Fatty Acid Biosynthesis from Chlorella in Autotrophic and Mixotrophic Cultivation

Abstract Microalgae are photosynthetic microorganisms whose composition and biomass production can be influenced by manipulating the cultivation conditions employed. However, few studies have evaluated the effects of various cultivation conditions in autotrophic and mixotrophic conditions. The present work aimed to evaluate the effects of cultivation conditions on the cell growth and biosynthesis of fatty acids (FAs) by microalgae of the genus Chlorella in autotrophic and mixotrophic cultivation. Evaluation of the effects of the conditions was performed using an experimental design methodology. The highest values of maximum biomass concentration (Xmax) and maximum biomass productivity (Pmax) were obtained in autotrophic cultures. Palmitic acid was the FA obtained at the highest concentration in both cultivation modes. The concentrations of polyunsaturated FAs (PUFAs) ranged from 12.2 to 41.2% in autotrophic cultures and from 11 to 34.3% in the mixotrophic cultures. The variables photoperiod and sodium bicarbonate concentration showed the greatest influence on the Xmax, Pmax, and PUFA concentration in autotrophic and mixotrophic cultivations, respectively. This study verified that the selection of conditions and mode of cultivation contribute to the production of microalgal biomass and FA biosynthesis.

Biosurfactant production by Phialemonium sp. using agroindustrial wastes: influence of culture conditions

Biosurfactant are surface active compounds with emulsifying capacity and are produced by microorganisms, and they may be affected by factors related to microbial cultivation, such as pH, salinity, incubation time, carbon and nitrogen sources. The aim of this work was to study the influence of the culture conditions on the production of biosurfactants by Phialemonium sp using agroindustrial wastes. The processing parameters of temperature, humidity and pH produced the most significant effects on the production of biosurfactant and emulsifying activity. The maximum concentration of biosurfactant obtained in this study was equivalent to a surface tension reduction of 8.5 mg L-1 surfactin commercial solution using wheat bran, pH of 4.5, and 0.5% of soybean oil added at 30°C. Under these conditions, 83.4 EU g-1 of emulsifying activity, 16.4 g L-1 of emulsifier index and 18.3 U g-1 lipolytic capacity were obtained.

Estudo da produção de lipase por Burkholderia cepacia / Study of lipase production by Burkholderia cepacia

RESUMO O uso de enzimas pelas indústrias possibilita o desenvolvimento de processos tecnológicos com eficiência similar aos realizados pela natureza, o que faz dessa tecnologia um dos campos mais promissores na síntese de compostos de alto valor agregado. O presente trabalho teve por objetivo estudar a produção de lipase por Burkholderia cepacia utilizando a metodologia de superfície de resposta. Foram utilizadas as variáveis concentrações de fonte de potássio, magnésio, óleo de soja, água de maceração de milho e pH. Foi observado que, dentro das concentrações utilizadas, o potássio, a água de maceração de milho e o óleo de soja influenciaram positivamente na produção de lipase. O Bioflo III se destacou dentre os biorreatores empregados para a produção da enzima, possivelmente devido a melhor distribuição dos fenômenos de transferência de massa e movimento, alcançando valores de até 2,43 U mL-1 em 120 horas de fermentação.

ABSTRACT The use of enzymes on an industrial scale has enabled the development of technological processes with an efficiency similar to those made by nature, which makes this technology one of the most promising fields in new technologies for synthesis of high-added value compounds. This paper aimed to study the production of lipase by Burkholderia cepacia using the response surface methodology. We used the following variables: concentrations of potassium, magnesium, soybean oil, corn steep liquor and pH. We observed that, among the used concentrations, potassium, corn steep liquor and soybean oil positively influenced the lipase production. Bioflo III showed the best performance among the bioreactors used for the enzyme production, possibly due to a better distribution of mass and movement transfer phenomena, reaching values of up to 2.43 U mL-1 at 120 hours of fermentation.

