Enhanced single-cell oil production by cold shock in cyanobacterial cultures / Aumento da produção de óleos unicelulares através de choques de frio em culturas de cianobactérias

The aim of this research was to evaluate the enhanced single-cell oil production by cold shock in Aphanothece microscopica Nägeli using dairy processing wastewater as culture medium. The study focused on (i) temperature optimization for biomass production, (ii) cold shock application to induce lipids biosynthesis and (iii) determination of fatty acids profile under different conditions. Results indicated that temperature of 20°C was the best condition in terms of kinetics parameter, reaching biomass productivities of 160.25mg/L.h. Under these conditions, a lipid content of 12.65% was also observed, resulting in a lipid productivity of 20.27mg/L.h. Additionally, the 0°C cold shock was the most efficient in increasing intracellular lipid content, reaching 28.4% in dry weight. Cold shocks also showed influence on the saturation of fatty acid composition, where the saturated fatty acids decreased, and the monounsaturated and polyunsaturated fatty acids increased by increasing the cold application. Thus, the use of cold shocks indicates to be a key condition for improving the prospects of efficient single-cell oils production.(AU)

O objetivo deste trabalho foi avaliar o aumento da produção de óleos unicelulares por Aphanothece microscopica Nägeli utilizando água residuária de processamento de laticínios como meio de cultura. O estudo concentrou-se na (i) otimização da temperatura para produção de biomassa, (ii) aplicação de choque frio para induzir a biossíntese de lipídios e (iii) determinação do perfil de ácidos graxos sob diferentes condições. Os resultados indicam que a temperatura de 20°C foi a melhor condição em termos de parâmetros cinéticos, atingindo produtividades de biomassa de 160,25mg/L.h. Nesta condição também foi observado um teor lipídico de 12,65%, o que resultou em uma produtividade lipídica de 20,27mg/L.h. Além disso, o choque frio de 0°C foi o mais eficiente para aumentar o conteúdo lipídico intracelular, que atingiu 28,4% em peso seco. Os choques frios também mostraram influência na saturação da composição de ácidos graxos, em que os ácidos graxos saturados diminuíram, e os ácidos graxos monoinsaturados e poli-insaturados ampliaram com o aumento da aplicação de frio. Assim, o uso de choques frios indica ser uma condição chave para melhorar as perspectivas de produção eficiente de óleos unicelulares.(AU)

Cytotoxicity and antioxidant activity of goldenberry extracts obtained with high intensity ultrasound / Citotoxicidade e atividade antioxidante de extratos de goldenberry obtidos com ultrassom de alta intensidade

The high intensity ultrasound-assisted extraction (HIU) is one of the most simple, quick and efficient techniques for the extraction of phenolic and other antioxidant compounds from plants. This is the first application of HIU for the extraction of these compounds from goldenberry fruit. The HIU and conventional extraction techniques showed similar results regarding to phenolic compounds and antioxidant capacity. However, the time required for HIU extraction (5min) was 24 times lower than conventional extraction (120min). Phenolic compounds reported were chlorogenic acid, caffeic acid and rutin. In vitro cytotoxicity assays were used for evaluation of extracts and the results showed that in a wide range of concentration, the extract maintains cell viability, thus indicating the possibility to use it as food with safety.(AU)

A extração assistida com ultrassom de alta intensidade (HIU) é uma das técnicas mais simples, rápidas e eficientes na extração de compostos fenólicos e antioxidantes de plantas. Este trabalho foi o primeiro a utilizar HIU na extração destes compostos presentes na fruta goldenberry. As técnicas HIU e extração convencional apresentaram resultados semelhantes com relação aos compostos fenólicos e capacidade antioxidante. Entretanto, o tempo necessário na HIU (5min) foi 24 vezes menor que na extração convencional (120min). Os compostos fenólicos encontrados foram ácido clorogênico, ácido cafeico e rutina. Ensaios de citotoxicidade in vitro foram usados para avaliação dos extratos e os resultados demonstraram que, em ampla faixa de concentração, o extrato mantém a viabilidade celular, indicando assim possível segurança para utilização em alimentos.(AU)

Cassava processing wastewater as a platform for third generation biodiesel production

This study aimed to evaluate third generation biodiesel production by microalgae Phormidium autumnale using cassava processing wastewater as a platform. Experiments were performed in a heterotrophic bubble column bioreactor. The study focused on the evaluation of the bioreactor (batch and fed-batch) of different operational modes and the analysis of biofuel quality. Results indicate that fed-batch cultivations improved system performance, elevating biomass and oil productions to 12.0 g L1 and 1.19 g L1, respectively. The composition of this oil is predominantly saturated (60 %) and monounsaturated (39 %), resulting in a biodiesel that complys with U.S., European and Brazilian standards. The technological route developed indicates potential for sustainable production of bulk oil and biodiesel, through the minimization of water and chemical demands required to support such a process.

