Crude oil-degrading microbial consortia were enriched from three oil-contaminated sites to achieve the efficient biodegradation of crude oil,especially its refractory residues.The gravimetric method was used to analyz...Crude oil-degrading microbial consortia were enriched from three oil-contaminated sites to achieve the efficient biodegradation of crude oil,especially its refractory residues.The gravimetric method was used to analyze the degradation efficiency of the enriched consortia and changes in the fractions of the crude oil.The effects of changes in environmental factors were also studied to determine the optimal oil-reducing conditions and assess the dominant bacteria of the mixed flora.Results show that all three consortia exhibit reliable crude oil-biodegradation abilities and that their mixture results in biodegradation rate are as high as(48.0±3.5)%over 30 d of incubation.The consortium mixture can degrade 11.1%of the refractory resins,79.7%of the saturated hydrocarbons,and 45.7%of the aromatics in crude oil.Neutral pH,an incubation temperature of 30℃,and low mineral salt concentrations(0.8%to 4.0%)are optimal for crude oil biodegradation.The dominant genera in the consortium mixture include Pseudomonas,Stenotrophomonas,Brucella,Serratia,Brevundimonas,and Achromobacter.The richness and diversity of the microbial community in the consortium remain stable during crude oil degradation.Therefore,microbial enrichment from multiple sources may be performed to construct a mixed consortium for crude oil pollution bioremediation.展开更多
The photochemical degradation of bisphenol A(BPA)was studied in the presence of natural humic sub stances from different origins under simulated solar irradiation.BPA underwent insignificant direct photolysis in neutr...The photochemical degradation of bisphenol A(BPA)was studied in the presence of natural humic sub stances from different origins under simulated solar irradiation.BPA underwent insignificant direct photolysis in neutral water,but rapid photosensitized degradation in four humic substances solutions via pseudo-first-order reaction occurred.The photo-degradation rate of BPA was insensitive to the different initial BPA concentrations and was inhibited in aerated solution compared with the deoxygenated medium.The reactive oxy-gen species(ROS)such as·OH and 1O2 produced from excita-tion of humic substances under irradiation was determined from the quenching kinetic experiment using molecular probe.The five main intermediate photoproducts of BPA in Nordic lake fulvic acid(NOFA)were tentatively identified using gas chromatography/mass spectrometer(GC/MS).Based on the identification of ROS and the analysis of photoproduct formation,the possible phototransformation pathways of BPA were proposed,involving the direct pho-tolysis due to the energy transfer from the triplet state humic substance(3HS*)to BPA molecules and hydroxyl radical addition and oxidation as well.展开更多
基金The National Natural Science Foundation of China(No.51878145)the National Key R&D Program of China(No.2018YFC1803100)+1 种基金the Key Research and Development Program of Department of Science and Technology of Jiangsu Province(No.BE2019709)the Six Talent Peaks Project of Jiangsu Province(No.JNHB-010).
文摘Crude oil-degrading microbial consortia were enriched from three oil-contaminated sites to achieve the efficient biodegradation of crude oil,especially its refractory residues.The gravimetric method was used to analyze the degradation efficiency of the enriched consortia and changes in the fractions of the crude oil.The effects of changes in environmental factors were also studied to determine the optimal oil-reducing conditions and assess the dominant bacteria of the mixed flora.Results show that all three consortia exhibit reliable crude oil-biodegradation abilities and that their mixture results in biodegradation rate are as high as(48.0±3.5)%over 30 d of incubation.The consortium mixture can degrade 11.1%of the refractory resins,79.7%of the saturated hydrocarbons,and 45.7%of the aromatics in crude oil.Neutral pH,an incubation temperature of 30℃,and low mineral salt concentrations(0.8%to 4.0%)are optimal for crude oil biodegradation.The dominant genera in the consortium mixture include Pseudomonas,Stenotrophomonas,Brucella,Serratia,Brevundimonas,and Achromobacter.The richness and diversity of the microbial community in the consortium remain stable during crude oil degradation.Therefore,microbial enrichment from multiple sources may be performed to construct a mixed consortium for crude oil pollution bioremediation.
基金This work was supported by the National Natural Science Foundation of China(Grant No.20207004)the Key Technologies Research and Development Program of China(Grant No.2003BA808A17)the Natural Science Foundation of Jiangsu(Grant No.BK2002413).
文摘The photochemical degradation of bisphenol A(BPA)was studied in the presence of natural humic sub stances from different origins under simulated solar irradiation.BPA underwent insignificant direct photolysis in neutral water,but rapid photosensitized degradation in four humic substances solutions via pseudo-first-order reaction occurred.The photo-degradation rate of BPA was insensitive to the different initial BPA concentrations and was inhibited in aerated solution compared with the deoxygenated medium.The reactive oxy-gen species(ROS)such as·OH and 1O2 produced from excita-tion of humic substances under irradiation was determined from the quenching kinetic experiment using molecular probe.The five main intermediate photoproducts of BPA in Nordic lake fulvic acid(NOFA)were tentatively identified using gas chromatography/mass spectrometer(GC/MS).Based on the identification of ROS and the analysis of photoproduct formation,the possible phototransformation pathways of BPA were proposed,involving the direct pho-tolysis due to the energy transfer from the triplet state humic substance(3HS*)to BPA molecules and hydroxyl radical addition and oxidation as well.
