Separation of microbial oil produced by Mortierella isabellina using polymeric membranes.

The objective of this work was to concentrate, through a membrane separation process, the fatty acids from oil/solvent mixture. The oil was obtained by ultrasound-assisted extraction from freeze-dried cells of Mortierella isabellina. The concentration of the fatty acids was investigated using flat-sheet polymer membranes of ultrafiltration and nanofiltration. The effects of temperature and pressure were evaluated by the retention of the fatty acids. Oil retentions between 45.23 and 58.20% to ultrafiltration membrane and 43.50 and 56.00% to nanofiltration membrane were observed. The best condition for the ultrafiltration membrane was 4 bar and 40 °C and for nanofiltration membrane was 12 bar and 50 °C. The oil contains a high concentration of oleic acid and palmitic acid that is a desirable property for the biodiesel production. The results showed the applicability of this technology in the solvent recovery step whereas the oil recovered contains a high concentration of fatty acids.

Antioxidant compounds extracted from Diaporthe schini using supercritical CO2 plus cosolvent.

Endophytic fungi have been highlight in the production of secondary metabolites with different bioactive properties, such as in the production of the antioxidant compounds. Therefore, the objective of this work was the extraction of the antioxidant compounds from the biomass of Diaporthe schini using supercritical carbon dioxide (CO2) without and with ethanol as cosolvent. The biomass was produced by submerged fermentation and the parameters evaluated in the extraction process were: pressure (150-250 bar), temperature (40-60 ºC) and cosolvent [biomass: cosolvent ratio, 1:0, 1:0.75 and 1:1.5 (w/v)]. Extraction yield, antioxidant activity and chemical composition of the extracts were determined. The highest extraction yield (3.24 wt.%) and the best antioxidant activity against the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical (96.62%) were obtained at 40 ºC, 250 bar and biomass:cosolvent ratio of 1:1.5 (w/v). The chemical compounds 1,4-diaza-2,5-dioxo-3-isobutyl bicyclo[4.3.0]nonane and benzeneethanol identified in GC/MS could be responsible for the antioxidant activity found in this study.

Production of metabolites with antioxidant activity by Botryosphaeria dothidea in submerged fermentation.

Antioxidants are able of inhibiting free radicals and play an important role in human diet, protection of foods, anti-aging cosmetics, among others. Fungi have been highlighted in production of metabolites with biological activity, such as antioxidant. The main objective of this study was to select a fungus from resources of Brazilians Pampa and Atlantic Forest biomes with hability for production of antioxidants by submerged fermentation. The scavenging activity of the compounds was determined against radical 2.2-diphenyl-1-picrylhydrazyl (DPPH), superoxide and hydroxyl. Botryosphaeria dothidea exhibited higher potential for the production of antioxidants, and its supernatant showed percentage inhibition values of 94.47, 94.87 and 89.78% against DPPH, superoxide and hydroxyl radicals and IC50 of 0.206 mg/mL. The identification of the volatile compounds present in the broth verified the presence of the hexahydropyrrolizin-3-one; 1.2-benzenedicarboxylic acid bis(2-methylpropyl) ester and 3.6-bis(2-methylpropyl)-2.5-piperazinedione. According to this study, Botryosphaeria dothidea presents great potential to produce compounds with antioxidant activity.

Antifungal and antibacterial activity of extracts produced from Diaporthe schini.

The aim of this work was the production of bioactive metabolites by submerged fermentation from the fungus Diaporthe schini, followed by their extraction, separation and characterization. Different solvents (methanol, dichloromethane and hexane) were used for the extraction of metabolites from the fermentation broth and the extracts obtained were evaluated by in vitro antibacterial and antifungal activity. The separation and characterization of the extract from the hexane extraction was performed by column chromatography and GC-MS, respectively. The extracts had a great inhibitory action on the Gram-positive bacteria Staphylococcus epidermidis and Staphylococcus aureus, on the Gram-negative bacteria Enterobacter aerogenes and Klebsiella pneumoniae and on the fungus Candida krusei. The main metabolites produced were: 13-docosenamide, (Z)-; 2-hexadecene, 3,7,11,15-tetramethyl; 9-octadecenamide and 11-octadecenoic acid. Studies related to the antibacterial and antifungal activities of metabolites extracted from microorganisms are found in the literature. However, works about the identification of metabolites produced by submerged fermentation from Diaporthe schini were not found until the present moment. This work is an initial study where the conditions of the process can be optimized by looking for the production of a specific compound and can be a promising source for obtaining new drugs.

Degradation of Amaranth azo dye in water by heterogeneous photo-Fenton process using FeWO4 catalyst prepared by microwave irradiation.

