Arsenic is a ubiquitous environmental pollutant.Microbe-mediated arsenic biotransformations significantly infuence arsenic mobility and toxicity.Arsenic transformations by soil and aquatic organisms have been well doc...Arsenic is a ubiquitous environmental pollutant.Microbe-mediated arsenic biotransformations significantly infuence arsenic mobility and toxicity.Arsenic transformations by soil and aquatic organisms have been well documented,while little is known regarding effects due to endophytic bacteria.An endophyte Pseudomonas putida ARS1 was isolated from rice grown in arsenic contaminated soil.P.putida ARS1 shows high tolerance to arsenite(As(Ⅲ))and arsenate(As(V)),and exhibits efficient As(V)reduction and As(Ⅲ)effux activities.When exposed to 0.6 mg/L As(V),As(V)in the medium was completely converted to As(Ⅲ)by P.putida ARS1 within 4 hr.Genome sequencing showed that P.putida ARS1 has two chromosomal arsenic resistance gene clusters(arsRCBH)that contribute to efficient As(V)reduction and As(Ⅲ)effux,and result in high resistance to arsenicals.Wolffia globosa is a strong arsenic accumulator with high potential for arsenic phytoremediation,which takes up As(Ⅲ)more efficiently than As(V).Co-culture of P.putida ARS1 and W.globosa enhanced arsenic accumulation in W.globosa by 69%,and resulted in 91%removal of arsenic(at initial concentration of 0.6 mg/L As(V))from water within 3 days.This study provides a promising strategy for in situ arsenic phytoremediation through the cooperation of plant and endophytic bacterium.展开更多
浮萍科芜萍属(Wolffi a Hork.ex Schleid.)是世界上最小的开花植物,可作为蔬菜、饲料使用.为促进科学地开发利用芜萍资源,采用MCI、硅胶柱层析、凝胶色谱以及高效液相色谱等方法对芜萍(Wolffia globosa)的化学成分进行研究.从乙醇提取...浮萍科芜萍属(Wolffi a Hork.ex Schleid.)是世界上最小的开花植物,可作为蔬菜、饲料使用.为促进科学地开发利用芜萍资源,采用MCI、硅胶柱层析、凝胶色谱以及高效液相色谱等方法对芜萍(Wolffia globosa)的化学成分进行研究.从乙醇提取物中分离得到8个化合物,利用质谱、核磁共振等波谱技术分别鉴定为芹菜素-7-O-β-D-吡喃葡糖苷(1)、牡荆苷(2)、异牡荆苷(3)、荭草苷(4)、异荭草苷(5)、木犀草素-7-O-β-D-吡喃葡糖苷(6)、异荭草苷-6′′-O-β-D-吡喃葡糖苷(7)和芹菜素-6,8-di-C-β-D-吡喃葡糖苷(8).本研究表明,芜萍(W.globosa)的主要化学成分为芹菜素和木犀草素的碳苷和氧苷化合物,其生物活性广泛,因此芜萍是一种黄酮类天然产物的新来源.展开更多
以积累总蛋白为目标,评估40个芜萍株系的干物质积累速率、蛋白质含量和蛋白质积累速率,筛选出1株最优株系D0039开展进一步系统研究.在单因素试验的基础上,采用中心组合试验设计(Central Composite Design,CCD)响应面法对D0039的培养条...以积累总蛋白为目标,评估40个芜萍株系的干物质积累速率、蛋白质含量和蛋白质积累速率,筛选出1株最优株系D0039开展进一步系统研究.在单因素试验的基础上,采用中心组合试验设计(Central Composite Design,CCD)响应面法对D0039的培养条件进行优化.根据实验模型预测最优的条件组合为尿素氮(NH_(2)^(+)-N)浓度90 mg/L、光照强度150μmol m^(-2)s^(-1)、覆盖率150%,该条件下的干物质积累速率为9.72 g m^(-2)d^(-1),蛋白含量为46.96%,蛋白积累速率为7.53 g m^(-2)d^(-1).对预测条件进行实验验证,结果显示实际干物质积累速率为10.38g m^(-2)d^(-1),蛋白含量为47.13%,蛋白积累速率为6.68 g m^(-2)d^(-1).实际实验结果与模型预测值比较,相对误差分别为6.79%、0.36%、11.29%.可见,响应面分析法提供的实验模型能真实地拟合实际情况;根据上述优化条件,D0039积累蛋白质效率高;结果可为利用芜萍作为蛋白质资源提供技术参考.(图5表3参29)展开更多
