Investigation into the effect of the culture conditions and optimization on limonene-1,2-diol production from the biotransformation of limonene using Pestalotiopsis mangiferae LaBMicrA-505.

Different bioproducts can be obtained by changing operative condition of biotechnological process, and this bioprocess aspect is a significant approach to be adopted on industrial scale leading to the creation of new natural aroma. Thus, this study aimed to investigate the culture conditions and optimization of the biotransformation of limonene into limonene-1,2-diol using Pestalotiopsis mangiferae LaBMicrA-505 obtained from the Brazilian Amazon. The study started with the investigation of the establishment of culture, followed by optimization of the conditions for biotransformation of R-(+)-limonene to limonene-1,2-diol, using shake flasks. The fresh biomass of P. mangiferae LaBMicrA-505 obtained in liquid media supplemented with yeast-malt extract under with 72 h (stationary phase) performed better diol productivity when compared to other biomasses. Finally, in the modeling of contour plots and surface responses of a central composite design, the use of 4 g l- 1 biomass, 2% of the substrate at 24 °C, 120 rpm, and pH of 6.0 could maximize the production of limonene-1,2-diol, accumulated up to 98.34 ± 1.53% after 96 h of reaction. This study contributed to identified operational condition for the R-(+)-limonene bioconversion scale-up. The endophytic fungus P. mangiferae LaBMicrA-505 proved to be a potent biocatalyst to biotechnologically produce limonene-1,2-diol, an aroma compounds with interesting bioactive features that up to now has been manufactured by extraction from plants with long and not environmentally friendly procedures.

Method optimization for the extraction of chlorogenic acids from coffee parchment: An ecofriendly alternative.

One of the principal byproducts of coffee roasting is the coffee parchment. It is abundant in bioactive substances, including derivatives of chlorogenic acids, which are well-known for their exceptional antioxidant effects. It is advantageous to use environmentally friendly extraction techniques on such residues since it adds value to the entire coffee production process supply chain. The aim of this work was to assess and enhance the ability of non-conventional extraction techniques to extract derivatives of chlorogenic acid from coffee parchment. A central composite design was used to maximize the recovery of those phenolic compounds. The optimized extraction conditions were with 5 min extraction period, at a temperature of 70 °C, and 80% ethanol in the extractor solvent. In this conditions extraction recovery of chlorogenic acids was of 0.8% by the use of microwave-aided extraction (MAE). The optimized conditions are practical, economical, and ecologically friendly method to extract phenolic compounds and, consequently, underscores the potential for sustainable utilization of coffee parchment, offering a valuable contribution to the development of environmentally conscious strategies within the coffee industry.

Statistical optimization of bioprocess parameters for enhanced production of bacterial cellulose from K. saccharivorans BC-G1.

Bacterial Cellulose (BC) offers a wide range of applications across various industries, including food, biomedical, and textiles, owing to its distinctive properties. Its unique 3D reticulated network of cellulose nanofibers, imparts excellent mechanical qualities, a high water-holding capacity, and thermal stability. Additionally, it possesses remarkable biocompatibility, biodegradability, high crystallinity, and purity. These attributes have offered significant interest in BC within both academic and industrial sectors. However, BC production is associated with high costs due to the use of expensive growth media and low yields. The study reports the potential of our indigenous isolate, Komagataeibacter saccharivorans BC-G1, as BC producer. Statistical optimization of BC production was carried out using Placket-Burman design and Central composite design, by selecting different parameters. Eight significant factors such as temperature, pH, glucose, yeast, peptone, acetic acid, incubation time and % inoculum were studies using ANOVA-based response surface methodology. Results showed that BC yield (8.5 g/L) with 1.8-fold after optimization of parameters. Maximum cellulose production (8.5 ± 1.8 g/L) was obtained using 2% glucose, 0.3% yeast extract, 0.3% peptone, 0.75% (v/v) acetic acid at pH 7.0 for 10 days of incubation with 4% inoculum at 25 °C under static culture. Main effect graph showed incubation time and acetic acid concentration as the most significant parameters affecting BC production in our study. The physicochemical characterization of produced BC was done using FTIR, XRD and SEM techniques.

