scholarly journals Impact of Chitosan on Water Stability and Wettability of Soils

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7724
Author(s):  
Agnieszka Adamczuk ◽  
Milena Kercheva ◽  
Mariana Hristova ◽  
Grzegorz Jozefaciuk
Keyword(s):  
Molecular Mass ◽  
Water Drop ◽  
Soil Aggregates ◽  
Water Stability ◽  
Soil Environment ◽  
Deacetylation Degree ◽  
Lower Viscosity ◽  
Lower Molecular Mass ◽  
C And N ◽  
First Time

Chitosan has become increasingly applied in agriculture worldwide, thus entering the soil environment. We hypothesized that chitosan should affect the water stability of soil. Since this problem has not been studied to date, we examined, for the first time, the influence of chitosan on the water stability and wettability of soil aggregates. The aggregates were prepared from four soils with various properties amended with different amounts of two kinds of powdered chitosan, and subjected to 1 and/or 10 wetting–drying cycles. The water stability was measured by monitoring air bubbling after aggregate immersion in water, and the wettability was measured by a water drop penetration test. The biopolymer with a lower molecular mass, lower viscosity, and higher degree of deacetylation was more effective in increasing the water stability of the soil than the biopolymer with a higher molecular mass, higher viscosity, and lower deacetylation degree. After a single wetting-drying cycle, the water stability of the soil aggregates containing chitosan with a higher molecular mass was generally lower than that of the soil; after ten wetting–drying cycles, the water stability increased 1.5 to 20 times depending on the soil. The addition of low-molecular-mass chitosan after a single wetting-drying cycle caused the water stability to become one to two hundred times higher than that of the soil. A trial to find out which soil properties (pH, C and N content, bulk density, porosity, and particle size distribution) are responsible for the effectiveness of chitosan action was not successful, and this will be the objective of further studies.

scholarly journals Alternative RNA splicing of the human endothelin-A receptor generates multiple transcripts

1996 ◽  
Vol 313 (3) ◽  
pp. 795-801 ◽  
Author(s):  
Yoshihiro MIYAMOTO ◽  
Takaaki YOSHIMASA ◽  
Hiroshi ARAI ◽  
Kazuhiko TAKAYA ◽  
Yoshihiro OGAWA ◽  
...  
Keyword(s):  
Molecular Mass ◽  
Rna Splicing ◽  
Cdna Clones ◽  
Human Tissues ◽  
Rt Pcr ◽  
Endothelin A Receptor ◽  
Lower Molecular Mass ◽  
Novel Transcripts ◽  
Exon 4 ◽  
Endothelin A

In order to elucidate the regulatory mechanisms of expression of the human endothelin-A receptor (hET-AR) gene, we characterized hET-AR transcripts using reverse transcriptase (RT)-PCR analysis in a variety of human tissues. RT-PCR of lung mRNA using a set of primers from exons 2 and 5 showed two lower-molecular-mass transcripts in addition to the expected fragment. When RT-PCR with primers from exons 4 and 8 was performed, no transcripts other than the expected one were detected. PCR cloning utilizing a set of primers from exons 2 and 8 which covered the entire coding sequence revealed that the cDNA clones corresponding to the two novel transcripts contained deletions of 199 bp and 327 bp respectively compared with the previously described hET-AR cDNA. Comparison of their sequences with that of the hET-AR gene showed that the deleted sequences correspond exactly to exon 4 and exons 3 and 4 respectively, indicating that these lower-molecular-mass ET-AR transcripts result from alternative RNA splicing (designated ET-AR∆4 and ET-AR∆3,4 respectively). Alternative splicing of exon 4 results in a transcript which would be translated into a C-terminal truncated protein containing the first, second and third transmembrane domains, while the splicing out of exons 3 and 4 would produce a protein with five membrane-spanning domains but lacking the third and fourth domains present in the ET-AR protein. An RNase protection assay revealed that ET-AR∆4 and ET-AR∆3,4, as well as ET-AR, transcripts were observed in various human tissues, including the lung, aorta, atrium, kidney and placenta, which are known to express ET-AR abundantly. Thus we have isolated the cDNAs of novel transcripts of hET-AR which are generated by alternative RNA splicing, and these results suggest that this alternative RNA splicing might contribute to the regulation of ET-AR gene expression.

