Saccharomyces pastorianus Residual Biomass Immobilized in a Polymer Matrix as a Biosorbent for Reactive Dye Removal: Investigations in a Dynamic System.

The use of residual microbial biomass from various industries in emerging pollutant removal strategies represents a new area of research in the field. In this case, we examined how to remove reactive dyes from an aqueous solution utilizing a biosorbent made of residual biomass from immobilized Saccharomyces pastorianus (S. pastorianus) in a polymer matrix using a dynamic system. Fluidized bed column biosorption investigations were carried out on a laboratory scale. Brilliant Red HE-3B was chosen as the target molecule. The main parameters considered for this purpose were the flow rate (4.0 mL/min; 6.1 mL/min), initial pollutant concentration (51.2 mg/L; 77.84 mg/L), and biosorbent mass (16 g; 20 g). The experimental data of the fluidized bed study were evaluated by mathematical modeling. The Yoon-Nelson, Bohart-Adams, Clark, and Yan models were investigated for an appropriate correlation with the experimental data. An acceptable fit was obtained for a flow rate of 4 mL/min, an initial pollutant concentration of 51.2 mg/L, and a biosorbent amount of 20 g. The obtained results indicate that the biosorbent can be used efficiently in a dynamic system both for the removal of the studied dye and in extended operations with a continuous flow of wastewater. As a conclusion, the investigated biocomposite material can be considered a viable biosorbent for testing in the removal of reactive dyes from aqueous environments and creates the necessary conditions for the extension of studies toward the application of these types of biosorbents in the treatment of industrial effluents loaded with organic dyes.

Bioactive Compounds for Combating Oxidative Stress in Dermatology.

There are extensive studies that confirm the harmful and strong influence of oxidative stress on the skin. The body's response to oxidative stress can vary depending on the type of reactive oxygen species (ROS) or reactive nitrogen species (RNS) and their metabolites, the duration of exposure to oxidative stress and the antioxidant capacity at each tissue level. Numerous skin diseases and pathologies are associated with the excessive production and accumulation of free radicals. title altered Both categories have advantages and disadvantages in terms of skin structures, tolerability, therapeutic performance, ease of application or formulation and economic efficiency. The effect of long-term treatment with antioxidants is evaluated through studies investigating their protective effect and the improvement of some phenomena caused by oxidative stress. This article summarizes the available information on the presence of compounds used in dermatology to combat oxidative stress in the skin. It aims to provide an overview of all the considerations for choosing an antioxidant agent, the topics for further research and the answers sought in order to optimize therapeutic performance.

Pesticides vs. Biopesticides: From Pest Management to Toxicity and Impacts on the Environment and Human Health.

The environmental pollution that occurs in direct response to the widespread use of man-made/conventional pesticides results from many chemicals that require a long period of time, often decades, to degrade. The synthetic nature of pesticides also harms animals, beneficial insects, microorganisms, and plants, as well as humans. Fortunately, however, there are many natural pesticides, the so-called biopesticides, that are also effective against pests and more importantly, do not interfere with the well-being of ecosystems. Consequently, most biopesticides are safer for use around people and pets than man-made pesticides because, for example, they can be easily washed away from fruits and vegetables. The natural habitat is a rich resource with a wide selection of plants, many of which are also used to treat diseases in humans, animals, and plants. Out of concern for public health, environmental safety, and the stringent regulation of pesticide residues in agricultural commodities, the use of biopesticides is becoming increasingly important, but questions regarding potential pest resistance to these products may arise, just as is the case with conventional pesticides. Therefore, the performance and potential role of biopesticides in the management of plant pests should be prioritized due to their sustainability and importance to human and environmental welfare. In this review, we propose to highlight a scenario in which we discuss in detail the main constraints posed by the use of pesticides compared to biopesticides, starting with issues regarding their definition and continuing on to issues related to their toxicity and their impact on the environment and human health.

Preliminary Approaches to Cosmeceuticals Emulsions Based on N-ProlylPalmitoyl Tripeptide-56 Acetat-Bakuchiol Complex Intended to Combat Skin Oxidative Stress.