Optimization of an Alternative Culture Medium for Phycocyanin Production from Arthrospira platensis under Laboratory Conditions.

Arthrospira platensis, known as spirulina, is a cyanobacterium with multiple nutritional benefits, as it contains substantial amounts of proteins, fatty acids, and pigments. However, the production of this microalga has faced significant challenges, primarily related to the cost and composition of the required culture medium for its optimal growth. This study focused on optimizing two nitrogen sources (urea and potassium nitrate) to maximize the growth of A. platensis and the production of phycocyanin, a photosynthetic pigment of significant commercial value. Optimization was performed using the response surface methodology (RSM) with a central composite design (CCD). Analysis of variance (ANOVA) was employed to validate the model, which revealed that the different concentrations of urea were statistically significant (p < 0.05) for biomass and phycocyanin production. However, potassium nitrate (KNO3) showed no significant influence (p > 0.05) on the response variables. The RSM analysis indicated that the optimal concentrations of KNO3 and urea to maximize the response variables were 3.5 g L-1 and 0.098 g L-1, respectively. This study offers valuable perspectives for the efficient production of A. platensis while reducing production costs for its cultivation on a larger scale.

Optimization of cultural and nutritional conditions to enhance mycelial biomass of Cordyceps militaris using statistical approach.

Cordyceps militaris is a fungus with numerous therapeutic properties that has gained worldwide popularity due to its potential health benefits. The fruiting body of this mushroom is highly expensive and takes a longer time to produce, making mycelial a sustainable and cost-effective alternative. The study investigates and optimizes cultural and nutritional conditions to maximize mycelial biomass. The initial optimization was done by the conventional single-factor approach, followed by Plackett-Burman design to screen the most significant variables, with yeast extract, temperature, and glucose being the most significant, contributing 11.58%, 49.74%, and 27.98%, respectively, in mycelial biomass production. These variables were then optimized using response surface methodology (RSM) based on central composite design (CCD). The study observed that temperature and glucose had the highest impact on mycelial biomass, with p-values of 0.0128 and 0.0191, respectively. Under the optimized conditions, temperature 20 °C, glucose 2.5% (w/v), and yeast extract 0.8% (w/v), the maximal yield of mycelial biomass reached 547 ± 2.09 mg/100 mL, which was 1.95-fold higher than the yield in the basal medium. These findings suggest that optimizing the cultural and nutritional conditions can enhance mycelial biomass production of Cordyceps militaris, offering a sustainable and cost-effective source of this valuable fungus.

Anaerobic digestion of crude glycerol from biodiesel production for biogas generation: Process optimization and pilot scale operation.

Anaerobic digestion of wastes and wastewater is a complex process that can be affected by many operational parameters. In this context, the purpose of the present study was to optimize biogas production using crude glycerol (GLY) generated in biodiesel production from waste cooking oil without pretreatment or nutrient supplementation. The study was divided into two parts: the first phase consisted of an experimental design based on central composite design (CCD) with two variables (food to microorganism (F/M) ratio and cycle time) at five levels (F/M of 0.20; 0.51; 1.02; 1.53 and 2.04 gCOD/gVS; tc of 3, 4, 5, 6, 7 days) focusing on optimizing the biogas production from crude GLY in lab-scale batch reactors (500 mL). The second phase was conducted on a pilot-scale biodigester (1.2 m3) based on the optimized variables obtained from the CCD. The optimized results showed that the F/M ratio of 2.04 gCOD/gVS and a cycle time (tc) of 6 days reached the highest specific methane production (SMP) of 46 LCH4/kgVS. However, the highest SMP of 14.7 LCH4/kgVSd was obtained during the operation of the pilot-scale biodigester for the optimized conditions of F/M ratio of 0.23 gCOD/gSV and a tc of 7 days. Therefore, pilot-scale biogas production from crude GLY was demonstrated to be feasible without the use of nutrients or GLY pretreatment at 0.15 LGLY/m3 d.

