Synthesis of Iron Oxides and Influence on Final Sizes and Distribution in Bacterial Cellulose Applications.

Iron oxide nanoparticles have been investigated due to their suitable characteristics for diverse applications in the fields of biomedicine, electronics, water or wastewater treatment and sensors. Maghemite, magnetite and hematite are the most widely studied iron oxide particles and have ferrimagnetic characteristics. When very small, however, these particles have superparamagnetic properties and are called superparamagnetic iron oxide nanoparticles (SPIONs). Several methods are used for the production of these particles, such as coprecipitation, thermal decomposition and microemulsion. However, the variables of the different types of synthesis must be assessed to achieve greater control over the particles produced. In some studies, it is possible to compare the influence of variations in the factors for production with each of these methods. Thus, researchers use different adaptations of synthesis based on each objective and type of application. With coprecipitation, it is possible to obtain smaller, more uniform particles with adjustments in temperature, pH and the types of reagents used in the process. With thermal decomposition, greater control is needed over the time, temperature and proportion of surfactants and organic and aqueous phases in order to produce smaller particles and a narrower size distribution. With the microemulsion process, the control of the confinement of the micelles formed during synthesis through the proportions of surfactant and oil makes the final particles smaller and less dispersed. These nanoparticles can be used as additives for the creation of new materials, such as magnetic bacterial cellulose, which has different innovative applications. Composites that have SPIONs, which are produced with greater rigour with regards to their size and distribution, have superparamagnetic properties and can be used in medical applications, whereas materials containing larger particles have ferromagnetic applications. To arrive at a particular particle with specific characteristics, researchers must be attentive to both the mechanism selected and the production variables to ensure greater quality and control of the materials produced.

Cookies and muffins containing biosurfactant: textural, physicochemical and sensory analyses.

Interest in products with more natural ingredients increases the potential for application of Biosurfactants in foods. The aim of the present study was to assess the toxicity of biosurfactant produced by Saccharomyces cerevisiae URM6670 and the effect of the incorporation of this biosurfactant on the physicochemical and textural characteristics of cookies and muffins, performing unprecedented assessment of the sensorial effects of this application. The toxicity analysis revealed that the biosurfactant is classified as a mild irritant, with irritation indices lower than 4.9. The physical analysis of the incorporation of the biosurfactant in the formulation revealed that the addition of 1% to cookies significantly increased the diameter and spread factor. In muffins, significant changes in these properties were found beginning at 0.25% biosurfactant. The moisture content in cookies was reduced by a maximum of 74%, while in muffins this reduction was approximately 6%. The lipid content increased significantly with the addition of 1% of the biosurfactant (11% in cookies and 25% in muffins). The textural analysis revealed that the biosurfactant at 1% led to a significant increase in firmness as a consequence of the reduction in the moisture content. In muffins, the same concentration increased the firmness and variables related to chewability. The sensory analysis revealed that the muffins with biosurfactant had greater acceptance compared to the cookies. Thus, the biosurfactant demonstrated potential application in bakery products due to low toxicity and positive evaluation in important sensorial parameters for its commercialisation.

Magnetic Bacterial Cellulose Biopolymers: Production and Potential Applications in the Electronics Sector.

Bacterial cellulose (BC) is a biopolymer that has been widely investigated due to its useful characteristics, such as nanometric structure, simple production and biocompatibility, enabling the creation of novel materials made from additive BC in situ and/or ex situ. The literature also describes the magnetization of BC biopolymers by the addition of particles such as magnetite and ferrites. The processing of BC with these materials can be performed in different ways to adapt to the availability of materials and the objectives of a given application. There is considerable interest in the electronics field for novel materials and devices as well as non-polluting, sustainable solutions. This sector influences the development of others, including the production and optimization of new equipment, medical devices, sensors, transformers and motors. Thus, magnetic BC has considerable potential in applied research, such as the production of materials for biotechnological electronic devices. Magnetic BC also enables a reduction in the use of polluting materials commonly found in electronic devices. This review article highlights the production of this biomaterial and its applications in the field of electronics.

Bacterial Cellulose as a Versatile Biomaterial for Wound Dressing Application.

