs and MGE-genes. The 30 most abundant families within the soil prokaryotic community accounted for 66% of the total variation of ARG and MGE-gene relative abundances. Soil prokaryotic α-diversity was negatively correlated with the relative abundance of ARGs and MGE-genes. We concluded that agricultural soils amended with thermally-dried anaerobically-digested sewage sludge showed increased risk of antibiotic resistance dissemination.

scholarly journals The effects of offshore petroleum exploitation on microbial community and antibiotic resistome of adjacent marine sediments

2020 ◽  
Vol 81 (12) ◽  
pp. 2501-2510
Author(s):  
Jing Wang ◽  
Jiti Zhou
Keyword(s):  
Antibiotic Resistance ◽  
Microbial Community ◽  
Marine Sediments ◽  
Microbial Community Composition ◽  
Antibiotic Resistance Genes ◽  
Multidrug Transporter ◽  
Class I Integrons ◽  
Abundance And Diversity ◽  
The Impact ◽  
Offshore Petroleum

Abstract The exploitation of petroleum in offshore areas is becoming more prosperous due to the increasing human demand for oil. However, the effects of offshore petroleum exploitation on the microbial community in the surrounding environment are still not adequately understood. In the present study, variations in the composition, function, and antibiotic resistance of the microbial community in marine sediments adjacent to an offshore petroleum exploitation platform were analyzed by a metagenomics-based method. Significant shifts in the microbial community composition were observed in sediments impacted by offshore petroleum exploitation. Nitrosopumilales was enriched in marine sediments with the activities of offshore petroleum exploitation compared to the control sediments. The abundances of function genes involved in carbon, butanoate, methane, and fatty acid metabolism in sediment microbial communities also increased due to the offshore petroleum exploitation. Offshore petroleum exploitation resulted in the propagation of some antibiotic resistance genes (ARGs), including a multidrug transporter, smeE, and arnA, in marine sediments via horizontal gene transfer mediated by class I integrons. However, the total abundance and diversity of ARGs in marine sediments were not significantly affected by offshore petroleum exploitation. This study is the first attempt to analyze the impact of offshore petroleum exploitation on the spread of antibiotic resistance.

Evaluating the stabilisation degree of digested sewage sludge: investigations at four municipal wastewater treatment plants

2006 ◽  
Vol 53 (8) ◽  
pp. 81-90 ◽  
Author(s):  
V. Parravicini ◽  
E. Smidt ◽  
K. Svardal ◽  
H. Kroiss
Keyword(s):  
Wastewater Treatment ◽  
Sewage Sludge ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Municipal Wastewater Treatment ◽  
Digested Sludge ◽  
Aerobic Conditions ◽  
Specific Oxygen Uptake Rate ◽  
Municipal Wastewater Treatment Plants ◽  
Digested Sewage Sludge

Further reduction of volatile suspended solids (VSS) during a post-stabilisation step was applied to evaluate the stabilisation degree of digested sewage sludge. For this purpose digested sludge was collected at four municipal wastewater treatment plants (WWTPs) and further stabilised in lab-scale chemostat reactors either under anaerobic or aerobic conditions. Experimental results showed that even in adequately digested sludge a consistent amount of VSS was degraded during aerobic post-stabilisation. It seems that aerobic conditions play a significant role during degradation of residual VSS. Additionally, specific VSS production (gVSS/peCOD110.d) as well as specific oxygen uptake rate were shown to be suitable parameters to assess the degree of sludge stabilisation at WWTPs. Fourier transform infrared spectroscopy was used to reveal changes in the sludge composition. Spectra of treated and untreated sludge samples indicated that the major component of residual VSS in stabilised sludge for instance consisted of biomass, while cellulose was absent.

