scholarly journals Evidence for biological shaping of hair ice

2015 ◽  
Vol 12 (14) ◽  
pp. 4261-4273 ◽  
Author(s):  
D. Hofmann ◽  
G. Preuss ◽  
C. Mätzler
Keyword(s):  
Organic Matter ◽  
Dead Wood ◽  
Complex Mixture ◽  
Fulvic Acids ◽  
Common Mechanism ◽  
Ice Growth ◽  
Physical Chemical ◽  
Broad Leaf ◽  
The Common

Abstract. An unusual ice type, called hair ice, grows on the surface of dead wood of broad-leaf trees at temperatures slightly below 0 °C. We describe this phenomenon and present physical, chemical, and biological investigations to gain insight in the properties and processes related to hair ice. Tests revealed that the biological activity of a winter-active fungus is required in the wood for enabling the growth of hair ice. We confirmed the fungus hypothesis originally suggested by Wegener (1918) by reproducing hair ice on wood samples. Treatment by heat and fungicide suppresses the formation of hair ice. Fruiting bodies of Asco- and Basidiomycota are identified on hair-ice-carrying wood. One species, Exidiopsis effusa (Ee), was present on all investigated samples. Both hair-ice-producing wood samples and those with killed fungus show essentially the same temperature variation, indicating that the heat produced by fungal metabolism is very small, that the freezing rate is not influenced by the fungus activity, and that ice segregation is the common mechanism of ice growth on the wood surface. The fungus plays the role of shaping the ice hairs and preventing them from recrystallisation. Melted hair ice indicates the presence of organic matter. Chemical analyses show a complex mixture of several thousand CHO(N,S) compounds similar to fulvic acids in dissolved organic matter (DOM). The evaluation reveals decomposed lignin as being the main constituent. Further work is needed to clarify its role in hair-ice growth and to identify the recrystallisation inhibitor.

scholarly journals Evidence for biological shaping of hair ice

2015 ◽  
Vol 12 (7) ◽  
pp. 5293-5332
Author(s):  
D. Hofmann ◽  
G. Preuss ◽  
C. Mätzler
Keyword(s):  
Organic Matter ◽  
Dead Wood ◽  
Complex Mixture ◽  
Fulvic Acids ◽  
Common Mechanism ◽  
Ice Growth ◽  
Physical Chemical ◽  
Broad Leaf ◽  
The Common

Abstract. An unusual ice type, called hair ice, grows on the surface of dead wood of broad-leaf trees at temperatures slightly below 0 °C. We describe this phenomenon and present physical, chemical, and biological investigations to gain insight in the properties and processes related to hair ice. Tests revealed that the biological activity of a winter-active fungus is required in the wood for enabling the growth of hair ice. We confirmed the fungus hypothesis originally suggested by Wegener (1918) by reproducing hair ice on wood samples. Treatment by heat and fungicide, respectively, suppresses the formation of hair ice. Fruiting bodies of Asco- and Basidiomycota are identified on hair-ice carrying wood. One species, Exidiopsis effusa (Ee), has been present on all investigated samples. Both hair-ice producing wood samples and those with killed fungus show essentially the same temperature variation, indicating that the heat produced by fungal metabolism is very small, that the freezing rate is not influenced by the fungus activity and that ice segregation is the common mechanism of ice growth at the wood surface. The fungus plays the role of shaping the ice hairs and to prevent them from recrystallisation. Melted hair ice indicates the presence of organic matter. Chemical analyses show a complex mixture of several thousand CHO(N,S)-compounds similar to fulvic acids in dissolved organic matter (DOM). The evaluation reveals decomposed lignin as the main constituent. Further work is needed to clarify its role in hair-ice growth and to identify the recrystallisation inhibitor.