Red sacaca essential oil-loaded nanostructured lipid carriers optimized by factorial design: cytotoxicity and cellular reactive oxygen species levels.

Amazonian flora includes several species with the potential to develop pharmaceutical and biotechnological products. The essential oils from Amazonian species possess some biological properties, such as antioxidant, antibacterial, and cytotoxic activities. The essential oil of red sacaca (RSO), Croton cajucara Benth., contains metabolites characterized by antioxidant and anti-inflammatory activities. Nanostructured lipid carriers (NLC) are an advantageous alternative for the effective delivery of drugs because they can solubilize lipophilic actives and reduce their cytotoxicity. This study aimed to optimize the synthesis of RSO-loaded nanostructured lipid carriers (NLC-RSO) using a 23 factorial design and investigate their antioxidant and cytotoxic effects. The red sacaca essential oil (RSO) metabolite profile was characterized using gas chromatography coupled with a mass spectrometer (GC-MS), identifying 33 metabolites, with linalool and 7-hydroxy-calamenene as the major ones, as reported in the literature. The optimized NLC-RSO formulation had a particle size less than 100 nm and a polydispersity index lower than 0.25. After characterizing NLC-RSO using Fourier-transform infrared spectroscopy, powder X-ray diffraction, zeta potential, moisture content, and wettability, in vitro cytotoxicity were performed in A549 and BEAS-2B cell lines using the resazurin metabolism assay. The data indicated a lower IC50 for RSO than for NLC-RSOs in both cell lines. Furthermore, low cytotoxicity of blank nanoparticles (blank NP) and medium chain triglycerides-loaded nanostructured lipid carriers (NLC-MCT) towards both pulmonary cell lines was noted. At a concentration of 50-100 µg/mL, free RSO exhibited higher cytotoxicity than NLC-RSO, demonstrating the protective effect of this lipid carrier in reducing cytotoxicity during metabolite delivery. Similarly, free RSO showed higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging than NLC-RSO, also indicating this protective effect. The 2',7'-dichlorofluorescein diacetate (DCFH-DA) intracellular reactive oxygen species (ROS) level assay did not show differences between the treatments at higher but non-cytotoxic dosages. Taken together, our results suggest that NLC-RSOs are potential RSO delivery systems for applications related to cancer treatment.

Sample pooling and incurred samples improve analytical throughput and quality control of lipophilic phycotoxins screening in bivalve mollusks.

Lipophilic marine biotoxins (LMBs) are one of the main risks associated with the consumption of mussels and oysters. Sanitary and analytical control programs are developed to detect the occurrence of these toxins in seafood before they reach toxic levels. To ensure quick results, methods must be easy and fast to perform. In this work, we demonstrated that incurred samples were a viable alternative to validation and internal quality control studies for the analysis of LMBs in bivalve mollusks. These samples were used to optimize, validate, and monitor a simple and fast ultrasound-assisted extraction (UAE) procedure. An internal quality control material containing okadaic acid (227 ± 46 µg kg-1) was produced and characterized. This material had its homogeneity and stability verified and was included as a quality control in all batches of analytical routine. Besides, a sample pooling protocol for extracts analysis was developed, based on tests for COVID-19. Up to 10 samples could be analyzed simultaneously, reducing the instrumental time of analysis by up to 80%. The UAE and sample pooling approaches were then applied to more than 450 samples, of which at least 100 were positive for the okadaic acid group of toxins.

Microbial diversity and metabolic inference of diclofenac removal in optimised batch heterotrophic-denitrifying conditions by means of factorial design.

