Neonicotinoids(NEOs),a fourth-generation pesticide group,are extensively utilized for crop protection in agriculture.However,their excessive use can negatively impact the environment and human health.Biodegradation of...Neonicotinoids(NEOs),a fourth-generation pesticide group,are extensively utilized for crop protection in agriculture.However,their excessive use can negatively impact the environment and human health.Biodegradation offers an eco-friendly method for eliminating these insecticides.This study employed bacterial strains Stutzerimonas sp.SA1 and Pseudomonas sp.SA3,isolated from pesticide-contaminated agricultural soil,to degrade the various NEOs including acetamiprid(AC),imidacloprid(IM),thiamethoxam(TH),and clothianidin(CL).Numerous intermediate compounds were detected during biodegradation,and potential pathways were discussed.The highest reduction of chemical oxygen demand of clothianidin(87%)and acetamiprid(72%)were observed in Stutzerimonas sp.SA1 and Pseudomonas sp.SA3 were AC 72%and CL 66%respectively.A bacterial consortium effectively breakdown the NEOs through the secretion of nitrile hydratase(NH)enzyme.Fourier-transform infrared spectroscopy results confirmed the presence of functional groups alkane and carbonyl in the NEOs residue.The Gas Chromatography Mass Spectrometry data revealed that the Stutzerimonas sp.SA1 has the highest potential of biodegradation efficiency(BE)AC(89%)and IM(87%)than the other NEOs respectively.The Pseudomonas sp.SA3 shoved the higher BE in the AC(90%),IM(97%)and TH(85%)than the bacterium Stutzerimonas sp.SA1.The results suggest that these bacteria produce the degradative enzymes effectively and utilize the NEOs as a carbon source.The results suggest that these bacteria produce the NH degradative enzymes and utilize the NEOs as a carbon source.In conclusion,the strains Stutzerimonas sp.SA1 and Pseudomonas sp.SA3 were identified as potential candidate for the biomineralization and removal of NEOs contaminated environment.展开更多
Hyperactivation of DNA repairing pathway is highly associated with the chemosensitivity and chemoresistance of cancer cells.In this manuscript,guided by cascaded one strain many compounds-global natural products socia...Hyperactivation of DNA repairing pathway is highly associated with the chemosensitivity and chemoresistance of cancer cells.In this manuscript,guided by cascaded one strain many compounds-global natural products social molecular networking(OSMAC-GNPS)strategy,a pair of epimeric environmental-induced metabolites were isolated from Aspergillus sp.EGF 15-0-3.Structurally,sterpiperazines A(1)and B(2)represent the first steroid-based indole alkaloids with unprecedented backbones.Biologically,compound 1 could be identified as a novel tyrosyl-DNA phosphodiesterase 1(Tdp1)inhibitor with a unique mechanism distinct from the reported modulators,and was able to significantly enhance the sensitivity of NCI-H460 cells to the clinic chemotherapeutic drug through inhibiting the DNA repairment and enhanced the DNA damage of cancer cells.展开更多
提出一种新的方法,用于富集苯并[a]芘耐受菌株。该方法使用多孔介质脱脂棉作为载体,从连续流动的流体——下水道污水中富集菌株。利用介质截留法、富集培养法等理论,为富集目标微生物提供了最佳条件。以苯并[a]芘为唯一碳源和能源,从下...提出一种新的方法,用于富集苯并[a]芘耐受菌株。该方法使用多孔介质脱脂棉作为载体,从连续流动的流体——下水道污水中富集菌株。利用介质截留法、富集培养法等理论,为富集目标微生物提供了最佳条件。以苯并[a]芘为唯一碳源和能源,从下水道沉积物中分离、筛选出4株苯并[a]芘耐受菌株,其中一株能在20天内将40 mg/L的苯并[a]芘降解28.7%。通过16S r RNA基因序列分析和部分生理生化特征分析,鉴定该菌株为Acinetobacter sp.Bap30。这是不动杆菌可降解苯并[a]芘的首次报道。添加其他碳源和低分子量多环芳烃——菲作为共代谢底物,研究菌株的共代谢作用。研究结果对石油污染的土壤或者焦化废水等工业污水中的高分子量多环芳烃——苯并[a]芘具有非常重要的实践意义。展开更多
A new phenol-degrading bacterium with high biodegradation activity and high tolerance of phenol, strain PD 12, was isolated from the activated sludge of Tianjin Jizhuangzi Wastewater Treatment Facility in China. This ...A new phenol-degrading bacterium with high biodegradation activity and high tolerance of phenol, strain PD 12, was isolated from the activated sludge of Tianjin Jizhuangzi Wastewater Treatment Facility in China. This strain was capable of removing 500 mg phenol/L in liquid minimal medium by 99.6% within 9 h and metabolizing phenol at concentrations up to 1100 mg/L. DNA sequencing and homologous analysis of 16S rRNA gene identified PD12 to be an Acinetobacter sp. Polyvinyl alcohol （PVA） was used as a gel matrix to immobilize Acinetobacter sp. strain PDI2 by repeated freezing and thawing. The factors affecting phenol degradation of immobilized cells were investigated, and the results showed that the immobilized cells could tolerate a high phenol level and protected the bacteria against changes in temperature and pH. Storage stability and reusability tests revealed that the phenol degradation functions of immobilized cells were stable after reuse for 50 times or storing at 4℃ for 50 d. These results indicate that immobilized Acinetobacter sp. strain PD 12 possesses a good application potential in the treatment of phenol-containing wastewater.展开更多