NITRIFICATION OF SEWAGE SLUDGE USING MISCIBLE DISPLACEMENT AND PERFUSION TECHNIQUES

1975 ◽  
Vol 55 (4) ◽  
pp. 467-472 ◽  
Author(s):  
N. E. STEWART ◽  
C. T. CORKE ◽  
E. G. BEAUCHAMP ◽  
L. R. WEBBER
Keyword(s):  
Sewage Sludge ◽  
Flow Rate ◽  
Organic Nitrogen ◽  
Nitrate Nitrogen ◽  
Ammonium Nitrogen ◽  
Miscible Displacement ◽  
Digested Sludge ◽  
Displacement Experiments ◽  
Digested Sewage Sludge ◽  
Lower Flow Rate

Miscible displacement and soil perfusion techniques were used to study the transformations of nitrogen in fractions of anaerobically digested sewage sludge. In miscible displacement experiments the rates of nitrification of NH4+-N of supernates of sludge were 115 μg NO3−-N/g soil/day at a flow rate of 0.17 cm h−1, and 81 μg NO3−-N/g soil/day at the lower flow rate of 0.10 cm h−1. The soil perfusion experiments indicated that only the ammonium-nitrogen of the sludge solids was oxidized to nitrate-nitrogen. The rates of nitrification of sludge were 37 μg NO3−-N/g soil/day for an application of 5.0 cm ha−1 and 15 μg NO3−-N/g soil/day for a sludge application equivalent to 2.5 cm ha−1. The experiments were not of sufficient duration to determine that mineralization of the organic-nitrogen in the digested sludge and subsequent nitrification occurred.

scholarly journals Hill-based Dissimilarity Indices and Null Models for Analysis of Microbial Community Assembly

2020 ◽  
Author(s):  
Oskar Modin ◽  
Raquel Liebana ◽  
Soroush Saheb-Alam ◽  
Britt-Marie Wilén ◽  
Carolina Suarez ◽  
...  
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Community Assembly ◽  
Null Model ◽  
Amplicon Sequencing ◽  
Null Models ◽  
Marker Genes ◽  
Experimental Systems ◽  
Microbial Community Assembly ◽  
The Impact

Abstract Background: High-throughput amplicon sequencing of marker genes, such as the 16S rRNA gene in Bacteria and Archaea, provides a wealth of information about the composition of microbial communities. To quantify differences between samples and draw conclusions about factors affecting community assembly, dissimilarity indices are typically used. However, results are subject to several biases and data interpretation can be challenging. The Jaccard and Bray-Curtis indices, which are often used to quantify taxonomic dissimilarity, are not necessarily the most logical choices. Instead, we argue that Hill-based indices, which make it possible to systematically investigate the impact of relative abundance on dissimilarity, should be used for robust analysis of data. In combination with a null model, mechanisms of microbial community assembly can be analyzed. Here, we also introduce a new software, qdiv, which enables rapid calculations of Hill-based dissimilarity indices in combination with null models.Results: Using amplicon sequencing data from two experimental systems, aerobic granular sludge (AGS) reactors and microbial fuel cells (MFC), we show that the choice of dissimilarity index can have considerable impact on results and conclusions. High dissimilarity between replicates because of random sampling effects make incidence-based indices less suited for identifying differences between groups of samples. Determining a consensus table based on count tables generated with different bioinformatic pipelines reduced the number of low-abundant, potentially spurious amplicon sequence variants (ASVs) in the data sets, which led to lower dissimilarity between replicates. Analysis with a combination of Hill-based indices and a null model allowed us to show that different ecological mechanisms acted on different fractions of the microbial communities in the experimental systems.Conclusions: Hill-based indices provide a rational framework for analysis of dissimilarity between microbial community samples. In combination with a null model, the effects of deterministic and stochastic community assembly factors on taxa of different relative abundances can be systematically investigated. Calculations of Hill-based dissimilarity indices in combination with a null model can be done in qdiv, which is freely available as a Python package (https://github.com/omvatten/qdiv). In qdiv, a consensus table can also be determined from several count tables generated with different bioinformatic pipelines.

scholarly journals A Meta-Omics Analysis Unveils the Shift in Microbial Community Structures and Metabolomics Profiles in Mangrove Sediments Treated with a Selective Actinobacterial Isolation Procedure

