This study presents a thorough investigation into the use of single and twin-tailed cationic and anionic surfactant-modified chitosan(SMCS)hydrogel beads as effective adsorbents for the elimination of hazardous polycy...This study presents a thorough investigation into the use of single and twin-tailed cationic and anionic surfactant-modified chitosan(SMCS)hydrogel beads as effective adsorbents for the elimination of hazardous polycyclic aromatic hydrocarbons(PAHs)from aqueous solutions.The Chitosan(CS)hydrogel beads were modified with single/twin-tailed anionic surfactants,sodium dodecyl sulfate(SDS)and sodium bis(2-ethylhexyl)sulfosuccinate(AOT),and cationic surfactants,dodecyltrimethylammonium bromide(DTAB)and didodecyldimethylammonium bromide(DDAB),to enhance their adsorption capacity of PAHs.The CS and SMCS beads were evaluated for their structural,mechanical,and adsorption properties using a range of techniques,including infrared spectroscopy(IR),energy-dispersive X-ray spectroscopy(EDX),rheometry,and field emission scanning electron microscopy(FESEM).Adsorption experiments of naphthalene(Nap),acenaphthene(Ace),and phenanthrene(Phe)on SMCS beads demonstrate that they have significantly higher adsorption capacities than CS beads,due to increase in hydrophobic interactions.Adsorption capacity followed the trend,Phen>Ace>Nap for all the beads revealing that twin-tailed SMCS bead possess much higher adsorption capacities(Qmax)compared to single-tailed SMCS beads.For twin tailed surfactants,the maximum adsorption capacities for Nap,Ace and Phe varied as CS-AOT(CS-DDAB):430.0(323.8)611.60(538.18)633.39(536.99)mg/g respectively,outperforming other reported hydrogel beads.The study highlights the simplicity,eco-friendliness,and enhanced performance of surfactant modification for developing high-efficiency adsorbents,paving the way for cost-effective solutions in water re-mediation.展开更多
Polycyclic Aromatic Hydrocarbons(PAHs),along with their derivatives nitro-PAHs and oxy-PAHs,are globally recognized toxic pollutants.This research conducted daily PM_(2.5)sampling in winter 2021 at three urban(YNCE,SW...Polycyclic Aromatic Hydrocarbons(PAHs),along with their derivatives nitro-PAHs and oxy-PAHs,are globally recognized toxic pollutants.This research conducted daily PM_(2.5)sampling in winter 2021 at three urban(YNCE,SWP,and NG)and three suburban sites(HC,CTV,and YNE)in the Ili River Valley(IRV).For the first time in the IRV,a comprehensive study on 39 PAHs and derivatives was carried out.The results showed that the average∑_(16)PAHs concentration was 130.21±98.94 ng/m^(3),with 16PAHs constituting the dominant fraction(112.51±86.48 ng/m^(3)).The mean BaP and the total BaP equivalent quotient(TEQ)concentrations were 10.28±8.85 ng/m^(3)and 19.74±16.70 ng/m^(3),respectively.Approximately 88%of the daily BaP averages and 98%of the daily TEQ averages exceeded the national daily average standard of BaP(2.5 ng/m^(3)),indicating severe local BaP pollution.Urban sites had notably higher∑PAHs and TEQ concentrations than suburban sites,attributed to increased vehicular traffic and coal combustion in urban areas.PMF results showed that traffic emissions(32.7%-60.5%),coal combustion(13.9%-24.3%)and secondary formation(14.7%-22.7%)were the primary contributors to∑PAHs.Urban sites experienced a greater influence from traffic,while suburban sites were more impacted by coal and biomass burning.On polluted days,traffic sources’contributions increased significantly at HC,YNE,NG and YNCE sites,and secondary formation sources’contributions grew at CTV and YNCE sites.The sourcedependent BaPeq results underscored the role of secondary-formed PAH derivatives in TEQ.展开更多
