Capture of Essential Trace Elements and Phosphate Accumulation as a Basis for the Antimicrobial Activity of a New Ultramicrobacterium—Microbacterium lacticum Str. F2E

Microbial interactions play an important role in natural habitat. The long-term coevolution of various species leads to the adaptation of certain types of microorganisms as well as to the formation of a wide variety of interactions such as competitive, antagonistic, pathogenic and parasitic relationships. The aim of this work is a comprehensive study of a new ultramicrobacterium Microbacterium lacticum str. F2E, isolated from perennial oil sludge, which is characterized by high antimicrobial activity and a unique ultrastructural organization of the cell envelope, which includes globular surface ultrastructures with a high negative charge. A previously undescribed mechanism for the antagonistic action of the F2E strain against the prey bacterium is proposed. This mechanism is based on the ability to preferentially capture essential microelements, in which charge interactions and the property of phosphate accumulation may play a significant role. The revealed type of intermicrobial interaction can probably be attributed to the non-contact type antagonistic action in the absence of any diffuse factor secreted by the antagonistic bacteria.

Determination of arsenic, cadmium, selenium, zinc and other trace elements in Bangladeshi fish and arsenic speciation study of Hilsa fish flesh and eggs: Implications for dietary intake

Exposure to As from drinking water and its impact on the health of the Bangladeshi population has received much attention. However, very little information is available regarding As exposure through consumption of fish, which is the main source of animal protein for the majority of Bangladeshis. In this study, concentrations of As, Cd, Pb, Mn Se and Zn in different types of fish, consumed by Bangladeshis, were determined using Inductively Coupled Plasma Mass Spectrometry. Daily intakes of the toxic elements As, Cd and Pb through fish consumption were estimated to be 31.8, 0.4 and 4.8 μg/day, respectively. Hilsa (Tenualosa ilisha) contained the highest concentrations of total As (mean ± SD was 2.55 ± 1.3 mg/kg; n = 15) among the fish analysed. However, toxic inorganic As species were not detected. The dominant As species in Hilsa fish were: dimethylarsenic acid, arsenobetaine and arsenosugars, at 69, 11 and 20% of total As, respectively. The high concentration of Cd detected in Hilsa eggs (average 278 ± 518 μg/kg; range 7.4–1725 μg/kg; n = 10) is of concern since this may have harmful effects on the development of embryos and lead to a decline in the Hilsa population or the quality of the fish. It can also be harmful to those who consume Hilsa eggs on a regular basis. Selenium was found to be highest in Shoal (Micropterus cataractae) fish and a type of small fish, and lowest in Mrigal (Cirrhinus cirrhosis). Small fish species contained Mn and Zn at 7.1- and 4.3-fold higher concentrations, respectively, compared to big fish species. Keski (Corica soborna), a small fish species, contained by far the highest concentrations of Mn (52 mg/kg) and Zn (140 mg/kg), although the concentration of As (1.4 mg/kg) in this fish was lower than that of several other fish species. Small fish species are often consumed whole, including the bones, and therefore the essential trace elements present are potentially bioavailable for cellular metabolism. Our study shows that the Bangladeshi population can easily meet their daily requirement of Se and Zn from consumption of fish such as Shoal fish (Se and Zn), Hilsa fish (Se and Zn) and Keski fish (Se and Zn). Consumption of small fish (such as Keski) and big fish (such as Hilsa) from Bangladesh can provide valuable sources of essential trace elements as part of a balanced diet and thus negate the need for supplements and biofortification of certain foods. Ours is a small study and a detailed total dietary intake and human biomonitoring studies, that includes coverage of different socio-economic groups, are needed in Bangladesh before giving people supplements or biofortified foods.