Aureobasidium pullulans Gene from Egypt

2021 ◽  
Vol 8 (1) ◽  
pp. 6-10
Author(s):  
Hani Moubasher ◽  
Salwa S Wahsh ◽  
Nabil Abo El-Kassem ◽  
Refaat Ali
Keyword(s):  
Molecular Mass ◽  
Genomic Dna ◽  
Aureobasidium Pullulans ◽  
Hypothetical Protein ◽  
Significant Alignment ◽  
First Time

Sequancing of pullulanase from the fungus Aureobasidium pullulans isolated from Egypt soil; Genomic DNA of pullulanase was determined for the first time using PCR, according to Baser program, Pullulanase nucleotide collection from Aureobasidium pullulans was blasted which showed similarity using NCBI significant alignment with Aureobasidium namibiae CBS 147.97 hypothetical protein partial mRNA and 46 % with Aureobasidium pullulans JQ624241 and AF470619; Identified sequenced fragment was 2051 bp. and G+C content is 50.5% with molecular mass 63 KDa.

scholarly journals Droplet infiltration dynamics and soil wettability related to soil organic matter of soil aggregate coatings and interiors

2016 ◽  
Vol 64 (2) ◽  
pp. 111-120 ◽  
Author(s):  
Miroslav Fér ◽  
Martin Leue ◽  
Radka Kodešová ◽  
Horst H. Gerke ◽  
Ruth H. Ellerbrock
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Preferential Flow ◽  
Water Drop ◽  
Soil Aggregates ◽  
High Water ◽  
Contact Angles ◽  
Surface Wettability ◽  
Mineral Coatings ◽  
Droplet Infiltration

Abstract The organo-mineral coatings of soil aggregates, cracks, and biopores control sorption and macropore-matrix exchange during preferential flow, in particular in the clay-illuvial Bt-horizon of Luvisols. The soil organic matter (SOM) composition has been hypothesized to explain temporal changes in the hydraulic properties of aggregate surfaces. The objective of this research was to find relations between the temporal change in wettability, in terms of droplet infiltration dynamics, and the SOM composition of coated and uncoated aggregate surfaces. We used 20 to 40 mm sized soil aggregates from the Bt2 horizon of a Haplic Luvisol from loess that were (i) coated, (ii) not coated (both intact), and (iii) aggregates from which coatings were removed (cut). The SOM composition of the aggregate surfaces was characterized by infrared spectroscopy in the diffuse reflection mode (DRIFT). A potential wettability index (PWI) was calculated from the ratio of hydrophobic and hydrophilic functional groups in SOM. The water drop penetration times (WDPT) and contact angles (CA) during droplet infiltration experiments were determined on dry and moist aggregate samples of the three types. The decrease in the CA with time was described using the power function (CA(t) = at−b). For dry aggregates, the WDPT values were larger for coated as compared to uncoated regions on the aggregate surfaces, and increased with increasing PWI value (R2 = 0.75). The a parameter was significantly related to the WDPT (R2 = 0.84) and to the PWI (R2 = 0.64). The relations between the b parameter and the WDPT (R2 = 0.61) and the PWI (R2 = 0.53) were also significant. The WDPT values of wet soil aggregates were higher than those of dry aggregates due to high water contents, which limited the droplet infiltration potential. At the wet aggregate surfaces, the WDPT values increased with the PWI of the SOM (R2 = 0.64). In contrast to dry samples, no significant relationships were found between parameters a or b of CA(t) and WDPT or PWI for wet aggregate surfaces. The results suggest that the effect of the SOM composition of coatings on surface wettability decreases with increasing soil moisture. In addition to the dominant impact of SOM, the wettability of aggregate surfaces could be affected by different mineralogical compositions of clay in coatings and interiors of aggregates. Particularly, wettability of coatings could be decreased by illite which was the dominant clay type in coatings. However, the influence of different clay mineral fractions on surface wettability was not due to small number of measurements (2 and 1 samples from coatings and interiors, respectively) quantified.

scholarly journals A Novel Shortwave Infrared Proximal Sensing Approach to Quantify the Water Stability of Soil Aggregates

2018 ◽  
Vol 82 (6) ◽  
pp. 1358-1366 ◽  
Author(s):  
Azadeh Gholoubi ◽  
Hojat Emami ◽  
Scott B. Jones ◽  
Markus Tuller
Keyword(s):  
Soil Aggregates ◽  
Water Stability ◽  
Proximal Sensing ◽  
Shortwave Infrared

Soil organic carbon and nitrogen sequestration and turnover in aggregates under subtropical leucaena–grass pastures