The Yellow River Delta(YRD)is rich in oil,natural gas,and land resources.With the expansion of an important oil production base in North China,the increased discharge of Polycyclic aromatic hydrocarbons(PAHs)and alkyl...The Yellow River Delta(YRD)is rich in oil,natural gas,and land resources.With the expansion of an important oil production base in North China,the increased discharge of Polycyclic aromatic hydrocarbons(PAHs)and alkylated/nitrated/oxygenated PAHs(APAHs/NPAHs/OPAHs)into the Yellow River poses a potential risk to the aquatic ecosystem and human health.A total of 42 samples were gathered from trunk streams and tributaries within the YRD region during the wet and dry seasons,and 19 PAHs,5 APAHs,16 NPAHs,and 7 OPAHswere measured.The concentrations of ƩPAHs,ƩAPAHs,ƩNPAHs and ƩOPAHs ranged between 29 and 620 ng/L,6.9–81 ng/L,0.64–9.0 ng/L,and 7.2–81 ng/L in water,respectively,and 27–420 ng/g,5.1–130 ng/g,0.19–1.8 ng/g and 3.9–51 ng/g in sediment,respectively.The oil extraction activities resulted in an increased presence of middle-high molecular weight PAHs and APAHs in sediment,and port activities had a notable influence on the proportion of 1-methylpyrene in both water and sediment.The fugacity fraction analysis suggested that sediment was a secondary source of OPAHs,while benzo[k]fluoranthene,benzo[e]pyrene,benzo[a]pyrene,and 5-methylchrysene migrated from water to sediment.The main contributors to PAHs,APAHs,NPAHs,and OPAHs in water and sediment were combustion and petroleum sources.Compared to water,sediment displayed a heightened ecological risk associated with PAHs,APAHs,NPAHs,and OPAHs.Adults residing in the YRD region were at higher risk of cancer than children,which deserves special attention.展开更多
目的本研究旨在基于双中心数据,开发并验证一个通过logistic回归与机器学习方法构建的复合模型(PAH评分),以提升阑尾黏液性肿瘤的术前鉴别诊断效能。方法研究采用双中心回顾性病例对照设计,纳入联勤保障部队第九〇〇医院(2014年1月至202...目的本研究旨在基于双中心数据,开发并验证一个通过logistic回归与机器学习方法构建的复合模型(PAH评分),以提升阑尾黏液性肿瘤的术前鉴别诊断效能。方法研究采用双中心回顾性病例对照设计,纳入联勤保障部队第九〇〇医院(2014年1月至2024年11月)及福建医科大学附属三明市第一医院(2018年12月至2023年12月)的阑尾黏液性肿瘤(appendiceal mucinous neoplasm,AMNs)患者108例、健康对照230人,用于特征筛选及模型构建;纳入同期经病理确诊的慢性阑尾炎(chronic appendicitis,CA)患者258例,作为鉴别验证组。采用LASSO(最小绝对收缩与选择算子)+传统logistic回归分析方法筛选预测因素,并采用随机森林、支持向量机、梯度提升、决策树4种算法进行因素的重要性排序,再整合两类方法共同识别的核心变量构建logistic回归模型,进一步构建PAH评分,最后验证PAH评分区分AMNs和CA的效能并开发AMNs风险可视化在线预测平台。结果AMNs组与对照组比较、AMNs组和CA组比较基线特征均均衡可比(P>0.05)。多因素logistic回归分析结果显示,预后营养指数(prognostic nutritional index,PNI;OR=0.81)、白蛋白/球蛋白比值(albumin-to-globulin ratio,AGR;OR=0.37)、血红蛋白/红细胞分布宽度比值(hemoglobin to red blood cell distribution width ratio,HRR;OR=0.36)为AMNs的预测因子(P<0.001),且4种机器学习算法均将PNI、AGR、HRR识别为重要性排名前3的特征变量。基于上述结果,构建PAH模型并基于标准化回归系数加权法计算:PAH评分=20.8–0.21×PNI–0.99×AGR–1.01×HRR。模型的受试者工作特征曲线下面积(area under curve,AUC)为0.918,具有优秀的AMNs识别能力;Hosmer-Lemeshow检验显示预测概率与实际观察概率高度一致(P=0.925);决策曲线分析显示在广泛风险阈值(0.05~0.95)区间具有较好的临床净获益;Bootstrap内部验证提示模型具有优异的鲁棒性(AUC=0.911)。PAH评分在AMNs组和CA组间的差异有统计学意义(MD=1.78分,P<0.001)。PAH评分区分AMNs和CA的AUC为0.758,截断值(–1.00分)时对应的灵敏度为70%、特异度为76%、准确率为74%;Hosmer-Lemeshow检验结果证实预测概率与实际观察概率高度一致(P=0.106),Bootstrap验证提示PAH评分具有良好的稳定性(AUC=0.783),决策曲线分析显示在阈值0.20~0.95区间具有较高的净获益。结论本研究构建的PAH评分能够有效预测AMNs的发生风险,并较为准确地鉴别CA,具有良好的临床应用潜力。但本研究为探索性研究,未来需进一步通过多中心、大样本、多对照前瞻性研究验证并提高评分系统的普适性与稳定性。展开更多
