A bacterial strain BAP5 with a relatively high degradation ability of benzo[a]pyrene （BaP） was isolated from marine sediments of Xiamen Western Sea, China and identified as Ochrobactrum sp. according to 16S rRNA gen...A bacterial strain BAP5 with a relatively high degradation ability of benzo[a]pyrene （BaP） was isolated from marine sediments of Xiamen Western Sea, China and identified as Ochrobactrum sp. according to 16S rRNA gene sequence as well as Biolog microbial identification system. Strain BAP5 could grow in mineral salt medium with 50 mg/L of BaP and degrade about 20% BaP after 30 d of incubation. Ochrobactrum sp. BAP5 was able to utilize other polycyclic aromatic hydrocarbons （PAHs） （such as phenanthrene, pyrene and fluoranthene） as the sole carbon source and energy source, suggesting its potential application in PAHs bioremediation. The profile of total soluble protein from Ochrobactrum sp. BAP5 was also investigated. Some over- and special-expressed proteins of strain BAP5 when incubated with the presence of BaP were detected by two-dimensional polyacrylamide gel electrophoresis, and found to be related with PAHs metabolism, DNA translation, and energy production based on peptide fingerprint analysis through matrix-assisted laser desorption/ionization-time of flight mass spectrometry.展开更多
An alginate-degrading bacterium, identified as Ochrobactrum sp. on the basis of 16S rDNA gene sequencing, was isolated from brown algal samples collected from the waters in close vicinity to the Dongtou isles of the E...An alginate-degrading bacterium, identified as Ochrobactrum sp. on the basis of 16S rDNA gene sequencing, was isolated from brown algal samples collected from the waters in close vicinity to the Dongtou isles of the East China Sea. The strain, designated WZUH09-1, is able to depolymerize alginates with higher enzyme activity than that of others reported so far.展开更多
麦草畏是理想的抗除草剂转基因工程的靶标除草剂;发掘新的麦草畏高效降解菌株和基因具有非常重要的理论和应用价值.从南京土壤样品中分离到一株麦草畏高效降解菌株,命名为3-3.根据生理生化特征和16S r DNA序列相似性分析,将其初步鉴定...麦草畏是理想的抗除草剂转基因工程的靶标除草剂;发掘新的麦草畏高效降解菌株和基因具有非常重要的理论和应用价值.从南京土壤样品中分离到一株麦草畏高效降解菌株,命名为3-3.根据生理生化特征和16S r DNA序列相似性分析,将其初步鉴定为苍白杆菌属(Ochrobactrum sp.).菌株3-3在48 h内完全降解100 mg/L的麦草畏.该菌株降解麦草畏的最适温度为30℃,最适p H为7.0.代谢产物高效液相和质谱鉴定结果表明该菌株降解麦草畏的起始步骤是脱甲基,形成没有除草活性的3,6-二氯水杨酸(DCSA).菌株粗酶液只在NADH存在时才有麦草畏脱甲基酶活性.PCR扩增和该菌基因组生物信息学分析表明该菌株没有已报道的麦草畏脱甲基酶基因DMO、Mtv及Dmt或其同源序列.总之,本研究首次分离筛选到苍白杆菌属的麦草畏降解菌,且该菌可能存在一个新的氧化酶类麦草畏脱甲基酶基因.展开更多
Pretreatment of Low-Density Polyethylene(LDPE)with physicochemical methods before biodegradation has been demonstrated as an effective strategy.The pretreatment of LDPE exhibited alterations in molecular structure,red...Pretreatment of Low-Density Polyethylene(LDPE)with physicochemical methods before biodegradation has been demonstrated as an effective strategy.The pretreatment of LDPE exhibited alterations in molecular structure,reducing hydrophobicity and decreasing tensile strength.Additionally,pretreating LDPE enhanced microbial biodegradability to improve biofilm formation and significantly reduced the physical weight of LDPE film.AS3–8 consortia exhibited a maximum weight loss of 8.0%±0.5%after 45 days of incubation.While Bacillus sp.AS3 and Sphingobacterium sp.AS8 demonstrated LDPE weight loss of 5.03%±1.6%and 1.6%±0.5%,respectively.The structure of LDPE was altered after incubation with the bacterial strains,resulting in a reduction in the intensity of functional groups,including C=O,C=C,N–H,and C–N.The carbonyl index(CI)of LDPE also decreased by 7.17%after the consortia AS3–8 degradation.Consortia AS3–8 significantly impacted the physical properties of LDPE by reducing the water contact angle(WCA),decreasing to 64.21°±3.69°,and tensile strength(TS),decreasing to 17.97±0.3 MPa.Moreover,the esterase activity was measured through 45 days of incubation.SDS-PAGE analysis of the AS3–8 consortia revealed bands at 35,48,and 70 kDa molecular weights,similar to known enzymes like laccase and esterase.Furthermore,SEM observations showed rough,cracked surfaces on pretreated LDPE,with biofilms present after incubation with the bacterial strains.GC–MS analysis revealed that AS3–8 consortia produced depolymerized chemicals,including alkanes,aldehydes,and esters.The LDPE biodegradation pathway was elucidated.This study addresses critical knowledge gaps in improving plastic degradation efficiency.展开更多