This study focuses on the development of a performant formulation for O/W dermato-cosmetic emulsions, which can be incorporated into novel dermato-cosmetic products or used as such. The O/W dermato-cosmetic emulsions contain an active complex based on a plant-derived monoterpene phenol, bakuchiol (BAK) and a signaling peptide named n-prolyl palmitoyl tripeptide-56 acetate (TPA). As a dispersed phase, we used a mix of vegetable oils, and as a continuous phase, Rosa damascena hydrosol was employed. Three emulsions containing different concentrations of the active complex were formulated (0.5% BAK + 0.5% TPA = E.1.1., 1% BAK + 1%TPA = E.1.2., 1% BAK + 2% TPA = E.1.3.). Stability testing was performed through sensory analysis, stability after centrifugation, conductivity and optical microscopy. A preliminary in vitro study regarding the diffusion ability of antioxidants through chicken skin was also undertaken. DPPH and ABTS assays were used to highlight the optimal concentration and combination in the formulation in terms of antioxidant properties and safety level of the active complex (BAK/TPA). Our results showed that the active complex used for preparing emulsions with BAK and TPA showed good antioxidant activity and is suitable for obtaining topical products with potential antiaging effects.

Biosorbent Based on Poly(vinyl alcohol)-Tricarboxi-Cellulose Designed to Retain Organic Dyes from Aqueous Media.

Methylene Blue, a cationic dye, was retained from aqueous solutions using a novel biosorbent made of poly(vinyl alcohol) reticulated with tricarboxi-cellulose produced via TEMPO oxidation (OxC25). The study of the Methylene Blue biosorption process was performed with an emphasis on operational parameters that may have an impact on it (such as biosorbent concentration, pH of the aqueous media, and temperature). The current study focused on three areas: (i) the physic-chemical characterization of the biosorbent (scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX)); (ii) biosorption data modeling to determine the quantitative characteristic parameters employing three equilibrium isotherms (Langmuir, Freundlich, and Dubinin-Radushkevich-DR); and (iii) the study of temperature influence. The results of the study showed that the Langmuir model provided a good fit for the experimental data of biosorption, realizing a maximum capacity of 806.45 mg/g at 20 °C. The free energy of biosorption (E) evaluated by the DR equation was in the range of 6.48-10.86 KJ/mol. The values of the thermodynamic parameters indicated an endothermic process because the free Gibbs energy ranged from -9.286 KJ/mol to -2.208 KJ/mol and the enthalpy was approximately -71.686 KJ/mol. The results obtained encourage and motivate the further study of this biosorption process by focusing on its kinetic aspects, establishing the biosorption's controlled steps, identifying the mechanism responsible for the retention of textile dyes presented in moderate concentration in aqueous media, and studying the biosorption process in a dynamic regime with a view to applying it to real systems.

Dermatocosmetic Emulsions Based on Resveratrol, Ferulic Acid and Saffron (Crocus sativus) Extract to Combat Skin Oxidative Stress-Trigger Factor of Some Potential Malignant Effects: Stability Studies and Rheological Properties.

The increasing incidence of skin diseases, against the background of increased pollution, urbanism, poor habits in lifestyle, work, rest, diet and general medication, led to the development of products with a protective effect. These new types of dermatocosmetic preparations ensure maximum benefits with minimal formulation. Antioxidants are, nowadays, ingredients that stand out with a proven role in skin protection from oxidative stress and its effects. Thus, research has shown that light-textured formulas, quickly absorbed into the skin, with optimum hydration and protection against excessive free radicals, uphold the skin integrity and appearance. This article aims to evaluate essential criteria for a newly marketed product: stability, rheological properties and microbiological characteristics of oil-in-water emulsions based on a mixture of 3% resveratrol 0.5% ferulic acid and 1mL alcoholic extract of Saffron. The tests led to the conclusion that O / W dermatocosmetic emulsions, based on 3% resveratrol and 0.5% ferulic acid, or also 1mL alcoholic extract of Saffron, show resistance to microbiological contamination, good rheological properties (viscoelastic behavior, structural stability, acceptable shearing behavior) that reveal satisfactory texture and high physical stability during storage. These results encourage the transition to dermatological testing as the final stage in considering a new commercial product.

Statistical Analysis and Optimization of the Brilliant Red HE-3B Dye Biosorption onto a Biosorbent Based on Residual Biomass.