Novel Food Supplements Formulated With S pirulina To Meet Athletes' Needs

ABSTRACT The food, training, and health are crucial for a good performance in sports. Intense physical activity takes the athlete to maintain a very unstable balance between energy demand and consumption of nutrients. Spirulina microalga has a nutritional profile that renders it an ideal food supplement, because has high protein content, also contains vitamins, minerals, and pigments. In this context, the study aimed to develop, characterize and evaluate the stability of foods enhanced with Spirulina, which are intended for athletes. In this study, six different supplements were developed (electrolyte replenisher, muscle enhancer, and recovery supplement), without and with Spirulina. The electrolyte replenisher with Spirulina compared to the product without the microalga, showed an increase of 0.35% (w/w) in mineral content. The carbohydrates content of the developed recovery supplement with Spirulina was 2% (w/w) higher than the muscle enhancer without Spirulina. It was not observed increased in the nutritional content of muscle recovery when added Spirulina. However, it is known that Spirulina presents active compounds with important functions for the body. Thus, the composition of the foods satisfied the nutritional needs of athletes. Regarding the stability of developed foods, the shelf life was estimated between 9 and 11 months.

Carbon Dioxide Biofixation and Production of Spirulina sp. LEB 18 Biomass with Different Concentrations of NaNO3 and NaCl

ABSTRACT Microalgae are efficient at using solar energy to turn CO2 and nutrients into biomass containing lipids, proteins, carbohydrates and other compounds that may be used to produce bioproducts for human and animal consumption and pharmaceutical use. The aim of this study was to assess the effect of the NaNO3 and NaCl concentration on the growth kinetics, the biomass composition and the ability to biofix CO2 using the microalga Spirulina sp. LEB 18. The assays were carried out according to a 22 central composite design (CCD) with different concentrations of NaNO3 (1.25, 1.88 and 2.50 g L-1) and NaCl (1.00, 15.0 and 30.0 g L-1). The assays were carried out in 2 L vertical tubular photobioreactors at 30°C, 12 h light/dark and an injection of 12.0% v/v of CO2 at 0.3 vvm. The best growing results (Xmax = 1.60 g L-1, Pmax = 0.109 g L-1 d-1, μmax = 0.208 d-1) and CO2 biofixation rate (197.4 mg L-1 d-1) were observed in the assay with 1.25 g L-1 NaNO3 and 1.00 g L-1 NaCl. Increasing the NaCl concentration produced biomass with a higher carbohydrate content, while increasing the NaNO3 concentration reduced the protein concentration. According to the results, in addition to using Spirulina as a source of protein, it can also be used as a source of carbohydrates and to biologically remove CO2 from the atmosphere.

Evaluation of CO2 Biofixation and Biodiesel Production by Spirulina (Arthospira) Cultivated In Air-Lift Photobioreactor

ABSTRACT Spirulina is a microalgal genre that has the capacity to produce various bioproducts with applications in several areas including the energy sector. The study aimed to assess the ability of CO2 biofixation, biodiesel and other biocompounds production by Spirulina sp LEB 18 cultured in air-lift photobioreactor. The microalgae presented a rich macronutrient composition: protein (47.3%), carbohydrates (13.4%) and a high lipid content (32.7%) in a media with nitrogen reduction, CO2 using air-lift photobiorector. Furthermore, 160 mg.L.d-1 of CO2 was biofixed, generating a maximum biomass yield of 0.02 g.L.d-1. The lipids evaluated for biodiesel production presented a theoretical yield of 19.8% for in situ transesterification and 47.9% for conventional transesterification. The microalgal biomass has potential for producing biodiesel that can be applied instead or in mixture with traditional diesel fuel. The study of obtaining energy associated with the production of other high value-added biocompounds from the microalgal biomass is of high importance because in this way, the viability of biofuel production by this microorganism can be increased.

Effect of Spirulina addition on the physicochemical and structural properties of extruded snacks

Abstract Nowadays the demand for practical food like snacks increases worldwide, however the nutritional value in most these formulations is reduced. Due to its chemical composition with high protein concentration, the microalga Spirulina has been used on the production of enriched foods. The present study aimed to evaluate the effects of Spirulina sp. LEB 18 addition on snacks formulations and extrusion conditions on the physicochemical and structural properties of snacks. Protein concentration and physical properties such as expansion index, bulk density, hardness, water absorption index, water solubility index and color were determined. The results showed that the addition of Spirulina sp. LEB 18, temperature in the last zone of the extruder and feed moisture influenced the product responses. The increase in feed moisture increased the hardness, bulk density and water absorption index of the snacks. Higher concentrations of microalga produced snacks with higher protein content, total color difference (ΔE) and compact structure. The addition of 2.6% Spirulina produced snacks with up to 11.3% protein and with adequate physical and structural properties for consumption. Thus, snacks containing Spirulina are an alternative to the demand for healthy food of practical consumption.