根据《实施卫生与植物卫生措施协定》(Agreementon the Application of Sanitary and Phytosanitary Measures,简称《SPS协定》)中的透明度原则,成员应保证迅速公布所有拟采用的但尚没有对应的国际标准、指南或建议或与其在内容实质上...根据《实施卫生与植物卫生措施协定》(Agreementon the Application of Sanitary and Phytosanitary Measures,简称《SPS协定》)中的透明度原则,成员应保证迅速公布所有拟采用的但尚没有对应的国际标准、指南或建议或与其在内容实质上不同的,且可能对其他成员贸易产生重大影响的卫生与植物卫生措施,以使利益相关方知晓。展开更多
In China,Xinjiang is a relatively independent epidemic region of wheat stripe rust,caused by Puccinia striiformis f.sp.tritici,due to great population genetic divergence of Xinjiang with other inland epidemic regions....In China,Xinjiang is a relatively independent epidemic region of wheat stripe rust,caused by Puccinia striiformis f.sp.tritici,due to great population genetic divergence of Xinjiang with other inland epidemic regions.In this region,race evolution was usually slower than inland populations.However,many new races have recently been found,and therefore,it is necessary for more understanding of the virulence evolution of the Xinjiang population.So,in this study,a 65 sexual progenies,derived from a Xinjiang single-urediospore isolate BGTB-1 of P.striiformis f.sp.tritici by selfing on alternate host barberry(Berberis aggregata).It was phenotyped on the 25 single Yr lines,and genotyped by 19 kompetitive allele-specific PCRsingle nucleotide polymorphism(KASP-SNP) markers.As a result,the 65 progenies were identified as 56 various virulence patterns(VPs),and neither of which was identical to the parental isolate,showed 100% virulence variation.Compared with the parental isolate,of all progenies,39(60.0%) had increased virulence,and 18(27.7%) had decreased virulence.All progenies exhibited avirulence to Yr10,Yr15,Yr32,and YrTr1 loci,and avirulence and virulence segregation at the remaining 21 Yr resistance loci.The results showed avirulence to Yr5,Yr7,and Yr76(A:V≈3:1) loci is controlled by a single dominant gene,and that to Yr6,Yr25,and Yr44(A:V≈1:3) loci by a single recessive gene.However,avirulence to the remaining 15 resistant loci including Yr1,Yr2,Yr3,Yr4,Yr8,Yr9,Yr17,Yr26(=Yr24),Yr28,Yr29,Yr43,YrSP,Yr27,YrA,and YrExp2,with various avirulence and virulence segregation ratios,is controlled by two genes with different gene effects,indicating complex genetic traits of the parental isolate.Totally,65 dissimilar genotypes detected among progenies using overall molecular markers,by which a linkage map was constructed,with a genetic distance of 441.0 cM.Interestingly,although the parental isolate was avirulent to Yr5,but 17 progenies showed virulence,showing the change of pathogenicity from avirulence to virulence at this resistance locus.It was for the first time to report that progenies with virulence to Yr5 produced sexually from avirulent parental isolate at this resistance locus.To our knowledge,this study offers an insight into inheritance,sexual reproduction and virulence variation of P.striiformis f.sp.tritici in Xinjiang,facilitating us to understand evolution of the rust pathogen in this region and accounting for Xinjiang population distinguished form other inland populations.Additionally,it is necessary to further confirm the roles of sexual reproduction in the emergence of new races and affecting population genetic diversity of P.striiformis f.sp.tritici under natural conditions in Xinjiang.展开更多
A 1602 bp fragment was cloned from a soil bacterium Ochrobactrum sp. 531. It contained an open reading frame (ORF) of 1092 bp which was identified as a multicopper oxidase (MCO) with potential laccase activity. After ...A 1602 bp fragment was cloned from a soil bacterium Ochrobactrum sp. 531. It contained an open reading frame (ORF) of 1092 bp which was identified as a multicopper oxidase (MCO) with potential laccase activity. After inserting the cloned gene into the expression vector pET23a, it was expressed in E. coli BL21(DE3)pLysS, and its product was purified to homogeneity through chromatography. The Ochrobactrum sp. 531 MCO, consisting of 533 amino acids with a molecular mass of 57.8 kDa, was quite stable