Using various techniques, natural polymers can be successfully used as a matrix to immobilize a residual microbial biomass in a form that is easy to handle, namely biosorbents, and which is capable of retaining chemical species from polluted aqueous media. The biosorption process of reactive Brilliant Red HE-3B dye on a new type of biosorbent, based on a residual microbial biomass of Saccharomyces pastorianus immobilized in sodium alginate, was studied using mathematical modeling of experimental data obtained under certain conditions. Different methods, such as computer-assisted statistical analysis, were applied, considering all independent and dependent variables involved in the reactive dye biosorption process. The optimal values achieved were compared, and the experimental data supported the possibility of using the immobilized residual biomass as a biosorbent for the studied reference dye. The results were sufficient to perform dye removals higher than 70-85% in an aqueous solution containing around 45-50 mg/L of reactive dye, and working with more than 20-22 g/L of prepared immobilized microbial biosorbent for more than 9.5-10 h. Furthermore, the proposed models agreed with the experimental data and permitted the prediction of the dye biosorption behavior in the experimental variation field of each independent variable.

Antioxidants from Galium verum as Ingredients for the Design of New Dermatocosmetic Products.

The aim of this study was to use plant extracts from spontaneous flora of Moldova (Rediu-Iasi area, Romania) as polyphenols and flavonoids source in order to obtain new dermato-cosmetic formulas to prevent the actions of oxidative stress on skin. Plant extracts (from raw and dried Galium verum sp.) were obtained by: cold classical maceration (M), heat reflux extraction (HTE) and ultrasound assisted extraction (UAE). The extracts were characterized by spectrophotometric method (for polyphenols and flavonoids content and for DPPH antioxidant activity evaluation). In order to evaluate the combating and/or attenuating effects of oxidative stress on skin, the study was continued with the elaboration of emulsions that incorporate one of these extracts. The emulsions were preliminarily characterized by determining the stability over time. The obtained results encourage research in the direction of deeper characterization of these emulsions to determine the microbiological stability and dermatological tests performed on the skin treated with these new products.

Biosorbents Based on Biopolymers from Natural Sources and Food Waste to Retain the Methylene Blue Dye from the Aqueous Medium.

The use of a biosorbent based on residual biomass from brewing industry (Saccharomyces pastorianus) immobilized in a natural biopolymer (sodium alginate) was investigated for Methylene Blue removal from aqueous medium. Saccharomyces pastorianus, immobilized by a simple entrapment technique and by microencapsulation in alginate was characterized using SEM, EDAX, pHPZC and the biosorption behavior toward organic pollutant, such as cationic dye. The biosorption experiments were studied by assessing, in a first stage, the influence of the most important operational physical parameters on the efficiency of the biosorbent: the initial concentration of the dye, the contact time between phases, the temperature, the dye solution pH, the biosorbent granule size, and the amount of biosorbent. The highest sorption capacity was obtained for the biosorbent obtained by microencapsulation, at pH 9, at biosorbent dose of 5.28 g/L and a contact time of about 100 min. The biosorption equilibrium was then studied by modeling the data on the Langmuir, Freundlich and Dubinin- Radushkevich isotherms. The Langmuir model is best suited for experimental data on both particle sizes leading to a maximum biosorption capacity of 188.679 mg/g at room temperature. The values of the adsorption energy, E, obtained with the help of the Dubinin-Radushkevich model-suggest that the type of mechanism (physical or chemical) involved in the biosorption process depends on the particle size of the biosorbent. The results confirm that the residual microbial biomass of Saccharomyces pastorianus immobilized in a polymeric matrix such as sodium alginate, can be considered an efficient biosorbent in retaining cationic organic dyes present in aqueous solutions in moderate concentrations.

Polysaccharides Used in Biosorbents Preparation for Organic Dyes Retaining from Aqueous Media.

