From cashew byproducts to biodegradable active materials: Bacterial cellulose-lignin-cellulose nanocrystal nanocomposite films

While the cashew culture is focused on processing and commercialization of cashew nuts, the pseudofruit (cashew apples) - highly perishable and of limited acceptance - are mostly wasted. The cashew tree pruning fiber (CTPF) is another interesting cashew byproduct. In this study, films have been made from bacterial cellulose produced from cashew apple juice, and added with lignin (0-15 wt%) and cellulose nanocrystals (0-8 wt%), both from CTPF, which enhanced tensile properties and decreased water vapor permeability of the films. Moreover, lignin, although imparting brown color and opacity to the films, was effective to provide the films with UV-absorbing and antioxidant properties, making the films interesting for packaging of food products susceptible to lipid oxidation. The films did not exhibit antimicrobial activity against bacteria or yeasts.

Inhalation of Bacterial Cellulose Nanofibrils Triggers an Inflammatory Response and Changes Lung Tissue Morphology of Mice

In view of the growing industrial use of Bacterial cellulose (BC), and taking into account that it might become airborne and be inhaled after industrial processing, assessing its potential pulmonary toxic effects assumes high relevance. In this work, the murine model was used to assess the effects of exposure to respirable BC nanofibrils (nBC), obtained by disintegration of BC produced by Komagataeibacter hansenii. Murine bone marrow-derived macrophages (BMMΦ) were treated with different doses of nBC (0.02 and 0.2 mg/mL, respectively 1 and 10 μg of fibrils) in absence or presence of 0.2% Carboxymethyl Cellulose (nBCMC). Furthermore, mice were instilled intratracheally with nBC or nBCMC at different concentrations and at different time-points and analyzed up to 6 months after treatments. Microcrystaline Avicel-plus® CM 2159, a plant-derived cellulose, was used for comparison. Markers of cellular damage (lactate dehydrogenase release and total protein) and oxidative stress (hydrogen peroxidase, reduced glutathione, lipid peroxidation and glutathione peroxidase activity) as well presence of inflammatory cells were evaluated in brochoalveolar lavage (BAL) fluids. Histological analysis of lungs, heart and liver tissues was also performed. BAL analysis showed that exposure to nBCMC or CMC did not induce major alterations in the assessed markers of cell damage, oxidative stress or inflammatory cell numbers in BAL fluid over time, even following cumulative treatments. Avicel-plus® CM 2159 significantly increased LDH release, detected 3 months after 4 weekly administrations. However, histological results revealed a chronic inflammatory response and tissue alterations, being hypertrophy of pulmonary arteries (observed 3 months after nBCMC treatment) of particular concern. These histological alterations remained after 6 months in animals treated with nBC, possibly due to foreign body reaction and the organism’s inability to remove the fibers. Overall, despite being a safe and biocompatible biomaterial, BC-derived nanofibrils inhalation may lead to lung pathology and pose significant health risks.

Green coconut shells applied as adsorbent for removal of toxic metal ions using fixed-bed column technology

This study applies green coconut shells as adsorbent for the removal of toxic metal ions from aqueous effluents using column adsorption. The results show that a flow rate of 2 mL/min and a bed height of 10 cm are most feasible. Furthermore, larger amounts of effluent can be treated for removal of single ions. The breakthrough curves for multiple elements gave the order of adsorption capacity: Cu(+2) > Pb(+2) > Cd(+2) > Zn(+2) > Ni(+2). Real samples arising from the electroplating industry can be efficiently handled.

Effect of fiber treatments on tensile and thermal properties of starch/ethylene vinyl alcohol copolymers/coir biocomposites

Coir fibers received three treatments, namely washing with water, alkali treatment (mercerization) and bleaching. Treated fibers were incorporated in starch/ethylene vinyl alcohol copolymers (EVOH) blends. Mechanical and thermal properties of starch/EVOH/coir biocomposites were evaluated. Fiber morphology and the fiber/matrix interface were further characterized by scanning electron microscopy (SEM). All treatments produced surface modifications and improved the thermal stability of the fibers and consequently of the composites. The best results were obtained for mercerized fibers where the tensile strength was increased by about 53% as compared to the composites with untreated fibers, and about 33.3% as compared to the composites without fibers. The mercerization improved fiber-matrix adhesion, allowing an efficient stress transfer from the matrix to the fibers. The increased adhesion between fiber and matrix was also observed by SEM. Treatment with water also improved values of Young's modulus which were increased by about 75% as compared to the blends without the fibers. Thus, starch/EVOH blends reinforced with the treated fibers exhibited superior properties than neat starch/EVOH.