in neutral pH and showed laccase-like activity oxidizing 2,6-dimethoxyphenol (DMP), 2,2’-azino-bis(3-ethylbe- nzthiazolinesulfonic acid) (ABTS), and syringaldazine (SGZ). The enzyme showed optimum activity towards DMP, ABTS, and SGZ at the pH 8.0, 3.6, and 7.5 respectively. Kinetic studies gave this enzyme Km, kcat and kcat//Km values of: 0.09 mM, 7.94 s–1, and 88.22 s–1?mM–1 for DMP;0.072 mM, 2.95 s–1, and 40.97 s–1.mM–1 for ABTS;and 0.015 mM, 2.4 s–1, and 160 s–1.mM–1 for SGZ. Our results demonstrate that Ochrobactrum sp. 531 MCO is a bacterial laccase which oxidized phenolic substrates DMP and SGZ effectively under alkaline conditions. These unusual properties make the enzyme an interesting biocatalyst in applications for which classical laccases are unsuitable.展开更多
基金supported by the National Natural Sci-ence Foundation of China (No 40206015, 30970106)the Fork Ying Tong Education Foundation (No 94002) the Science and Technology Project of Guangdong Province,China (No 2006A36502001, 2007A032600003)
文摘A bacterial strain BAP5 with a relatively high degradation ability of benzo[a]pyrene （BaP） was isolated from marine sediments of Xiamen Western Sea, China and identified as Ochrobactrum sp. according to 16S rRNA gene sequence as well as Biolog microbial identification system. Strain BAP5 could grow in mineral salt medium with 50 mg/L of BaP and degrade about 20% BaP after 30 d of incubation. Ochrobactrum sp. BAP5 was able to utilize other polycyclic aromatic hydrocarbons （PAHs） （such as phenanthrene, pyrene and fluoranthene） as the sole carbon source and energy source, suggesting its potential application in PAHs bioremediation. The profile of total soluble protein from Ochrobactrum sp. BAP5 was also investigated. Some over- and special-expressed proteins of strain BAP5 when incubated with the presence of BaP were detected by two-dimensional polyacrylamide gel electrophoresis, and found to be related with PAHs metabolism, DNA translation, and energy production based on peptide fingerprint analysis through matrix-assisted laser desorption/ionization-time of flight mass spectrometry.
文摘An alginate-degrading bacterium, identified as Ochrobactrum sp. on the basis of 16S rDNA gene sequencing, was isolated from brown algal samples collected from the waters in close vicinity to the Dongtou isles of the East China Sea. The strain, designated WZUH09-1, is able to depolymerize alginates with higher enzyme activity than that of others reported so far.
文摘Pretreatment of Low-Density Polyethylene(LDPE)with physicochemical methods before biodegradation has been demonstrated as an effective strategy.The pretreatment of LDPE exhibited alterations in molecular structure,reducing hydrophobicity and decreasing tensile strength.Additionally,pretreating LDPE enhanced microbial biodegradability to improve biofilm formation and significantly reduced the physical weight of LDPE film.AS3–8 consortia exhibited a maximum weight loss of 8.0%±0.5%after 45 days of incubation.While Bacillus sp.AS3 and Sphingobacterium sp.AS8 demonstrated LDPE weight loss of 5.03%±1.6%and 1.6%±0.5%,respectively.The structure of LDPE was altered after incubation with the bacterial strains,resulting in a reduction in the intensity of functional groups,including C=O,C=C,N–H,and C–N.The carbonyl index(CI)of LDPE also decreased by 7.17%after the consortia AS3–8 degradation.Consortia AS3–8 significantly impacted the physical properties of LDPE by reducing the water contact angle(WCA),decreasing to 64.21°±3.69°,and tensile strength(TS),decreasing to 17.97±0.3 MPa.Moreover,the esterase activity was measured through 45 days of incubation.SDS-PAGE analysis of the AS3–8 consortia revealed bands at 35,48,and 70 kDa molecular weights,similar to known enzymes like laccase and esterase.Furthermore,SEM observations showed rough,cracked surfaces on pretreated LDPE,with biofilms present after incubation with the bacterial strains.GC–MS analysis revealed that AS3–8 consortia produced depolymerized chemicals,including alkanes,aldehydes,and esters.The LDPE biodegradation pathway was elucidated.This study addresses critical knowledge gaps in improving plastic degradation efficiency.