Novel Food Supplements Formulated With Spirulina To Meet Athletes' Needs

ABSTRACT The food, training, and health are crucial for a good performance in sports. Intense physical activity takes the athlete to maintain a very unstable balance between energy demand and consumption of nutrients. Spirulina microalga has a nutritional profile that renders it an ideal food supplement, because has high protein content, also contains vitamins, minerals, and pigments. In this context, the study aimed to develop, characterize and evaluate the stability of foods enhanced with Spirulina, which are intended for athletes. In this study, six different supplements were developed (electrolyte replenisher, muscle enhancer, and recovery supplement), without and with Spirulina. The electrolyte replenisher with Spirulina compared to the product without the microalga, showed an increase of 0.35% (w/w) in mineral content. The carbohydrates content of the developed recovery supplement with Spirulina was 2% (w/w) higher than the muscle enhancer without Spirulina. It was not observed increased in the nutritional content of muscle recovery when added Spirulina. However, it is known that Spirulina presents active compounds with important functions for the body. Thus, the composition of the foods satisfied the nutritional needs of athletes. Regarding the stability of developed foods, the shelf life was estimated between 9 and 11 months.

Surface response methodology for the optimization of lipase production under submerged fermentation by filamentous fungi

Abstract A Plackett–Burman Factorial Design of 16 experiments was conducted to assess the influence of nine factors on the production of lipases by filamentous fungi. The factors investigated were bran type (used as the main carbon source), nitrogen source, nitrogen source concentration, inducer, inducer concentration, fungal strain (Aspergillus niger or Aspergillus flavus were selected as good lipase producers via submerged fermentation), pH and agitation. The concentration of the yeast extract and soybean oil and the pH had a significant effect (p < 0.05) on lipase production and were consecutively studied through a Full Factorial Design 23, with the concentration of yeast extract and pH being significant (p < 0.05). These variables were optimized using a central composite design, obtaining maximum lipolytic activities with the use of 45 g/L of yeast extract and pH 7.15. The statistical model showed a 94.12% correlation with the experimental data.

Use of Solid Waste from Thermoelectric Plants for the Cultivation of Microalgae

ABSTRACT The aim of this study was to analyze the influence of solid waste on the cultivation of the microalgae Spirulina sp. LEB 18 and Chlorella fusca LEB 111 with 0, 40, 80 and 120 ppm of mineral coal ash. The addition of the ash did not inhibit the cultivation of microalgae at the tested concentrations, showing that it could be used for the cultivation of these microalgae due to the minerals present in the ash, which might substitute the nutrients needed for their growth.

Spirulina platensis Enhances the Beneficial Effect of Exercise on Oxidative Stress and the Lipid Profile in Rats

ABSTRACT This study aimed to evaluate the effect of Spirulina platensis and moderate exercise on oxidative stress and lipid profiles in the rats. Forty male Wistar rats were allocated to the following 10-week treatments, three times a week: exercise (E, 30 min swimming),S. platensis (SP, 26 mg/Kg); exercise andSpirulina (ES); and control (C). Outcomes were Thiobarbituric Acid Reactive Substances (TBARS) in serum and brain, and cholesterol and triglycerides (TG) in serum. Rats treated with exercise showed lower brain TBARS than the controls, mostly in association withS. platensis. In the groups E and ES, serum TBARS decreased after intervention. Compared with the controls, both E and ES prevented an increase in cholesterol and reduced triglycerides. Results demonstrated thatS. platensis enhanced the beneficial effect of exercise on oxidative stress and lipid profiles in rats, which might be a promising approach for treating metabolic syndrome in humans.

