Mechanisms for altering phosphorus sorption characteristics induced by low-molecular-weight organic acids

2016 ◽  
Vol 96 (3) ◽  
pp. 289-298 ◽  
Author(s):  
Yongzhuang Wang ◽  
Joann K. Whalen ◽  
Xin Chen ◽  
Yanhong Cao ◽  
Bin Huang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Organic Acids ◽  
Low Molecular Weight ◽  
Minor Effect ◽  
Phosphorus Sorption ◽  
Sorption Data ◽  
P Fractionation ◽  
Soil P ◽  
P Sorption ◽  
A Minor

Exudation of low-molecular-weight organic acids (LMWOAs) from plant roots enhances phosphorus (P) acquisition from soil, either by dissolving P fixed in secondary minerals or by reducing P sorption to organo-minerals. How LMWOAs may modify P sorption in soils with contrasting pH is not well understood, much less the mechanisms involved. The effects of three common LMWOAs (oxalic, citric, and malic acids) on P sorption in calcareous, neutral, and acidic soils were studied in batch experiments, followed by sequential P fractionation to elucidate the mechanisms whereby LMWOAs alter P sorption. The sorption data of the three soils fitted better to the Freundlich equation (r2 = 0.325–0.994, P < 0.05) than the Langmuir and linear equations. Oxalic, citric, and malic acids at 10 mmol kg−1 soil decreased the Freundlich P sorption parameters Kf and n, which represent P sorption capacity and energy, due to the fact that LMWOAs reduced P sorption in NaHCO3-Pi (soil soluble and exchangeable Pi, 23.8–30.9%) and NaOH-Pi (Fe-Pi and Al-Pi, 21.6–54.2%) fractions of the three soils. Comparing acidified P-LMWOAs solutions with the pH-adjusted P-LMWOAs solutions (pH = 7) had a minor effect on P sorption. Our results indicated that the reduction in soil P sorption was due to ligand exchange and chelation of LMWOAs with Fe and Al minerals, and the acid strength of LMWOAs had a minor effect on P sorption in calcareous, neutral, and acid soils.

scholarly journals Utilization of low molecular weight organic compounds by the filterable fraction of a lotic microbiome

2020 ◽  
Author(s):  
Lydia-Ann J Ghuneim ◽  
Marco A Distaso ◽  
Tatyana N Chernikova ◽  
Rafael Bargiela ◽  
Evgenii A Lunev ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Community Dynamics ◽  
Lag Phase ◽  
Minor Role ◽  
Low Molecular Weight ◽  
Freshwater Systems ◽  
North Wales ◽  
Clusters Of Orthologous Groups ◽  
A Minor ◽  
Substrate Addition

Abstract Filterable microorganisms participate in dissolved organic carbon (DOC) cycling in freshwater systems, however their exact functional role remains unknown. We determined taxonomic identity and community dynamics of prokaryotic microbiomes in the 0.22 µm-filtered fraction and unfiltered freshwater from the Conwy River (North Wales, UK) in microcosms and, using targeted metabolomics and 14C-labelling, examined their role in utilization of amino acids, organic acids, and sugars spiked at environmentally-relevant (nanomolar) concentrations. To identify changes in community structure, we used 16S rRNA amplicon and shotgun sequencing. Unlike the unfiltered water samples where the consumption of DOC was rapid, the filtered fraction showed a 3-days lag phase before the consumption started. Analysis of functional categories of clusters of orthologous groups of proteins (COGs) showed COGs associated with energy production increased in numbers in both fractions with substrate addition. The filtered fraction utilized low-molecular-weight (LMW) DOC at much slower rates than the whole community. Addition of nanomolar concentrations of LMW DOC did not measurably influence the composition of the microbial community nor the rate of consumption across all substrate types in either fraction. We conclude that due to their low activity, filterable microorganisms play a minor role in LMW DOC processing within short residence time of lotic freshwater systems.