文摘根据《实施卫生与植物卫生措施协定》(Agreementon the Application of Sanitary and Phytosanitary Measures,简称《SPS协定》)中的透明度原则,成员应保证迅速公布所有拟采用的但尚没有对应的国际标准、指南或建议或与其在内容实质上不同的,且可能对其他成员贸易产生重大影响的卫生与植物卫生措施,以使利益相关方知晓。
基金financially supported by Xinjiang Major Science and Technology Projects,China (2023A02009)。
文摘In China,Xinjiang is a relatively independent epidemic region of wheat stripe rust,caused by Puccinia striiformis f.sp.tritici,due to great population genetic divergence of Xinjiang with other inland epidemic regions.In this region,race evolution was usually slower than inland populations.However,many new races have recently been found,and therefore,it is necessary for more understanding of the virulence evolution of the Xinjiang population.So,in this study,a 65 sexual progenies,derived from a Xinjiang single-urediospore isolate BGTB-1 of P.striiformis f.sp.tritici by selfing on alternate host barberry(Berberis aggregata).It was phenotyped on the 25 single Yr lines,and genotyped by 19 kompetitive allele-specific PCRsingle nucleotide polymorphism(KASP-SNP) markers.As a result,the 65 progenies were identified as 56 various virulence patterns(VPs),and neither of which was identical to the parental isolate,showed 100% virulence variation.Compared with the parental isolate,of all progenies,39(60.0%) had increased virulence,and 18(27.7%) had decreased virulence.All progenies exhibited avirulence to Yr10,Yr15,Yr32,and YrTr1 loci,and avirulence and virulence segregation at the remaining 21 Yr resistance loci.The results showed avirulence to Yr5,Yr7,and Yr76(A:V≈3:1) loci is controlled by a single dominant gene,and that to Yr6,Yr25,and Yr44(A:V≈1:3) loci by a single recessive gene.However,avirulence to the remaining 15 resistant loci including Yr1,Yr2,Yr3,Yr4,Yr8,Yr9,Yr17,Yr26(=Yr24),Yr28,Yr29,Yr43,YrSP,Yr27,YrA,and YrExp2,with various avirulence and virulence segregation ratios,is controlled by two genes with different gene effects,indicating complex genetic traits of the parental isolate.Totally,65 dissimilar genotypes detected among progenies using overall molecular markers,by which a linkage map was constructed,with a genetic distance of 441.0 cM.Interestingly,although the parental isolate was avirulent to Yr5,but 17 progenies showed virulence,showing the change of pathogenicity from avirulence to virulence at this resistance locus.It was for the first time to report that progenies with virulence to Yr5 produced sexually from avirulent parental isolate at this resistance locus.To our knowledge,this study offers an insight into inheritance,sexual reproduction and virulence variation of P.striiformis f.sp.tritici in Xinjiang,facilitating us to understand evolution of the rust pathogen in this region and accounting for Xinjiang population distinguished form other inland populations.Additionally,it is necessary to further confirm the roles of sexual reproduction in the emergence of new races and affecting population genetic diversity of P.striiformis f.sp.tritici under natural conditions in Xinjiang.
文摘A 1602 bp fragment was cloned from a soil bacterium Ochrobactrum sp. 531. It contained an open reading frame (ORF) of 1092 bp which was identified as a multicopper oxidase (MCO) with potential laccase activity. After inserting the cloned gene into the expression vector pET23a, it was expressed in E. coli BL21(DE3)pLysS, and its product was purified to homogeneity through chromatography. The Ochrobactrum sp. 531 MCO, consisting of 533 amino acids with a molecular mass of 57.8 kDa, was quite stable in neutral pH and showed laccase-like activity oxidizing 2,6-dimethoxyphenol (DMP), 2,2’-azino-bis(3-ethylbe- nzthiazolinesulfonic acid) (ABTS), and syringaldazine (SGZ). The enzyme showed optimum activity towards DMP, ABTS, and SGZ at the pH 8.0, 3.6, and 7.5 respectively. Kinetic studies gave this enzyme Km, kcat and kcat//Km values of: 0.09 mM, 7.94 s–1, and 88.22 s–1?mM–1 for DMP;0.072 mM, 2.95 s–1, and 40.97 s–1.mM–1 for ABTS;and 0.015 mM, 2.4 s–1, and 160 s–1.mM–1 for SGZ. Our results demonstrate that Ochrobactrum sp. 531 MCO is a bacterial laccase which oxidized phenolic substrates DMP and SGZ effectively under alkaline conditions. These unusual properties make the enzyme an interesting biocatalyst in applications for which classical laccases are unsuitable.