Hydrochemical Characteristics of Surface Waters and Their Relationships to the Kashin–Beck Disease in Longzi County, Tibet

Although previous studies have been reported between the Kashin–Beck Disease (KBD) epidemic and the hydrochemical characteristics of surface waters, the etiology of the disease remains unclear. In the present study, we investigated the relationship between the KBD and the environment by comprehensively examining the hydrochemical characteristics of surface waters in Longzi County, Tibet, and the spatial incidence of the disease. Results show that, the pH (mean = 7.27±0.30), TH (mean = 57.08±45.74 mg L–1), and TDS (mean = 67.56±44.00 mg L–1) of surface waters in KBD endemic areas are lower than for those in the non-KBD endemic areas (means of pH = 7.49±0.30; TH = 262.06±123.29 mg L–1; TDS = 253.25±100.39 mg L–1). These results suggest that long-term consumption of low TDS, essential trace elements (e.g., nickel, cobalt, iron, selenium, zinc, molybdenum, and iodine) deficient, and potential toxic elements (such as arsenic) enriched waters by humans likely causes the KBD. Environmental factors such as the geology and geomorphology may produce biogeochemical imbalance, geomorphic, vegetation types and local climatic conditions may have significant impact on food fungi toxin poisoning and water organic compound poisoning, and these are also important in the KBD occurrence.

Dose-dependent effect of chronic exposure to lead acetate on the dynamics of the content of delta-aminolevulinic acid and essential trace elements in the serum of laying hens

One of the most global and dangerous pollutants is considered to be lead, due to its ability to accumulate in living organisms, to be included in the metabolic cycle, to form highly toxic organometallic compounds, not being biodegradable. To study the chronic effects of lead acetate, an experiment was performed on laying hens of Lohmann Brown cross. For research, one control and three experimental groups were formed, 20 chickens in each. Birds of the experimental groups were administered lead acetate daily with compound feed in doses (in terms of metal): Group I – 50 mg/kg of feed, II – 75 mg/kg of feed, III – 150 mg/kg of feed. Access to water was not restricted. The birds of the control group received a complete diet without lead acetate. On the 30th, 90th, 120th days of the experiment and the 20th day after withdrawal of the toxicant (the 140th day of the experiment), we took blood samples from birds for biochemical and toxicological studies. The concentration of delta-aminolevulinic acid (δ-ALA) in the serum of laying hens was determined by reversed-phase high-performance liquid chromatography. Determination of the content of lead in the serum of laying hens was performed by X-ray fluorescence analysis. The concentration of total calcium, inorganic phosphorus, and magnesium in the serum of the laying hens was determined using production kits. We detected the dose-dependent chronic effect of lead acetate on the dynamics of the content of delta-aminolevulinic acid and essential trace elements in the serum of laying hens. The administration of lead acetate into the body of productive poultry for 120 days in doses of 50, 75, and 150 mg/kg with feed did not cause visible clinical signs of poisoning, but caused a violation of porphyrin metabolism, manifested in a reliable increase in the concentration of delta-aminolevulinic acid in serum on the 30th, 90th and 120th days of the experiment. It has been experimentally proven that the administration into the body of laying hens of lead acetate in doses of 50, 75 and 150 mg/kg of feed for 120 days leads to the maximum accumulation of lead in the serum on the 30th, 90th, and 120th days of the experiment. Prolonged administration of lead acetate to laying hens at high concentrations is characterized by a reliable decrease in the content of total calcium, inorganic phosphorus and magnesium in the serum of laying hens and a reliable increase in the content of ferrum. In the future it is necessary to study the intensity of lipid peroxidation processes in laying hens under chronic exposure to lead acetate.