Objective To purify a low-temperature hydroxylamine oxidase （HAO） from a heterotrophic nitrifying bacterium Acinetobacter sp. Y26 and investigate the enzyme property. Methods A HAO was purified by an anion-exchange ...Objective To purify a low-temperature hydroxylamine oxidase （HAO） from a heterotrophic nitrifying bacterium Acinetobacter sp. Y26 and investigate the enzyme property. Methods A HAO was purified by an anion-exchange and gel-filtration chromatography from strain Y16. The purity and molecular mass were determined by RP-HPLC and SDS-PAGE. The HAO activity was detected by monitoring the reduction of potassium ferricyanide using hydroxylamine as substrate and ferricyanide as electron acceptor. The partial amino acid sequence was determined by mass spectrometry. Results The low-temperature HAO with a molecular mass of 61 kDa was purified from strain Y26 by an anion-exchange and gel-filtration chromatography. The enzyme exhibited an ability to oxidize hydroxylamine in wide temperature range （4-40 ℃） in vitro using hydroxylamine as substrate and ferricyanide as electron acceptor. It was stable in the temperature range of 4 to 25 ℃ and pH range of 6.0 to 8.5 with less than 30% change in its activity. The optimal temperature and pH were 15 ℃ and 7.5, respectively. Three peptides were determined by mass spectrometry which were shown to be not identical to other reported HAOs. Conclusion This is the first study to purify a low-temperature HAO from a heterotrophic nitrifier Acinetobecter sp. It differs from other reported HAOs in molecular mass and enzyme properties. The findings of the present study have suggested that the strain Y26 passes through a hydroxylamine-oxidizing process catalyzed by a low-temperature HAO for ammonium removal.展开更多
基金supported by the Ongoing Research Funding program(No.ORF-2025-398),King Saud University,Riyadh,Saudi Arabia.
文摘Neonicotinoids(NEOs),a fourth-generation pesticide group,are extensively utilized for crop protection in agriculture.However,their excessive use can negatively impact the environment and human health.Biodegradation offers an eco-friendly method for eliminating these insecticides.This study employed bacterial strains Stutzerimonas sp.SA1 and Pseudomonas sp.SA3,isolated from pesticide-contaminated agricultural soil,to degrade the various NEOs including acetamiprid(AC),imidacloprid(IM),thiamethoxam(TH),and clothianidin(CL).Numerous intermediate compounds were detected during biodegradation,and potential pathways were discussed.The highest reduction of chemical oxygen demand of clothianidin(87%)and acetamiprid(72%)were observed in Stutzerimonas sp.SA1 and Pseudomonas sp.SA3 were AC 72%and CL 66%respectively.A bacterial consortium effectively breakdown the NEOs through the secretion of nitrile hydratase(NH)enzyme.Fourier-transform infrared spectroscopy results confirmed the presence of functional groups alkane and carbonyl in the NEOs residue.The Gas Chromatography Mass Spectrometry data revealed that the Stutzerimonas sp.SA1 has the highest potential of biodegradation efficiency(BE)AC(89%)and IM(87%)than the other NEOs respectively.The Pseudomonas sp.SA3 shoved the higher BE in the AC(90%),IM(97%)and TH(85%)than the bacterium Stutzerimonas sp.SA1.The results suggest that these bacteria produce the degradative enzymes effectively and utilize the NEOs as a carbon source.The results suggest that these bacteria produce the NH degradative enzymes and utilize the NEOs as a carbon source.In conclusion,the strains Stutzerimonas sp.SA1 and Pseudomonas sp.SA3 were identified as potential candidate for the biomineralization and removal of NEOs contaminated environment.
基金supported by the National Natural Science Foundation of China(Nos.82273845,82304331,and 82360695)Guangxi Natural Science Foundation project(No.2023GXNSFBA026305).
