Alternative green solvents associated with ultrasound-assisted extraction: A green chemistry approach for the extraction of carotenoids and chlorophylls from microalgae.

This study proposes a method for the ultrasonic extraction of carotenoids and chlorophyll from Scenedesmus obliquus and Arthrospira platensis microalgae with green solvents. Ethanol and ethanolic solutions of ionic liquids were tested with a variety of extraction parameters, including number of extractions, time of extraction, and solid-liquid ratio R(S/L), to determine the optimal conditions. After selecting the most effective green solvent (ethanol), the process conditions were established: R(S/L) of 1:10, three extraction cycles at 3 min each), giving an extraction yield of 2602.36 and 764.21 µgcarotenoids.gdried biomass-1; and 22.01 and 5.81 mgchlorophyll.gdried biomass-1 in S. obliquus and A. platensis, respectively. The carotenoid and chlorophyll extracts obtained using ethanol were shown to be potent scavengers of peroxyl radical, being 5.94 to 26.08 times more potent α-tocopherol. These findings pave the way for a green strategy for valorizing microalgal biocompounds through efficient and environmentally friendly technological processes.

Decarbonizing the Transport of Microalgae-based Products - The Role of E-mobility.

BACKGROUND: The decarbonization of road transport is a precondition for achieving carbon neutrality. Battery-electric vehicle technology can make this a reality. In this bias, the objective of the article is to shed light on the ongoing debate about the potentially important role of the adoption of electric vehicles in the transport of microalgae- based products to help them advance to a cleaner life cycle. METHODS: Five routes, including unimodal and multimodal conditions, were defined to assess the carbon emissions of the transport system and, more specifically, of road transport. The headquarters of market-leading microalgae manufacturers were selected as the origin of the routes and, as the destination, regions that sustain them. RESULTS: The results reveal the supremacy of road transport of microalgae-based products using electric vehicles powered by nuclear, hydroelectric, and wind, followed by biomass and photovoltaic energy. They also show that the positive impact of wind, water, and photovoltaic energy on the climate, added to the lower battery charging costs and the greater opportunity to generate revenue from the sale of carbon credits, make their tradeoffs. CONCLUSION: The exquisite results of this study convey key messages to decision-makers and stakeholders about the role of electromobility in building a zero-carbon delivery route.

The Role of Light on the Microalgae Biotechnology: Fundamentals, Technological Approaches, and Sustainability Issues.

Light energy directly affects microalgae growth and productivity. Microalgae in natural environments receive light through solar fluxes, and their duration and distribution are highly variable over time. Consequently, microalgae must adjust their photosynthetic processes to avoid photo limitation and photoinhibition and maximize yield. Considering these circumstances, adjusting light capture through artificial lighting in the main culture systems benefits microalgae growth and induces the production of commercially important compounds. In this sense, this review provides a comprehensive study of the role of light in microalgae biotechnology. For this, we present the main fundamentals and reactions of metabolism and metabolic alternatives to regulate photosynthetic conversion in microalgae cells. Light conversions based on natural and artificial systems are compared, mainly demonstrating the impact of solar radiation on natural systems and lighting devices, spectral compositions, periodic modulations, and light fluxes when using artificial lighting systems. The most commonly used photobioreactor design and performance are shown herein, in addition to a more detailed discussion of light-dependent approaches in these photobioreactors. In addition, we present the principal advances in photobioreactor projects, focusing on lighting, through a patent-based analysis to map technological trends. Lastly, sustainability and economic issues in commercializing microalgae products were presented.

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

ABSTRACT: 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.

RESUMO: 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.

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.

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.

Microencapsulation of probiotics using sodium alginate / Microencapsulação de probióticos utilizando alginato de sódio

The consumption of probiotics is constantly growing due to the numerous benefits conferred on the health of consumers. In this context, Microencapsulation is a technology that favors the viability of probiotic cultures in food products, mainly by the properties of protection against adverse environmental conditions and controlled release. Currently there are different procedures for microencapsulation using polymers of various types of natural and synthetic origin. The use of sodium alginate polymers is one of the largest potential application in the encapsulation of probiotics because of their versatility, biocompatibility and toxicity exemption. The aim of this review is to present viable encapsulation techniques of probiotics with alginate, emphasizing the internal ionic gelation and external ionic gelation, with the possibility of applying, as well as promising for improving these techniques.