Chronic ulcers are among the main causes of morbidity and mortality due to the high probability of infection and sepsis and therefore exert a significant impact on public health resources. Numerous types of dressings are used for the treatment of skin ulcers-each with different advantages and disadvantages. Bacterial cellulose (BC) has received enormous interest in the cosmetic, pharmaceutical, and medical fields due to its biological, physical, and mechanical characteristics, which enable the creation of polymer composites and blends with broad applications. In the medical field, BC was at first used in wound dressings, tissue regeneration, and artificial blood vessels. This material is suitable for treating various skin diseases due its considerable fluid retention and medication loading properties. BC membranes are used as a temporary dressing for skin treatments due to their excellent fit to the body, reduction in pain, and acceleration of epithelial regeneration. BC-based composites and blends have been evaluated and synthesized both in vitro and in vivo to create an ideal microenvironment for wound healing. This review describes different methods of producing and handling BC for use in the medical field and highlights the qualities of BC in detail with emphasis on biomedical reports that demonstrate its utility. Moreover, it gives an account of biomedical applications, especially for tissue engineering and wound dressing materials reported until date. This review also includes patents of BC applied as a wound dressing material.

Design of a Naturally Dyed and Waterproof Biotechnological Leather from Reconstituted Cellulose.

Consumerism in fashion involves the excessive consumption of garments in modern capitalist societies due to the expansion of globalisation, especially at the beginning of the 21st Century. The involvement of new designers in the garment industry has assisted in creating a desire for new trends. However, the fast pace of transitions between collections has made fashion increasingly frivolous and capable of generating considerable interest in new products, accompanied by an increase in the discarding of fabrics. Thus, studies have been conducted on developing sustainable textile materials for use in the fashion industry. The aim of the present study was to evaluate the potential of a vegan leather produced with a dyed, waterproof biopolymer made of reconstituted bacterial cellulose (BC). The dying process involved using plant-based natural dyes extracted from Allium cepa L., Punica granatum, and Eucalyptus globulus L. The BC films were then shredded and reconstituted to produce uniform surfaces with a constant thickness of 0.10 cm throughout the entire area. The films were waterproofed using the essential oil from Melaleuca alternifolia and wax from Copernicia prunifera. The characteristics of the biotechnological vegan leather were analysed using scanning electron microscopy (SEM), thermogravimetric analysis (TGA), flexibility and mechanical tests, as well as the determination of the water contact angle (°) and sorption index (s). The results confirmed that the biomaterial has high tensile strength (maximum: 247.21 ± 16.52 N) and high flexibility; it can be folded more than 100 times at the same point without breaking or cracking. The water contact angle was 83.96°, indicating a small water interaction on the biotextile. The results of the present study demonstrate the potential of BC for the development of novel, durable, vegan, waterproof fashion products.

Application of a biosurfactant from Pseudomonas cepacia CCT 6659 in bioremediation and metallic corrosion inhibition processes.

Biosurfactants are capable of meeting the challenges of the oil industry by reducing its social, economic, and environmental impacts. The aim of the present study was to produce a biosurfactant from Pseudomonas cepacia CCT6659 in 2.0-L and 5.0-L bioreactors and evaluate its long-term stability over 120 days of storage. Ecotoxicological tests were performed with Artemia salina larvae during the use of the biosurfactant to increase in solubilisation of heavy oil in seawater compared to the use of a chemical surfactant. The biosurfactant was also applied as a bioremediation agent for sand contaminated with a petroleum product and as an inhibitor of corrosion on metallic surfaces. A concentration of 35.0 g/L of the biosurfactant was achieved in the 5.0-L reactor and low toxicity to the bioindicator was found, with an approximate 40% reduction in the mortality rate compared to the chemical surfactant. The stability of the biosurfactant was demonstrated by the maintenance of its tensioactive properties throughout the entire storage period. Besides its advantageous bioremediating capacity, with the removal of 94.5% of oil from sand, the biosurfactant proved to be an effective inhibitor of both metallic corrosion and microbial biofilm, with minimal loss of mass (15.7%) compared to the control condition, demonstrating its potential for industrial applications.

A Biosurfactant from Candida bombicola: Its Synthesis, Characterization, and its Application as a Food Emulsions.

