RUI: Polyhalomethanes in Marine Waters: The Role of DOC and Extracellular Bromoperoxidase

RUI：海水中的多卤甲烷：DOC 和细胞外溴过氧化物酶的作用

• 批准号: 0350746
• 负责人: Steven Manley
• 金额: --
• 依托单位: California State University-Long Beach Foundation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0350746&HistoricalAwards=false
• 关键词: RUI; Polyhalomethanes; Marine; Waters; Role

ABSTRACTOCE-0350746Polyhalomethanes produced by marine algae, supply reactive bromine and iodine atoms to the atmosphere where they promote the destruction of both tropospheric and stratospheric ozone, and in the case of iodomethanes, promote the formation of marine aerosols. Polyhalomethanes are indirect products of marine algal haloperoxidase activity, formed as a consequence to destroy toxic H2O2 produced both within and outside their cells.Looking to link algal physiology, marine chemistry and atmospheric science, researchers at the California State University at Long Beach will demonstrate that marine DOC can form polybromo- and polyiodo- methanes catalyzed by algal extracellular bromoperoxidases (BrPO). Measurement of polyhalomethane production will be quantified using a GC-ECD; GC-MS will confirm peak identity. The active DOC fraction(s) will be characterized by their MW size class, using stirred N2-pressurized ultrafiltration. Seawater collected from different coastal locations during the summer and winter will be used to ensure differences in DOC quantity and quality, and will be analyzed for salinity, DOC (high temperature combustion technique) and H2O2 (fluorometric assay). Polybromomethane production from DOC (i.e. ng CHBr3 - biomass-1) by a seaweed and diatom species will be determined from measuring the number of BrPO units present on their surfaces (spectrophotometric assay) and from measuring the rate of polybromomethane production from DOC per commercial BrPO units (similarly defined). Other experiments will directly contrast total polyhalomethane production from these species in seawater of known DOC concentration, to production in seawater in which the DOC has been removed. Comparison of results from these two different methods will allow for the assessment of the significance of this process. This biologically mediated transformation of DOC to polyhalomethanes, which is eventually lost to the atmosphere, is a unique biogeochemical process. Unlike the extracellular enzymes of heterotrophic bacteria that degrade DOC as a source of nutrition (with the production of respiratory CO2), marine algae do not derive any nutritional benefit from the halogenation of DOC and may compete with certain bacteria for the same compounds.

摘要-0350746海洋藻类生产的丙甲酸酯，向对流层和平流层臭氧的破坏以及碘甲烷的破坏，供应促进碘甲烷的销毁，并促进海洋气球酚的形成。 Polyhalomethanes are indirect products of marine algal haloperoxidase activity, formed as a consequence to destroy toxic H2O2 produced both within and outside their cells.Looking to link algal physiology, marine chemistry and atmospheric science, researchers at the California State University at Long Beach will demonstrate that marine DOC can form polybromo- and polyiodo- methanes catalyzed by algal extracellular溴过氧化物酶（BRPO）。将使用GC-ECD来量化聚合甲烷的测量； GC-MS将确认峰值身份。主动DOC分数将使用搅拌的N2压力超滤以其MW尺寸类别为特征。夏季和冬季从不同沿海地区收集的海水将用于确保DOC数量和质量的差异，并将分析盐度，DOC，DOC（高温燃烧技术）和H2O2（荧光测定法）。通过测量其表面上存在的BRPO单元的数量（分光光度计测定法），通过测量每个商业BRPO单元（类似定义的DOC），通过测量其表面上存在的BRPO单元的数量（分光光度法测定法）和测量多溴生产的速率（类似定义）来确定来自DOC（即NG CHBR3 -Biomass -1）的多溴甲烷（即NG CHBR3 -Biomass -1）。其他实验将直接将来自已知DOC浓度的海水中的这些物种直接对比，并将其去除DOC的海水生产。比较这两种不同方法的结果将允许评估该过程的重要性。这种生物地球化学过程是最终丢失到大气中的生物学上介导的DOC向聚去甲烷的转化。与降解DOC作为营养来源的异养细菌的细胞外酶（随着呼吸二氧化碳的产生），海洋藻类不会从DOC的卤化中获得任何营养益处，并且可以与某些细菌竞争相同化合物。