Comparison of the Mineral and Nutraceutical Profiles of Elephant Garlic (Allium ampeloprasum L.) Grown in Organic and Conventional Fields of Valdichiana, a Traditional Cultivation Area of Tuscany, Italy

In the Valdichiana area (Tuscany, Italy) an ancient native landrace of elephant garlic (Allium ampeloprasum L.), locally known as “Aglione della Valdichiana”, has long been cultivated. The aim of this study was to check whether there are differences in the mineral and nutraceutical profiles of the Aglione della Valdichiana cultivated conventionally and organically. Based on the analysis by ICP-MS of a wide array of major, minor, essential, and non-essential trace elements as well as rare earth elements, and the evaluation of the content of polyphenols, flavonoids, antioxidants, soluble proteins, soluble sugars, and starch, as well as the weight and water content, it was concluded that differences in the mineral and nutraceutical profiles of organically and conventionally grown bulbs were very limited. Only a statistically (p < 0.05) higher concentration of Cd (+2620%), Co (+113%), Mn (+55%), Rb (+180%), and Sb (+180%), as well as glucose (+37%) in conventionally cultivated bulbs emerged. Cadmium was the only element slightly higher than in the “reference plant,” but with a negligible risk (three orders of magnitude lower) for human health based on consumption. It is concluded that we failed to find evidence of healthier food or a higher nutraceutical quality for organically cultivated elephant garlic.

Genotoxicity of chromium (III) and cobalt (II) and interactions between them

Introduction. Chromium and cobalt are essential trace elements that are required only in a small amount, otherwise their excess can cause toxic effects. Aim. The aim of this study was to determine the effects of chromium (III) and cobalt (II) and their combinations on genotoxicity in human fibroblasts cells (BJ). Material and methods. In this work, comet and micronucleus assays were used. The BJ cells were exposed to chromium chloride and cobalt chloride at concentration ranges from 100 to 1400 µM. Mixtures of these elements were prepared so as to examine interactions between them. Results. The present study shows the genotoxic effects of chromium (III) and cobalt (II) and their mixtures on BJ cells. In the comet assay, no comets were observed at the lowest concentrations; in the higher, a significant increase in their percentage was observed. In the other assay (formation of micronuclei), a statistically significant increase in the number of cells with micronuclei was observed in the BJ cells spiked with cobalt chloride and chromium chloride. In the case of simultaneous incubation of chromium chloride at 200 µM and cobalt chloride at 1000 µM in the BJ line, antagonism was observed. However, the interaction of chromium chloride at the 1000 µM and cobalt chloride at 200 µM leads to synergism between the studied elements. Conclusions. Cobalt (II) and chromium (III) show genotoxic properties, they induce breaks in double and single-stranded DNA and they cause formation of AP-sites that do not have purine or pyrimidine bases.

Benefit-Risk Assessment of Fish And Shrimp Consumption From A Large Eutrophic Freshwater Lake, Southeastern China

Obtaining beneficial nutrients meanwhile ingesting hazardous contaminants through freshwater fish consumption remains a concern for inland residents in China. In this study, contents of fatty acids, essential trace elements (Fe, I, Zn, Se, Cu, Mo, Cr) and non-essential trace elements (As, Cd, Hg, Ni, Pb) were quantified in nine fish and two shrimp species from large eutrophic Chaohu Lake, southeastern China. Benefit-risk assessment for fish and shrimp consumption was conducted on basis of nutrients and contaminants. Total fat acids in the samples were 104.2-2405.2 mg/100g, included which DHA+EPA were 29.0-238.6 mg/100g. Mean content of essential trace elements (μg/g) in fish and shrimp species followed the order of Fe (10.3)>Cu (9.9)>Zn (7.7)> >Cr (1.42)>Se (0.337)>Mo (0.285)>I (0.023). The As, Cd, Hg, Ni, Pb content in the samples were nd-218, 14-97, 3-47, 4200-11300 and 144-1127 μg/kg, respectively, which was below the national maximum limit with the exception of Pb content in several samples. Though no obvious bioaccumulation pattern was found among species, species living in the demersal layers or with higher trophic levels tend to accumulate more trace elements. To achieve the recommended 250 mg of DHA+EPA daily intake, results of benefit-risk assessment indicated that fish and shrimp consumption can be major source of Se, Cu, Mo and Cr intake, whereas fish consumption was potential non-carcinogenic risk exposure for Ni and microcystins. Benefit-risk assessment contributed to the identification of main benefits and hazards of freshwater fish and shrimp consumption for inland populations around the large eutrophic lake.