This study investigated environmental distribution and human exposure of polycyclic aromatic hydrocarbons(PAHs)and their derivatives in one Chinese petroleum refinery facility.It was found that,following with high con...This study investigated environmental distribution and human exposure of polycyclic aromatic hydrocarbons(PAHs)and their derivatives in one Chinese petroleum refinery facility.It was found that,following with high concentrations of 16 EPA PAHs(∑Parent-PAHs)in smelting subarea of studied petroleum refinery facility,total derivatives of PAHs[named as XPAHs,including nitro PAHs(NPAHs),chlorinated PAHs(Cl-PAHs),and brominated PAHs(Br-PAHs)]in gas(mean=1.57×10^(4)ng/m^(3)),total suspended particulate(TSP)(mean=4.33×10^(3) ng/m^(3))and soil(mean=4.37×10^(3) ng/g)in this subarea had 1.76-6.19 times higher levels than those from other subareas of this facility,surrounding residential areas and reference areas,indicating that petroleum refining processes would lead apparent derivation of PAHs.Especially,compared with those in residential and reference areas,gas samples in the petrochemical areas had higher∑NPAH/∑PAHs(mean=2.18),but lower∑Cl-PAH/∑PAHs(mean=1.43×10^(-1))and∑Br-PAH/∑PAHs ratios(mean=7.49×10^(-2)),indicating the richer nitrification of PAHs than chlorination during petrochemical process.The occupational exposure to PAHs and XPAHs in this petroleum refinery facility were 24-343 times higher than non-occupational exposure,and the ILCR(1.04×10^(-4))for petrochemical workers was considered to be potential high risk.Furthermore,one expanded high-resolution screening through GC Orbitrap/MS was performed for soils from petrochemical area,and another 35 PAHs were found,including alkyl-PAHs,phenyl-PAHs and other species,indicat-ing that profiles and risks of PAHs analogs in petrochemical areas deserve further expanded investigation.展开更多
Microalgae can effectively degrade polycyclic aromatic hydrocarbons (PAHs) in water.However,the remediation mechanism of microalgae in PAH-contaminated soil remains unclear.In this study,the growth-promoting effects o...Microalgae can effectively degrade polycyclic aromatic hydrocarbons (PAHs) in water.However,the remediation mechanism of microalgae in PAH-contaminated soil remains unclear.In this study,the growth-promoting effects of wheat by Chlorella vulgaris in PAH-contaminated soil were studied.Structural changes in the rhizosphere bacterial community and the bacterial metabolism were further explored.It revealed that the addition of C.vulgaris promoted wheat’s dry weight and height by 10.22% and 122.15%,respectively.One explanation was the degradation and transformation of PAHs by C.vulgaris,which relieved the inhibitory effect on wheat growth.Compared with the blank control group,C.vulgaris addition enhanced the degradation efficiencies of phenanthrene (Phe) and pyrene (Pry) by 4.81% and 8.34%,respectively (with the initial concentrations in soil of 1.03×10^(4) and 2.21×10^(4)μg/g,respectively).The binding state of Phe and Pyr changed to a free state,which facilitated microbial degradation.The Phe and Pyr contents in wheat decreased by 22.23% and 18.54%,respectively.The presence of C.vulgaris increased the abundance of Sphingosinomonas bacteria capable of degrading PAHs by 95.24%.Enzyme activities related to the transport,oxidation,and dehydrogenation of PAHs in the bacterial community also increased.This study demonstrated C.vulgaris’multiple pathways for remediating PAH-polluted soil,including PAH degradation,nutrient and hormone release,and bacterial community adjustment.In conclusion,C.vulgaris addition enhanced the algae-bacteria symbiosis,which was of great significance for the removal of PAHs from the soil and the promotion of plant growth.展开更多