The present study aimed to produce a biosurfactant from Candida yeast cultivated in a low-cost medium made of sugar-cane molasses (5%), frying oil waste (5%), and corn steep liquor (5%). Initially, the production at the flask-scale was investigated and then scaled up in bioreactors to 1.2, 3.0, and 50 L to simulate a real production scale. The products obtained an excellent reduction in surface tensions from 70 to 29 mN·m-1 in the flask-scale, comparable to 33 mN·m-1 in the 1.2-L reactor, to 31 mN·m-1 in the 3-L reactor, and to 30 mN·m-1 in the 50-L reactor. Regarding the yield, it was observed that the isolation by liquid-to-liquid extraction aided biosurfactant production up to 221.9 g·L-1 with a critical micellar concentration of 0.5%. The isolated biosurfactant did not exhibit an inhibitory effect on the germination of vegetable seeds and presented no significant acute toxicity in assays with Artemia salina and Allium cepa. Among the different formulations of mayonnaise-like sauces, the most stable formula was observed with the addition of the biosurfactant at a concentration of 0.5% and the greatest results were associated with the guar and carboxymethyl cellulose gums. Thus, the biosurfactant from C. bombicola represents a promising alternative as a food additive in emulsions.

Oily water treatment in a multistage tower operated under a novel induced pre-saturation process in the presence of a biosurfactant as collector.

The increase in water-oil separation efficiency as a function of biosurfactant in a novel process of a continuous induced pre-saturation tower (IPST) with stages was described. The pre-saturation of the effluent in a new IPST prior to its entrance in each stage enabled enhancing the effect of the biosurfactant on the flocculation of oil droplets due to the close contact with the air during the formation of microbubbles inside a centrifuge pump. This change of a conventional dissolved-air flotation device enabled each stage to serve as a final flocculation chamber and flotation separator. The initial flocculation step occurred nearly entirely within the centrifugation pump adapted for the generation of microbubbles. Experimental tests in a bench-scale prototype of an IPST enabled drafting two operation diagrams based on the absence and presence of the biosurfactant produced by the bacterium Pseudomonas cepacia CCT 6659. We used an effluent composed of water and semi-synthetic motor oil at 500 ± 13 mg L-1. The oil removal efficiency was estimated with the aid of Damköhler numbers applied under the analogy of considering the IPST to be a set of perfect-mixture tanks in series. To quantify the increase in efficiency achieved with the addition of the biosurfactant, we identified the kinetic laws corresponding to the addition and non-addition of the biosurfactant. The addition of the biosurfactant led to an increase in the oil removal rate in the IPST from 92.5 % to 97.0 %.

Potential Food Application of a Biosurfactant Produced by Saccharomyces cerevisiae URM 6670.

Biosurfactants have aroused considerable interest due to the possibility of acquiring useful products that are tolerant to processing techniques used in industries. Some yeasts synthesize biosurfactants that offer antioxidant activity and thermal resistance and have no risk of toxicity or pathogenicity, demonstrating potential use in food formulations. The aim of the present study was to assess the use of a biosurfactant produced by Saccharomyces cerevisiae URM 6670 to replace egg yolk in a cookie formulation. The yeast was grown in a medium containing 1% waste soybean oil and 1% corn steep liquor. The biosurfactant was isolated using a novel method and was structurally characterized using FT-IR, NMR, and GC/FID. Thermal stability was determined using thermogravimetry (TG)/differential scanning calorimetry (DSC) and antioxidant activity was investigated using three methods. Cytotoxicity tests were performed using the MTT assay with mouse fibroblast and macrophage lines. In the final step, the biosurfactant was incorporated into the formulation of a cookie dough replacing egg yolk. The physical properties and texture profile were analyzed before and after baking. The surface and interfacial tensions of the culture medium after the production process were 26.64 ± 0.06 and 9.12 ± 0.04 mN/m, respectively, and the biosurfactant concentration was 5.84 ± 0.17 g/L after isolation. In the structural characterization by NMR and FT-IR, the biosurfactant from S. cerevisiae exhibited a glycolipid structure, with the fatty acid profile revealing a high percentage of linoleic acid (50.58%). The thermal analysis demonstrated stability at the industrial application temperature, with the negligible loss of mass at temperatures of up to 200°C. The biosurfactant was non-toxic to the fibroblast and macrophage cell lines, with cell inhibition less than 15%. The incorporation of the biosurfactant into the cookie dough did not alter the physical or physicochemical properties of the product after baking. In the analysis of the texture profile before baking, the substitution of egg yolk with the biosurfactant did not alter the properties of firmness, cohesiveness, or elasticity compared to the standard formulation. Therefore, the biosurfactant produced by S. cerevisiae URM 6670 has potential applications in the food industry as a replacement for egg yolk.

