Effect of fulvic acids with different characteristics on biological denitrification

Humic substances are important environmental components since they represent a very large part of organic compounds on earth. According to many reports, dissolved humic substances are a determinant parameter for the bioavailability of xenobiotic compounds. For the present bioavailability studies, two kinds of dissolved humic substances, a commercially available humic acid and fulvic acids isolated from peat were used. As the relevant xenobiotic, a defined branched nonylphenol isomer, 4(3′,5′-dimethyl-3′-heptyl)-phenol (p353NP) was synthesised according to Friedel-Crafts alkylation. Equilibrium dialysis studies were implemented in order to investigate the association between 14C-labelled p353NP and dissolved humic substances. The biodegradability in the presence of dissolved humic substances was examined in experiments with the nonylphenol degrading bacterium strain Sphingomonas TTNP3 and with p353NP as sole carbon source. The results showed that p353NP-humic acid associates were formed in high amounts, whereas no adducts with fulvic acids occurred. In the degradation studies with Sphingomonas TTNP3, no effects of dissolved humic substances on the bioavailability of p353NP could be observed. It was assumed that the association between nonylphenol and humic acids occurs rapidly and is reversible. Thus, the formation of "labile" complexes did not influence biodegradation rates, which were quite low.

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Methylglyoxal detoxification by an aldo-keto reductase in the cyanobacterium Synechococcus sp. PCC 7002

Microbiology ◽

10.1099/mic.0.28870-0 ◽

2006 ◽

Vol 152 (7) ◽

pp. 2013-2021 ◽

Cited By ~ 27

Author(s):

Dongyi Xu ◽

Xianwei Liu ◽

Cong Guo ◽

Jindong Zhao

Keyword(s):

Enzyme Activity ◽

Carbon Source ◽

Toxic Metabolite ◽

Heterotrophic Growth ◽

Null Mutant ◽

Wild Type ◽

Activity Profile ◽

Aldehydes And Ketones ◽

Synechococcus Sp ◽

Ph Dependent

Aldo-keto reductases (AKRs) are a superfamily of enzymes that reduce aldehydes and ketones, and have a broad range of substrates. An AKR gene, sakR1, was identified in the cyanobacterium Synechococcus sp. PCC 7002. A mutant strain with sakR1 inactivated was sensitive to glycerol, a carbon source that can support heterotrophic growth of Synechococcus sp. PCC 7002. It was found that the sakR1 null mutant accumulated more toxic methylglyoxal than the wild-type when glycerol was added to growth medium, suggesting that SakR1 is involved in the detoxification of methylglyoxal, a highly toxic metabolite that can damage cellular macromolecules. Enzymic analysis of recombinant SakR1 protein showed that it can efficiently reduce methylglyoxal with NADPH. Based on immunoblotting, SakR1 was not upregulated at an increased cellular methylglyoxal concentration. A pH-dependent enzyme-activity profile suggested that SakR1 activity could be regulated by cellular pH in Synechococcus sp. PCC 7002. The broad substrate specificity of SakR1 implies that SakR1 could play other roles in cellular metabolism.

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Carbon source utilization and hydrogen production by isolated anaerobic bacteria

Acta Chimica Slovaca ◽

10.1515/acs-2016-0011 ◽

2016 ◽

Vol 9 (1) ◽

pp. 62-67 ◽

Cited By ~ 2

Author(s):

R. Jame ◽

V. Zelená ◽

B. Lakatoš ◽

Ľ. Varečka

Keyword(s):

Carbon Source ◽

Anaerobic Fermentation ◽

Carbon Sources ◽

Anaerobic Bacteria ◽

Growth Yield ◽

Bacterial Isolates ◽

Carbon Source Utilization ◽

Bacterial Strains ◽

Monocarboxylic Acids ◽

Sheep Rumen

Abstract Five bacterial isolates were tested for their ability to generate hydrogen during anaerobic fermentation with various carbon sources. One isolate from sheep rumen was identified as Escherichia coli and four isolates belonged to Clostridium spp. Glucose, arabinose, ribose, xylose, lactose and cellobiose were used as carbon sources. Results showed that all bacterial strains could utilize these compounds, although the utilization of pentoses diminished growth yield. The excretion of monocarboxylic acids (acetate, propionate, formiate, butyrate) into medium was changed after replacing glucose by other carbon sources. Di- and tricarboxylic acids were excreted in negligible amounts only. Spectra of excreted carboxylic acids were unique for each strain and all carbon sources. All isolates produced H2 between 4—9 mmol·L−1 during the stationary phase of growth with glucose as energy source. This value was dramatically reduced when pentoses were used as carbon source. Lactose and cellobiose, starch and cellulose were suitable substrates for the H2 production in some but not all isolates. No H2 was produced by proteinaceous substrate, such as blood. Results show that both substrate utilization and physiological responses (growth, excretion of carboxylates, H2 production) are unique functions of each isolate.

