Deleting individual genes for outer surface c-type cytochromes in Geobacter sulfurreducens partially inhibited the reduction of humic substances and anthraquinone-2,6,-disulfonate. Complete inhibition was obtained only when five of these genes were simultaneously deleted, suggesting that diverse outer surface cytochromes can contribute to the reduction of humic substances and other extracellula...

Role of humic acids (HA) in plant tissue culture as plant growth regulators has been reviewed. Humic acid is a principal component of humic substances, which are the most important organic constituents of the soil (humus). Humus is defined as the organic matter in soil, a mixture of partially and totally humified substances. Leonardite is the best source for humic acid and it is extracted by us...

Since the day humic substances have been isolated by Berzelius, they are commonly considered polymeric in nature. The biopolymer theory became so popular that the concept was embraced by most scientists for more than 1.5 centuries. It has provided a suitable hypothesis that is among other things not running afoul of with the elemental composition of the humic compounds, which shows relatively c...

The potential for humic substances to stimulate the reduction of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) was investigated. This study describes a novel approach for the remediation of RDX-contaminated environments using microbially mediated electron shuttling. Incubations without cells demonstrated that reduced AQDS transfers electrons directly to RDX, which was reduced without significan...

An understanding of the chemistry and reactions of humic acids and related substances is crucial to an understanding of the nature and properties of soils. A comprehensible structural representation of humic substances is presented and the simplified model is used to illustrate: (i) the way in which stable humus is formed from lignin; (ii) forms of organic N in soils; (iii) the interaction of h...

subsequent accretion of layers of the complexes might represent a combination of chemical and physical proSince twice as much C is sequestered in soils as is contained in the tection from enzymes. atmosphere, the factors controlling the decomposition rate of soil C are important to the assessment of the effects of climatic change. Humic substances are operationally defined, but have The formati...

The mechanism of formation of chloroacetates, which are important toxic environmental substances, has been controversial. Whereas the anthropogenic production has been well established, a natural formation has also been suggested. In this study the natural formation of chloroacetic acids from soil, as well as from humic material which is present in soil and from phenolic model substances has be...

Degradation of humic substances in water is important due to its adverse effects on the environment and human health. The aim of this study was modeling and investigating the degradation of humic substances in water using immobilized ZnO as a catalyst. ZnO nanoparticles were synthesized through simple coprecipitation (CPT) method and immobilized on glass plates. The immobilized ZnO nanocatalyst...

Organic matter, compost, humus, humates, humic acid, and fulvic acid are all related to, and parts of, decaying plant materials. It’s food for soil life and a storehouse for minerals, energy and water. These organic materials are mediums for certain organisms to grow on. The biological/organic farming system is based on balanced minerals and lots of soil life in terms of diversity and volume. S...