Anaerobic treatment of coconut husk liquor for biogas production

The market for coconut water causes environmental problems as it is one of the major agro-industrial solid wastes in some developing countries. With the aim of reusing the coconut husk, Embrapa developed a system for processing this raw material. During the dewatering stage Coconut Husk Liquor (CHL) is generated with chemical oxygen demand (COD) varying from 60 to 70 g/L due to high concentrations of sugars and tannins. The present study evaluated the feasibility of anaerobic treatment of CHL through Anaerobic Toxicity Assay and the operation of a lab-scale Upflow Anaerobic Sludge Blanket (UASB) reactor. Results showed that CHL can be treated through a UASB reactor operating with an OLR that reaches up to 10 kg/m3.d and that is maintained stable during the whole operation. With this operational condition, the removal efficiency was higher than 80% for COD and approximately 78% for total tannins, and biogas production was 20 m3 of biogas or 130 KWh per m3 of CHL. Seventy-five percent of the biogas composition was methane and toxicity tests demonstrated that CHL was not toxic to the methanogenic consortia. Conversely, increasing the concentration of CHL leads to increased methanogenic activity.

Immunohematological findings in myelodysplastic syndrome

BACKGROUND

Few immunohematological studies have been done in myelodysplastic syndrome (MDS).

METHODS

Twenty-nine MDS patients were retrospectively evaluated with a direct antiglobulin test (DAT), antibody screening, serum electrophoresis and immunoelectrophoresis. Clinical and laboratory studies (hemoglobin level, reticulocyte count, DHL, total and indirect bilirubin) were done simultaneously, as well as the French-American-British subtype and bone marrow biopsy findings.

RESULTS

Alloantibodies were demonstrated in 17 patients (58.6%), autoantibodies in 10 (34.4%) patients and cold agglutinin in 18 (62%) patients. DAT was mediated by only IgG in 8 patients (80%), by IgG and C3 in 1 patient (10%) and by IgG, IgA and C3 in 1 (10%) patient. No hemolytic disease occurred in patients with autoantibodies. Increased serum gammaglobulin was observed in 16 (54.4%) patients. There was no correlation between the incidence of allo-/autoantibodies and the gammaglobulin level (p = 0.937) and the presence of lymphocyte infiltrates in bone marrow biopsies (p = 0.156). No significant difference was observed when the incidence of autoantibodies and number of red blood cell transfusions were compared (p = 0.334). Patients with refractory anemia and refractory anemia with ringed sideroblasts subtypes had a higher incidence of allo-/autoantibodies than other MDS subtypes (p = 0.03).

CONCLUSION

Patients with MDS, in particular refractory anemia and refractory anemia with ringed sideroblasts have a high incidence of allo- and autoantibodies, probably related to intrinsic immune disorder, without clinical or laboratory hemolysis.

Hydroxyl radical scavengers inhibit TNF-alpha production in mononuclear cells but not in polymorphonuclear leukocytes

The hydroxyl radical (HO*) scavengers dimethylthiourea (DMTU), tetramethylthiourea (TMTU), dimethylsulfoxide (DMSO) and deferoxamine (DFX), the latter being an iron chelator which prevents HO* formation by blocking the Fenton reaction, were found to inhibit TNF-alpha production in LPS-stimulated human PBMC but not in PMN. Furthermore, this effect was not LPS-specific, as TNF-alpha production was reduced by HO* radical scavengers to a similar extent upon stimulation of PBMC with immune complexes (IC), concanavalin A (Con A) and phorbol myristate acetate (PMA). Other scavengers such as glutathione (GSH), N-acetylcysteine (NAC), ascorbic acid (ASC) and mannitol (MAN) do not have effect on the production of TNF-alpha either in PBMC or PMN. These results provide evidence that the participation of ROI in the regulation of TNF-alpha production differ in different cell types. Particularly, the data presented in this work indicate that HO* radicals have a central role in the production of this inflammatory cytokine by human PBMC.