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Application of Bio-Carrier in a Ecological Floating Bed for Removal of Nitrogenous Pollutants: A Review

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.518-523.2064 ◽

2012 ◽

Vol 518-523 ◽

pp. 2064-2067 ◽

Cited By ~ 1

Author(s):

Yin Mei Wang

Keyword(s):

Carbon Source ◽

Ion Beam ◽

Beam Irradiation ◽

Ion Beam Irradiation ◽

Immobilized Bacteria ◽

Biological Denitrification

The article reviewed the advanced methods of ecological floating bed including usage of non-biodegradable bio-carrier, choosen of excellent plants, ion-beam irradiation, immobilized bacteria and aeration. Based on the review, the authors present the idea using biodegrable materials as bio-carrier, which not only could enhance the biomass in the ecological floating bed, but also could overcome the insufficience in carbon source for biological denitrification.

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Effect of thermal hydrolysis sludge supernatant as carbon source for biological denitrification with pilot-scale two-stage anoxic/oxic process and nitrogen balance model establishment

Biochemical Engineering Journal ◽

10.1016/j.bej.2018.08.013 ◽

2018 ◽

Vol 139 ◽

pp. 132-138 ◽

Cited By ~ 8

Author(s):

Yuqi Wu ◽

Kang Song ◽

Yinghe Jiang ◽

Xiaoyan Sun ◽

Lu Li

Keyword(s):

Carbon Source ◽

Nitrogen Balance ◽

Pilot Scale ◽

Balance Model ◽

Thermal Hydrolysis ◽

Two Stage ◽

Biological Denitrification

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Structural characterization of soil organic matter individual fractions (fulvic acids, humic acids and humins) in relation to potential sorption of organic contaminants

10.5194/egusphere-egu21-4125 ◽

2021 ◽

Author(s):

Aleksandra Ukalska-Jaruga ◽

Romualda Bejger ◽

Guillaume Debaene ◽

Bozena Smreczak

Keyword(s):

Molecular Weight ◽

Humic Substances ◽

Organic Contaminants ◽

Particle Diameter ◽

Fulvic Acids ◽

Molecular Structures ◽

Sorption Properties ◽

Binding Potential ◽

Aliphatic Chains

The objective of this paper was to investigate the molecular characterization of individual humic substances ( fulvic acids-FAs, humic ascids-HAs, and humins-HNs), which are the most reactive soil components and exhibit high sorption capacity in relation to various groups of organic contaminants. A wide spectrum of spectroscopic (UV-VIS, VIS-nearIR), as well as electrochemical (zeta potential, particle size diameter, polidyspersity index), methods were applied to find the relevant differences in the behavior, formation, composition and sorption properties of HS fractions derived from various mineral soils.Soil material (n = 30) used for the study were sampled from the surface layer (0&#8211;30 cm) of agricultural soils. FAs and HAs were isolated by sequential extraction in alkaline and acidic solutions, according to the International Humic Substances Society method, while HNs was determined in the soil residue (after FAs and HAs extraction) by mineral fraction digestion using a 0.1M HCL/0.3M HF mixture and DMSO.Our study showed that significant differences in the molecular structures of FAs, HAs and HNs occurred. Optical analysis confirmed the lower molecular weight of FAs with high amount of lignin-like compounds and the higher weighted aliphatic&#8211;aromatic structure of HAs. The HNs were characterized by a very pronounced and strong condensed structure associated with the highest molecular weight. HAs and HNs molecules exhibited an abundance of acidic, phenolic and amine functional groups at the aromatic ring and aliphatic chains, while FAs mainly showed the presence of methyl, methylene, ethenyl and carboxyl reactive groups. HS was characterized by high polydispersity related with their structure. FAs were characterized by ellipsoidal shape as being associated to the long aliphatic chains, while HAs and HNs revealed a smaller particle diameter and a more spherical shape caused by the higher intermolecular forcing between the particles.&#160;&#160;The observed trends directly indicate that individual HS fractions differ in behavior, formation, composition and sorption properties, which reflects their binding potential to different group of organic contaminants, but the general properties of individual fractions are similar and do not depend on the type of soil.Acknowledgement: The studies were supported from the National Science Centre project No. 2018/29/N/ST10/01320 &#8220;Analysis of the fractional composition and sorption properties of humic substances in relation to various groups of organic contaminants&#8221;

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