An extended siderophore suite from Synechococcus sp. PCC 7002 revealed by LC-ICPMS-ESIMS

Author Posting. © The Author(s), 2015. This is the author's version of the work. It is posted here by permission of Royal Society of Chemistry for personal use, not for redistribution. The definitive version was published in Metallomics 7 (2015): 877-884, doi:10.1039/C5MT00005J.Siderophores are thought to play an important role in iron cycling in the ocean, but relatively few marine siderophores have been identified. Sensitive, high throughput methods hold promise for expediting the discovery and characterization of new siderophores produced by marine microbes. We developed a methodology for siderophore characterization that combines liquid chromatography (LC) inductively coupled plasma mass spectrometry (ICPMS) with high resolution electrospray ionization mass spectrometry (ESIMS). To demonstrate this approach, we investigated siderophore production by the marine cyanobacteria Synechococcus sp. PCC 7002. Three hydroxamate siderophores, synechobactin A-C, have been previously isolated and characterized from this strain. These compounds consist of an iron binding head group attached to a fatty acid side chain of variable length (C12, C10, and C8 respectively). In this study, we detected six iron-containing compounds in Synechococcus sp. PCC 7002 media by LC-ICPMS. To identify the molecular ions of these siderophores, we aligned the chromatographic retention times of peaks from the LC-ICPMS chromatogram with features detected from LC-ESIMS spectra using an algorithm designed to recognize metal isotope patterns. Three of these compounds corresponded to synechobactins A (614 m/z), B (586m/z), and C (558m/z). The MS2 spectra of these compounds revealed diagnostic synechobactin fragmentation patterns which were used to confirm the identity of the three unknown compounds (600, 628, and 642 m/z) as new members of the synechobactin suite with side chain lengths of 11, 13, and 14 carbons. These results demonstrate the potential of combined LCMS techniques for the identification of novel iron-organic complexes.This work was supported by the National Science Foundation program in Chemical Oceanography (OCE-1356747), and by the National Science Foundation Science and Technology Center for Microbial Oceanography Research and Education (C-MORE; DBI-0424599).2016-03-1

Regulation of parameters relief of UV-varnishes on the flexographic imprints

Исследовано влияние температуры на вязкость и растекание трафаретных УФ-лаков при их нанесении на оттиски флексографской печати и формировании рельефных изображений. В соответствии с изменениями вязкости УФ-лаков была предложена система контроля и регулирования параметров лакового рельефа, в том числе и геометрии элементов Брайля.This article describes the process of relief image forming by screen UV-varnishes on flexographic imprints. The influence of temperature on viscosity UV-varnishes on the process of UV-varnish wetting has been investigated. According to the changes of varnish viscosity, the system of control and regulation of varnish reliefs was proposed, including geometry of Braille elements

The role of the picoeukaryote Aureococcus anophagefferens in cycling of marine high molecular weight dissolved organic nitrogen

Environmental evidence suggests that Aureococcus anophagefferens (Pelagophyceae), a eukaryotic picoplankton that blooms in coastal seawaters, can outcompete other organisms because of its ability to use abundant dissolved organic nitrogen (DON). To test this hypothesis, we isolated A. anophagefferens in axenic culture and monitored its growth on high-molecular weight (HMW) DON collected from sediment pore waters, a putative source for DON in bays where blooms occur. HMW DON originating from pore water had a substantially higher protein content than surface seawater DON. We found that A. anophagefferens could deplete 25-36% of the available nitrogen in cultures with HMW DON as the sole source of nitrogen and that this corresponded well with the protein fraction in pore-water HMW DON. High rates of cell surface peptide hydrolysis and no detectable N-acetyl polysaccharide hydrolysis, together with the high percentage of hydrolyzable amino acids compared to hydrolyzable aminosugars present in the HMW DON, pointed to the protein fraction as the more likely source of nitrogen used for growth. Whether or not nitrogen scavenging from protein is a common mechanism in phytoplankton is at present unknown but needs to be investigate

Ранжирование значимости факторов качества узкорулонной УФ-флексографской печати

В соответствии с установленными факторами качества узкорулонной УФ-флексографской печати был сформирован ориентированный граф. Используя иерархическое представление соотношений между факторами, проведен расчет соответствующих коэффициентов их значимости. В работе установлено, что наиболее значимы такие факторы, как сложность сюжета продукции, вид запечатываемого материала, вязкость УФ-красок, скорость печати, тип и параметры печатной формы. Полученные результаты ранжирования позволят синтезировать модель приоритетности факторов для последующего прогнозирования качества печати.Oriented graph has been drawn in the article according to fixed factors of the quality of Narrow web flexography UV-printing. Using hierarchical representation of relationships between factors in the form of oriented graphs we have ranked the factors of the flexography UV-printing process and calculated their corresponding coefficients. We have found that the most ranked are such factors as the complexity of the product plot, the type of the printing material, the printing speed, the viscosity of UV-inks. Received results of ranking will enable to synthesize of the model of priority factors for subsequent predicting print quality

Influence of theplot label complexity on the UV-flexo printing process

В статье проведен анализ процесса узкорулонной флексографской УФ-печати этикетки. Предлагается распределение этикеток на три группы по сложности их сюжета. Установлено влияние сложности сюжетана скорость печати и выбор типа анилоксовых валиков. Предложено использование таких факторов как скорость, тип анилокса и свойства запечатываемого материала в качестве лингистических переменных для расчета и прогнозирования качества продукции разной сложности средствами нечеткой логики.The process of narrow web flexo UV-printing labels is analyzed in the article. Proposed distribution of labels into three groups according to the complexity of the plot. The influence of the plot labels complexity on the printing speed and the choice of anilox rollers was detected. It is suggested the use of such factors as speed, type of anilox, printing material properties as the linguistic variables for calculating and predicting the quality of products of varying complexity by means of fuzzy logic

Hidden cycle of dissolved organic carbon in the deep ocean

Marine dissolved organic carbon (DOC) is a large (660 Pg C) reactive carbon reservoir that mediates the oceanic microbial food web and interacts with climate on both short and long timescales. Carbon isotopic content provides information on the DOC source via δ[superscript 13]C and age via Δ[superscript 14]C. Bulk isotope measurements suggest a microbially sourced DOC reservoir with two distinct components of differing radiocarbon age. However, such measurements cannot determine internal dynamics and fluxes. Here we analyze serial oxidation experiments to quantify the isotopic diversity of DOC at an oligotrophic site in the central Pacific Ocean. Our results show diversity in both stable and radio isotopes at all depths, confirming DOC cycling hidden within bulk analyses. We confirm the presence of isotopically enriched, modern DOC cocycling with an isotopically depleted older fraction in the upper ocean. However, our results show that up to 30% of the deep DOC reservoir is modern and supported by a 1 Pg/y carbon flux, which is 10 times higher than inferred from bulk isotope measurements. Isotopically depleted material turns over at an apparent time scale of 30,000 y, which is far slower than indicated by bulk isotope measurements. These results are consistent with global DOC measurements and explain both the fluctuations in deep DOC concentration and the anomalous radiocarbon values of DOC in the Southern Ocean. Collectively these results provide an unprecedented view of the ways in which DOC moves through the marine carbon cycle.National Science Foundation (U.S.) (Grant OCE-0930866)National Science Foundation (U.S.) (Grant OCE-0930551