Soil Research ◽  
2018 ◽  
Vol 56 (6) ◽  
pp. 632 ◽  
Author(s):  
Kathryn Conrad ◽  
Ram C. Dalal ◽  
Ryosuke Fujinuma ◽  
Neal W. Menzies
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Aggregates ◽  
Soil Mass ◽  
Δ13c And Δ15n ◽  
Organic C ◽  
Carbon And Nitrogen ◽  
Nitrogen Sequestration ◽  
C And N

Stabilisation and protection of soil organic carbon (SOC) in macroaggregates and microaggregates represents an important mechanism for the sequestration of SOC. Legume-based grass pastures have the potential to contribute to aggregate formation and stabilisation, thereby leading to SOC sequestration. However, there is limited research on the C and N dynamics of soil organic matter (SOM) fractions in deep-rooted legume leucaena (Leucaena leucocephala)–grass pastures. We assessed the potential of leucaena to sequester carbon (C) and nitrogen (N) in soil aggregates by estimating the origin, quantity and distribution in the soil profile. We utilised a chronosequence (0–40 years) of seasonally grazed leucaena stands (3–6 m rows), which were sampled to a depth of 0.3 m at 0.1-m intervals. The soil was wet-sieved for different aggregate sizes (large macroaggregates, >2000 µm; small macroaggregates, 250–2000 µm; microaggregates, 53–250 µm; and <53 µm), including occluded particulate organic matter (oPOM) within macroaggregates (>250 µm), and then analysed for organic C, N and δ13C and δ15N. Leucaena promoted aggregation, which increased with the age of the leucaena stands, and in particular the formation of large macroaggregates compared with grass in the upper 0.2 m. Macroaggregates contained a greater SOC stock than microaggregates, principally as a function of the soil mass distribution. The oPOM-C and -N concentrations were highest in macroaggregates at all depths. The acid nonhydrolysable C and N distribution (recalcitrant SOM) provided no clear distinction in stabilisation of SOM between pastures. Leucaena- and possibly other legume-based grass pastures have potential to sequester SOC through stabilisation and protection of oPOM within macroaggregates in soil.

Water Stability of Soil Aggregates in a 50-Year-Old Soil Formation Experiment on Calcareous Glacial Till

2020 ◽  
Vol 53 (5) ◽  
pp. 619-631
Author(s):  
M. Are ◽  
K. Kauer ◽  
T. Kaart ◽  
A. Selge ◽  
A. Astover ◽  
...  
Keyword(s):  
Soil Aggregates ◽  
Soil Formation ◽  
Glacial Till ◽  
Water Stability ◽  
Formation Experiment

Darstellung von Peroxotantalaten durch Perhydrolyse von Tantal(V)-äthanolat / Preparation of Peroxotantalates by Perhydrolysis of Tantalum(V)ethoxide

1973 ◽  
Vol 28 (9-10) ◽  
pp. 590-594 ◽  
Author(s):  
J. Fuchs ◽  
D. Lubkoll
Keyword(s):  
Petroleum Ether ◽  
Molecular Mass ◽  
Water Soluble ◽  
Organic Cations ◽  
Water Soluble Compound ◽  
Soluble Compound ◽  
First Time

Tetraperoxotantalates with organic cations as well as an oligomeric peroxopolytantalate were prepared for the first time by perhydrolysis of tantalum(V)ethoxide, Ta(OC2H5)5, in the presence of bases. Guanidinium, tert-butylammonium and cyclohexylammonium salts of tetraperoxotantalic acid crystallize from ethanol as relatively stable compounds. The cell constants of these compounds are determined. By perhydrolysis of the ester in petroleum ether the tert-butylammonium salt of a peroxododecantalic acid was obtained. The molecular mass of this water soluble compound was determined with the ultracentrifuge.

The effect of krilium soil conditioner on the yield of wheat

1964 ◽  
Vol 4 (15) ◽  
pp. 363
Author(s):  
TC Stoneman
Keyword(s):  
Field Trial ◽  
Soil Structure ◽  
Soil Aggregates ◽  
Wheat Yield ◽  
Water Stability ◽  
Soil Conditioner ◽  
Barrel Medic

A field trial investigated the effect of improved soil structure on wheat yield. Krilium, a synthetic polyelectrolyte soil conditioner, was used to improve structure. The water stability of the soil aggregates was significantly increased on the plots treated with the conditioner. The conditioner treated plots also had significantly higher yields and 1000-grain weights than the untreated plots. The effect of the soil conditioner persisted into the year after cropping, when the plots were sown to Barrel Medic (Medicago tribuloides Desr.). The Barrel Medic establishment was significantly greater on the conditioner treated plots.

Sign in / Sign up

Export Citation Format

Share Document