Evaluation of dietary single probiotic isolates and probiotic multistrain consortia in growth performance, gut histology, gut microbiota, immune regulation, and infection resistance of Nile tilapia, Oreochromis niloticus, shows superior monostrain performance

The probiotic potential of a designed bacterial consortia isolated from a competitive exclusion culture originally obtained from the intestinal contents of tilapia juveniles were evaluated on Nile tilapia alevins. The growth performance, intestinal histology, microbiota effects, resistance to Streptococcus agalactiae challenge, and immune response were assessed. In addition, the following treatments were included in a commercial feed: A12+M4+M10 (Lactococcus lactis A12, Priestia megaterium M4, and Priestia sp. M10), M4+M10 (P. megaterium M4, and Priestia sp. M10) and the single bacteria as controls; A12 (L. lactis A12), M4 (P. megaterium M4), M10 (Priestia sp. M10), also a commercial feed without any probiotic addition was included as a control. The results showed that all probiotic treatments improved the growth performance, intestinal histology, and resistance during experimental infection with S. agalactiae in comparison to the control fish. Also, the administration of probiotics resulted in the modulation of genes associated with the innate and adaptive immune systems that were non-dependent on microbial colonization. Surprisingly, L. lactis A12 alone induced benefits in fish compared to the microbial consortia, showing the highest increase in growth rate, survival during experimental infection with S. agalactiae, increased intestinal fold length, and the number of differentially expressed genes. Lastly, we conclude that a competitive exclusion culture is a reliable source of probiotics, and monostrain L. lactis A12 has comparable or even greater probiotic potential than the bacterial consortia.

Insights into the Design of Polyurethane Dressings Suitable for the Stages of Skin Wound-Healing: A Systematic Review

Dressings made with polyurethanes have been found to exhibit good and varied biological properties that make them good candidates for this application. However, as has been seen, the wound-healing process is complex, which includes four different stages. So far, the design and evaluation of polyurethane for wound dressing has focused on achieving good properties (mechanical, physicochemical, and biological), but each of them separates from the others or even directed at only one of the stages of skin wound-healing. Therefore, the aim of this systematic review is to explore the applications of polyurethanes in wound dressings and to determine whether could be designed to cover more than one stage of skin wound-healing. The PRISMA guidelines were followed. The current research in this field does not consider each stage separately, and the design of polyurethane dressings is focused on covering all the stages of wound healing with a single material but is necessary to replace polyurethanes in short periods of time. Additionally, little emphasis is placed on the hemostasis stage and further characterization of polyurethanes is still needed to correlate mechanical and physicochemical properties with biological properties at each stage of the wound-healing. Current research demonstrates an effort to characterize the materials physiochemically and mechanically, but in terms of their biological properties, most of the literature is based on the performance of histological tests of explants morphologically probing the compromised tissues, which give an indication of the potential use of polyurethanes in the generation of wound-healing dressings.

Streptomyces as Potential Synthetic Polymer Degraders: A Systematic Review

The inherent resistance of synthetic plastics to degradation has led to an increasing challenge of waste accumulation problem and created a pollution issue that can only be addressed with novel complementary methods such as biodegradation. Since biocontrol is a promising eco-friendly option to address this challenge, the identification of suitable biological agents is a crucial requirement. Among the existing options, organisms of the Streptomyces genus have been reported to biodegrade several complex polymeric macromolecules such as chitin, lignin, and cellulose. Therefore, this systematic review aimed to evaluate the potential of Streptomyces strains for the biodegradation of synthetic plastics. The results showed that although Streptomyces strains are widely distributed in different ecosystems in nature, few studies have explored their capacity as degraders of synthetic polymers. Moreover, most of the research in this field has focused on Streptomyces strains with promising biotransforming potential against polyethylene-like polymers. Our findings suggest that this field of study is still in the early stages of development. Moreover, considering the diverse ecological niches associated with Streptomyces, these actinobacteria could serve as complementary agents for plastic waste management and thereby enhance carbon cycle dynamics.