Purification of C-phycocyanin from Spirulina platensis in aqueous two-phase systems using an experimental design

C-phycocyanin from Spirulina platensis was purified in aqueous two-phase systems (ATPS) of polyethylene glycol (PEG)/potassium phosphate, varying the molar mass of the PEG. Results using a full factorial design showed that an increase in the concentration of salt and decrease in the concentration of PEG caused an increment in the purification factor for all the ATPS studied. Optimization of the conditions of the purification was studied using a central composite rotatable design for each molar mass of PEG. The ATPS composed of 7% (w/w) PEG 1500 or 4% (w/w) PEG 8000 (g/gmol) and 23 or 22.5% (w/w) of phosphate resulted a purification factor of 1.6-fold for C-phycocyanin, with total and 57% recovery, respectively. Process conditions were optimized for the purification factor for the system with PEG 1500. The ATPS with 4% (w/w) PEG 4000 or 4% (w/w) PEG 6000 and 21% (w/w) phosphate resulted purification factors of 2.1 and 2.2-fold, recovering 100% and 73.5%, respectively of C-phycocyanin in the top phase.

Hydrolysis of insoluble fish protein residue from whitemouth croaker (Micropogonias furnieri) by fungi

A significant amount of insoluble fibrous protein, in the form of feather, hair, scales, skin and others are available as co-products of agro industrial processing. These wastes are rich in keratin and collagen. This study evaluated different fungi for the hydrolysis of insoluble fish protein residues. Proteins resulting from Micropogonias furnieri wastes through pH-shifting process were dried and milled for fermentation for 96 h. This resulted the production of keratinolytic enzymes in the medium. Trichoderma sp. on alkaline substrate (28.99 U mL-1) and Penicillium sp. on acidic substrate (31.20 U mL-1) showed the highest proteolytic activities. Penicillium sp. showed the largest free amino acid solubilization (0.146 mg mL-1) and Fusarium sp. the highest protein solubilization (6.17 mg mL-1).

Spirulina as a protein source in the nutritional recovery of Wistar rats

This study was aimed at evaluating the effects of Spirulina (Arthrospira) as a protein source in the nutritional recovery of rats subjected to protein malnutrition. In order to understand such effects, responses of the developing body, serum biochemical profile, and blood count of animals were analyzed. A total of, 23 Wistar Rattus norvegicus were given a proteic diet (AIN-93G adapted) in malnutrition phase (phase I) for 10 days. After this period, the rats were separated into four groups according to the protein source (recovery phase): Control (C), casein 12%; Spirulina level I (S1), Spirulina 8.8% + casein 5.0%; Spirulina level II (S2), Spirulina 17.6% + casein 0.15%, and Spirulina level III (S3), Spirulina 26.4%. Recovery phase (phase II) lasted 30 days. In both the phases, the consumption and body weight of the rats were monitored daily and weekly, respectively. The S1 treatment showed the highest values of Feed Efficiency Ratio (FER) and Quotient of Protein Efficiency Ratio (QPE) (p<0.05). Significant differences among the treatments were found mainly in the levels of serum lipids, and S2 diet caused an increase in such responses (p<0.05). These results demonstrated that the nutritional recovery of animals was enabled by different concentrations of Spirulina.

Antioxidant effect of phycocyanin on oxidative stress induced with monosodium glutamate in rats

The objective of this work was to study the antioxidant effect of phycocyanin on the oxidative stress induced by monosodium glutamate in the rats. The tests were performed with 32 rats of Wistar breed, divided into four groups, which were administered saline solution of phycocyanin, monosodium glutamate and monosodium glutamate plus phycocyanin. Sulfhydryl groups and the secondary substances derived from lipid oxidation were determined through the level of TBA. The evaluation of these values and the level of sulfhydryl showed that the administration of phycocyanin presented significant antioxidant effect (p < 0.05) reducing the oxidative stress induced by the monosodium glutamate in vivo.

Capacidade antioxidante da microalga Spirulina platensis em células da levedura Saccharomyces cerevisiae submetidas ao estressor paraquat / Antioxidant capacity of the Spirulina platensis microalgae on Saccharomyces cerevisiae yeast cells exposed to paraquat stressor