FeWO4 particles were synthesized by a simple, rapid and facile microwave technique and their catalytic properties in heterogeneous photo-Fenton reaction were evaluated. This material was employed in the degradation of Amaranth azo dye. Individual and interactive effects of operational parameters such as pH, dye concentration and H2O2 dosage on the decolorization efficiency of Amaranth dye were evaluated by 2(3) central composite design. According to characterization techniques, a porous material and a well-crystallized phase of FeWO4 oxide were obtained. Regarding the photo-Fenton reaction assays, up to 97% color and 58% organic carbon removal were achieved in the best experimental conditions. In addition, the photo-Fenton process maintained treatment efficiency over five catalyst reuse cycles to indicate the durability of the FeWO4 catalyst. In summary, the results reveal that the synthesized FeWO4 material is a promising catalyst for wastewater treatment by heterogeneous photo-Fenton process.

Evaluation of biobutanol production by Clostridium beijerinckii NRRL B-592 using sweet sorghum as carbon source / Avaliação da produção de biobutanol por Clostridium beijerinckii NRRL B-592 usando sorgo sacarino como fonte de carbono

In this research it was evaluated the production of biobutanol by Clostridium beijerinckiiNRRL B-592 using sweet sorghum juice as carbon source. Operational variables, like pH and initial inoculum size, as well as supplementation of industrial media with yeast extract and tryptone, were evaluated. The maximum butanol obtained was 2.12g kg^-1 using 12.5% of inoculum size, 0.05g 100mL^-1 of tryptone and 0.1g 100mL^-1 of yeast extract and initial pH of 5.5. The main contribution of this research was to show a systematic procedure for development of a low cost industrial media for biobutanol production from sweet sorghum.

Neste trabalho, foi avaliada a produção de biobutanol por Clostridium beijerinckiiNRRL B-592 usando o caldo de sorgo sacarino como fonte de carbono. Foram avaliadas as variáveis operacionais como pH e densidade de inóculo, bem como a suplementação de meios industriais com extrato de levedura e triptona. A máxima concentração de butanol obtida foi de 2,12g kg^-1, utilizando 12,5% de inóculo, 0,05g 100mL^-1 de triptona e 0,1g 100ml^-1 de extrato de levedura e pH inicial de 5,5. A principal contribuição deste trabalho foi o de mostrar um procedimento sistemático para o desenvolvimento de um meio industrial de baixo custo para a produção de biobutanol a partir de sorgo sacarino.

Evaluation of fructooligosaccharides separation using a fixed-bed column packed with activated charcoal.

Recent studies have shown that the chromatographic separation of mixtures of saccharides may be improved by making use of activated charcoal, a promising low cost material for the separation of sugars, including fructooligosaccharides. In this work, the development of a methodology to separate fructooligosaccharides from glucose, fructose and sucrose, using a fixed bed column packed with activated charcoal is proposed. The influence of temperature, eluant concentration and step gradients were evaluated to increase the separation efficiency and fructooligosaccharide purity. The final degree of fructooligosaccharide purification and separation efficiency were about 94% and 3.03 respectively, using ethanol gradient concentration ranging from 3.5% to 15% (v/v) at 40°C. The fixed bed column packed with the activated charcoal was shown to be a promising alternative for sugar separation, mainly those rich in fructooligosaccharides, leading to solutions of acceptable degrees of purification.

Separation and purification of fructooligosaccharides on a zeolite fixed-bed column.

Fructooligosaccharides (FOS), a well-known prebiotic product, are obtained by enzymatic synthesis and consist of a mixture of mono- and disaccharides. In this work, a methodology for their separation and purification was developed using a zeolite fixed-bed column. The effects of column temperature (40-60°C), eluent flow rate (0.10-0.14 mL/min), injected to bed volume percent ratio (2.6-5.1%), and ethanol concentration in the eluent (40-60%, v/v) were investigated using a fractionary factorial design (2(4-1)), having the separation efficiency and purity as target responses. Additional experiments were performed as well, where the temperature and ethanol concentration were studied in a central composite design (2(2)). In this work, the zeolite fixed-bed column was shown to be a good alternative for FOS purification, allowing a FOS purity of 90% and separation efficiency of 6.86 between FOS and glucose, using an eluent at 45°C with 60% ethanol concentration.

Effects of Solvent Diols on the Synthesis of ZnFe2O4 Particles and Their Use as Heterogeneous Photo-Fenton Catalysts.

A solvothermal method was used to prepare zinc ferrite spinel oxide (ZnFe2O4) using ethylene glycol and 1,4 butanediol as solvent diols, and the influence of diols on the physical properties of ZnFe2O4 particles was investigated. The produced particles were characterized by X-ray powder diffraction (XRD), atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR) and nitrogen adsorption isotherms, and the catalytic activity for the organic pollutant decomposition by heterogeneous photo-Fenton reaction was investigated. Both solvents produced particles with cubic spinel structure. Microporous and mesoporous structures were obtained when ethylene glycol and 1,4 butanediol were used as diols, respectively. A higher pore volume and surface area, as well as a higher catalytic activity for the pollutant degradation were found when 1,4 butanediol was used as solvent.

