Natural Mineral Clay Research Articles

Antibacterial Activity of a Natural Clay Mineral against Burkholderia cepacia Complex and Other Bacterial Pathogens Isolated from People with Cystic Fibrosis.

There is an impending crisis in healthcare brought about by a new era of untreatable infections caused by bacteria resistant to all available antibiotics. Thus, there is an urgent need to identify novel antimicrobial agents to counter the continuing threat posed by formerly treatable infections. We previously reported that a natural mineral clay known as Kisameet clay (KC) is a potent inhibitor of the organisms responsible for acute infections. Chronic bacterial infections present another major challenge to treatment by antimicrobials, due to their prolonged nature, which results in repeated exposure to antibiotics and a constant selection for antimicrobial resistance. A prime example is bacteria belonging to the Burkholderia cepacia complex (Bcc), which particularly causes some of the most serious chronic lung infections in patients with cystic fibrosis (CF) associated with unpredictable clinical outcomes, poor prognosis, and high mortality rates. Eradication of these organisms from CF patients with limited effective antimicrobial options is a major challenge. Novel therapeutic approaches are urgently required. Here, we report the in vitro antibacterial activity of KC aqueous suspensions (1-10% w/v) and its aqueous extract (L100) against a collection of extensively and multi-drug resistant clinical isolates of Bcc, Pseudomonas aeruginosa, and Stenotrophomonas maltophilia isolated from patients with CF. These findings present a potential novel therapy for further investigation in the clinic.

Preparation of Cement Clinker from Geopolymer-Based Wastes.

In order to avoid potential environmental pollution from geopolymer-based material wastes, this work investigated the feasibility of using these materials as alternative raw materials in the preparation of cement clinker. The geopolymer binders and mortars were used as substitutes for natural mineral clays since they are rich in silica and alumina. Simulated geopolymer wastes were prepared by the activation of metakaolin or fly ash by an alkaline silicate solution. The cement-clinkers fired at 1450 °C for 1h were characterized by XRD, XRF, SEM-EDS, and a free lime (CaOf) content test. The anhydrous clinker mineral phases C3S (Ca3SiO5), C2S (Ca2SiO4), C3A (Ca3Al2O6), and C4AF (Ca4Al2Fe2O10) were well-crystallized in all investigated formulations. The free lime was lower than 1.3 wt% in all elaborated clinkers, which indicates a high degree of clinkerization. The results demonstrate that geopolymer binder and mortar materials are suitable substitutes for natural mineral clay incement clinker preparation.

Antimicrobial activities of different agents including pyrophyllite against foodborne pathogens: A brief review

There has been worldwide an increasing interest and more strict criteria for food/feed safety including absence or reduction of the total number of microorganisms (bacteria, moulds and yeasts). Besides heavy metals, materials of biological origin (plant extracts, bio waste, chitosan etc.), some mineral adsorbents also have antimicrobial properties. There is much information about the antibacterial activity of the modified bentonite, montmoriollonite, smectute, zeolites and antifungal activity of various metal ion-exchanged zeolites and natural mineral clay, but there is almost no information about the antimicrobial properties of pyrophyllite, a monoclinic mineral from the group of phyllosilicates. This work summarizes the recent developments of antimicrobial agents and their application, current research, and trends in the area, highlighting pyrophyllite and its potential applications. Pyrophyllite, an unexploited mineral, possesses antimicrobial properties such as antibacterial and antifungal activities against foodborne pathogens which contributes to the protection of consumer?s health and preservation of the environment. Results from preliminary investigations indicate that pyrophyllite showed antibacterial properties against Escherichia coli, Staphylococcus aureus, Enterococcus faecalis, and antifungal properties against fungal pathogens (Fusarium oxysporum, Phoma glomerata and Rhizoctonia solani). This mineral can also be used for biological control of F. oxysporum in the soil for growing potato.