Intracellular acidification does not account for inhibition of Saccharomyces cerevisiae growth in the presence of ethanol

Intracellular acidification has been considered one of a number of mechanisms underlying the inhibition of growth and fermentation by ethanol in yeast. However, most of the studies on the effect of ethanol on yeast intracellular pH (pHi) were carried out by using unadapted cells to which ethanol was added. In this paper we show that the pHi of exponential cells of Saccharomyces cerevisiae IGC 3507 III grown in a medium with glucose and inhibitory concentrations of ethanol only decreased to values below those in unstressed cells (6.9) for concentrations equal to or above 7% (v/v). Only at these supracritical levels (7-10% (v/v)) was pH homeostasis in ethanol-adapted yeast affected. This is consistent with the significant increase of plasma membrane permeability and decrease of plasma membrane H(+)-ATPase in comparison with the corresponding values in unstressed cells. These deleterious effects were only observed with those high concentrations of toxin. These results indicate that intracellular acidification does not account for inhibition of yeast growth in the presence of ethanol. In fact, growth was inhibited by ethanol concentrations (3-6% (v/v)) that did not lead to the decrease of pHi. Furthermore, even for supracritical concentrations, close to the maximal that allowed growth (10% (v/v)), the decrease of pHi was not important reaching, at the most, values of 6.5-6.6.

In vivo activation by ethanol of plasma membrane ATPase of Saccharomyces cerevisiae

Ethanol, in concentrations that affect growth and fermentation rates (3 to 10% [vol/vol]), activated in vivo the plasma membrane ATPase of Saccharomyces cerevisiae. The maximal value for this activated enzyme in cells grown with 6 to 8% (vol/vol) ethanol was three times higher than the basal level (in cells grown in the absence of ethanol). The Km values for ATP, the pH profiles, and the sensitivities to orthovanadate of the activated and the basal plasma membrane ATPases were virtually identical. A near-equivalent activation was also observed when cells grown in the absence of ethanol were incubated for 15 min in the growth medium with ethanol. The activated state was preserved after the extraction from the cells of the membrane fraction, and cycloheximide appeared to prevent this in vivo activation. After ethanol removal, the rapid in vivo reversion of ATPase activation was observed. While inducing the in vivo activation of plasma membrane ATPase, concentrations of ethanol equal to and greater than 3% (vol/vol) also inhibited this enzyme in vitro. The possible role of the in vivo activation of the plasma membrane proton-pumping ATPase in the development of ethanol tolerance by this fermenting yeast was discussed.

Inhibition of Yeast Growth by Octanoic and Decanoic Acids Produced during Ethanolic Fermentation

The inhibition of growth by octanoic or decanoic acids, two subproducts of ethanolic fermentation, was evaluated in Saccharomyces cerevisiae and Kluyveromyces marxianus in association with ethanol, the main product of fermentation. In both strains, octanoic and decanoic acids, at concentrations up to 16 and 8 mg/liter, respectively, decreased the maximum specific growth rate and the biomass yield at 30°C as an exponential function of the fatty acid concentration and increased the duration of growth latency. These toxic effects increased with a decrease in pH in the range of 5.4 to 3.0, indicating that the undissociated form is the toxic molecule. Decanoic acid was more toxic than octanoic acid. The concentrations of octanoic and decanoic acids were determined during the ethanolic fermentation (30°C) of two laboratory media (mineral and complex) by S. cerevisiae and of Jerusalem artichoke juice by K. marxianus . Based on the concentrations detected (0.7 to 23 mg/liter) and the kinetics of growth inhibition, the presence of octanoic and decanoic acids cannot be ignored in the evaluation of the overall inhibition of ethanolic fermentation.