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7332
Author(s):  
Miguel David Marfil-Santana ◽  
Anahí Martínez-Cárdenas ◽  
Analuisa Ruíz-Hernández ◽  
Mario Vidal-Torres ◽  
Norma Angélica Márquez-Velázquez ◽  
...  
Keyword(s):  
Microbial Community ◽  
Secondary Metabolites ◽  
Microbial Communities ◽  
Secondary Metabolite ◽  
Resistant Bacteria ◽  
Mangrove Sediments ◽  
Molecular Networking ◽  
Mangrove Tree ◽  
Enhanced Production ◽  
The Impact

Mangrove sediment ecosystems in the coastal areas of the Yucatan peninsula are unique environments, influenced by their karstic origin and connection with the world’s largest underground river. The microbial communities residing in these sediments are influenced by the presence of mangrove roots and the trading chemistry for communication between sediment bacteria and plant roots can be targeted for secondary metabolite research. To explore the secondary metabolite production potential of microbial community members in mangrove sediments at the “El Palmar” natural reserve in Sisal, Yucatan, a combined meta-omics approach was applied. The effects of a cultivation medium reported to select for actinomycetes within mangrove sediments’ microbial communities was also analyzed. The metabolome of the microbial communities was analyzed by high-resolution liquid chromatography-tandem mass spectrometry, and molecular networking analysis was used to investigate if known natural products and their variants were present. Metagenomic results suggest that the sediments from “El Palmar” harbor a stable bacterial community independently of their distance from mangrove tree roots. An unexpected decrease in the observed abundance of actinomycetes present in the communities occurred when an antibiotic-amended medium considered to be actinomycete-selective was applied for a 30-day period. However, the use of this antibiotic-amended medium also enhanced production of secondary metabolites within the microbial community present relative to the water control, suggesting the treatment selected for antibiotic-resistant bacteria capable of producing a higher number of secondary metabolites. Secondary metabolite mining of “El Palmar” microbial community metagenomes identified polyketide synthase and non-ribosomal peptide synthetases’ biosynthetic genes in all analyzed metagenomes. The presence of these genes correlated with the annotation of several secondary metabolites from the Global Natural Product Social Molecular Networking database. These results highlight the biotechnological potential of the microbial communities from “El Palmar”, and show the impact selective media had on the composition of communities of actinobacteria.

scholarly journals Spatiotemporal Correlations Between Water Quality And Microbial Community of Typical Inflow River Into Taihu Lake, China

2021 ◽  
Author(s):  
Yajie Zhang ◽  
Ye Zhang ◽  
Lecheng Wei ◽  
Mengyan Li ◽  
Weitang Zhu ◽  
...  
Keyword(s):  
Water Quality ◽  
Microbial Community ◽  
Microbial Communities ◽  
Taihu Lake ◽  
Wastewater Treatment Plants ◽  
Ammonia Nitrogen ◽  
Pollution Sources ◽  
Storm Water ◽  
Urban Wastewater Treatment ◽  
The Impact

Abstract Changxing River, which is a typical inflow river into the Taihu Lake and occurs severe algae invasion, is selected to study the effect of different pollution sources on the water quality and ecological system. Four types of pollution sources, including the estuary of Taihu Lake, discharge outlets of urban wastewater treatment plants, storm water outlets, and non-point source agricultural drainage areas are chosen, and next-generation sequencing and multi-variate statistical analyses are used to characterize the microbial communities and reveal their relationship with water physicochemical properties. Results showed that ammonia nitrogen (NH4+-N), total nitrogen (TN), and total phosphorus (TP) are the main pollutant in Changxing River, especially at storm water outlets. At the same time, the diversity of microbial communities was the highest in the summer, and dominant phyla included Proteobacteria (40.9%), Bacteroidetes (21.0%) and Euryarchaeota (6.1%) under the condition of algal bloom. Water temperature (T), air pressure (P), concentrations of TP and CODMn were the important variables for the succession of microbial community. From the perspective of different pollution types, relative abundances of Microcystis and Nostocaceae at the estuary of Taihu Lake were correlated positively with dissolved oxygen (DO) and pH, and Pseudomonas and Arcobacter were correlated positively with concentrations of TN and nitrate nitrogen (NO3--N) at storm water outlets. The results provide a reference for the impact of pollution types on river microbial ecosystem under complex hydrological condition and a guidance for the selection of restoration techniques for polluted rivers entering an important lake.

