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
A gram negative bacterium,named JDC-16,which can grow well on the substrate of phthalic acid esters(PAEs) as the sole source of carbon and energy,was isolated from river sludge.Based on the morphology,physiological an...A gram negative bacterium,named JDC-16,which can grow well on the substrate of phthalic acid esters(PAEs) as the sole source of carbon and energy,was isolated from river sludge.Based on the morphology,physiological and biochemical properties and analysis of 16S rRNA gene sequence,it was preliminarily identified belonging to the genus Acinetobacter.The result of substrates utilization range indicates that strain JDC-16 can utilize a variety of phthalates except for diisononyl phthalate(DINP) .The degradation tests using diethyl phthalate(DEP) as the model compound show that the optimal pH and temperature for DEP degradation by Acinetobacter sp.JDC-16 is 8.0 and 35℃,respectively.Meanwhile,degradation kinetics under various initial concentrations of DEP reveals that substrate depletion curves fit well with the modified Gompertz model with high correlation coefficient(R 2 >0.99) .Furthermore,the substrate induction test indicates that DEP-induction can apparently shorten the lag phase and enhance the degradation rate.This work highlights the potential of this isolate for bioremediation of phthalates-contaminated environments.展开更多
BACKGROUND:The Acinetobacter baumannii group,including Acinetobacter baumannii,Acinetobacter genomospecies 3 and 13 TU,is phenotypically indistinguishable and uniformly identified as Acinetobacter baumannii by laborat...BACKGROUND:The Acinetobacter baumannii group,including Acinetobacter baumannii,Acinetobacter genomospecies 3 and 13 TU,is phenotypically indistinguishable and uniformly identified as Acinetobacter baumannii by laboratories of clinical microbiology.This review aimed to demonstrate the differences among them.METHODS:Literatures associated with the Acinetobacter baumannii group were identified and selected from PubMed databases and relevant journals.RESULTS:Acinetobacter genospecies 3 and 13 TU possess a certain proportion in clinical isolates.There were considerable differences in epidemiologic features,clinical manifestations,antimicrobial resistances and therapeutic options among the Acinetobacter baumannii group.Compared with Acinetobacter genomospecies 3 and 13 TU,Acinetobacter baumannii with a higher resistance to antimicrobial agents are easier to be treated inappropriately,and present a worse outcome in patients.CONCLUSION:The Acinetobacter baumannii group comprises three distinct clinical entities,and their clinical value are not equal.展开更多
Strain EDP3 was isolated from an industrial-activated sludge. It belonged to the gamma group of Pro-teobacteria with an identity of 97.0% to Acinetobacter calcoaceticus according to the 16S rRNA gene sequences. It can...Strain EDP3 was isolated from an industrial-activated sludge. It belonged to the gamma group of Pro-teobacteria with an identity of 97.0% to Acinetobacter calcoaceticus according to the 16S rRNA gene sequences. It can tolerate up to 1000mg·L^-1 phenol at room temperature with a much longer lag phase. This indicates that higher phenol concentration has induced some physiological and genotypic changes in the bacterium. The aim of this study is, therefore, to investigate these responses to phenol concentration variations in strain EDP3. Proteome analysis is conducted by means of a two-dimensional polyacrylamide gel electrophoresis （2D PAGE） and matrix-assisted laser desorption ionization time of flight mass spectrometry （MALDI-TOF-MS） was conducted to obtain a deeper insight into the adaptive responses inside the bacterium. Comparative analysis of the proteome profiles of strain EDP3. grown in 400mg·L^-1 and 1000mg·L^-1 phenol allowed us to identify that among all the proteins up-regulated under the higher phenol concentration, oxidative stress proteins were dominant. The synthesis of a heat shock protein, 60000 chaperonin GroEL, was also amplified. In addition, the expression of one membrane protein, adenosine 5＇-triphosphate （ATP）-binding cassette （ABC） type sugar transporter, was found up-regulated. The inhibition of adenosine 5＇-triphosphate （ATP） and RNA/protein synthesis was also observed.展开更多
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.
基金Project(30770388) supported by the National Natural Science Foundation of China
文摘A gram negative bacterium,named JDC-16,which can grow well on the substrate of phthalic acid esters(PAEs) as the sole source of carbon and energy,was isolated from river sludge.Based on the morphology,physiological and biochemical properties and analysis of 16S rRNA gene sequence,it was preliminarily identified belonging to the genus Acinetobacter.The result of substrates utilization range indicates that strain JDC-16 can utilize a variety of phthalates except for diisononyl phthalate(DINP) .The degradation tests using diethyl phthalate(DEP) as the model compound show that the optimal pH and temperature for DEP degradation by Acinetobacter sp.JDC-16 is 8.0 and 35℃,respectively.Meanwhile,degradation kinetics under various initial concentrations of DEP reveals that substrate depletion curves fit well with the modified Gompertz model with high correlation coefficient(R 2 >0.99) .Furthermore,the substrate induction test indicates that DEP-induction can apparently shorten the lag phase and enhance the degradation rate.This work highlights the potential of this isolate for bioremediation of phthalates-contaminated environments.
基金supported by a from grant Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘BACKGROUND:The Acinetobacter baumannii group,including Acinetobacter baumannii,Acinetobacter genomospecies 3 and 13 TU,is phenotypically indistinguishable and uniformly identified as Acinetobacter baumannii by laboratories of clinical microbiology.This review aimed to demonstrate the differences among them.METHODS:Literatures associated with the Acinetobacter baumannii group were identified and selected from PubMed databases and relevant journals.RESULTS:Acinetobacter genospecies 3 and 13 TU possess a certain proportion in clinical isolates.There were considerable differences in epidemiologic features,clinical manifestations,antimicrobial resistances and therapeutic options among the Acinetobacter baumannii group.Compared with Acinetobacter genomospecies 3 and 13 TU,Acinetobacter baumannii with a higher resistance to antimicrobial agents are easier to be treated inappropriately,and present a worse outcome in patients.CONCLUSION:The Acinetobacter baumannii group comprises three distinct clinical entities,and their clinical value are not equal.
文摘Strain EDP3 was isolated from an industrial-activated sludge. It belonged to the gamma group of Pro-teobacteria with an identity of 97.0% to Acinetobacter calcoaceticus according to the 16S rRNA gene sequences. It can tolerate up to 1000mg·L^-1 phenol at room temperature with a much longer lag phase. This indicates that higher phenol concentration has induced some physiological and genotypic changes in the bacterium. The aim of this study is, therefore, to investigate these responses to phenol concentration variations in strain EDP3. Proteome analysis is conducted by means of a two-dimensional polyacrylamide gel electrophoresis （2D PAGE） and matrix-assisted laser desorption ionization time of flight mass spectrometry （MALDI-TOF-MS） was conducted to obtain a deeper insight into the adaptive responses inside the bacterium. Comparative analysis of the proteome profiles of strain EDP3. grown in 400mg·L^-1 and 1000mg·L^-1 phenol allowed us to identify that among all the proteins up-regulated under the higher phenol concentration, oxidative stress proteins were dominant. The synthesis of a heat shock protein, 60000 chaperonin GroEL, was also amplified. In addition, the expression of one membrane protein, adenosine 5＇-triphosphate （ATP）-binding cassette （ABC） type sugar transporter, was found up-regulated. The inhibition of adenosine 5＇-triphosphate （ATP） and RNA/protein synthesis was also observed.