Toxic effects of a modified montmorillonite clay on the human intestinal cell line Caco-2

The incorporation of the natural mineral clay montmorillonite into polymeric systems enhances their barrier properties as well as their thermal and mechanical resistance, making them suitable for a wide range of industrial applications, e.g., in the food industry. Considering humans could easily be exposed to these clays due to migration into food, toxicological and health effects of clay exposure should be studied. In the present work, the cytotoxic effects induced by two different clays (the unmodified clay Cloisite(®) Na(+) , and the organically modified Cloisite(®) 30B) on Caco-2 cells were studied after 24 and 48 h of exposure. The basal cytotoxicity endpoints assessed were total protein content, neutral red uptake and a tetrazolium salt reduction. Our results showed that only Cloisite(®) 30B induced toxic effects. Therefore, the effects of subcytotoxic concentrations of this clay on the generation of intracellular reactive oxygen species, glutathione content and DNA damage (comet assay) were investigated. Results indicate that oxidative stress may be implicated in the toxicity induced by Closite(®) 30B, in regards of the increases in intracellular reactive oxygen species production and glutathione content at the highest concentration assayed, while no damage was observed in DNA. The most remarkable morphological alterations observed were dilated cisternae edge in the Golgi apparatus and nucleolar segregation, suggesting impairment in the secretory functions, which could be related to inhibition in the synthesis of proteins.

Mineralogical, Crystal Structure and Chemical Composition Characterization of Iraqi Natural Rich-Montmorillonite Mineral Clays

This study provides the mineralogical and compositional characterization locally natural mineral clay deposits of Iraq and their parent and enclosing rocks. The mineral assemblage of the raw clays of these primary deposits has been determined to include disordered montmorillonite, quartz, gypsum, calcite, in addition to trace amounts of other mineral clays like feldspar and kaolinite. Such results have been investigated using powder x-ray diffraction, x-ray fluorescence, thermo gravimetric analysis, differential thermal analysis, infrared spectroscopy, and technical chemical analysis. Physical properties, crystal structure, and, chemical composition of this montmorillonite rich mineral clays also have been performed to attribute that influence the industrial usage of Iraqi natural mineral clays are high lighted.

Carbon paste electrodes modified with a new phenothiazine derivative adsorbed on zeolite and on mineral clay for NADH oxidation

Two new composite electrodes, based on carbon paste (CP) incorporating a synthetic zeolite (13X type; Z) or a natural mineral clay (bentonite; B), both impregnated with a new phenothiazine derivative [3,7-di(m-aminophenyl)-10-ethyl phenothiazine; EPh], were developed. The physical properties of the EPh-Z and EPh-B composite materials have been investigated using scanning electron microscopy, energy dispersive X ray spectroscopy, Fourier transform infrared spectroscopy. Cyclic voltammetry (CV) and rotating disk electrode measurements were used for electrochemical characterization of the EPh-Z-CPEs and EPh-B-CPEs electrodes. CV measurements revealed a reasonably fast electron transfer rate for both modified electrodes. No significant differences, concerning the pH effect on the formal standard potential, the magnitude of the rate constants for heterogeneous electron transfer and the electrode response stability, were observed between the investigated electrodes. Both electrodes showed a good electrocatalytic activity for β-nicotinamide adenine dinucleotide (NADH) oxidation (for example, in the case of EPh-Z-CPEs the electrocatalytic rate constant was 1.1×104M−1s−1, at pH 7).