scholarly journals Role of Klotho in Chronic Calcineurin Inhibitor Nephropathy

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Kang Luo ◽  
Sun Woo Lim ◽  
Yi Quan ◽  
Sheng Cui ◽  
Yoo Jin Shin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Aging Process ◽  
Calcineurin Inhibitor ◽  
Calcineurin Inhibitors ◽  
Common Mechanism ◽  
Protective Mechanism ◽  
Klotho Protein ◽  
The Common ◽  
And Oxidative Stress

Calcineurin inhibitors (CNIs) are the most popular immunosuppressants in organ transplantation, but nephrotoxicity is a major concern. The common mechanism underlying chronic CNI nephropathy is oxidative stress, and the process of chronic CNI nephropathy is similar to that of aging. Current studies provide evidence that antiaging Klotho protein plays an important role in protecting against oxidative stress, and its signaling is a target for preventing oxidative stress-induced aging process. In this review, we focus on the association between Klotho and oxidative stress and the protective mechanism of action of Klotho against oxidative stress in chronic CNI nephropathy. In addition, we discuss the delivery strategy for Klotho in CNI-induced nephropathy.

scholarly journals Prospects for Irradiation in Cellulosic Ethanol Production

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Anita Saini ◽  
Neeraj K. Aggarwal ◽  
Anuja Sharma ◽  
Anita Yadav
Keyword(s):  
Ethanol Production ◽  
Cellulosic Ethanol ◽  
Electron Beam Irradiation ◽  
Structural Characteristics ◽  
Ultrasonic Waves ◽  
Beam Irradiation ◽  
Second Generation Bioethanol ◽  
Physical Chemical ◽  
The Common

Second generation bioethanol production technology relies on lignocellulosic biomass composed of hemicelluloses, celluloses, and lignin components. Cellulose and hemicellulose are sources of fermentable sugars. But the structural characteristics of lignocelluloses pose hindrance to the conversion of these sugar polysaccharides into ethanol. The process of ethanol production, therefore, involves an expensive and energy intensive step of pretreatment, which reduces the recalcitrance of lignocellulose and makes feedstock more susceptible to saccharification. Various physical, chemical, biological, or combined methods are employed to pretreat lignocelluloses. Irradiation is one of the common and promising physical methods of pretreatment, which involves ultrasonic waves, microwaves, γ-rays, and electron beam. Irradiation is also known to enhance the effect of saccharification. This review explains the role of different radiations in the production of cellulosic ethanol.

Influence of humus acids on mobility and biological availability of iron, zinc and copper

2015 ◽  
Vol 2 (1) ◽  
pp. 73-78
Author(s):  
A. Fateev ◽  
D. Semenov ◽  
K. Smirnova ◽  
A. Shemet
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Humic Acids ◽  
Fulvic Acids ◽  
Sand Culture ◽  
Humic And Fulvic Acids ◽  
Cultivation Medium ◽  
Mobile Forms

Soil organic matter is known as an important condition for the mobility of trace elements in soils, their geo- chemical migration and availability to plants. However, various components of soil organic matter have differ- ent effect on these processes due to their signifi cant differences in structure and properties. Aim. To establish the role of humic and fulvic acids in the process of formation of microelement mobility in soils and their accu- mulation in plants. Methods. A model experiment with sand culture was used to investigate the release of trace elements from preparations of humic and fulvic acids and their uptake by oat plants. Results. It was found that among biologically needed elements humic acids are enriched with iron, fulvic acids – with zinc, and copper distribution between these two groups of substances may be characterized as even. These elements have un- equal binding power with components of soil organic matter, as evidenced by their release into the cultivation medium and accumulation in plants. In the composition of fulvic acids zink has the most mobility – up to 95 % of this element is in the form, accessible for plants; the lowest mobility was demonstrated by copper in the composition with humic acids, for which no signifi cant changes in the concentration of mobile forms in the substrate and in the introduction to the test culture were registered. Despite signifi cantly higher iron content in humic acids, the application of fulvic acids in the cultivation medium provides a greater increase in the con- centration of mobile forms of this element. Conclusions. The results confi rm the important role of organic sub- stances of fulvic nature in the formation of zinc and iron mobility in the soil and their accumulation in plants.