Differences in solubility parameters and susceptibility to salting-out between softwood and hardwood lignosulfonates

Holzforschung ◽  
2016 ◽  
Vol 70 (11) ◽  
pp. 1015-1021 ◽  
Author(s):  
Bernt O. Myrvold
Keyword(s):  
Molecular Weight ◽  
Salt Tolerance ◽  
Plant Species ◽  
Post Treatment ◽  
Solubility Parameters ◽  
Minor Effect ◽  
Hofmeister Series ◽  
Salt Tolerant ◽  
Salting Out ◽  
A Minor

Abstract The salting-out of lignosulfonates (LSs) follows the Hofmeister series, but different LSs show different susceptibility to salting-out. By comparing results for a large number of LSs from different plant species, pulping conditions, and post-treatment of the LS, it was found that the salting-out concentration for different LSs is mainly due to differences in the plant species with guaiacyl LS being much more salt-tolerant than guaiacyl-syringyl LS. The pulping conditions have only a minor effect on the salt tolerance of the different LSs. Post-treatment that increases the molecular weight or reduces the sulfonation also reduces the salt tolerance.

scholarly journals INFLUENCE OF VARIOUS FEED ADDITIVES ON THE ACTIVITY OF CHYME AND BLOOD PLASMA ENZYMES OF YOUNG MEAT CHICKEN OF ORIGINAL LINE

THE BULLETIN ◽  
2021 ◽  
Vol 2 (390) ◽  
pp. 12-17
Author(s):  
A. Grozina
Keyword(s):  
Molecular Weight ◽  
Organic Acids ◽  
Blood Plasma ◽  
Digestive Enzymes ◽  
Feed Additives ◽  
Pancreatic Enzymes ◽  
Control Group ◽  
Physiological Status ◽  
Low Molecular Weight ◽  
Original Line

The research aimed to determine the effect of a mixture of low molecular weight organic acids and complex phytobiotics when replacing a feed antibiotic with them on the activity of digestive enzymes in the duode-nal chyme and the activity of pancreatic enzymes in the blood plasma of young stock B5 and B9 meat chicken lines. The experiments were carried out on the original lines of meat poultry lines B5 (Cornish) and B9 (Plymouth rock). There was an operation to insert a cannula into the duodenum at the age of 6 weeks. The enzymatic activity of the duodenum chyme and the content of pancreatic enzymes in the blood plasma in the groups of chickens receiving antibiotics, low molecular weight organic acids, and phytobiotics with the diet. The data showed that the influence of feed additives on the physiological status of poultry was different. The use of low molecular weight organic acids of the B5 and B9 chicken lines had a significant effect on the production of digestive enzymes due to an increase in the activity of chyme lipase (by 98.3%) and blood plasma lipase (by 26.6%) in B9 chickens and an increase in chyme proteases (by 30.9%) in B5 chickens compared with the control group, where the antibiotic was used. The introduction of complex phytobiotics into the diet had a negative effect on chickens of the B5 line (Cornish), reducing the activity of amylase and lipase of the duodenal chyme (by 29.2 and 26.9%) compared with the control group. In B9 (Plymouth rock) chickens, only the chyme amylase activity increased by 30.8% that indicates an improvement in the availability of feed carbohydrates. These data confirm the need to take into account the different effects of feed additives on the digestion processes in different poultry crosses.

scholarly journals Short-term effects of phosphate fertilizer enriched with low molecular weight organic acids on phosphorus release kinetic and availability under calcareous conditions in arid region

2018 ◽  
Vol 2 ◽  
pp. 66
Author(s):  
Adil Mihoub ◽  
Mustapha Daddi Bouhoun ◽  
Asif Naeem
Keyword(s):  
Molecular Weight ◽  
Acid Solution ◽  
Organic Acids ◽  
Phosphorus Release ◽  
Favorable Effect ◽  
Available Phosphorus ◽  
Low Molecular Weight ◽  
Release Kinetic ◽  
P Availability ◽  
Phosphate Fertilizers

Phosphate reactions and retention in the soil are of paramount importance from the perspective of plant nutrition and fertilizer use efficiency. The objective of this work was to investigate the effect of some low molecular weight organic acids (LMWOAs) on phosphorus release kinetic and its availability in calcareous soil. Experiments were conducted in laboratory. Soil-limestone mixtures were prepared to achieve highly calcareous samples (i.e. 50% CaCO3). The prepared samples were mixed thoroughly with phosphate fertilizers i.e. Triple super phosphate (TSP) and Monoammonium Phosphate (MAP) and watered with distilled water only (CK), with citric acid solution (CA) and with oxalic acid solution (OA). The treatments were arranged in a CRD with three replications and incubated at 25 ± 2°C and 80% soil moisture for a period of 960 h. The parabolic model was used for describing the decrease in P with time. As a result, all treatments showed a significant decrease in available P with time. Using LMWOAs showed important results and combination of phosphate fertilizers with both LMWOAs solutions exerted a very favorable effect on P availability in soil. The parabolic diffusion equation used was fitted well to experimental data. Addition of LMWOAs decreased loss in extractability of P with increasing soil available phosphorus fraction. Moreover, treatments irrigated by LMWOAs solutions released a lot of phosphorus compared to untreated treatments.

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