Evaluación de las condiciones de crecimiento celular para la producción de astaxantina a patir de la microalga Haematococcus pluvialis

<p>En la actualidad la astaxantina de origen natural es uno de los pigmentos carotenoides con importantes aplicaciones en la industria alimenticia, farmacéutica y cosmética, debido a sus grandes propiedades dentro de las que se destaca su gran poder antioxidante, efecto preventivo del cáncer, incremento de la respuesta inmune, inhibición de los radicales libres entre muchas otras.<br />Haematococcus pluvialis es una microalga verde de agua dulce y es una de las fuentes naturales con mayor producción de astaxantina ya que es capaz de acumular hasta un 3% de astaxantina en peso seco. El objetivo del presente trabajo fue determinar el medio de cultivo y las condiciones óptimas para el crecimiento y la producción de astaxantina a partir de Haematococcus pluvialis. La influencia de diferentes factores como el pH, temperatura, agitación, aireación CO2 e iluminación favorecen el crecimiento celular, al darle un ambiente óptimo a la microalga. Para determinar las condiciones nutricionales óptimas, se evaluó el efecto de diferentes medios de cultivo (BBM, OHM, RM) en Birreactores de 500mL con 350mL de medio y 1x104cel/ml de inóculo en fase exponencial, las condiciones de cultivo empleadas fueron: pH. 6.7 a 7, CO2 al 5%, fotoperiodo de 16 horas luz 8 oscuridad, irradianza 70μE/m2s; Los resultados mostraron que el mayor crecimiento o producción celular se obtuvo en el medio RM con 7,5 x 105 cel/ml en el día 36, y la mayor producción de astaxantina se obtuvo en el medio RM con una concentración de 8.3 μg/ml en el tratamiento 4.</p>

Chitin nanowhiskers as alternative antimicrobial controlled release carriers

Antimicrobial finishings protect users from pathogenic and odor-generating microorganisms, which are of medical and hygiene concerns.

Chitin hybrid materials reinforced with graphene oxide nanosheets: chemical and mechanical characterisation

A novel hybrid material of chitin–nGO was obtained. nGO reinforces the material by rearrangement of chitin chains, improving its chemical and mechanical properties.

Immobilized chitosan as biosorbent for the removal of Cd(II), Cr(III) and Cr(VI) from aqueous solutions

The generation of layer-by-layer silicate-chitosan composite biosorbent was studied. The films were evaluated on its stability regarding the polymer leakage and its capability in the removal of Cd(II), Cr(III) and Cr(VI) from an aqueous solution. SEM, EDAX and ATR-IR techniques were applied for material characterization. Silicate-chitosan films with a final layer of silicate demonstrated chitosan retention and had better sorption capacities than those without it. For metal species, such as Cd(II) and Cr(III), the greatest adsorption was obtained when the pH of the solution was 7. When Cr(VI) was evaluated, pH 4 was the optimal for its adsorption. Langmuir and Freundlich isotherms were modeled for the equilibrium data. An 80% of the adsorbed metal was recovered by HNO(3) incubation. This non-covalent immobilization method allowed chitosan surface retention and did not affect its adsorption properties. The use of a coated surface would facilitate sorbent removal from medium after adsorption.

[Does beer have an impact on weight gain? Effects of moderate beer consumption on body composition]

BACKGROUND

The effects of alcohol consumption on body weight have been evaluated in a large number of studies suggesting to be inversely as well as positively related to body weight and body fat.

OBJECTIVE

This study examined the relationships between moderate beer consumption and anthropometrical parameters in Spanish healthy adults.

METHOD

After a 30 day alcohol abstemious period, 58 healthy volunteers were submitted to a daily moderate consumption of beer during the following 30 days. Weight, height, skinfolds and circumferences were measured at three points: (a) basal; (b) abstemious and (c) after moderate consumption of beer.

RESULTS

Biceps skinfold (mm) increased (p < 0.05) in men after moderate beer consumption in regard to abstinence period (5.74 +/- 1.70 vs. 6.23 +/- 1.74). No significant differences were observed in the rest of anthropometrical parameters studied in both women and men along the study intervention.

CONCLUSION

Moderate beer consumption during one month did not mostly change weight and weight-related parameters in healthy adults.