The problem of soil polycyclic aromatic hydrocarbon(PAH)pollution in coking plant sites has been widely studied in recent years,but there is a lack of research on the correlation between soil microorganisms,soil metab...The problem of soil polycyclic aromatic hydrocarbon(PAH)pollution in coking plant sites has been widely studied in recent years,but there is a lack of research on the correlation between soil microorganisms,soil metabolomics,and soil properties.Thus,in this study,the long-term impact of coke combustion on soil microbial community structure,enzyme activities,and metabolic pathways within a former coking plant site was investigated.Soil samples were collected from both the coking production area(CA group)and office area(OLA group),approximately 0 to 20 cm in depth.Compared with OLA group,elevated levels of 16 PAHs in the list of US EPA were detected by gas chromatography-mass spectrometry in the CA group.Several dominant microorganisms,such as Altererythrobacter,Lysobacter,and Sulfurifustis,were identified by 16 s ribosomal DNA sequencing in the CA group.The fatty acid biosynthesis pathway exhibited specific inhibition,while the phenylalanine metabolic pathwaywas promoted in response to PAH stress.Long-term PAH exposure led to the inhibition of soil urease activity.The co-occurrence network ofmicroorganisms revealed intricate patterns of co-metabolism and co-adaptation within complex bacterial communities,facilitating their adaptation to and decomposition of soil-borne PAHs.This research could provide valuable insights into the community characteristics andmetabolic mechanisms of microorganisms inhabiting PAH-polluted soil within coking plant sites.The findings enhance our understanding of the indigenous soil microbiome and its intricate network dynamics under the persistent stress of PAHs,contributing to a more comprehensive knowledge of soil ecosystems in such environments.展开更多
基金the Department of Science and Technology(DST),Govt.of India for providing funds under the FIST program and PURSE grant vide No.SR/PURSE/2020/31 to the department of Chemistry,University of Kashmir.
文摘This study presents a thorough investigation into the use of single and twin-tailed cationic and anionic surfactant-modified chitosan(SMCS)hydrogel beads as effective adsorbents for the elimination of hazardous polycyclic aromatic hydrocarbons(PAHs)from aqueous solutions.The Chitosan(CS)hydrogel beads were modified with single/twin-tailed anionic surfactants,sodium dodecyl sulfate(SDS)and sodium bis(2-ethylhexyl)sulfosuccinate(AOT),and cationic surfactants,dodecyltrimethylammonium bromide(DTAB)and didodecyldimethylammonium bromide(DDAB),to enhance their adsorption capacity of PAHs.The CS and SMCS beads were evaluated for their structural,mechanical,and adsorption properties using a range of techniques,including infrared spectroscopy(IR),energy-dispersive X-ray spectroscopy(EDX),rheometry,and field emission scanning electron microscopy(FESEM).Adsorption experiments of naphthalene(Nap),acenaphthene(Ace),and phenanthrene(Phe)on SMCS beads demonstrate that they have significantly higher adsorption capacities than CS beads,due to increase in hydrophobic interactions.Adsorption capacity followed the trend,Phen>Ace>Nap for all the beads revealing that twin-tailed SMCS bead possess much higher adsorption capacities(Qmax)compared to single-tailed SMCS beads.For twin tailed surfactants,the maximum adsorption capacities for Nap,Ace and Phe varied as CS-AOT(CS-DDAB):430.0(323.8)611.60(538.18)633.39(536.99)mg/g respectively,outperforming other reported hydrogel beads.The study highlights the simplicity,eco-friendliness,and enhanced performance of surfactant modification for developing high-efficiency adsorbents,paving the way for cost-effective solutions in water re-mediation.