基金Supported by the Forestry Industry Public Welfare Project of State Forestry Bureau(200904001)the National Natural Science Foundation of China(NSFC J0730641)~~
基金supported by the National Natural Science Foundation of China (Nos.41991332,41977323 and 42090063)the National Institutes of Health (No.R35 GM136211)。
文摘Arsenic is a ubiquitous environmental pollutant.Microbe-mediated arsenic biotransformations significantly infuence arsenic mobility and toxicity.Arsenic transformations by soil and aquatic organisms have been well documented,while little is known regarding effects due to endophytic bacteria.An endophyte Pseudomonas putida ARS1 was isolated from rice grown in arsenic contaminated soil.P.putida ARS1 shows high tolerance to arsenite(As(Ⅲ))and arsenate(As(V)),and exhibits efficient As(V)reduction and As(Ⅲ)effux activities.When exposed to 0.6 mg/L As(V),As(V)in the medium was completely converted to As(Ⅲ)by P.putida ARS1 within 4 hr.Genome sequencing showed that P.putida ARS1 has two chromosomal arsenic resistance gene clusters(arsRCBH)that contribute to efficient As(V)reduction and As(Ⅲ)effux,and result in high resistance to arsenicals.Wolffia globosa is a strong arsenic accumulator with high potential for arsenic phytoremediation,which takes up As(Ⅲ)more efficiently than As(V).Co-culture of P.putida ARS1 and W.globosa enhanced arsenic accumulation in W.globosa by 69%,and resulted in 91%removal of arsenic(at initial concentration of 0.6 mg/L As(V))from water within 3 days.This study provides a promising strategy for in situ arsenic phytoremediation through the cooperation of plant and endophytic bacterium.
文摘浮萍科芜萍属(Wolffi a Hork.ex Schleid.)是世界上最小的开花植物,可作为蔬菜、饲料使用.为促进科学地开发利用芜萍资源,采用MCI、硅胶柱层析、凝胶色谱以及高效液相色谱等方法对芜萍(Wolffia globosa)的化学成分进行研究.从乙醇提取物中分离得到8个化合物,利用质谱、核磁共振等波谱技术分别鉴定为芹菜素-7-O-β-D-吡喃葡糖苷(1)、牡荆苷(2)、异牡荆苷(3)、荭草苷(4)、异荭草苷(5)、木犀草素-7-O-β-D-吡喃葡糖苷(6)、异荭草苷-6′′-O-β-D-吡喃葡糖苷(7)和芹菜素-6,8-di-C-β-D-吡喃葡糖苷(8).本研究表明,芜萍(W.globosa)的主要化学成分为芹菜素和木犀草素的碳苷和氧苷化合物,其生物活性广泛,因此芜萍是一种黄酮类天然产物的新来源.
文摘以积累总蛋白为目标,评估40个芜萍株系的干物质积累速率、蛋白质含量和蛋白质积累速率,筛选出1株最优株系D0039开展进一步系统研究.在单因素试验的基础上,采用中心组合试验设计(Central Composite Design,CCD)响应面法对D0039的培养条件进行优化.根据实验模型预测最优的条件组合为尿素氮(NH_(2)^(+)-N)浓度90 mg/L、光照强度150μmol m^(-2)s^(-1)、覆盖率150%,该条件下的干物质积累速率为9.72 g m^(-2)d^(-1),蛋白含量为46.96%,蛋白积累速率为7.53 g m^(-2)d^(-1).对预测条件进行实验验证,结果显示实际干物质积累速率为10.38g m^(-2)d^(-1),蛋白含量为47.13%,蛋白积累速率为6.68 g m^(-2)d^(-1).实际实验结果与模型预测值比较,相对误差分别为6.79%、0.36%、11.29%.可见,响应面分析法提供的实验模型能真实地拟合实际情况;根据上述优化条件,D0039积累蛋白质效率高;结果可为利用芜萍作为蛋白质资源提供技术参考.(图5表3参29)