[Immunocytochemical and molecular studies with primary cultures of molar tissue]

INTRODUCTION

Gestational trophoblastic disease includes a group of pathologies characterized by abnormal trophoblast growth and invasion. The molecular bases of the disease are largely unknown, due in part to the lack of appropriate biological models. The insulin-like growth factor (IGF) system plays a fundamental role in the growth and development of many tissues and is involved in the progression of several diseases.

OBJECTIVES

Primary cell cultures derived from first trimester placenta were characterized from patients with complete hydatidiform mole and spontaneous non molar abortion by immunocytochemical and molecular methods.

MATERIALS AND METHODS

The immunocytochemical method used specific markers for trophoblastic cells, whereas RT-PCR was used to identify insulin-like growth factor gene expression.

RESULTS

Histochemical staining with hematoxilin-eosin revealed that the cultures contained heterogeneous cell types, including trophoblast and endometrial decidual cells. The ratio of trophoblast cells in the cultures varied between 16% and 37%, as detected by cytokeratine-7 as the specific trophoblast marker. Gene expression analysis corroborated the presence of trophoblasts by detecting insulin-like growth factor II mRNA, whereas GH-V transcripts were correlated with the presence of syncitiotrophoblasts. Insulin-like growth factor I and insulin-like growth factor binding protein 1 mRNAs were related to mesenchyimal and decidual cells, respectively. Higher insulin-like growth factor II expression levels were found in molar tissues in comparison with non-molar abortions.

CONCLUSION

By combining three methodologies-morphology, immunocytochemistry and gene expression, characterization and follow-up of placenta cultures from abnormal tissues is found to facilitate diagnosis.

Cheese whey: an alternative growth and protective medium for Rhizobium loti cells

Cheese whey (CW)-based growth medium efficiently protects Rhizobium loti cells during freezing and desiccation and can maintain their growth in a manner similar to that of traditional mannitol-based medium (YEM). The cheese-whey-based medium (CW) improved viability when used to re-suspend cell pellets kept at -20 degrees C and -80 degrees C and resulted in the survival of over 90% of the cells. Moreover, bacterial pellets obtained from cells grown in CW withstand desiccation better than cells grown in YEM. Survival was over 60% after 30 days at 4 degrees C. No differences were observed in nodulation efficiency between YEM-grown and CW-grown cells. Fast protein liquid chromatography (FPLC) protocols are presented for total protein profile analyses of sweet and acid cheese whey.

Influence of alcohol consumption on immunological status: a review

The aim of this review is to present and discuss the effect of different levels of alcohol consumption on the immune system. Not only the amount consumed but also the type of alcoholic beverage have to be taken into account in order to determine the consequences on activity, number, distribution, balance, interaction and response of immunocompetent cells. The association between alcohol exposure and the risk of developing an alcohol-related disease is multifactorial. In fact, age, gender, smoking habits, dietary intake and exercise are involved among other factors. The evaluation of the host cellular and humoral immune responses has shown that alcohol may induce some benefits when consumption is moderate. Moreover, those alcoholic beverages that contain antioxidants, such as red wine, could be protectors against immune cell damage. According to the literature consulted, the daily consumption of 10-12 g and 20-24 g of alcohol for women and men, respectively, is considered to be a moderate intake; the type of beverage has been established not to be important when defining moderation. Particular attention is often focused on the U- or J-shaped curve which also suggests that light to moderate drinking produces a protective effect. Such an inverse relationship indicates a reduction of risk for both light and moderate consumers and a higher risk not only for hard drinkers, but also for non-consumers.

Comparative analysis of storage proteins of Lotus spp. seeds by CGE and SDS-PAGE

L. tenuis and L. corniculatus seeds are morphologically very similar but their purchase prices are quite different. Chromosome number counting is the only test used thus far in laboratories for the identification of these seeds. Recently, the flavonol's pattern has been used as a criterion for differentiation. In the present work, we studied the storage protein patterns of different Lotus seed samples by capillary gel electrophoresis (CGE), as an alternative method, comparing it with sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The seeds were treated according to International Seed Testing Association (ISTA) recommendations. CGE separations were performed using an uncoated capillary of 18 cm effective length and 50 microns i.d. and the Bio-Rad Protein Kit (Hercules, CA, U.S.A.). On-line detection was carried out at 220 nm.