Using the Response Surface Methodology (RSM) and Rotational Central Composite Design (RCCD), this study evaluated the removal of DCF under denitrifying conditions, with ethanol as cosubstrate, in batch reactors, being 1 L Erlenmeyer flasks (330 mL of reactional volume) containing Dofing medium and kept under agitation at 130 rpm and incubated at mesophilic temperature (30 °C). It considered the individual and multiple effects of the variables: nitrate (130 - 230 mg NO3- L-1), DCF (60-100 µg DCF L-1) and ethanol (130 - 230 mg EtOH L-1). The highest drug removal efficiency (17.5%) and total nitrate removal were obtained at 176.6 ± 4.3 mg NO3 -L-1, 76.8 ± 3.7 µg DCF L-1, and 180.0 ± 2.5 mg EtOH L-1. Under such conditions, the addition of ethanol and nitrate was significant for the additional removal of diclofenac (p > 0.05). The prevalence of Rhodanobacter, Haliangium and Terrimonas in the inoculum biomass (activated sludge systems) was identified through the 16S rRNA gene sequencing. The potential of these genera to remove nitrate and degrade diclofenac was inferred, and the main enzymes potentially involved in this process were α-methylacyl-CoA racemase, long-chain fatty acid-CoA ligase, catalases and pseudoperoxidases.

Pectin Extraction from Residues of the Cocoa Fruit (Theobroma cacao L.) by Different Organic Acids: A Comparative Study.

Ecuador is the world's fifth largest cocoa producer, generating hundreds of tons of residues from this fruit annually. This research generates value from the residual (cocoa pod husk) by using it as raw material to obtain pectin, which is widely used in the food and pharmaceutical industries. Extraction of three different organic acids with GRAS status (safe for use), the citric, malic and fumaric acids, was studied. In addition, two other factors, temperature (70-90 °C) and extraction time (60-90 min), were explored in a central composite design of experiments. We determined the conditions of the experiments where the best yields were garnered for citric acid, malic acid and fumaric acid, along with a ~86 min extraction time. The temperature did not show a significant influence on the yield. The pectin obtained under optimal conditions was characterised, showing the similarity with commercial pectin. However, the equivalent weight and esterification degree of the pectin obtained with fumaric acid led us to classify it as having a high equivalent weight and a low degree of esterification. In these regards, it differed significantly from the other two acids, perhaps due to the limited solubility of fumaric acid.

Application of Lactose-Free Whey Protein to Greek Yogurts: Potential Health Benefits and Impact on Rheological Aspects and Sensory Attributes.

The application of ß-galactosidase in the fermentation of milk enables the acquirement of lower levels of lactose that are tolerated by lactose maldigesters and can reduce the nutritional consequences of avoiding dairy products. The present study evaluated the viability of the fortification of lactose-free prebiotic Greek yogurt formulas with whey protein concentrate (WPC). Two rotational central composite designs (RCCDs) were applied: one to perform the hydrolysis of the whey protein concentrate and another for the yogurt formulations (α = 2 with 2 central points and 4 axial points). Two ß-galactosidase enzymes obtained from Kluyveromyces lactis were used. The content of lactose, glucose, galactose, and lactic acid were determined in the WPC, milk (pasteurized and powdered), and yogurts. The three best formulations regarding the attributes' viscosity, syneresis, firmness, and elasticity were sensorially evaluated by using a nine-point hedonic scale. A microbiological analysis was performed after 48 h of yogurt production. The characterization of the products and the comparison of the results obtained were evaluated using the Student's T test and the analysis of variance with Tukey's test (p-values < 0.05). The application of a lactose-free WPC promoted viscosity, firmness, and elasticity. The syneresis was reduced, and whey increased the protein and calcium content. Lactose-free WPC can be used as a partial substitute for skimmed powdered milk in yogurts. The obtained results are encouraging with respect to the production of lactose-free Greek yogurts by the dairy industry.