O consumo de probióticos está em constante crescimento, devido aos inúmeros benefícios conferidos à saúde dos consumidores. Neste contexto, a microencapsulação é uma tecnologia que favorece a viabilidade das culturas probióticas em produtos alimentícios, principalmente pelas propriedades de proteção contra as condições ambientais adversas e a liberação controlada. Atualmente, existem diversos procedimentos para a microencapsulação, com a utilização de vários tipos de polímeros de origem natural e sintética. O alginato de sódio é um dos polímeros com maior potencial para aplicação na encapsulação de probióticos, devido à sua versatilidade, biocompatibilidade e isenção de toxicidade. O objetivo desta revisão é apresentar técnicas viáveis de encapsulação de probióticos com alginato, enfatizando a gelificação iônica interna e gelificação iônica externa, com a possibilidade de aplicação, bem como as tecnologias promissoras para o melhoramento destas.

Microencapsulação de probióticos: avanços e perspectivas / Microencapsulation of probiotics: progress and prospects

Devido aos seus efeitos benéficos, os probióticos têm sido incorporados nos mais diversos alimentos, incluindo iogurtes, queijos, sorvetes, leites fermentados e sobremesas congeladas. No entanto, existem ainda diversos problemas com relação à viabilidade e resistência das culturas probióticas nesses alimentos. Neste artigo de revisão, são abordados os aspectos tecnológicos utilizados na microencapsulação de probióticos que permitem aumentar a sua viabilidade durante a fermentação, processamento e utilização nos produtos comerciais. A microencapsulação de bactérias probióticas pode ser utilizada para aumentar a viabilidade durante o processamento, como também para liberá-las de maneira controlada no trato gastrointestinal.

Because of their health benefits, probiotics have been incorporated into a range of dairy products, including yogurts, soft-, semi-hard and hard cheeses, ice cream, milk powders and frozen dairy desserts. However, there are still several problems with respect to the low viability of probiotic bacteria in dairy foods. This review focuses mainly on current knowledge and techniques used in the microencapsulation of probiotic microorganisms to enhance their viability during fermentation, processing and utilization in commercial products. Microencapsulation of probiotic bacteria can be used to enhance the viability during processing, and also for the targeted delivery in gastrointestinal tract.

Cultivation of algae in photobioreator and obtention of biodiesel

In this work we described the cultivation of Chlorella vulgaris in a photobioreactor to algal biomass production. The dried biomass was used as feedstock for biodiesel production, it presented 26 percent lipids and via sonocatalysis stage of the methodology resulted in 60 percent of fatty acid methyl esters (FAME). The FAME content was confirmed by Gas Chromatography (GC).

Influência das condições de secagem nas propriedades funcionais da Aphanothece microscopica Nageli cultivada no efluente da parbolização do arroz / Influence of drying conditions in the functional properties of Aphanothece microscopica Nageli cultivated in the rice parbolizing efluent

O objetivo deste trabalho foi caracterizar a solubilidade e a capacidade emulsificante da biomassa da cianobactéria Aphanothece microscopica Nageli em diferentes condições de secagem. Produziu-se a biomassa na água residuária do processo de parbolização do arroz, inoculando 100 mg.L de Aphanothece microscopica Nageli na fase exponencial de crescimento em reator cilíndrico de mistura completa, na ausência de luz, pH 8,0, 30ºC, razão C/N 50 e tempo de detenção hidráulica de 72 h. A biomassa foi separada do efluente por centrifugação e desidratada em secador descontínuo de bandejas nas condições de 40, 50 e 60ºC em espessuras de biomassa de 3, 5 e 7 mm. A solubilidade pritéica foi avaliada em pH 2, 3, 4, 6, 8, 9 e 10 e a capacidade emulsificante determinada em pH 7,0. Os resultados demonstraram que as maiores solubilidades protéicas ocorreram em pH 10, havendo incremento da capacidade emulsificante nas camadas de biomassa de 3 mm de espessura.