Production, formulation and cost estimation of a commercial biosurfactant.

Due to their amphipathic nature, biosurfactants are multifunctional molecules that have considerable potential in several industries, especially the petroleum industry. In this study, the commercial production of a biosurfactant from Pseudomonas cepacia CCT6659 grown on industrial waste was investigated in a semi-industrial 50-L bioreactor for use in the removal of hydrocarbons from oily effluents. A concentration of 40.5 g/L was achieved in the scale up and the surface tension was reduced to 29 mN/m. The biosurfactant was formulated with an added preservative, tyndallization and the combination of fluent vaporization plus the preservative. Formulated biosurfactant samples were stored for 120 days. Tensioactive properties and stability were evaluated with different pH values, temperatures and salt concentrations. The commercial biosurfactant obtained with all formulation methods demonstrated good stability, with tolerance to a wide range of pH values as well as high temperature and high salinity, enabling application in extreme environmental conditions, as it occurs in industrial plants. The biosurfactant proved to be economically viable for large-scale application, as demonstrated by the cost of the product, estimated at around US$ 0.14-0.15/L and US$ 0.02/g for the formulated and the isolated biosurfactant, respectively. Both products were applied in an oil-fired thermoelectric plant for the treatment of oily effluents and removed up to 100% of the oil. Therefore, this biosurfactant is suitable for application under extreme conditions, such as in the petroleum industry, and can be produced at a more attractive price compared to other commercially available products on the market.

Optimization of the osmotic dehydration of ginger / Otimização da desidratação osmótica do gengibre

ABSTRACT: The present research aimed to optimize the process of osmotic dehydration (OD) of ginger with hypertonic sucrose solution employing response surface methodology. A 23 experimental planning was carried out and 17 experimental assays were performed based on three independent variables (temperature, concentration of the osmotic solution and immersion time) and three dependent variables (moisture loss (ML), solids gain (SG) and dehydration efficiency index (DEI)). The selected assay conditions exhibited the preferred DEI value (the highest ML and lower SG), which were considered in the optimization. Assay 16 demonstrated to be the most favorable conditions for the osmotic dehydration of ginger (DEI =1.61) at 40 40 °C, 50 °Brix and 90 minutes of immersion time. Assay 1 performed at 34 °C, 44 °Brix and 120 minutes of immersion time also displayed desirable response (DEI =1.45). Thus, these two assays were evaluated for the presence of thermal-tolerant coliforms: Bacillus cereus and Salmonella sp.. The analyses presented values below the acceptable limits, which assured high quality hygienic and sanitary conditions of the product.

RESUMO: A presente pesquisa teve como objetivo otimizar o processo de desidratação osmótica (DO) do gengibre, com solução hipertônica de sacarose, pelo método de superfície de resposta. Foi utilizado um planejamento fatorial 23 completo, totalizando 17 ensaios, tendo como variáveis independentes: temperatura, concentração da solução osmótica e tempo de imersão e variáveis dependentes, como,: perda de umidade (PU), ganho de sólidos (GS) e índice de eficiência de desidratação osmótica (IED). Para otimizar foi considerado o melhor ensaio, o que obteve maior IED, ou seja, maior PU e menor GS. As melhores condições para a desidratação osmótica de gengibre foram obtidos a 40 °C, 50 °Brix e 90 minutos de imersão (Ensaio 16) com IED de 1.61 vindo em seguida o Ensaio 1 (34 ºC, 44 ºBrix e 120 minutos de imersão) com IED de 1.45. Estes ensaios foram avaliados quanto à coliformes tolerantes térmicas, Bacillus cereus e Salmonella spp., apresentando valores abaixo dos limites aceitáveis, indicando boas condições higiênicas sanitárias do produto.