Em virtude de várias publicações terem mostrado a alta associação entre a geração de radicais livres e as doenças crônico-degenerativas, tem havido grande interesse por alimentos funcionais antioxidantes. O excesso de espécies reativas no organismo resulta no estresse oxidativo que provoca danos celulares e teciduais. A microalga Spirulina tem sido pesquisada em função de suas propriedades nutricionais e antioxidantes. O objetivo desse trabalho foi de avaliar a atividade antioxidante da microalga Spirulina, utilizando-se a levedura Saccharomyces cerevisiae como modelo biológico. A levedura foi submetida ao estressor 1,1'-dimetil-4,4'-bipiridilio (paraquat), nas concentrações 0,10 e 15 mM. O potencial antioxidante foi avaliado pela técnica de sobrevivência celular (plaqueamento) e pelo ensaio de lipoperoxidação (valores de TBA). Observou-se aumento significativo de sobrevivência celular (p≤0,05), quando submetidos aos tratamentos com paraquat e Spirulina, em comparação com o experimento em que foi utilizado somente o paraquat. O agente estressor gerou aumento significativo (p≤0,05) na lipoperoxidação (valores de TBA), o qual foi atenuado pelo tratamento com Spirulina, não diferindo do tratamento controle (p>0,05). A microalga Spirulina apresentou capacidade antioxidante, que protege as células da levedura contra os danos oxidantes provocados pelo paraquat.

Because of some studies that have shown the occurrence of high correlation between free radicals generation and chronic degenerative diseases, the option for consuming antioxidant functional foods has beenincreasing. The excess of reactive species in the organism results in an oxidative stress that causes cellularand tissues damages. The microalgae Spirulina has been investigated due to its nutritional and antioxidantproperties. The present study assessed the antioxidant capacity of microalgae Spirulina on Saccharomycecerevisiae yeast, as a biological model, which has been exposed to stressor 1.1’ - dimethyl - 4.4’ - bipyridyl (paraquat) at 0.10 and 15 mM concentrations. The antioxidant potential was evaluated on cellular survival by plaque assay and on lipoperoxidation technique (values of TBA). The cellular survival rate increased significantly (p ≤ 0.05) when treated with both paraquat and Spirulina, in comparison to those treated only with paraquat. The stressor agent caused a significant increase (p ≤ 0.05) in lipoperoxidation values (TBA), which was attenuated by treating with Spirulina, not differing from the control treatment (p >0.05). Therefore, the microalgae Spirulina shows antioxidant capacity, which protects yeast cells against theoxidative damages caused by paraquat.

Effect of microalga Spirulina platensis (Arthrospira platensis) on hippocampus lipoperoxidation and lipid profile in rats with induced hypercholesterolemia

Studies have been conducted on microalga Spirulina platensis (Arthrospira platensis) due to its therapeutic potential in several areas, including the capacity for preventing and decreasing the damages caused by hyperlipidemia and the antioxidant activity. The aim of the study was to evaluate the effect of microalga Spirulina platensis on hippocampus lipoperoxidation and lipid profile in rats with induced hypercholesterolemia during 60 days. The measurement of hippocampus lipoperoxidation did not demonstrate significant difference (p>0.05) when Spirulina platensis was added to hypercholesterolemic diet. The evaluation of lipid profile showed that the administration of the microalga in therapeutic and preventive ways led to a significant protective effect (p<0.05) from hypercholesterolemia.

A microalga Spirulina platensis (Arthrospira platensis) vem sendo fonte de pesquisas devido a evidências de seu potencial terapêutico em diversas áreas, dentre elas a capacidade de prevenção e diminuição dos danos causados por dislipidemias e sua atividade antioxidante. Objetivou-se avaliar o efeito da microalga Spirulina platensis sobre a lipoperoxidação no hipocampo e perfil lipídico sérico em ratos com hipercolesterolemia induzida durante 60 dias. A dosagem da lipoperoxidação no hipocampo não demonstrou diferença significativa (p>0,05) quando Spirulina platensis foi adicionada na dieta hipercolêsterolemica. A avaliação do perfil lipídico demonstrou que a administração da microlaga de forma terapêutica e preventiva demonstrou efeito significativo (p<0,05) na proteção do desenvolvimento de hipercolesterolemia.

