Role of Humic Substances in the Environmental Chemistry of Chlorinated Phenoxyalkanoic Acids and Esters

1986 ◽  
pp. 183-196 ◽  
Author(s):  
N. Senesi ◽  
T. Miano ◽  
C. Testini
Keyword(s):  
Humic Substances ◽  
Environmental Chemistry

scholarly journals Phylogenetic and Functional Diversity of Saprolegniales and Fungi Isolated from Temperate Lakes in Northeast Germany

2021 ◽  
Vol 7 (11) ◽  
pp. 968
Author(s):  
Hossein Masigol ◽  
Jason Nicholas Woodhouse ◽  
Pieter van West ◽  
Reza Mostowfizadeh-Ghalamfarsa ◽  
Keilor Rojas-Jimenez ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Enzymatic Activity ◽  
Humic Substances ◽  
Plant Litter ◽  
Freshwater Ecosystems ◽  
Chitinolytic Activity ◽  
Ecological Implications ◽  
Eukaryotic Organisms

The contribution of fungi to the degradation of plant litter and transformation of dissolved organic matter (humic substances, in particular) in freshwater ecosystems has received increasing attention recently. However, the role of Saprolegniales as one of the most common eukaryotic organisms is rarely studied. In this study, we isolated and phylogenetically placed 51 fungal and 62 Saprolegniales strains from 12 German lakes. We studied the cellulo-, lignino-, and chitinolytic activity of the strains using plate assays. Furthermore, we determined the capacity of 10 selected strains to utilize 95 different labile compounds, using Biolog FF MicroPlates™. Finally, the ability of three selected strains to utilize maltose and degrade/produce humic substances was measured. Cladosporium and Penicillium were amongst the most prevalent fungal strains, while Saprolegnia, Achlya, and Leptolegnia were the most frequent Saprolegniales strains. Although the isolated strains assigned to genera were phylogenetically similar, their enzymatic activity and physiological profiling were quite diverse. Our results indicate that Saprolegniales, in contrast to fungi, lack ligninolytic activity and are not involved in the production/transformation of humic substances. We hypothesize that Saprolegniales and fungi might have complementary roles in interacting with dissolved organic matter, which has ecological implications for carbon cycling in freshwater ecosystems.

scholarly journals First Quantification of the Controlling Role of Humic Substances in the Transport of Iron Across the Surface of the Arctic Ocean

2019 ◽  
Vol 53 (22) ◽  
pp. 13136-13145 ◽  
Author(s):  
Luis M. Laglera ◽  
Camila Sukekava ◽  
Hans A. Slagter ◽  
Javier Downes ◽  
Alberto Aparicio-Gonzalez ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Humic Substances ◽  
The Arctic ◽  
The Arctic Ocean

Role of organic matter and humic substances in the binding and mobility of arsenic in a Gangetic aquifer

2011 ◽  
Vol 46 (11) ◽  
pp. 1231-1238 ◽  
Author(s):  
Sandeep Kar ◽  
Jyoti Prakash Maity ◽  
Jiin-Shuh Jean ◽  
Chia-Chuan Liu ◽  
Bibhash Nath ◽  
...  
Keyword(s):  
Organic Matter ◽  
Humic Substances

Binding of Pyrene to Aquatic and Commercial Humic Substances:  The Role of Molecular Weight and Aromaticity

1997 ◽  
Vol 31 (6) ◽  
pp. 1630-1635 ◽  
Author(s):  
Yu-Ping Chin ◽  
George R. Aiken ◽  
Karlin M. Danielsen
Keyword(s):  
Molecular Weight ◽  
Humic Substances

Effect of light on birnessite catalysis of the Maillard reaction and its implication in humification

2001 ◽  
Vol 81 (3) ◽  
pp. 277-283 ◽  
Author(s):  
A. Jokic ◽  
A I Frenkel ◽  
P M Huang
Keyword(s):  
Humic Substances ◽  
Maillard Reaction ◽  
Solid Phase ◽  
Natural Environments ◽  
Promoting Effect ◽  
Nitrogenous Compounds ◽  
Heterogeneous Catalytic ◽  
Catalytic Role ◽  
Effect Of Light

The Maillard reaction between carbohydrates and nitrogenous compounds originally investigated in 1912 has subsequently been proposed as a possible pathway for the formation of humic substances in natural environments. However, the role of mineral catalysis of the Maillard reaction is little understood and the promoting effect of light on such catalysis is not known. Birnessite (δ-MnO2), which is commonly present in soil environments, was investigated for its activity in promoting the Maillard reaction between glucose and glycine at a light intensity of 168 µE s–1 m–2 or in the dark. The presence of substantial quantities of Mn(II) was detected in both the supernatant and solid phase of the glucose-glycine-birnessite systems. The spectroscopic evidence indicates that birnessite, in the presence of light, is a very effective catalyst in abiotic browning of solutions of glucose and glycine. Furthermore, birnessite significantly promoted the reaction even in the absence of light. Therefore, the abiotic heterogeneous catalytic role of soil minerals such as birnessite in polycondensation of simple sugars and amino acids merits close attention in the formation of humic substances in natural environments. Key words: Maillard reaction, heterogeneous catalysis, light, birnessite, humic substance formation, XANES

scholarly journals Effect of organic amendments on the mobility of trace elements in phytoremediated techno-soils: role of the humic substances

2014 ◽  
Vol 21 (17) ◽  
pp. 10470-10480 ◽  
Author(s):  
N. Hattab ◽  
M. Soubrand ◽  
R. Guégan ◽  
M. Motelica-Heino ◽  
X. Bourrat ◽  
...  
Keyword(s):  
Trace Elements ◽  
Humic Substances ◽  
Organic Amendments
Sign in / Sign up

Export Citation Format

Share Document