title: Antibiotic Resistance Genes and Correlations with Microbial Community and Metal Resistance Genes in Full-Scale Biogas Reactors As Revealed by Metagenomic Analysis.
abstract: Digested residues from biogas plants are often used as biofertilizers for agricultural crops cultivation. The antibiotic resistance genes (ARGs) in digested residues pose a high risk to public health due to their potential spread to the disease-causing microorganisms and thus reduce the susceptibility of disease-causing microorganisms to antibiotics in medical treatment. A high-throughput sequencing (HTS)-based metagenomic approach was used in the present study to investigate the variations of ARGs in full-scale biogas reactors and the correlations of ARGs with microbial communities and metal resistance genes (MRGs). The total abundance of ARGs in all the samples varied from 7 × 10-3to 1.08 × 10-1copy of ARG/copy of 16S-rRNA gene, and the samples obtained from thermophilic biogas reactors had a lower total abundance of ARGs, indicating the superiority of thermophilic anaerobic digestion for ARGs removal. ARGs in all the samples were composed of 175 ARG subtypes; however, only 7 ARG subtypes were shared by all the samples. Principal component analysis and canonical correspondence analysis clustered the samples into three groups (samples from manure-based mesophilic reactors, manure-based thermophilic reactors, and sludge-based mesophilic reactors), and substrate, temperature, and hydraulic retention time (HRT) as well as volatile fatty acids (VFAs) were identified as crucial environmental variables affecting the ARGs compositions. Procrustes analysis revealed microbial community composition was the determinant of ARGs composition in biogas reactors, and there was also a significant correlation between ARGs composition and MRGs composition. Network analysis further revealed the co-occurrence of ARGs with specific microorganisms and MRGs.
authors.affiliation: Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science and Engineering, Fudan University , 200433, Shanghai, China.
authors.forename: Gang
authors.identifier: 0000-0002-9711-9619
authors.initials: G
authors.lastname: Luo
authors.affiliation: Key Laboratory of Microorganism Application and Risk Control of Shenzhen, Graduate School at Shenzhen, Tsinghua University , Shenzhen, Guangdong 518055, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Li
authors.affiliation: Environmental Biotechnology Laboratory, The University of Hong Kong , Hong Kong SAR, China.
authors.forename: Li-Guan
authors.initials: LG
authors.lastname: Li
authors.affiliation: Environmental Biotechnology Laboratory, The University of Hong Kong , Hong Kong SAR, China.
authors.forename: Tong
authors.identifier: 0000-0003-1148-4322
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Department of Environmental Engineering, Technical University of Denmark , DK-2800, Kongens Lyngby, Denmark.
authors.forename: Irini
authors.initials: I
authors.lastname: Angelidaki
mesh_terms: D000900:Anti-Bacterial Agents; D056804:Biofuels; D004352:Drug Resistance, Microbial / Q000235:genetics*; D005798:Genes, Bacterial; D054892:Metagenome; D008670:Metals / Q000494:pharmacology
chemical_list: D000900:Anti-Bacterial Agents; D056804:Biofuels; D008670:Metals