Bioavailability Of Essential Elements Research Articles

Assessment of Biofortification Approaches Used to Improve Micronutrient-Dense Plants That Are a Sustainable Solution to Combat Hidden Hunger.

Malnutrition causes diseases, immune system disorders, deterioration in physical growth, mental development, and learning capacity worldwide. Micronutrient deficiency, known as hidden hunger, is a serious global problem. Biofortification is a cost-effective and sustainable agricultural strategy for increasing the concentrations or bioavailability of essential elements in the edible parts of plants, minimizing the risks of toxic metals, and thus reducing malnutrition. It has the advantage of delivering micronutrient-dense food crops to a large part of the global population, especially poor populations. Agronomic biofortification and biofertilization, traditional plant breeding, and optimized fertilizer applications are more globally accepted methods today; however, genetic biofortification based on genetic engineering such as increasing or manipulating (such as CRISPR-Cas9) the expression of genes that affect the regulation of metal homeostasis and carrier proteins that serve to increase the micronutrient content for higher nutrient concentration and greater productivity or that affect bioavailability is also seen as a promising high-potential strategy in solving this micronutrient deficiency problem. Data that micronutrients can help strengthen the immune system against the COVID-19 pandemic and other diseases has highlighted the importance of tackling micronutrient deficiencies. In this study, biofortification approaches such as plant breeding, agronomic techniques, microbial fertilization, and some genetic and nanotechnological methods used in the fight against micronutrient deficiency worldwide were compiled.

Enhanced Nutritional Quality of Sweet Maize Kernel in Response to Cover Crops and Bio-Fertilizer

Cover crops (CC) are an important low-input strategy in sustainable agricultural systems. The impact of different CC (common vetch, field pea, winter oats, fodder kale, common vetch + winter oats and field pea + winter oats), organic mulch, control treatment-fallow, and bio-fertilizer (BF) application, on yield and quality of sweet maize kernel was evaluated. CC biomass was higher in mixtures: field pea + winter oats, and common vetch + winter oats, as well as in fodder kale. Kernel yield and its chemical composition varied significantly by CC, BF, year, and their interaction. Organic mulch enhanced the concentration of sugars and glutathione in maize kernel. BF increased kernel yield, the concentration of sugars, vitamin C, Mg, Fe, Zn, and reduced phytate concentration. The highest Mg and Mn concentration in maize kernel was achieved with fodder kale, Zn concentration with common vetch + winter oats + BF, and Fe concentration with winter oats. The same treatments expressed the highest impact on variability in concentration of the phytate, phenolics, and yellow pigment, thus affecting further bio-availability of essential elements. Results indicate that in a semi-arid climate, under rain-fed conditions, CC such as fodder kale and winter oats + common vetch could enhance sweet maize productivity and kernel quality, serving as an important part of a sustainable cropping system, to facilitate food security.

Relationship between soil cobalt and vitamin B12 levels in the liver of livestock in Saudi Arabia: role of competing elements in soils.

This study aimed to analyze the agricultural soils from different regions in Saudi Arabia for cobalt and related metals as Cu(2+), Ni(2+), Cr(3+), Zn(2+) and Pb(2+). Liver and muscle tissues of livestock grazing on the selected areas were analyzed for the content of Co and vitamin B12. Our results indicated that the levels of Co in surface soil (0-15 cm) were higher than in sub-surface soil (>15 cm-45 cm). In contrast, Pb and Zn were higher in sub-surface soil than in surface soil. A significant positive correlation existed between the levels of Co and vitamin B12 in the liver of livestock. However, Co was not detected in muscle tissues while vitamin B12 was present at very low levels in comparison with the levels found in the liver. The results indicated that Zn(2+), Pb(2+) compete with Co in soil, which eventually affected the levels of vitamin B12 in liver. It was recommended that survey of heavy metals in grazing fields of cattle should consider inclusion of multiple elements that compete with the bioavailability of essential elements in plants and animals for the prevention of deficiency of essential elements such as Co.

Mobilisation of Radionuclides by Ligands Produced by Bacteria from the Deep Subsurface

ABSTRACTMicrobial processes can influence retention of radionuclides directly or indirectly in several different ways. Many microorganisms produce various kinds of ligands or chelating compounds to increase the bioavailability of essential elements needed for metabolism. These ligands are not always highly specific, and several of them will also mobilise other elements such as heavy metals and radionuclides. Three bacterial species (Shewanella putrefaciens, Pseudomonas fluorescensandPseudomonas stutzerii), isolated from the deep subsurface, and four radionuclides,59Fe(III),147Pm(III),234Th(IV) and241Am(III), were selected for this study. The microbes were cultured in the laboratory, separated from their exudates by centrifugation, and the supernatants were collected. The supernatants were mixed with radionuclide and solid phase (TiO2or SiO2). The pH ranged from 7.5–9.0. All three bacterial species produced ligands that were able to complex up to 90% of the radionuclides in competition with the solid phases. High performance liquid chromatography analysis detected four Fe-complexing substances in the supernatant from P. fluorescens and two peaks and one peak, respectively, fromP. stutzeriiandS. putrefaciens. All substances eluted from the column varied in retention times, indicating that the microbes studied produced several metabolites that have different chelating abilities.

Multi-elemental fractionation in milk whey by size exclusion chromatography coupled on line to ICP-MS

A fast hybrid technique based on HPLC coupled to ICP-MS was used to study elemental fractionation patterns in milk whey of different types of milk (human, cow and formula milk) taking advantage of the multi-elemental capability of ICP-MS. Milk whey was obtained from the corresponding whole milk samples by resorting to ultra-centrifugation. The method described separated the different fractions in a high-pressure column, based on size exclusion chromatography (SEC) on a TSK G 2000 SWXL column, coupled on-line to the inductively coupled plasma mass spectrometer for multi-elemental detection. After optimisation of the instrumental conditions, the method was applied to investigate the fractionation pattern of Fe, Cu, Zn, Mn, Sr, I, Br, Ca and Mg in four different samples of each kind of milk whey under study (human, raw cow, UHT cow and formula milk whey). As a result of this, it was found that the elemental binding patterns in human milk were different from those observed in cow and formula milks. This finding seems to indicate the presence in human milk of specific ligands. Thus, bioavailability of essential elements seems to be different in man. Therefore, more care and further study should be given to the characteristics of cow and formula milks used for human nutrition, particularly in babies and infants.