Response of activated sludge to the treatment of oxytetracycline production waste stream

Abstract

To investigate how the microbial community in activated sludge responded to high antibiotic levels, a benchscale aerobic wastewater treatment system was used to treat oxytetracycline (OTC) mother liquor (OTC-ML). Removal efficiency of chemical oxygen demand decreased from 64.9 to 51.0 % when the OTC level increased from 191.6 to 620.5 mg/L, respectively. According to the cloning results, Psychrobacter and Cryptophyta were the dominant bacterium and eukaryote in the inoculated sludge, respectively, both of which related to low temperature. After OTC exposure, Alphaproteobacteria and Betaproteobacteria became the dominant bacteria, with a small proportion of Firmicutes, Actinobacteria appeared, and fungi (mainly Saccharomycotina) became the dominant eukaryotes, indicating the possible functions of these microorganisms in the wastewater treatment of OTC-ML. The relative abundance of nine tetracycline resistance genes and four mobile elements (class 1 integron, class 2 integron, transposon Tn916/1545, and pattern 1 insertion sequence common region) significantly increased from undetectable to 2.1×10 −3 in the inoculated sludge to 1.7×10 −4 -9.8×10 −1 in sludge exposed to 620.5 mg/L OTC by using real-time PCR. The variety of gene cassette arrays of class 1 integron in the sludge samples increased with increasing OTC exposure concentration.

Bacterial Communities and Antibiotic Resistance Communities in a Full-Scale Hospital Wastewater Treatment Plant by High-Throughput Pyrosequencing

“…Interestingly, Cytophagia (14.8%) and Anaerolineae (7.6%) were predominant classes in the HWW, compared to the DWW (1.4% Cytophagia and 1.2% Anaerolineae). Anaerolineae was reported as having high resistance to antibiotics (i.e., tetracycline) [31,36], corresponding to the characteristics of the HWW receiving major antibiotics from hospital chemicals and clinics. In terms of taxonomic classification of class levels, influent characteristics seem to affect microbial richness and diversity, but further investigation is required regarding what types of antibiotics influence microbial communities.…”

Influence of the amoxicillin concentration on organics removal and microbial community structure in an anaerobic EGSB reactor treating with antibiotic wastewater

“…For the anaerobic reactors receiving antibiotic-bearing (mainly streptomycin) wastewater, Deltaproteobacteria (51%) mainly affiliated with sulfate-reducing bacteria (SRB) were dominated [34]. In a benchscale aerobic wastewater treating oxytetracycline mother liquor, Alphaproteobacteria and Betaproteobacteria were the dominant bacteria [53]. However, in the study, clones results combined with T-RFs (Table 3) showed that Firmicute, Bacteroidetes, Cloacimonetes, Ignavibacteriae and Thermotogae were the key groups under different concentrations of AMX.…”

Evaluation of residual antibacterial potency in antibiotic production wastewater using a real-time quantitative method

“…The pilot WWTS consisted of a sequential up-ow anaerobic sludge bed (UASB), an anoxic reactor and an oxic reactor, and was operated for nine months, as described in our previous study. 29 One UASB effluent sample (SPM (P)-W1 1 ), three anoxic samples (SPM (P)-W2 1-3 ) and three aerobic samples (SPM (P)-W3 1-3 ) were collected from the pilot system over the experimental period (Fig. S1(a) †).…”