Potencial amilolítico do grão de milho maltado no processo de sacarificação do mesmo cereal / Amylolytic potential of maize malt in the process of sacarification of the same cereal

Objetivou-se avaliar o potencial de sacarificação do malte de milho para produção de álcool deste cereal. Para tal, foi realizada germinação do grão de milho a 20 ºC por 5 dias. O potencial amilolítico do malte de milho foi otimizado por meio de um PlanejamentoFatorial Completo 22 com 3 pontos centrais, sendo as variáveis de estudo a temperatura de incubação e concentração de substrato [S]. A sacarificação foi realizada por meio de um Planejamento de Mistura com três pontos centrais, sendo as variáveis de estudo a concentração de malte e concentração de substrato, durante 6 horas. A fermentação foi conduzida com a melhor condição de sacarificação, em reator de 5 L e volume útil de 2 L. O pH foi fixado em 4,5-5. O Brix foi acertado para o valor de 14º. O mosto hidrolisado foi esterilizado e inoculado com 5,0 g.L-1 de Saccharomyces cerevisiae proveniente de fermento comercial liofilizado. O sistema foi submetido a 2 horas de aeração inicial (170 LO2.h -1) e mantido na temperatura de 30 °C. Durante o processo de fermentação, foram realizadas determinações da concentração de células (g.L-1), açúcares redutores (mg.mL-1) e álcool (g.L-1). As variáveis temperatura de incubação e concentração de substrato foram significativos (p< 0,05) na condição de estudo de 20 % de substrato e incubação a 70 °C. Os experimentos centrais com 50 % de malte apresentaram os melhores parâmetros cinéticos com taxa volumétrica de formação de produto em etanol de 2,81 getanol.L-1.h-1 que corresponde a 8,0 ºGL e conversão de substrato em células 0,127 gcélula.gglicose-1.

The aim of this research was the production of maize malt and the evaluation of its use for alcohol production. The maize grain was allowed to germinate at 20°C for five days. The amylolitic potential of malt was optimized through a Complete Factorial Planning 22 with three central points, where the study variables were the temperature of incubation and the substrate concentration [S]. The sacarification was performed through a Planning of Mixture with three central points, where the study variables were the malt concentration and [S] during six 6 hours. The fermentation was carried out using the best sacarification condition, in a five-liter reactor and a two-liter working volume. The pH was maintained at 4.5 – 5.0. The Brix was corrected to 14º. The sterile hydrolyzedproduct was inoculated with 5.0 g.L-1 Saccharomyces cerevisiae. The system was submitted to two hours of initial aeration (170 LO2.h-1) and kept at 30°C. During the fermentation process, analyses were made to determine the cell concentrations (g.L-1), reducingsugars (mg.mL-1), alcohol (g.L-1) and °Brix. The temperature of incubation and substrate concentration were significant factors (p<0.05) in the determination of the amylolytic potential under the conditions of study utilizing 20% of substrate and incubation at 70°C. The central experiments with 50% malt presented the best kinetic parameters with a volumetric rate of ethanol formation of 2.81 gethanol.L-1.h-1, which correspond to 8.0 ºGL, and a substrate conversion in cells of 0.127gcells.gglucose -1.

Compostos fenólicos totais, atividade antioxidante e antifúngica de multimisturas enriquecidas com a microalga Spirulina platensis / Total phenolic compounds, antioxidant and antifungal activities of multimixtures enriched by adding microalgae Spirulina platensis

Com o objetivo de avaliar o conteúdo fenólico e as atividades antioxidantes e antifúngicas de multimisturas enriquecidas com Spirulina platensis, foram formuladas quatro multimisturas com farelo de arroz ou trigo, duas contendo Spirulina platensis e duas com sementes de girassol. Os compostos fenólicos foram estimados pela técnica de Folin-Ciocalteau. A atividade antioxidante foi avaliada por meio de inibição do radical livre DPPH e a atividade antifúngica foi analisada por meio de ensaio de inibição do halo de crescimento de Aspergillusorizae. O conteúdo de compostos fenólicos totais e a atividade antioxidante nas multimisturas contendo farelo de arroz foram em média 0,6 vezes superiores aos encontrados nas multimisturas contendo farelo de trigo. As multimisturas formuladas com 1% da microalga não apresentaram diferença significativa (α=0,05) quanto ao conteúdo fenólico, quando comparadas às multimisturas padrão. A multimistura contendo farelo de arroz e Spirulina platensis apresentou maior atividade antioxidante, em comparação à multimistura padrão com o mesmo farelo, ao contrário do observado nas multimisturas contendo farelo de trigo, o que indica que a associação do farelo de arroz com a microalga é mais eficiente do que a formulação com farelo de trigo quanto à proteção contra processos oxidantes. Quanto à atividade antifúngica, as multimisturas com farelo de trigo apresentaram 28% de inibição, comparado a 21% das multimisturas contendo farelo de arroz.