Aeration of anaerobically digested sewage sludge for COD and nitrogen removal: optimization at large-scale

2008 ◽  
Vol 57 (2) ◽  
pp. 257-264 ◽  
Author(s):  
V. Parravicini ◽  
K. Svardal ◽  
R. Hornek ◽  
H. Kroiss
Keyword(s):  
Wastewater Treatment ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Nitrogen Removal ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Process Conditions ◽  
Nitrite Accumulation ◽  
Digested Sludge ◽  
Digested Sewage Sludge

The paper will report about the experiences at an Austrian large wastewater treatment plant of 720,000 population equivalents, where anaerobically digested sewage sludge is further stabilised under aerobic conditions. Enhanced stabilisation of the anaerobically digested sludge was required at the plant in order to get a permit for landfill disposal of the dewatered stabilized sludge. By implementing a post-aeration treatment (SRT ∼ 6d; 36 °C) after anaerobic digestion the organic content of the anaerobically well digested sludge can be decreased by 16%. Investigations on site showed that during digested sludge post-aeration anoxic phases for denitrification are needed to provide stable process conditions. In this way the pH value can be kept in a more favourable range for micro-organisms and concrete structures. Additionally, inhibition of the biological process due to nitrite accumulation can be avoided. By optimising the aeration/pause ratio ∼ 45% of total nitrogen in digested sludge can be removed. This significantly improves nitrogen removal efficiency at the wastewater treatment plant. NH4-removal occurs mainly through nitritation and denitritation with an efficiency of 98%. The costs/benefit analysis shows that post-aeration of digested sludge results in an increase of total annual costs for wastewater treatment of only 0.84%, corresponding to 0.19 Euro/pe/a. Result of molecular biological analyses (DGGE) indicate that all four ammonium-oxidizing bacteria species present in activated sludge can survive anaerobic digestion, but only two of them can adapt in the digested sludge post-aeration tanks. Additionally, in the post-aerated digested sludge a further ammonium-oxidizing bacteria species was identified.

scholarly journals Plasmids persist in a microbial community by providing fitness benefit to multiple phylotypes

2019 ◽  
Author(s):  
Liguan Li ◽  
Arnaud Dechesne ◽  
Jonas Stenløkke Madsen ◽  
Joseph Nesme ◽  
Søren J. Sørensen ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Microbial Community ◽  
Microbial Communities ◽  
Sewage Treatment ◽  
Sewage Treatment Plant ◽  
Treatment Plant ◽  
Antibiotic Resistance Genes ◽  
Amplicon Sequencing ◽  
Broad Host Range ◽  
Fitness Effects

AbstractThe current epidemic of antibiotic resistance has been facilitated by the wide and rapid horizontal dissemination of antibiotic resistance genes (ARGs) in microbial communities. Indeed, ARGs are often located on plasmids, which can efficiently shuttle genes across diverse taxa. While the existence conditions of plasmids have been extensively studied in a few model bacterial populations, their fate in complex bacterial communities is poorly understood. Here, we coupled plasmid transfer assays with serial growth experiments to investigate the persistence of the broad-host-range IncP-1 plasmid pKJK5 in microbial communities derived from a sewage treatment plant. The cultivation conditions combined different nutrient and oxygen levels, and were non-selective and non-conducive for liquid-phase conjugal transfer. Following initial transfer, the plasmid persisted in almost all conditions during a 10-day serial growth experiment (equivalent to 60 generations), with a transient transconjugant incidence up to 30%. By combining cell enumeration and sorting with amplicon sequencing, we mapped plasmid fitness effects across taxa of the microbial community. Unexpected plasmid fitness benefits were observed in multiple phylotypes of Aeromonas, Pseudomonas and Enterobacteriaceae, which resulted in community-level plasmid persistence. We demonstrate, for the first time, that plasmid fitness effects across community members can be estimated in a high-throughput way without prior isolation. By gaining a fitness benefit when carrying plasmids, members within complex microbial communities might have a hitherto unrecognized potential to maintain plasmids for long-term community-wide access.

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