文摘Hyperactivation of DNA repairing pathway is highly associated with the chemosensitivity and chemoresistance of cancer cells.In this manuscript,guided by cascaded one strain many compounds-global natural products social molecular networking(OSMAC-GNPS)strategy,a pair of epimeric environmental-induced metabolites were isolated from Aspergillus sp.EGF 15-0-3.Structurally,sterpiperazines A(1)and B(2)represent the first steroid-based indole alkaloids with unprecedented backbones.Biologically,compound 1 could be identified as a novel tyrosyl-DNA phosphodiesterase 1(Tdp1)inhibitor with a unique mechanism distinct from the reported modulators,and was able to significantly enhance the sensitivity of NCI-H460 cells to the clinic chemotherapeutic drug through inhibiting the DNA repairment and enhanced the DNA damage of cancer cells.
文摘提出一种新的方法,用于富集苯并[a]芘耐受菌株。该方法使用多孔介质脱脂棉作为载体,从连续流动的流体——下水道污水中富集菌株。利用介质截留法、富集培养法等理论,为富集目标微生物提供了最佳条件。以苯并[a]芘为唯一碳源和能源,从下水道沉积物中分离、筛选出4株苯并[a]芘耐受菌株,其中一株能在20天内将40 mg/L的苯并[a]芘降解28.7%。通过16S r RNA基因序列分析和部分生理生化特征分析,鉴定该菌株为Acinetobacter sp.Bap30。这是不动杆菌可降解苯并[a]芘的首次报道。添加其他碳源和低分子量多环芳烃——菲作为共代谢底物,研究菌株的共代谢作用。研究结果对石油污染的土壤或者焦化废水等工业污水中的高分子量多环芳烃——苯并[a]芘具有非常重要的实践意义。
基金Project supported by the Undergraduate Research Foundation of Nankai University (2004).
文摘A new phenol-degrading bacterium with high biodegradation activity and high tolerance of phenol, strain PD 12, was isolated from the activated sludge of Tianjin Jizhuangzi Wastewater Treatment Facility in China. This strain was capable of removing 500 mg phenol/L in liquid minimal medium by 99.6% within 9 h and metabolizing phenol at concentrations up to 1100 mg/L. DNA sequencing and homologous analysis of 16S rRNA gene identified PD12 to be an Acinetobacter sp. Polyvinyl alcohol （PVA） was used as a gel matrix to immobilize Acinetobacter sp. strain PDI2 by repeated freezing and thawing. The factors affecting phenol degradation of immobilized cells were investigated, and the results showed that the immobilized cells could tolerate a high phenol level and protected the bacteria against changes in temperature and pH. Storage stability and reusability tests revealed that the phenol degradation functions of immobilized cells were stable after reuse for 50 times or storing at 4℃ for 50 d. These results indicate that immobilized Acinetobacter sp. strain PD 12 possesses a good application potential in the treatment of phenol-containing wastewater.
基金supported by grants from National Natural Science Foundation of China(51078106)Heilongjiang Provincial Science Foundation for Distinguished Youth Scholar(JC200708)Heilongjiang Provincial Finance Foundation for Basic Sciences(CZ12BZSM06)
文摘Objective To purify a low-temperature hydroxylamine oxidase （HAO） from a heterotrophic nitrifying bacterium Acinetobacter sp. Y26 and investigate the enzyme property. Methods A HAO was purified by an anion-exchange and gel-filtration chromatography from strain Y16. The purity and molecular mass were determined by RP-HPLC and SDS-PAGE. The HAO activity was detected by monitoring the reduction of potassium ferricyanide using hydroxylamine as substrate and ferricyanide as electron acceptor. The partial amino acid sequence was determined by mass spectrometry. Results The low-temperature HAO with a molecular mass of 61 kDa was purified from strain Y26 by an anion-exchange and gel-filtration chromatography. The enzyme exhibited an ability to oxidize hydroxylamine in wide temperature range （4-40 ℃） in vitro using hydroxylamine as substrate and ferricyanide as electron acceptor. It was stable in the temperature range of 4 to 25 ℃ and pH range of 6.0 to 8.5 with less than 30% change in its activity. The optimal temperature and pH were 15 ℃ and 7.5, respectively. Three peptides were determined by mass spectrometry which were shown to be not identical to other reported HAOs. Conclusion This is the first study to purify a low-temperature HAO from a heterotrophic nitrifier Acinetobecter sp. It differs from other reported HAOs in molecular mass and enzyme properties. The findings of the present study have suggested that the strain Y26 passes through a hydroxylamine-oxidizing process catalyzed by a low-temperature HAO for ammonium removal.
