Thermal and Photoinduced Reduction of Ionic Au(III) to Elemental Au Nanoparticles by Dissolved Organic Matter in Water: Possible Source of Naturally Occurring Au Nanoparticles

2014 ◽  
Vol 48 (5) ◽  
pp. 2671-2679 ◽  
Author(s):  
Yongguang Yin ◽  
Sujuan Yu ◽  
Jingfu Liu ◽  
Guibin Jiang
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Au Nanoparticles ◽  
Naturally Occurring

Dissolved Organic Matter Sorption and Molecular Fractionation by Naturally Occurring Bacteriogenic Iron (Oxyhydr)oxides

2019 ◽  
Vol 53 (8) ◽  
pp. 4295-4304 ◽  
Author(s):  
Tyler D. Sowers ◽  
Kathryn L. Holden ◽  
Elizabeth K. Coward ◽  
Donald L. Sparks
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Naturally Occurring ◽  
Molecular Fractionation

scholarly journals Quantitative Transcriptomics Reveals the Growth- and Nutrient-Dependent Response of a Streamlined Marine Methylotroph to Methanol and Naturally Occurring Dissolved Organic Matter

mBio ◽  
2016 ◽  
Vol 7 (6) ◽  
Author(s):  
Scott M. Gifford ◽  
Jamie W. Becker ◽  
Oscar A. Sosa ◽  
Daniel J. Repeta ◽  
Edward F. DeLong
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Carbon Metabolism ◽  
Marine Organic Matter ◽  
Naturally Occurring ◽  
Genome Wide ◽  
Carbon Substrates ◽  
Mrna Content ◽  
Nutrient Conditions

ABSTRACT The members of the OM43 clade of Betaproteobacteria are abundant coastal methylotrophs with a range of carbon-utilizing capabilities. However, their underlying transcriptional and metabolic responses to shifting conditions or different carbon substrates remain poorly understood. We examined the transcriptional dynamics of OM43 isolate NB0046 subjected to various inorganic nutrient, vitamin, and carbon substrate regimes over different growth phases to (i) develop a quantitative model of its mRNA content; (ii) identify transcriptional markers of physiological activity, nutritional state, and carbon and energy utilization; and (iii) identify pathways involved in methanol or naturally occurring dissolved organic matter (DOM) metabolism. Quantitative transcriptomics, achieved through addition of internal RNA standards, allowed for analyses on a transcripts-per-cell scale. This streamlined bacterium exhibited substantial shifts in total mRNA content (ranging from 1,800 to 17 transcripts cell −1 in the exponential and deep stationary phases, respectively) and gene-specific transcript abundances (>1,000-fold increases in some cases), depending on the growth phase and nutrient conditions. Carbon metabolism genes exhibited substantial dynamics, including those for ribulose monophosphate, tricarboxylic acid (TCA), and proteorhodopsin, as well as methanol dehydrogenase ( xoxF ), which, while always the most abundant transcript, increased from 5 to 120 transcripts cell −1 when cultures were nutrient and vitamin amended. In the DOM treatment, upregulation of TCA cycle, methylcitrate cycle, vitamin, and organic phosphorus genes suggested a metabolic route for this complex mixture of carbon substrates. The genome-wide inventory of transcript abundances produced here provides insight into a streamlined marine bacterium’s regulation of carbon metabolism and energy flow, providing benchmarks for evaluating the activity of OM43 populations in situ . IMPORTANCE Bacteria exert a substantial influence on marine organic matter flux, yet the carbon components targeted by specific bacterial groups, as well as how those groups’ metabolic activities change under different conditions, are not well understood. Gene expression studies of model organisms can identify these responses under defined conditions, which can then be compared to environmental transcriptomes to elucidate in situ activities. This integration, however, is limited by the data’s relative nature. Here, we report the fully quantitative transcriptome of a marine bacterium, providing a genome-wide survey of cellular transcript abundances and how they change with different states of growth, nutrient conditions, and carbon substrates. The results revealed the dynamic metabolic strategies this methylotroph has for processing both simple one-carbon compounds and the complex multicarbon substrates of naturally derived marine organic matter and provide baseline quantitative data for identifying their in situ activities and impact on the marine carbon cycle.

Effects of reverse osmosis isolation on reactivity of naturally occurring dissolved organic matter in physicochemical processes

2004 ◽  
Vol 38 (4) ◽  
pp. 1026-1036 ◽  
Author(s):  
James E Kilduff ◽  
Supatpong Mattaraj ◽  
Andrew Wigton ◽  
Mehmet Kitis ◽  
Tanju Karanfil
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Reverse Osmosis ◽  
Physicochemical Processes ◽  
Naturally Occurring

Dissolved organic matter-mediated reduction of ionic Au(III) to elemental Au nanoparticles and their growth to visible granules

2020 ◽  
Vol 31 (7) ◽  
pp. 1970-1973
Author(s):  
Ying Chen ◽  
Yingying Guo ◽  
Guangliang Liu ◽  
Maoyong Song ◽  
Yong Cai ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Au Nanoparticles ◽  
Mediated Reduction
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