基金supported by the National Key R&D Program of China(No.2017YFC0212501)the Fundamental Research Funds for the Central Universities(No.2021YJSMT09)the research project on deep source apportionment of urban air pollution and pollution control strategies in the core area of the Ili River Valley。
文摘Polycyclic Aromatic Hydrocarbons(PAHs),along with their derivatives nitro-PAHs and oxy-PAHs,are globally recognized toxic pollutants.This research conducted daily PM_(2.5)sampling in winter 2021 at three urban(YNCE,SWP,and NG)and three suburban sites(HC,CTV,and YNE)in the Ili River Valley(IRV).For the first time in the IRV,a comprehensive study on 39 PAHs and derivatives was carried out.The results showed that the average∑_(16)PAHs concentration was 130.21±98.94 ng/m^(3),with 16PAHs constituting the dominant fraction(112.51±86.48 ng/m^(3)).The mean BaP and the total BaP equivalent quotient(TEQ)concentrations were 10.28±8.85 ng/m^(3)and 19.74±16.70 ng/m^(3),respectively.Approximately 88%of the daily BaP averages and 98%of the daily TEQ averages exceeded the national daily average standard of BaP(2.5 ng/m^(3)),indicating severe local BaP pollution.Urban sites had notably higher∑PAHs and TEQ concentrations than suburban sites,attributed to increased vehicular traffic and coal combustion in urban areas.PMF results showed that traffic emissions(32.7%-60.5%),coal combustion(13.9%-24.3%)and secondary formation(14.7%-22.7%)were the primary contributors to∑PAHs.Urban sites experienced a greater influence from traffic,while suburban sites were more impacted by coal and biomass burning.On polluted days,traffic sources’contributions increased significantly at HC,YNE,NG and YNCE sites,and secondary formation sources’contributions grew at CTV and YNCE sites.The sourcedependent BaPeq results underscored the role of secondary-formed PAH derivatives in TEQ.
基金supported by the Natural Science Foundation of Qingdao(No.23-2-1-224-zyyd-jch).
文摘The Yellow River Delta(YRD)is rich in oil,natural gas,and land resources.With the expansion of an important oil production base in North China,the increased discharge of Polycyclic aromatic hydrocarbons(PAHs)and alkylated/nitrated/oxygenated PAHs(APAHs/NPAHs/OPAHs)into the Yellow River poses a potential risk to the aquatic ecosystem and human health.A total of 42 samples were gathered from trunk streams and tributaries within the YRD region during the wet and dry seasons,and 19 PAHs,5 APAHs,16 NPAHs,and 7 OPAHswere measured.The concentrations of ƩPAHs,ƩAPAHs,ƩNPAHs and ƩOPAHs ranged between 29 and 620 ng/L,6.9–81 ng/L,0.64–9.0 ng/L,and 7.2–81 ng/L in water,respectively,and 27–420 ng/g,5.1–130 ng/g,0.19–1.8 ng/g and 3.9–51 ng/g in sediment,respectively.The oil extraction activities resulted in an increased presence of middle-high molecular weight PAHs and APAHs in sediment,and port activities had a notable influence on the proportion of 1-methylpyrene in both water and sediment.The fugacity fraction analysis suggested that sediment was a secondary source of OPAHs,while benzo[k]fluoranthene,benzo[e]pyrene,benzo[a]pyrene,and 5-methylchrysene migrated from water to sediment.The main contributors to PAHs,APAHs,NPAHs,and OPAHs in water and sediment were combustion and petroleum sources.Compared to water,sediment displayed a heightened ecological risk associated with PAHs,APAHs,NPAHs,and OPAHs.Adults residing in the YRD region were at higher risk of cancer than children,which deserves special attention.