Formulation and application of a biosurfactant from Bacillus methylotrophicus as collector in the flotation of oily water in industrial environment.

The present study describes the formulation of a biosurfactant produced by Bacillus methylotrophicus UCP1616 and investigates its long-term stability for application as a collector in a bench-scale dissolved air flotation (DAF) prototype. For formulation, the conservative potassium sorbate was added to the biosurfactant with or without prior heat treatment at 80 °C for 30 min. After formulation, the biosurfactant samples were stored at room temperature for 180 days and the tensioactive properties of the biomolecule were determined with different pH values, temperatures and concentrations of salt. Then, a central composite rotatable design was used to evaluate the influence of the independent variables (effluent flow rate and formulated biosurfactant flow rate) on the oil removal efficiency in the DAF prototype. The formulated biosurfactant demonstrated good stability in both conservation methods, with tolerance to a wide pH range, salinity and high temperatures, enabling its use in environments with extreme conditions. The efficiency of the formulated biomolecule through heating and addition of sorbate was demonstrated by the 92% oil removal rate in the DAF prototype. The findings demonstrate that the biosurfactant from Bacillus methylotrophicus enhances the efficiency of the DAF process, making this technology cleaner. This biosurfactant can assist in the mitigation and management of industrial effluents, contributing toward a reduction in environmental pollution caused by petroleum-based hydrocarbons.

Applications of biosurfactants in the petroleum industry and the remediation of oil spills.

Petroleum hydrocarbons are important energy resources. However, petroleum is also a major pollutant of the environment. Contamination by oil and oil products has caused serious harm, and increasing attention has been paid to the development and implementation of innovative technologies for the removal of these contaminants. Biosurfactants have been extensively used in the remediation of water and soil, as well as in the main stages of the oil production chain, such as extraction, transportation, and storage. This diversity of applications is mainly due to advantages such as biodegradability, low toxicity and better functionality under extreme conditions in comparison to synthetic counterparts. Moreover, biosurfactants can be obtained with the use of agro-industrial waste as substrate, which helps reduce overall production costs. The present review describes the potential applications of biosurfactants in the oil industry and the remediation of environmental pollution caused by oil spills.

Nutritional and lipid profiles in marine fish species from Brazil.

Centesimal composition and lipid profiles were evaluated in muscle tissue of four species of Brazilian fish using the Kjeldahl and Bligh & Dyer gravimetric methods and gas chromatography, respectively. The moisture, protein, total lipid, and ash values (g/100g) ranged from 71.13 to 78.39; 18.10 to 19.87; 1.05 to 9.03; and 1.03 to 1.73, respectively. Palmitic acid was prevalent among the saturated fatty acids (10.89-20.38%) and oleic acid was the main monounsaturated acid identified (4.26-15.77%). The eicosapentaenoic-EPA (6.41-10.66%) and docosahexaenoic-DHA (9.12-30.20%) acids were the most prevalent polyunsaturated acids. The average values, which are indicative of nutritional quality, were: Polyunsaturated/saturated (P/S) (1.11-1.47), ω6/ω3 (0.08-0.21), hypocholesterolemic/hypercholesterolemic acid ratios (HH) (0.87-2.43), atherogenicity index (IA) (0.26-0.60), and thrombogenicity index (IT) (0.20-0.44). These results demonstrated that the lipid profiles of the studied species are of nutritional quality.

Synthesis of silver nanoparticles using a biosurfactant produced in low-cost medium as stabilizing agent

Background A biosurfactant produced by Pseudomonas aeruginosa cultivated in a low-cost medium formulated with 2.5% vegetable oil refinery residue and 2.5% corn steep liquor and distilled water was employed to stabilize silver nanoparticles in the liquid phase. The particles were initially synthesized using NaBH4 as reducing agent in biosurfactant reverse micelles and were extracted from the micellar solution to disperse in heptane. Results A silver particle size in the range of 1.13 nm was observed. The UV-vis absorption spectra proposed that silver nanoparticles could be formed in the reverse micelles and relatively stabilized for at least 3 months without passivator addition. The Transmission Electron Microscope (TEM) shows that the silver nanoparticles are of spherical form and relatively uniform. Conclusions This process provided a simpler route for nanoparticle synthesis compared to existing systems using whole organisms or partially purified biological extracts, showing that the low-cost biosurfactant can be used for nanoparticle synthesis as a non-toxic and biodegradable stabilizing agent.