Potato waste as feedstock to produce biohydrogen and organic acids: A comparison of acid and alkaline pretreatments using response surface methodology.

The effects of physicochemical pre-treatment were evaluated on hydrogen (H2) production and organic acids from hydrolyzed potato peel. Central composite design (CCD) and response surface methodology (RSM) were used to evaluate the effects of different substrate concentrations on a wet basis (38.8-81.2 g.L-1) and hydrolyser ratios (6M NaOH and 30% HCl: 1.6-4.4% v.v-1; and H2SO4: 2.2-7.8% v.v-1). The experiments were conducted in batch reactors at 37 °C, using a heat-treated microbial consortium. The maximum H2 production potential (P), lag phase (λ), and maximum H2 production rate (Rm) were evaluated for untreated and pre-treated potato peel waste. H2 production was positively influenced under hydrolyzed substrate concentrations ≥75 g.L-1 in the three CCDs performed. Only the increase in the H2SO4 proportions (≥5% v.v-1) had a negative influence on H2 production. Increasing the 30% HCl and 6M NaOH proportions did not significantly influence the cumulative H2 production. The highest hydrogen production was obtained after alkaline pre-treatment by dark fermentation (P: 762.09 mL H2.L-1; λ: 14.56 h; Rm: 38.39 mL H2.L-1.h-1). Based on the CCD and RSM, the highest H2 production (1060.10 mL H2.L-1) was observed with 81.2 g.L-1 hydrolyzed potato peel with 3.0% v.v-1 of 6M NaOH. The highest yield liquid metabolites were acetic (513.70 mg. g-1 COD) and butyric acids (491.90 mg. g-1 COD).

High protein, gluten-free cookies made with rice, beans and avocado

Cookies are versatile foods that can supply specific needs and can be used as food vehicles to increase the intake of various nutrients. The objective was to create a gluten-free butter cookie based on rice flour (Oryza sativa). A central composite design 22 was used for analyzing the substitution of rice flour for bean flour (Phaseolus vulgaris, L.) (0-60%) and the substitution of butter for avocado puree (Persea americana) (0-100%). Response Surface Methodology were used to analyze the data with a significance of 10% (p<0.1) and a minimum R2 of 0.6. Variables analyzed were protein content (%), fat content (%), spread ratio, weight loss (%), water activity, moisture content (%), and ash content (%). Increases in the percentage of substitution of bean flour and avocado puree increased the amount of protein, ash, and moisture significantly. Fat content increased significantly following the decrease in avocado substitution. The minimum weight loss was obtained on intermediate values of bean flour. Water activity and spread ratio were not affected by changes in the variables measured. Three different formulas were obtained for the optimization: 46% bean flour and 86% of avocado puree, a formulation with an appropriate moisture range by reducing the lipid oxidation (59% bean flour and 82% avocado puree), and a formulation with 100% avocado (40% bean flour and 100% avocado puree). Sensory evaluation results of optimized treatments indicated that the formula with 46% bean flour and 86% avocado puree presented the highest global acceptance. Results from this study showcase the possibility of producing gluten-free cookies with good protein content.