Natural polymers can themselves be efficient as materials with biosorptive properties but can also be used to transform microbial biomass into an easy-to-handle form, respectively, into biosorbents, through immobilization. The article aims to study biosorbents based on residual microbial biomass (Saccharomyces pastorianus yeast, separated after the brewing process by centrifugation and dried at 80 °C) immobilized in sodium alginate. The biosorptive properties of this type of biosorbent (spherical particles 2 and 4 mm in diameter) were studied for removal of reactive dye Brilliant Red HE-3B (with concentration in range of 16.88-174.08 mg/L) from aqueous media. The paper aims at three aspects: (i) the physico-chemical characterization of the biosorbent (Scanning Electron Microscopy (SEM), Energy-dispersive X-ray spectroscopy (EDX) and Fourier Transform Infrared (FTIR) spectra); (ii) the modeling of biosorption data in order to calculate the quantitative characteristic parameters using three equilibrium isotherms (Langmuir, Freundlich, and Dubinin-Radushkevich-DR); and (iii) the evaluation of thermal effect and the possible mechanism of action. The results of the study showed that biosorption capacity evaluated by Langmuir (I) model is 222.22 mg/g (ϕ = 2 mm) and 151.51 mg/g (ϕ = 4 mm) at 30 °C, and the free energy of biosorption (E) is in the range of 8.45-13.608 KJ/mol (from the DR equation). The values of thermodynamic parameters suggested an exothermic process due the negative value of free Gibbs energy (ΔG0 = -9.031 kJ/mol till -3.776 kJ/mol) and enthalpy (about ΔH0 = -87.795 KJ/mol). The obtained results underline our finding that the immobilization in sodium alginate of the residual microbial biomass of Saccharomyces pastorianus led to an efficient biosorbent useful in static operating system in the case of effluents with moderate concentrations of organic dyes.

Composites Based on Natural Polymers and Microbial Biomass for Biosorption of Brilliant Red HE-3B Reactive Dye from Aqueous Solutions.

Natural polymers have proven to be extremely interesting matrices for the immobilization of microbial biomasses, via various mechanisms, in order to bring them into a form easier to handle-the form of composites. This article aimed to study composites based on a residual microbial biomass immobilized in sodium alginate via an encapsulation technique as materials with adsorbent properties. Thus, this study focused on the residual biomass resulting from beer production (Saccharomyces pastorianus yeast, separated after the biosynthesis process by centrifugation and dried at 80 °C)-an important source of valuable compounds, used either as a raw material or for transformation into final products with added value. Thus, the biosorptive potential of this type of composite was tested-presenting in the form of spherical microcapsules 900 and 1500 µm in diameter-in a biosorption process applied to aqueous solutions containing the reactive dye Brilliant Red HE-3B (16.88-174.08 mg/L), studied in a batch system. The preparation and characterization of the obtained polymeric composites (pHPZC, SEM, EDS and FTIR spectra) and an analysis of different equilibrium isotherms (Langmuir, Freundlich and Dubinin-Radushkevich-D-R) were investigated in order to estimate the quantitative characteristic parameters of the biosorption process, its thermal effects, and its possible mechanisms of action. The modelling of the experimental data led to the conclusion that the studied biosorption process took place after reaching the Langmuir isotherm (LI), and that the main mechanism was possibly physical, being spontaneous and probably exothermic according to the values obtained for the free energy of biosorption (E = 8.45-13.608 kJ/mol, from the DR equation), as well as the negative values for the Gibbs free energy and the enthalpy of biosorption (ΔH0 = -87.795 kJ/mol). The results obtained lead to the conclusion that encapsulation of this residual microbial biomass in sodium alginate leads to an easier-to-handle form of biomass, thus being an efficient biosorbent for static or dynamic operating systems for effluents containing moderate concentrations of reactive organic dyes.

Polysaccharides as Support for Microbial Biomass-Based Adsorbents with Applications in Removal of Heavy Metals and Dyes.

The use of biosorbents for the decontamination of industrial effluent (e.g., wastewater treatment) by retaining non-biodegradable pollutants (antibiotics, dyes, and heavy metals) has been investigated in order to develop inexpensive and effective techniques. The exacerbated water pollution crisis is a huge threat to the global economy, especially in association with the rapid development of industry; thus, the sustainable reuse of different treated water resources has become a worldwide necessity. This review investigates the use of different natural (living and non-living) microbial biomass types containing polysaccharides, proteins, and lipids (natural polymers) as biosorbents in free and immobilized forms. Microbial biomass immobilization performed by using polymeric support (i.e., polysaccharides) would ensure the production of efficient biosorbents, with good mechanical resistance and easy separation ability, utilized in different effluents' depollution. Biomass-based biosorbents, due to their outstanding biosorption abilities and good efficiency for effluent treatment (concentrated or diluted solutions of residuals/contaminants), need to be used in industrial environmental applications, to improve environmental sustainability of the economic activities. This review presents the most recent advances related the main polymers such as polysaccharides and microbial cells used for biosorbents production; a detailed analysis of the biosorption capability of algal, bacterial and fungal biomass; as well as a series of specific applications for retaining metal ions and organic dyes. Even if biosorption offers many advantages, the complexity of operation increased by the presence of multiple pollutants in real wastewater combined with insufficient knowledge on desorption and regeneration capacity of biosorbents (mostly used in laboratory scale) requires more large-scale biosorption experiments in order to adequately choose a type of biomass but also a polymeric support for an efficient treatment process.