Microbial biosurfactants as additives for food industries.

Microbial biosurfactants with high ability to reduce surface and interfacial surface tension and conferring important properties such as emulsification, detergency, solubilization, lubrication and phase dispersion have a wide range of potential applications in many industries. Significant interest in these compounds has been demonstrated by environmental, bioremediation, oil, petroleum, food, beverage, cosmetic and pharmaceutical industries attracted by their low toxicity, biodegradability and sustainable production technologies. Despite having significant potentials associated with emulsion formation, stabilization, antiadhesive and antimicrobial activities, significantly less output and applications have been reported in food industry. This has been exacerbated by uneconomical or uncompetitive costing issues for their production when compared to plant or chemical counterparts. In this review, biosurfactants properties, present uses and potential future applications as food additives acting as thickening, emulsifying, dispersing or stabilising agents in addition to the use of sustainable economic processes utilising agro-industrial wastes as alternative substrates for their production are discussed.

Assessment of toxicity of a biosurfactant from Candida sphaerica UCP 0995 cultivated with industrial residues in a bioreactor

Background: The aim of the present study was to propose a low-cost method for the production of a biosurfactant by the yeast Candida sphaerica and assess its toxicity and phytotoxicity. The medium was formulated with distilled water supplemented with residue from a soy oil refinery (5%) and corn steep liquor (2.5%) as substrates. These two products were the sources of carbon and nitrogen as well as mineral elements to encourage the growth of the microorganism and production of a biosurfactant. Results: The isolated biosurfactant yield was 6.364 g/l. The biosurfactant exhibited an excellent ability to reduce surface tension (26 mN/m) and demonstrated no toxicity against seeds of Brassica oleracea, Chicoria intybus and Solanum gilo or the micro crustacean Artemia salina employed as a bioindicator. The biosurfactant exhibited no antimicrobial activity against the fungi and bacteria tested. Conclusions: The promising results obtained in this study indicate the feasibility of producing biosurfactants from powerful non-toxic organic residues and their application in the bioremediation of contaminated soil and water.

Environmentally friendly biosurfactants produced by yeasts.

Some yeasts are preferred to bacteria as sources for biosurfactants, mainly due to their GRAS status for environmental and health safety reasons. This chapter thus focuses on the production of biosurfactants by some yeast cultures using renewable resources like fatty wastes from household and vegetable oil refineries as major substrates. The chapter also emphasizes on the importance of the application of response surface methodology and artificial neural network techniques for the optimization of biosurfactant production by yeasts.

Production and stability studies of the bioemulsifier obtained from a new strain of Candida glabrata UCP 1002

Evaluation of both tenso-active and emulsifying activities indicated that a biosurfactant was produced by the newly isolated and promising strain Candida glabrata isolated from mangrove sediments. The extracellular water-soluble emulsifying agent was isolated and identified as a heteropolymer. The maximum of bioemulsifier production was observed when the strain was grown on soluble and insoluble substrates cotton seed oil plus glucose, reaching values of 10.0 g/l after 144 hrs at 200 rpm. The cell-free culture broth containing the examined agent lowered the surface tension of the medium to 31 mN/m. Stable and compact emulsions with emulsifying activity of 75 percent of cotton seed oil were detected. The emulsification capacity remained practically unaltered within a wide pH (2-12), temperature (4-80°C) ranges and under NaCl concentrations up to 10 percent.

Partition of proteins in aqueous two-phase systems based on Cashew-nut tree gum and poly(ethylene glycol)

A partição de duas proteínas, albumina de soro bovino (BSA) e tripsina foi estudada no sistema bifásico aquoso Polietileno glicol(PEG) - Goma do cajueiro. O diagrama de fases foi estabelecido para a Goma do Cajueiro e para PEG de peso molecular 1500 em duas diferentes temperaturas. A influência de vários parâmetros na partição destas proteínas, incluindo concentração dos polímeros, pH, adição de sal e temperatura foi investigada. Os resultados desta pesquisa demonstraram a importância das características da proteína na partição em sistemas bifásicos aquosos.