Las galletas son alimentos versátiles que pueden suplir necesidades específicas y ser utilizados como vehículos para aumentar la ingesta de distintos nutrientes. El objetivo fue elaborar galletas de mantequilla libres de gluten a base de harina de arroz. Se realizó un diseño central compuesto 22 donde se estudió la sustitución parcial de harina de arroz por harina de frijol (Phaseolus vulgaris, L.) (0-60%) y la sustitución de la mantequilla por puré de aguacate (Persea americana) (0-100%). Los resultados fueron analizados por la Metodología de Superficie de Respuesta con un nivel de significancia del 10% (p<0.1) y con un mínimo R2 de 0.6. Las variables de respuesta fueron: proteína (%), grasa (%), diámetro/altura, pérdida de peso (%), humedad (%) y cenizas (%). A valores altos de las dos variables estudiadas la cantidad de proteína, de cenizas y de humedad aumentó significativamente. La cantidad de grasa se incrementó al utilizar bajos niveles de puré de aguacate. Los menores valores de pérdida de peso se obtuvieron en niveles intermedios de harina de frijol. La relación diámetro/altura no fue afectada por las variables estudiadas. Al optimizar se obtuvieron 3 formulaciones diferentes: 46% de harina de frijol y 86% puré de aguacate; 59% de frijol y 82% de puré de aguacate y otra (no estadística) 40% de frijol y 100% de puré de aguacate. Los resultados del análisis sensorial de las muestras optimizadas indicaron que la formulación con mayor aceptación global fue la elaborada con 46% de harina de frijol y 86% de puré de aguacate, concluyendo que es posible elaborar una galleta libre de gluten y con una adecuada cantidad de proteína.

Chemometric optimization of trypsin digestion method applying infrared, microwave and ultrasound energies for determination of caseins and ovalbumin in wines.

Caseins and ovalbumin are frequently used as wine fining agents to remove undesirable compounds like polymeric phenols. Their presence in wines is a subject of concern because may cause adverse effects on susceptible consumers, especially when their presence is not labeled. A key step for its determination is trypsin digestion, which is considered the bottleneck of bottom-up approach workflow because usually requires several hours. To reduce this time, the objective of this work was to carry out a chemometric optimization of trypsin digestion method applying infrared, microwave and ultrasound energies to determine caseins and ovalbumin in wines. The conditions of each accelerated digestion method were optimized using a Response Surface Methodology based on central composite design. The parameters optimized were digestion time and trypsin: protein ratio. The response variable evaluated was digestion yield, which was determined through the peak area of each protein transition determined by liquid chromatography-mass spectrometry. The most effective technique was microwave followed by ultrasound and infrared. Since optimal values of microwave and ultrasound-assisted digestion were the same, the later was chosen considering sample preparation and cost. Applying the proposed approach, a reduction of ca. 140 and 240-fold on digestion time was achieved compared with optimized and non-optimized conventional methods, respectively. With this workflow, both proteins were digested in a single 3 min process allowing its detection by liquid chromatography-mass spectrometry at µg L-1 level, which is ca. 60 times lower than the current limit of 0.25 mg L-1.

Design of experiments (DoE) to develop and to optimize nanoparticles as drug delivery systems.

Nanotechnology has been widely applied to develop drug delivery systems to improve therapeutic performance. The effectiveness of these systems is intrinsically related to their physicochemical properties, so their biological responses are highly susceptible to factors such as the type and quantity of each material that is employed in their synthesis and to the method that is used to produce them. In this context, quality-oriented manufacturing of nanoparticles has been an important strategy to understand and to optimize the factors involved in their production. For this purpose, Design of Experiment (DoE) tools have been applied to obtain enough knowledge about the process and hence achieve high-quality products. This review aims to set up the bases to implement DoE as a strategy to improve the manufacture of nanocarriers and to discuss the main factors involved in the production of the most common nanocarriers employed in the pharmaceutical field.

Microbial and functional characterization of an allochthonous consortium applied to hydrogen production from Citrus Peel Waste in batch reactor in optimized conditions.