Cassava processing wastewater as a platform for third generation biodiesel production

This study aimed to evaluate third generation biodiesel production by microalgae Phormidium autumnale using cassava processing wastewater as a platform. Experiments were performed in a heterotrophic bubble column bioreactor. The study focused on the evaluation of the bioreactor (batch and fed-batch) of different operational modes and the analysis of biofuel quality. Results indicate that fed-batch cultivations improved system performance, elevating biomass and oil productions to 12.0 g L1 and 1.19 g L1, respectively. The composition of this oil is predominantly saturated (60 %) and monounsaturated (39 %), resulting in a biodiesel that complys with U.S., European and Brazilian standards. The technological route developed indicates potential for sustainable production of bulk oil and biodiesel, through the minimization of water and chemical demands required to support such a process.(AU)

Produção de biodiesel de terceira geração a partir de microalgas / Third generation biodiesel production from microalgae

O objetivo do estudo foi avaliar o biodiesel de 3 a geração produzido a partir do cultivo heterotrófico da microalga Phormidium sp., empregando amido de mandioca como fonte de carbono orgânico. Um planejamento experimental foi realizado para determinar as condições ótimas de temperatura e razão C/N. A partir da obtenção das melhores condições de cultivo desenvolveram-se cultivos em batelada e batelada alimentada em biorreator e avaliaram-se as características do biodiesel produzido. Os resultados indicaram que a temperatura de 30ºC e a razão C/N de 68 são as condições ideais do processo. As maiores produtividades em biomassa (50,41mgL-1h-1) e lipídica (7,49mgL-1h-1) foram obtidas no cultivo em batelada. Os ácidos graxos com maior representatividade foram os ácidos caproico (65,29%) e oleico (23,88%). As propriedades de combustão do biodiesel: conteúdo de ésteres (99,9%), número de cetano (54,88), índice de iodo (21,47gI2100g-1), grau de instauração (23,88%) e ponto de entupimento de filtro a frio (39,21ºC) se mostraram adequadas às principais normativas nacionais e internacionais.(AU)

The aim of the study was to evaluate the third generation biodiesel produced from heterotrophic cultivation of the microalgae Phormidium sp. employing cassava starch as source of organic carbon. An experimental design was performed to determine the optimal conditions of temperature and C/N ratio. From the best growing conditions, was developed cultivations in batch and fed-batch in a bioreactor and evaluated the biodiesel quality. The results indicate that the temperature of 30ºC and the C/N ratio of 68 are the ideal conditions of the process. The highest biomass productivity (50.41mgL-1h-1) and lipid productivity (7.49mgL-1h-1) were obtained in batch cultivations. The fatty acids most representative were caproic acid (65.29%) and oleic acid (23.88%). The fuel properties of biodiesel: ester content of 99.9%, cetane number of 54.88, iodine value of 21.47gI100g-1, unsaturation degree of 23.88% and a cold filter plugging point of 39.21ºC, comply with the main international and national standards.(AU)

Treatment of cattle-slaughterhouse wastewater and the reuse of sludge for biodiesel production by microalgal heterotrophic bioreactors

Microalgal heterotrophic bioreactors are a potential technological development that can convert organic matter, nitrogen and phosphorus of wastewaters into a biomass suitable for energy production. The aim of this work was to evaluate the performance of microalgal heterotrophic bioreactors in the secondary treatment of cattle-slaughterhouse wastewater and the reuse of microalgal sludge for biodiesel production. The experiments were performed in a bubble column bioreactor using the microalgae Phormidium sp. Heterotrophic microalgal bioreactors removed 90 % of the chemical oxygen demand, 57 % of total nitrogen and 52 % of total phosphorus. Substantial microalgal sludge is produced in the process (substrate yield coefficient of 0.43 mg sludge mg chemical oxygen demand¹), resulting in a biomass with high potential for producing biodiesel (ester content of more than 99 %, cetane number of 55, iodine value of 73.5 g iodine 100 g¹, unsaturation degree of ~75 % and a cold filter plugging point of 5 ºC).