Postharvest analysis of vitamin C and inorganic cations in lettuce by CZE

In the present work, we used capillary zone electrophoresis (CZE) for the analysis of Vitamin C and inorganic cations (potassium, sodium, calcium, and magnesium) in lettuce (Lactuca sativa) during postharvest storage. The leaves of the creasphead lettuce samples were treated with 18 M omega water for cation analysis and, alternatively, with 3% wt/vol oxalic acid solution for ascorbic acid extraction. They were then homogenized and centrifuged, and the supernatants were introduced into the capillary for CE analysis. The cation analysis was performed on an uncoated fused-silica capillary column of 75 microns i.d. and 50 cm total length, using 15 mM creatinine, 15 mM alpha-hydroxyisobutyric acid, acetic acid, pH 4.00, as running buffer at an applied voltage of 20 kV. Indirect on-line UV detection was carried out at 214 nm. The content of Vitamin C was measured using an uncoated fused-silica capillary column of 50 microns i.d. and 45 cm total length; 10 mM sodium tetraborate, 10 mM sodium biphosphate, pH 9.00, as background electrolyte at an applied voltage of 20 kV. On-line UV detection was achieved at 254 nm.

Simultaneous determination of S-adenosylmethionine and S-adenosylhomocysteine by capillary zone electrophoresis

A reproducible, rapid procedure for the simultaneous quantitative separation of S-adenosylmethionine and S-adenosylhomocysteine by capillary zone electrophoresis has been developed. Separations were performed by using an uncoated capillary of 60 cm effective length and 50 microm ID, 40 mM sodium phosphate buffer, pH 2.50, as background electrolyte solution, and 30 kV. On-line detection was carried out at 254 nm. Under the conditions selected we resolved a standard solution containing S-adenosylmethionine and S-adenosylhomocysteine in a run time shorter than 8 min. A mass detection limit in the range of 10 fmol was achieved. Adenosyl-L-methionine, S[methyl-3H] has also been assayed under the same experimental conditions. Other related compounds did not show interference, including those derived from the hydrolysis of S-adenosylmethionine. The present method allows simultaneous determination of these compounds, which play an important role in many microbiological and enzymatic research studies.

Direct determination of glutathione in human blood by micellar electrokinetic chromatography: simultaneous determination of lipoamide and lipoic acid

A reproducible, rapid procedure for the determination of glutathione in human blood by micellar electrokinetic chromatography has been developed. Whole blood samples were deproteinized with 5% w/v sulfosalicylic acid (final concentration). After centrifugation, the supernatant was directly injected for analysis, without further derivatization. Separations were performed by using an uncoated capillary of 30 cm effective length and 50 microns internal diameter (ID), 50 mM Tris-HCl, 30 mM sodium dodecyl sulfate (SDS), pH 7.00, as running buffer, and 10-20 kV. On-line detection was carried out at 214 nm and a detection limit in the range of femtomoles was achieved. Under the same experimental conditions, we resolved a mixed standard solution containing glutathione in its oxidize and reduced forms, lipoamide and alpha-lipoic acid. The corresponding migration times were reproducible. The present method allows rapid determination of these compounds, which play a critical role in oxidative stress, in cellular defense against injurious agents and whose levels are related to the toxicology and metabolism of several toxins and drugs, such as antineoplastic agents.

Purification and characterization of two forms of antigen 5 from polybia scutellaris venom

Two polypeptides from the venom of Polybia scutellaris were purified to homogeneity by RP-HPLC. They differ very slightly in mol. wt (both are about 23,000) and hydrophobicity, and have isoelectric points greater than 9. Amino acid analyzes show close similarity between them and with antigen 5 of vespids from different species. The two polypeptides have an identical N-terminal sequence (18 amino acids) which shows a high degree of homology with those of other vespids. Owing to the fact that the venom of this species is non-allergenic, the data for the mol. wt, isoelectric point, amino acid composition and N-terminal sequence allow us to identify the isolated polypeptides as two forms of antigen 5. Amino acids at positions 5 and 11 in P. scutellaris antigen 5 differ from those of the previously known sequences for antigen 5, suggesting that one or other might be responsible for the lack of allergenicity of the P. scutellaris venom.