CHARACTERISTICS OF ORGANIC MATTER EXTRACTED FROM PODZOL B HORIZONS

1970 ◽  
Vol 50 (2) ◽  
pp. 199-204 ◽  
Author(s):  
M. SCHNITZER
Keyword(s):  
Organic Matter ◽  
Water Solubility ◽  
Fulvic Acids ◽  
Structural Features ◽  
Root Initiation ◽  
Ring Structures ◽  
Radical Content ◽  
Stable Free Radicals ◽  
Stem Segments

Organic matter was extracted from Podzol B horizons from nine different sites and analyzed by chemical and spectroscopic methods. The biological activity of each extract was also assessed. After purification, all extracts, which represented between 31 and 56% of the organic matter in the original soil samples, were soluble in base, acid and water, which classified them as fulvic acids. The chemical and spectroscopic data for the nine fulvic acids indicated great similarities in gross structural features and functional groups. As could be judged from the E4/E6 ratios, the acids contained few condensed ring structures. All fulvic acids contained stable free radicals and increased root initiation in bean stem segments. While the free radical content of the fulvic acids did not correlate statistically with their ability to increase root initiation, this aspect merits further investigation. The high acidity, the predominance of COOH groups and the water solubility exhibited by all fulvic acid preparations point to a significant role of these materials not only in soils and waters but also within plants.

The Role of Oxidative Treatment on the Trivalent Cation Complexation Properties of Natural Organic Matter

2010 ◽  
Vol 13 (2) ◽  
Author(s):  
Sibel Sen Kavurmaci ◽  
Miray Bekbolet
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Trivalent Cation ◽  
Cation Complexation ◽  
Physico Chemical ◽  
Trivalent Cations ◽  
The Common ◽  
Pre Treatment ◽  
Acid Structure

AbstractHumic acids (HA) which constitute the major subgroup of natural organic matter (NOM) are mainly composed of heterogeneous and polydisperse macromolecules. Considering the reactivities of the humic moieties towards the common coagulants during physico-chemical treatment of drinking water, different pre-oxidation conditions could exhibit various changes in humic acid structure leading to diverse reactivities towards the trivalent cations. The aim of this study was to evaluate the effects of the oxidative pre-treatment schemes applied by ozonation, TiO

scholarly journals Transformations of phenolic compounds in meadow soils

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Anna Ziolkowska ◽  
Bozena Debska ◽  
Magdalena Banach-Szott
Keyword(s):  
Organic Matter ◽  
Chemical Composition ◽  
Phenolic Compounds ◽  
Humic Substances ◽  
Humic Acids ◽  
Plant Material ◽  
Fulvic Acids ◽  
Humic And Fulvic Acids

Abstract The aim of the research has been to determine the role of phenolic compounds in the processes of transformations of organic matter in meadow soils, leading to the formation of humic substances. The research has been performed based on the plant material and soil sampled from Europe’s unique complex of permanent grasslands irrigated continuously for 150 years applying the slope-and-flooding system, the Czerskie Meadows. Phenolic compounds were isolated from the plant material samples (hay, sward and roots) and soils (horizon A, AE and Bsv) and from the fraction of humic and fulvic acids. It was found that the contents of phenolic compounds decrease in the following order: hay > sward > roots > A horizon soil > AE horizon soil > Bsv horizon soil > A horizon fulvic acids > AE horizon fulvic acids > Bsv horizon fulvic acids > A horizon fulvic acids > AE horizon fulvic acids > Bsv horizon fulvic acids. A significantly higher share of cinnamyl than vanillyl and syringyl compounds in the extracts of fulvic acids and slightly higher in the hydrolysates of humic acids confirms the effect of the chemical composition of the plant material undergoing decomposition on the properties of the emerging humic substances.

