Mixed bacteria were enriched from heavy metals mine soil for cadmium(Cd(Ⅱ))-containing wastewater treatment. Batch adsorption experiment results showed that the optimal pH, temperature, initial Cd(Ⅱ) concentration, ...Mixed bacteria were enriched from heavy metals mine soil for cadmium(Cd(Ⅱ))-containing wastewater treatment. Batch adsorption experiment results showed that the optimal pH, temperature, initial Cd(Ⅱ) concentration, and biomass dosage were 6.0, 30 ℃, 20 mg/L, and 1 g/L, respectively. Living biomass exhibited better Cd(Ⅱ) removal efficiency(91.97%) than autoclaved biomass(79.54%) under optimal conditions. The isotherms and kinetics of living biomass conformed to the Langmuir isotherm model and pseudo-first-order kinetic model, respectively. FTIR results implied that amine groups, hydroxyl groups and phosphoric acid play an important role in the Cd(Ⅱ) adsorption process, while XRD results showed that crystalline Cd(OH)and CdO were obtained. After Cd(Ⅱ)-containing wastewater treatment exposure, the dominant bacteria genera included Comamonas(39.94%), unclassified_f__Enterobacteriaceae(34.96%), Ochrobactrum(14.07%), Alcaligenes(4.84%), Bordetella(2.07%), Serratia(1.04%), and Bacillus(1.01%). Function prediction showed that the abundance of metabolic genes changed significantly. This study proposes the potential application of mixed bacteria for Cd(Ⅱ)-containing wastewater treatment.展开更多
Algal blooms significantly affect microbial communities in wetland ecosystems.However,little is known about the succession of sediment microbial communities during algal blooms.This study aimed to investigate the temp...Algal blooms significantly affect microbial communities in wetland ecosystems.However,little is known about the succession of sediment microbial communities during algal blooms.This study aimed to investigate the temporal patterns of sediment bacterial community structure and function succession during algal blooms(March to May 2022)with high-throughput sequencing technology.To this end,algal blooms were divided into the bloom stage(BS),decomposition stage(DS)and end stage(ES).The results showed that:(i)The algal blooms were dominated by Microcystis species within Cyanobacteria.Both phytoplankton abundance and biomass reached the peak in the BS,with 45.78×105 cells/L and 5.97 mg/L,respectively.(ii)The alpha diversity indices of the sediment bacterial community showed a monotonically increasing trend,with the lowest value in the BS.Cyanobacterial blooms reduced the relative abundance of Actinobacteria and Chloroflexi,and raised that of Firmicutes,Proteobacteria and Bacteroidetes.(iii)Cyanobacterial blooms remarkably decreased the complexity of the co-occurrence network of the sediment bacterial community,which resisted extreme environmental conditions in the BS and DS by increasing positive relationships.(iv)Mantel test showed that phytoplankton biomass,T,dissolved oxygen and organic carbon had significant effects on the sediment bacterial community.The results of this study are important for the ecological management of algal blooms through microorganisms.展开更多
基金supported by the National Natural Science Foundation of China (No. 52170164)the Open Project of Key Laboratory of Environmental Biotechnology,CAS (No. kf2018001)the Scientific Research Foundation for Returned Scholars at the University of South China (No. 2018XQD25)
文摘Mixed bacteria were enriched from heavy metals mine soil for cadmium(Cd(Ⅱ))-containing wastewater treatment. Batch adsorption experiment results showed that the optimal pH, temperature, initial Cd(Ⅱ) concentration, and biomass dosage were 6.0, 30 ℃, 20 mg/L, and 1 g/L, respectively. Living biomass exhibited better Cd(Ⅱ) removal efficiency(91.97%) than autoclaved biomass(79.54%) under optimal conditions. The isotherms and kinetics of living biomass conformed to the Langmuir isotherm model and pseudo-first-order kinetic model, respectively. FTIR results implied that amine groups, hydroxyl groups and phosphoric acid play an important role in the Cd(Ⅱ) adsorption process, while XRD results showed that crystalline Cd(OH)and CdO were obtained. After Cd(Ⅱ)-containing wastewater treatment exposure, the dominant bacteria genera included Comamonas(39.94%), unclassified_f__Enterobacteriaceae(34.96%), Ochrobactrum(14.07%), Alcaligenes(4.84%), Bordetella(2.07%), Serratia(1.04%), and Bacillus(1.01%). Function prediction showed that the abundance of metabolic genes changed significantly. This study proposes the potential application of mixed bacteria for Cd(Ⅱ)-containing wastewater treatment.
基金supported by the National Natural Science Foundation of China(52070108)Project of Philosophy and Social Sciences of Qinghai Province(23ZCY042).
文摘Algal blooms significantly affect microbial communities in wetland ecosystems.However,little is known about the succession of sediment microbial communities during algal blooms.This study aimed to investigate the temporal patterns of sediment bacterial community structure and function succession during algal blooms(March to May 2022)with high-throughput sequencing technology.To this end,algal blooms were divided into the bloom stage(BS),decomposition stage(DS)and end stage(ES).The results showed that:(i)The algal blooms were dominated by Microcystis species within Cyanobacteria.Both phytoplankton abundance and biomass reached the peak in the BS,with 45.78×105 cells/L and 5.97 mg/L,respectively.(ii)The alpha diversity indices of the sediment bacterial community showed a monotonically increasing trend,with the lowest value in the BS.Cyanobacterial blooms reduced the relative abundance of Actinobacteria and Chloroflexi,and raised that of Firmicutes,Proteobacteria and Bacteroidetes.(iii)Cyanobacterial blooms remarkably decreased the complexity of the co-occurrence network of the sediment bacterial community,which resisted extreme environmental conditions in the BS and DS by increasing positive relationships.(iv)Mantel test showed that phytoplankton biomass,T,dissolved oxygen and organic carbon had significant effects on the sediment bacterial community.The results of this study are important for the ecological management of algal blooms through microorganisms.