文摘目的本研究旨在基于双中心数据,开发并验证一个通过logistic回归与机器学习方法构建的复合模型(PAH评分),以提升阑尾黏液性肿瘤的术前鉴别诊断效能。方法研究采用双中心回顾性病例对照设计,纳入联勤保障部队第九〇〇医院(2014年1月至2024年11月)及福建医科大学附属三明市第一医院(2018年12月至2023年12月)的阑尾黏液性肿瘤(appendiceal mucinous neoplasm,AMNs)患者108例、健康对照230人,用于特征筛选及模型构建;纳入同期经病理确诊的慢性阑尾炎(chronic appendicitis,CA)患者258例,作为鉴别验证组。采用LASSO(最小绝对收缩与选择算子)+传统logistic回归分析方法筛选预测因素,并采用随机森林、支持向量机、梯度提升、决策树4种算法进行因素的重要性排序,再整合两类方法共同识别的核心变量构建logistic回归模型,进一步构建PAH评分,最后验证PAH评分区分AMNs和CA的效能并开发AMNs风险可视化在线预测平台。结果AMNs组与对照组比较、AMNs组和CA组比较基线特征均均衡可比(P>0.05)。多因素logistic回归分析结果显示,预后营养指数(prognostic nutritional index,PNI;OR=0.81)、白蛋白/球蛋白比值(albumin-to-globulin ratio,AGR;OR=0.37)、血红蛋白/红细胞分布宽度比值(hemoglobin to red blood cell distribution width ratio,HRR;OR=0.36)为AMNs的预测因子(P<0.001),且4种机器学习算法均将PNI、AGR、HRR识别为重要性排名前3的特征变量。基于上述结果,构建PAH模型并基于标准化回归系数加权法计算:PAH评分=20.8–0.21×PNI–0.99×AGR–1.01×HRR。模型的受试者工作特征曲线下面积(area under curve,AUC)为0.918,具有优秀的AMNs识别能力;Hosmer-Lemeshow检验显示预测概率与实际观察概率高度一致(P=0.925);决策曲线分析显示在广泛风险阈值(0.05~0.95)区间具有较好的临床净获益;Bootstrap内部验证提示模型具有优异的鲁棒性(AUC=0.911)。PAH评分在AMNs组和CA组间的差异有统计学意义(MD=1.78分,P<0.001)。PAH评分区分AMNs和CA的AUC为0.758,截断值(–1.00分)时对应的灵敏度为70%、特异度为76%、准确率为74%;Hosmer-Lemeshow检验结果证实预测概率与实际观察概率高度一致(P=0.106),Bootstrap验证提示PAH评分具有良好的稳定性(AUC=0.783),决策曲线分析显示在阈值0.20~0.95区间具有较高的净获益。结论本研究构建的PAH评分能够有效预测AMNs的发生风险,并较为准确地鉴别CA,具有良好的临床应用潜力。但本研究为探索性研究,未来需进一步通过多中心、大样本、多对照前瞻性研究验证并提高评分系统的普适性与稳定性。
基金supported by the National Key Research and Development Program of China(No.2019YFC1804501)the National Natural Science Foundation of China(Nos.22036007 and 22122611)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2020ME228)the Introduction and Cultivation Plan for Young Innovative Talents of Colleges and Universities.
文摘This study investigated environmental distribution and human exposure of polycyclic aromatic hydrocarbons(PAHs)and their derivatives in one Chinese petroleum refinery facility.It was found that,following with high concentrations of 16 EPA PAHs(∑Parent-PAHs)in smelting subarea of studied petroleum refinery facility,total derivatives of PAHs[named as XPAHs,including nitro PAHs(NPAHs),chlorinated PAHs(Cl-PAHs),and brominated PAHs(Br-PAHs)]in gas(mean=1.57×10^(4)ng/m^(3)),total suspended particulate(TSP)(mean=4.33×10^(3) ng/m^(3))and soil(mean=4.37×10^(3) ng/g)in this subarea had 1.76-6.19 times higher levels than those from other subareas of this facility,surrounding residential areas and reference areas,indicating that petroleum refining processes would lead apparent derivation of PAHs.Especially,compared with those in residential and reference areas,gas samples in the petrochemical areas had higher∑NPAH/∑PAHs(mean=2.18),but lower∑Cl-PAH/∑PAHs(mean=1.43×10^(-1))and∑Br-PAH/∑PAHs ratios(mean=7.49×10^(-2)),indicating the richer nitrification of PAHs than chlorination during petrochemical process.The occupational exposure to PAHs and XPAHs in this petroleum refinery facility were 24-343 times higher than non-occupational exposure,and the ILCR(1.04×10^(-4))for petrochemical workers was considered to be potential high risk.Furthermore,one expanded high-resolution screening through GC Orbitrap/MS was performed for soils from petrochemical area,and another 35 PAHs were found,including alkyl-PAHs,phenyl-PAHs and other species,indicat-ing that profiles and risks of PAHs analogs in petrochemical areas deserve further expanded investigation.