Hydrogel Based on Tricarboxi-Cellulose and Poly(Vinyl Alcohol) Used as Biosorbent for Cobalt Ions Retention.

A biomaterial based on poly(vinyl alcohol) reticulated with tricarboxi-cellulose obtained by TEMPO oxidation (OxC25) was used as a new biosorbent for Co(II) ions retention from aqueous solutions. The biosorption process of Co(II) ions was studied while mainly considering the operational factors that can influence it (i.e., biosorbent concentration, pH of the aqueous media, temperature and contact time of the phases). The maximum adsorption capacity was 181.82 mg/g, with the biosorption well fitted by the Langmuir model. The kinetic modeling of the biosorption process was based on certain models: Lagergreen (pseudo first order model), Ho (pseudo second order model), Elovich (heterogeneous biosorbent model), Webber-Morris (intraparticle diffusion model) and McKay (film diffusion model). The corresponding kinetic model suggests that this biosorption process followed a pseudo-second order kinetic model and was developed in two controlled steps beginning with film diffusion and followed by intraparticles diffusion.

Green synthesis of the silver nanoparticles mediated by pullulan and 6-carboxypullulan.

Unoxidized and carboxylated pullulan (obtained by pullulan oxidation using TEMPO-sodium hypochlorite-sodium bromide system) have been used as mediators for the silver nanoparticles formation (AgNPs), under environment-friendly conditions: using aqueous solutions, room temperature and notably, by using both mediators as reducing and stabilizing agents. The formation of AgNPs was first screened by measuring the surface plasmon resonance peak in the range of 380-440 nm using UV-vis spectroscopy. The morphology of the synthesized silver nanoparticles was determined by TEM, which indicated that the AgNPs differ on shape and thickness of the polymer shell by varying the silver nitrate concentration, different size and shape of AgNPs was achieved. The presence of elemental silver and the crystalline structure of the AgNPs were confirmed by EDX and XRD analyses. Moreover, the possible functional groups of pullulan (oxidized pullulan) responsible for the reduction and stabilization of AgNPs were evaluated using FT-IR. The results showed that both, pullulan and 6-carboxypullulan could be successfully used as reducing as well as capping agents for the AgNPs synthesis which shows potential antimicrobial activity against Gram positive and Gram negative bacteria.

Coal fly ash as adsorptive material for treatment of a real textile effluent: operating parameters and treatment efficiency.

The experimental results performed after the application of one single-stage treatment by sorption onto coal fly ash are evaluated in order to decolorize a real textile effluent of a private company specializing in manufacturing of cotton fabrics (i.e., sorption performance applied for a real textile effluent collected after the fabric dyeing, rinsing, and final finishing steps). The experiments are focused on studying the effect of initial textile effluent pH, adsorbent dose, temperature and adsorption time, considered as operating parameters of sorption process for high pollutant removals (e.g., organic pollutants as dyes, phenols, polymeric, and degradation compounds), and decoloration. The results indicate high values of decoloration degree (55.42-83.00%) and COD removal (44.44-61.11%) when it is worked at pH ≤2 with coal ash dose of 12-40 g/L, temperature higher than 20-25 °C, and continuous static operating regime (with an initial agitation step of 3-5 min). The treated textile effluent fulfills the quality demand, and is recyclable, inside reused or discharged after a stage of neutralization (standard pH of 6.5-8.5 for all textile effluent discharges). Also, the final effluent is able to follow the common path to the central biological treatment plant (i.e., a centralized treatment plant for all companies acting in the industrial site area with mechanical-biological steps for wastewater treatment) or may be directly discharged in the nearly watercourse.