The Influence of Biological Feed Additives on Broiler Performance

3 Abstract: An experiment was designed to evaluate the effect of some natural feed additives as alternatives of antibiotic growth promoters for broiler chicks. A total number of 1188 unsexed one-day old Ross 308 chicks were used. Two trials were conducted simultaneously using the same control treatments, a negative control (NC) with no feed additive and a positive control (PC) supplemented with Enramycine (0.025%) as antibiotic growth promoter. In the fist trial, natural mineral clay commercial products of Diatomaceous earth , 1 at 0.2% (DE0. 2%) and 0.5% (DE0. 5%) and Farmagulator , at 0.125% (Fg. 125%) and, 0.25% (Fg 0.25%) 2 were compared with the control treatments. In the 2 trial, pre/pro-biotics commercial products of Diamond nd VXPC , 0.075% (DV 0.075%) and 0.10% (DV 0.10%); Tomoko , 0.05% (Tom 0.05%) and 0.1% (Tom 0.1%); 3 4 and Primalac , 0.15% (PL 0.15) were compared with the two control treatments. Diets were formulated to 5 meet nutrient requirements of chicks recommended for Ross 308. Results indicated that performance and immune response of the chicks fed diets containing pro/pre-biotic products were higher than those fed diets containing natural mineral clay products. The positive control or the treated group significantly recorded higher body weight than the negative control, with an exception of Diatomaceous earth treatment. Diatomaceous earth treatments (0.2% or 0.5%) significantly recorded the worst performance and the lowest economical efficiency compared to the negative control or the other treatments. From commercial point of view, biological feed additives of pre/pro-bioti cs or natural mineral clay as alternative of antibiotic growth promoter are beneficial with exception of Diatomaceous earth. Diets supplemented with biological feed additives enhanced the digestibility coefficients of most nutrients better than the controls, however, DE lowered the digestibility coefficients of most nutrients. It is concluded that performance and immune response of chicks fed on biological feed additives were equivalent or even superior to that of antibioti c growth promoter except for Diatomaceous earth. The tested materials were superior to the negative control when added to the diet in the term of performance.

In vivo iontophoretic delivery of calcium ions through guinea pig skin enhanced by direct and pulsating current

Studies were initiated to investigate the effect of the delivery mode of45Ca ions through guinea pig skin in vivo. Direct current (DC), pulsating current (PC) and a Bernard current form, the “courtes periodes” current profile (CP) were applied with the same current density (0.16 mA/cm2) and for the same duration (30 minutes). The45Ca ions were delivered from a Ca-bentonite patch radiolabeled with45Ca (a natural mineral clay rich in calcium, 50 mgCa/g). The total quantity of applied bentonite was 1.5g×10 days=15g.45Ca was counted in different biological samples of the animals. The delivery of45Ca ions into the body (systemic effect) is the highest when CP current is applied (6.87±0.95·10−12g/samples). The local effect appears to be more effective in case of DC current mode (5.89±0.12·10−12g/0.5g bone). Total calcium measurements proved that the result of transdermal radiocalcium delivery is not only an ion exchange process at the surface of the bone but a deposition of calcium ions into the hydroxiapatite matrix (the net calcium introduction, which represent the difference between the total calcium into the treated bone and total calcium into untreated bone varied from 15.52±2.42·10−3g/0.5g bone to 44.30±3.50·10−3g/0.5g bone). The results suggest that iontophoresis could be used to accumulate calcium into different target tissues using the appropriate current system.

Effect of the different factors on the iontophoretic delivery of calcium ions from bentonite

The calcium content of mud patches used for therapy is very small. Several mineral clays originating from Hungary served as a base material for experiments in order to find a suitable drug for transdermal introduction of calcium ions into the body. The Ca ++ transport through the pig skin has been investigated in vitro in diffusion cells applying iontophoresis. Studies of electrical and physicochemical factors acting on the permeation kinetics of in vitro experiments were performed. The utilization of direct current has intensified the Ca ++ transport through the pig skin (129.78±26.15 μg Ca/cm 2). On using pulsate currents the amount of the Ca ++ penetrating through the skin was 5–10 times higher (283.18±16.89 μg Ca/cm 2, 388.71±19.90 μg Ca/cm 2) than that of the passive transport (36.22±14.20 μg Ca/cm 2). The amount of Ca ++ cumulated in the receptor compartment was directly proportional to the amount of bentonite (a natural mineral clay with a large cation exchange capacity) in the donor compartment and to the concentration of Ca ++ in the lattice of the applied mineral clay. Therefore, the experiments were carried out on a bentonite previously enriched in Ca ++ in its lattice (50 mg Ca/g bentonite). The results of the in vitro studies could open a new field of application in the therapy of osteoporosis or in the use of mineral substances.