Energy recovery from lignocellulosic waste has been studied as an alternative to the problem of inappropriate waste disposal. The present study aimed at characterizing the microbial community and the functional activity of reactors applied to H2 production through lignocellulosic waste fermentation in optimized conditions. The latter were identified by means of Rotational Central Composite Design (RCCD), applied to optimize allochthonous inoculum concentration (2.32-5.68 gTVS/L of granular anaerobic sludge), pH (4.32-7.68) and Citrus Peel Waste (CPW) concentration (1.55-28.45 g/L). After validation, the conditions identified for optimal H2 production were 4 gSTV/L of allochthonous inoculum, 29.8 g/L of CPW (substrate) and initial pH of 8.98. In these conditions, 48.47 mmol/L of H2 was obtained, which is 3.64 times higher than the concentration in unoptimized conditions (13.31 mmol H2/L using 15 g/L of CPW, 2 gTVS/L of allochthonous inoculum, pH 7.0). Acetogenesis was the predominant pathway, and maximal concentrations of 3,731 mg/L of butyric acid and 3,516 mg/L of acetic acid were observed. Regarding the metataxonomic profile, Clostridium genus was dramatically favored in the optimized condition (79.78%) when compared to the allochthonous inoculum (0.43%). It was possible to identify several genes related to H2 (i.e dehydrogenases) and volatile fatty acids (VFA) production and with cellulose degradation, especially some CAZymes from the classes Auxiliary Activities, Glycoside Hydrolases and Glycosyl Transferase. By means of differential gene expression it was observed that cellulose degradation and acetic acid production pathways were overabundant in samples from the optimized reactors, highlighting endo-ß-1,4-glucanase/cellulose, endo-ß-1,4-xylanase, ß-glucosidase, ß-mannosidase, cellulose ß-1,4-cellobiosidase, cellobiohydrolase, and others, as main the functions.

Optimization of the cultivation conditions of Bacillus licheniformis BCLLNF-01 for cellulase production.

The objective of this study was to optimize the production of CMCase by Bacillus licheniformis BCLLNF-01, a strain associated with the mucus of the zoanthid Palythoa caribaeorum (Cnidaria, Anthozoa). Production of total cellulase and CMCase was investigated in the supernatant, intracellular content and wall content. Cultivation was carried out in BLM medium supplemented with 1.5 % (w/v) CMC, 5.5 % (v/v) inoculum, 40 °C, pH 6.5, 500 rpm for 72 h, and the highest activity was recorded in the supernatant. A Rotational Central Composite Design (RCCD) 2³ was used to investigate the influence of the carbon source concentration (CMC-0.5 to 1.5 % w/v), inoculum concentration (1-10 % v/v) and temperature (35-45 °C) on CMCase production. The maximum enzyme activity was achieved for a CMC concentration of 1.5 % w/v at 40 °C, attaining 0.493 IU/mL after 96 h of cultivation.

Optimization of growing conditions for pigments production from microalga Navicula incerta using response surface methodology and its antioxidant capacity.

Navicula incerta is a marine microalga distributed in Baja California, México, commonly used in aquaculture nutrition, and has been extended to human food, biomedical, and pharmaceutical industries due to its high biological activity. Therefore, the study aimed to optimize culture conditions to produce antioxidant pigments. A central composite experimental design and response surface methodology (RSM) was employed to analyze the best culture conditions. The medium (nitrogen-deficient concentrations), salinity (PSU = Practical Salinity Unity [g/kg]), age of culture (days), and solvent extraction (ethanol, methanol, and acetone) were the factors used for the experiment. Chlorophyll a (Chl a) and total carotenoids (T-Car), determined spectroscopically, were used as the response variables. The antioxidant capacity was evaluated by DPPH• and ABTS•+ radical inhibition, FRAP, and anti-hemolytic activity. According to the overlay plots, the optimum growth conditions for Chl a and T-Car production were the following conditions: medium = 0.44 mol·L-1 of NaNO3, salinity = 40 PSU, age of culture: 3.5 days, and solvent = methanol. The pigment extracts obtained in these optimized conditions had high antioxidant activity in ABTS•+ (86.2-92.1% of inhibition) and anti-hemolytic activity (81.8-96.7% of hemolysis inhibition). Low inhibition (33-35%) was observed in DPPH•. The highest value of FRAP (766.03 ± 16.62 µmol TE/g) was observed in the acetonic extract. The results demonstrated that RSM could obtain an extract with high antioxidant capacity with potential applications in the biomedical and pharmaceutical industry, which encourages the use of natural resources for chemoprevention of chronic-degenerative pathologies.