scholarly journals Mineralization of organic matter in boreal lake sediments: Rates, pathways and nature of the fermenting substrates

2020 ◽  
Author(s):  
François Clayer ◽  
Yves Gélinas ◽  
André Tessier ◽  
Charles Gobeil
Keyword(s):  
Organic Matter ◽  
Lake Sediments ◽  
Environmental Changes ◽  
Dissolved Inorganic Carbon ◽  
Biogeochemical Models ◽  
Mineralization Of Organic Matter ◽  
The Common ◽  
Reaction Transport ◽  
Lake Basins

Abstract. The complexity of organic matter (OM) degradation mechanisms represents a significant challenge for developing biogeochemical models to quantify the role of aquatic sediments in the climate system. The common representation of OM by carbohydrates formulated as CH2O in models comes with the assumption that its degradation by fermentation produces equimolar amounts of methane (CH4) and dissolved inorganic carbon (DIC). To test the validity of this assumption, we modeled using reaction-transport equations vertical profiles of the concentration and isotopic composition (δ13C) of CH4 and DIC in the top 25 cm of the sediment column from two lake basins, one whose hypolimnion is perennially oxygenated and one with seasonal anoxia. Our results reveal that methanogenesis only occurs via hydrogenotrophy in both basins. Furthermore, we calculate, from CH4 and DIC production rates associated with methanogenesis, that the fermenting OM has an average carbon oxidation state (COS) below −0.9. Modeling solute porewater profiles reported in the literature for four other seasonally anoxic lake basins also yields negative COS values. Collectively, the mean (±SD) COS value of −1.4 ± 0.3 for all the seasonally anoxic sites is much lower than the value of zero expected from carbohydrates fermentation. We conclude that carbohydrates do not adequately represent the fermenting OM and that the COS should be included in the formulation of OM fermentation in models applied to lake sediments. This study highlights the need to better characterize the labile OM undergoing mineralization to interpret present-day greenhouse gases cycling and predict its alteration under environmental changes.

scholarly journals Photocatalytic Bactericidal Performance of LaFeO3 under Solar Light in the Presence of Natural Organic Matter: Spectroscopic and Mechanistic Evaluation

Water ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 2785
Author(s):  
Nazmiye Cemre Birben ◽  
Ezgi Lale ◽  
Renato Pelosato ◽  
Nazli Turkten ◽  
Isabella Natali Sora ◽  
...  
Keyword(s):  
Organic Matter ◽  
Natural Organic Matter ◽  
Natural Water ◽  
Fulvic Acids ◽  
Experimental Conditions ◽  
E Coli ◽  
Comprehensive Information ◽  
Indicator Microorganism ◽  
Inactivation Mechanism

Solar photocatalytic inactivation (SPCI) of E. coli as the indicator microorganism using LaFeO3 (LF) has already been investigated under various experimental conditions, excluding any role of natural organic matter (NOM). However, comprehensive information about the behavior of E. coli and its inactivation mechanism in the presence of NOM, as well as the behavior of NOM components via solar photocatalysis using LF as a photocatalyst, has prime importance in understanding real natural water environments. Therefore, in this study, further assessment was devoted to explore the influence of various NOM representatives on the SPCI of E. coli by using LF as a novel non-TiO2 photocatalyst. The influence of NOM as well as its sub-components, such as humic acids (HA) and fulvic acids (FA), was also investigated to understand different NOM-related constituents of real natural water conditions. In addition to spectroscopic and mechanistic investigations of cell-derived organics, excitation emission matrix (EEM) fluorescence spectra with parallel factor multiway analysis (PARAFAC) modeling revealed further information about the occurrence and/or disappearance of NOM-related and bacteria-related fluorophores upon LF SPCI. Both the kinetics as well as the mechanism of the LF SPCI of E. coli in the presence of NOM compounds displayed substrate-specific variations under all conditions.

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