Estabilidade do farelo de arroz sob diferentes tratamentos: micro-ondas, peletização e desengorduramento / Stability of rice bran under different treatment: pelleting, microwave, and degreasing

O arroz é um cereal cultivado e consumido em todos os continentes, possui alto valor nutricional, rico em proteínas, fibras, sais minerais e antioxidantes. Porém, parte destes nutrientes é perdida durante o beneficiamento e retida no farelo de arroz produzido através da etapa de polimento do grão. O shelf-life do farelo é reduzido devido à ação da lipase, enzima altamente reativa que decompõe os lipídios em ácidos graxos livres, promovendo a rancificação do farelo e impossibilitando o consumo humano e animal. O objetivo do presente estudo foi verificar a estabilidade do farelo de arroz através dos diferentes tratamentos, peletização (FAP), micro-ondas (FAM), e desengorduramento (FAD), avaliando o nível de rancificação por meio da atividade da lipase e acidez dos farelos, em comparação ao farelo controle (FAC) (sem tratamento). As características físico-químicas (umidade, proteínas, lipídios e cinzas) dos farelos variaram devido aos diferentes genótipos dos grãos, condições climáticas de plantio e tipos de beneficiamento. Todos os farelos de arroz submetidos à estabilização apresentaram valores inferiores ao controle para a atividade da lipase, comprovando que a estabilização auxiliou na prevenção da rancidez hidrolítica. O FAD e o FAM apresentaram as menores atividades da lipase, 3,66 U/ml e 3,83 U/ml, respectivamente. O FAM também apresentou o menor teor de acidez, tornando-se uma boa opção de estabilização, agregando maior shelf-life ao produto e viabilizando sua utilização como insumo alimentício.

Rice is a cereal grown and consumed on every continent, has high nutritional value, rich in protein, fiber, minerals and antioxidants. However, part of these nutrients are lost during processing and retained in the rice bran produced by the grain polishing step. The bran has its shelf-life reduced to a few days due to lipase action, which is a highly reactive enzyme that breaks down lipids into free fatty acids, promoting rancidity bran, disabling to human and animal consumption. The aim of this study was to investigate the stabilization of rice bran through different treatments such as pelleting (FAP), microwave (FAM) and defatting (FAD), assessing the level of rancidity by lipase activity and acidity of the brans compared to the control (FAC) (without treatment). The physicochemical composition (moisture, protein, fat and ash) of the brans varied significantly due to the different genotypes of grain, planting, weather conditions and types of processing. All rice brans showed lower values for lipase activity, indicating that the stabilization helped to prevent hydrolytic rancidity. The FAD and FAM had the lowest lipase activity, 3.66 U/ml and 3.83 U/ml, respectively. The FAM also had the lowest acidity, which makes microwave treatment a good choice for stabilization, thus increasing its shelf-life and allowing its use as a food ingredient.

Separation of fructooligosaccharides using zeolite fixed bed columns.

Recent studies have shown that the chromatographic separation of mixtures of monosaccharides and disaccharides may be improved by employing Y zeolites, a procedure which holds promise in the separation of oligosaccharides. In the present study, a column packed with zeolite was employed to study the separation of fructooligosaccharides (FOS). FOS were produced by an enzyme isolated from Rhodotorula sp., which produces GF2 (kestose), GF3 (nystose) and GF4 (frutofuranosyl nystose). The identification and quantification of the sugars were carried out by ion exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The separation of fructooligosaccharides was carried out using a fixed bed column packed with Ba2+-exchange Y zeolites. The effects of temperature (40-50 degrees C), injected volume per bed volume (2.55-7.64%), superficial velocity (0.1-0.15 cm min(-1)) and eluent composition (40-60% ethanol) were investigated using a fractionary factorial design with separation efficiency as the response. The results showed that the most favorable conditions for the separation of the oligosaccharide-glucose mixture were 60% ethanol as eluent, temperature of 50 degrees C, superficial velocity of 0.1 cm min(-1) and 2.55% injection volume per bed volume of injection mixture, using two columns in series. The values for separation efficiency were 0.60 for oligosaccharide-glucose, 1.00 for oligosaccharide-fructose, 0.22 for oligosaccharide-sucrose, 0.43 for glucose-fructose, 0.82 for glucose-sucrose and 1.23 for fructose-sucrose.

Purification of fructooligosaccharides in an activated charcoal fixed bed column.

Fructooligosaccharides (FOS) are mixtures of oligosaccharides containing mono and disaccharides, therefore, the separation of these sugars results in purer products for human consumption and can be added to various food products (drinks, cookies and yogurt). The aim of this work was the purification of fructooligosaccharides from a mixture of sugars, obtained by enzymatic synthesis, containing fructooligosaccharides, glucose, fructose and sucrose using activated charcoal fixed bed column. Temperature and ethanol concentration effects were analyzed using a 2² central composite design. Good separation conditions were obtained through central composite design. The best separation coefficient between fructooligosaccharides and glucose (ES(fructoolig/gluc)) was 3.99 ± 0.07 and between fructose and fructooligosaccharides (ES(fructoolig/fruct)) was 2.89 ± 0.36 using ethanol 15% (v/v) as eluent, at 50°C. The final FOS purification degree and recovery were about 80% and 97.8%, respectively. The activated charcoal fixed bed columns were shown to be a good alternative for sugar separation, especially for rich mixtures of fructooligosaccharides.