基金supported by the National Natural Science Foundation of China (Nos.U24A20613 and 52370043)China National Funds for Distinguished Young Scientists (No.51925803)。
文摘Microalgae can effectively degrade polycyclic aromatic hydrocarbons (PAHs) in water.However,the remediation mechanism of microalgae in PAH-contaminated soil remains unclear.In this study,the growth-promoting effects of wheat by Chlorella vulgaris in PAH-contaminated soil were studied.Structural changes in the rhizosphere bacterial community and the bacterial metabolism were further explored.It revealed that the addition of C.vulgaris promoted wheat’s dry weight and height by 10.22% and 122.15%,respectively.One explanation was the degradation and transformation of PAHs by C.vulgaris,which relieved the inhibitory effect on wheat growth.Compared with the blank control group,C.vulgaris addition enhanced the degradation efficiencies of phenanthrene (Phe) and pyrene (Pry) by 4.81% and 8.34%,respectively (with the initial concentrations in soil of 1.03×10^(4) and 2.21×10^(4)μg/g,respectively).The binding state of Phe and Pyr changed to a free state,which facilitated microbial degradation.The Phe and Pyr contents in wheat decreased by 22.23% and 18.54%,respectively.The presence of C.vulgaris increased the abundance of Sphingosinomonas bacteria capable of degrading PAHs by 95.24%.Enzyme activities related to the transport,oxidation,and dehydrogenation of PAHs in the bacterial community also increased.This study demonstrated C.vulgaris’multiple pathways for remediating PAH-polluted soil,including PAH degradation,nutrient and hormone release,and bacterial community adjustment.In conclusion,C.vulgaris addition enhanced the algae-bacteria symbiosis,which was of great significance for the removal of PAHs from the soil and the promotion of plant growth.
基金supported by the National Key Research and Development Program of China(Nos.2018YFA0901100 and 2018YFC1801103)the National Natural Science Foundation of China(Nos.22206202 and 22076216)。
文摘The problem of soil polycyclic aromatic hydrocarbon(PAH)pollution in coking plant sites has been widely studied in recent years,but there is a lack of research on the correlation between soil microorganisms,soil metabolomics,and soil properties.Thus,in this study,the long-term impact of coke combustion on soil microbial community structure,enzyme activities,and metabolic pathways within a former coking plant site was investigated.Soil samples were collected from both the coking production area(CA group)and office area(OLA group),approximately 0 to 20 cm in depth.Compared with OLA group,elevated levels of 16 PAHs in the list of US EPA were detected by gas chromatography-mass spectrometry in the CA group.Several dominant microorganisms,such as Altererythrobacter,Lysobacter,and Sulfurifustis,were identified by 16 s ribosomal DNA sequencing in the CA group.The fatty acid biosynthesis pathway exhibited specific inhibition,while the phenylalanine metabolic pathwaywas promoted in response to PAH stress.Long-term PAH exposure led to the inhibition of soil urease activity.The co-occurrence network ofmicroorganisms revealed intricate patterns of co-metabolism and co-adaptation within complex bacterial communities,facilitating their adaptation to and decomposition of soil-borne PAHs.This research could provide valuable insights into the community characteristics andmetabolic mechanisms of microorganisms inhabiting PAH-polluted soil within coking plant sites.The findings enhance our understanding of the indigenous soil microbiome and its intricate network dynamics under the persistent stress of PAHs,contributing to a more comprehensive knowledge of soil ecosystems in such environments.