Treatment of cattle-slaughterhouse wastewater and the reuse of sludge for biodiesel production by microalgal heterotrophic bioreactors

Microalgal heterotrophic bioreactors are a potential technological development that can convert organic matter, nitrogen and phosphorus of wastewaters into a biomass suitable for energy production. The aim of this work was to evaluate the performance of microalgal heterotrophic bioreactors in the secondary treatment of cattle-slaughterhouse wastewater and the reuse of microalgal sludge for biodiesel production. The experiments were performed in a bubble column bioreactor using the microalgae Phormidium sp. Heterotrophic microalgal bioreactors removed 90 % of the chemical oxygen demand, 57 % of total nitrogen and 52 % of total phosphorus. Substantial microalgal sludge is produced in the process (substrate yield coefficient of 0.43 mg sludge mg chemical oxygen demand¹), resulting in a biomass with high potential for producing biodiesel (ester content of more than 99 %, cetane number of 55, iodine value of 73.5 g iodine 100 g¹, unsaturation degree of ~75 % and a cold filter plugging point of 5 ºC).(AU)

Determinação do teor de umidade em grãos empregando radiação micro-ondas / Determination of grain moisture content using microwave radiation

A determinação de umidade em grãos é um parâmetro de qualidade importante, uma vez que o teor de água presente no alimento tem influência tanto no armazenamento quanto na comercialização do produto. Os métodos usados como referência na determinação de umidade em grãos empregam a perda por dessecação em estufa (LOD). Apesar de ser de fácil execução, esse método dispende cerca de 24h de aquecimento, normalmente, em 105°C, para obtenção do resultado. No presente estudo, é proposta a determinação da perda por dessecação assistida por radiação micro-ondas (MALOD) para amostras de grãos moídos de arroz branco, arroz integral, ervilha, feijão branco, feijão carioca, feijão preto, grão-de-bico, lentilha e milho, buscando reduzir o tempo de análise. Parâmetros como potência irradiada, massa de amostra, influência do recipiente e tempo de irradiação com micro-ondas foram avaliados e os resultados obtidos foram comparados com a LOD (sugerido pelo MAPA) e, também, por radiação infravermelha (IRLOD). Verificou-se que não houve diferença significativa do teor de umidade empregando massas de amostra entre 2 e 15g por LOD, porém, para MALOD, ocorreram hot spots (carbonização da amostra) com massas superiores a 2g. Resultados similares de umidade foram encontrados entre os diferentes recipientes (pesa-filtros e frascos de polipropileno), optando-se pela utilização dos frascos de polipropileno, devido à diminuição do tempo de pré-condicionamento. A MALOD apresentou concordância entre 94% e 102% com o método oficial, sendo que apenas 50min foram suficientes para determinar a umidade para todos os grãos, perfazendo uma redução do tempo de análise de até 29 vezes.(AU)

The determination of moisture in grains is an important quality parameter, since the water content in food has an influence on both storage and commercialization of product. The methods often used for determination of moisture in grains are based on the loss on drying in an oven (LOD). Although it is easy to perform, this method spent about 24h of heating, usually at 105°C, to obtain the result. In the present study is proposed the determination of the loss on drying assisted by microwave radiation (MALOD) for samples of grounded grains of white rice, brown rice, peas, beans, bean, black beans, chick-peas, lentils and corn, in order to reduce the analysis time. Parameters such as irradiated power, sample mass, container and influence of irradiation time with microwave were evaluated and the results were compared with those obtained by LOD (suggested by MAPA) and also by infrared radiation (IRLOD). It was found that there was no significant difference in moisture content in samples between 2 and 15g using LOD, but there were hot spots for MALOD (carbonization of the sample) with masses higher than 2g. Similar results for moisture content were found by the use of different containers (glass weighing bottle and polypropylene flasks) and the polypropylene cups were selected due to the reduction of conditioning time of flasks. The agreement of MALOD with the official method was between 94% and 102% and only 50min were enough to determine the moisture of all grains, making a reduction of analysis time by 29 times.(AU)