Toxicity treatment of tobacco wastes using experimental design by filamentous fungi.

Cigarette product waste contains toxic chemicals, including human carcinogens, which leach into and accumulate in the environment and represent a current environmental problem neglected for too long. This study aimed to select filamentous fungi capable of decreasing tobacco extract toxicity as an alternative to a future bioremediation process. The 38 isolates obtained from Culture collection of microorganisms to biotechnological and environmental importance - CCMIBA (Brazil) were cultivated in yeast extract (10 g.L-1) and dextrose (10 g.L-1) containing cigarette tobacco extract (200 mL.L-1) for seven days at 28 °C on a rotary shaker at 150 rpm. The fungal growth rate was determined to infer fungal tolerance to tobacco extract, and supernatants from cultivated fungi were used to run the toxicity test using Allium cepa assay. The Fusarium sp. strain I.17, isolated from cigarette waste, was the only lineage capable of growing in 20% (v/v) of cigarette tobacco extract, allowed the onions to root, and was selected for optimization. Initially, for the experimental design to selected fungus, a fractional factorial experimental design 25-1 was used to examine the effects of yeast extract, cigarette tobacco extract concentration, dextrose, copper sulfate and pH fungal cultivation. The supernatants of these assays were used to run the toxicity test, and yeast extract and copper sulfate were statistically significant in the fungal growth for the decreasing toxicity process and this variable as were select to central composite design. The highest concentration of yeast extract negatively influenced the toxicity decrease, 0.5% of yeast extract in the culture media is the maximum concentration to achieve the best result and to copper sulfate the best result was using 10 µmol.L-1. In conclusion, the experimental design optimized more than seven times the efficiency of tobacco toxicity reducing, resulting in more than 50% of onion root growth, demonstrating the methodology success. And ITS region was used to taxonomy and molecular phylogeny of the isolate Fusarium sp. strain I.17. These results suggest that Fusarium sp. strain I.17 can be used as a potential microorganism to toxicity treatment of cigarette wastes, minimizing the environmental impact of direct burning.

New insights on the removal of diclofenac and ibuprofen by CWPO using a magnetite-based catalyst in an up-flow fixed-bed reactor.

This research has been focused on the removal of two anti-inflammatory drugs, diclofenac (DCF) and ibuprofen (IBU), by a continuous catalytic wet peroxide oxidation (CWPO) process using a lab-synthesized nanomagnetic catalyst (Fe3O4/MWCNTs). The central composite rotatable design (CCRD) method was used to study the effect of DCF and IBU concentration (expressed as theoretical oxygen demand (ThOD) between 0 and 52.5 mg L-1) and of the feed stream pH (from 3 to 7) on the removal of total organic carbon (TOC) and the concentration of aromatic compounds (Arm) and total phenolic compounds (TP) by CWPO. It could be observed that DCF was preferably removed from the DCF-IBU aqueous mixture at pH values ranging from 3 to 5. In addition, feed stream pH had a significant effect on the pollutants removal, as well as on TOC, TP and aromatic compounds removal, observing an increasing in the pollutants degradation when feed stream pH decreased from 7 to 3. Quadratic models predicted for response variable, such as TOC, TP and aromatic compounds removal, and their maximum model-predicted removal values were of 90.0, 80.2 and 90.0%, respectively. Finally, as a proof of concept, three environmentally-relevant aqueous matrices, spiked with DCF-IBU mixture, were treated. In this case, relatively high TOC degradation values were found after 20 h reaction time (ca. 57.7, 73.9 and 54.5% in surface water, WWTP effluent and hospital wastewater, respectively). This work deals the first study about DCF-IBU removal in aqueous solution by CWPO, as well as a continuous study using real wastewater that allow to extend the experimental results to a real scenario.