Eduardo Jacob-Lopes

Nutritional evaluation of single-cell protein produced by Aphanothece microscopica Nägeli

The aim of this research was to evaluate the nutritional characteristics of Aphanothece microscopica Nägeli microalgae developed in the effluent of parboiled rice. The biomass was biologically evaluated by rat growth, during 10 days for nitrogen balance studies and 28 days for blood analysis. The feeding of Aphanothece biomass diets resulted in a nitrogen balance of 1.42 g/rat/day, an apparent biological value of 73.33%, an apparent digestibility of 82.12%, an apparent net protein utilization of 60.21% and a net protein retention of 2.40. Significant differences between the glycemic indices of rats fed with the Aphanothece and those fed with the control diet were not observed. However, the total cholesterol levels in the plasma of rats fed the test diet proved to be significantly lower. These results suggest the use of A. microscopica Nägeli developed in parboiled rice effluent as a potential source of single-cell protein.

Microalgae-Based Systems for Carbon Dioxide Sequestration and Industrial Biorefineries

The bulk of the evidence indicating that global climatic alterations occur as a result of increasing concentrations of greenhouse gases in the atmosphere has created pressure to develop strategies to reduce these changes (IPCC, 2001). Carbon dioxide is considered to be the main gas of the greenhouse effect, both in terms of emission and its climate-altering potential. In 1997, the signatory countries of the Kyoto Protocol agreed to reduce CO2 emissions in an agreement that established the need to develop carbon dioxide sequestering processes. Thus the various technologies available for carbon capture and storage need to be evaluated from the point of view of obtaining carbon credits, aiming to stabilize emissions of this pollutant (UNFCCC, 1997). In addition to technologies available for immediate use, other CO2 capture methods are being developed for application in the near future. The choice of these methodologies will depend on factors such as cost, capture capacity, environmental impact and the speed with which the technology can be introduced in addition to social factors such as public acceptance (IPCC, 2007a). In this context, the use of biotechnological processes for carbon dioxide biofixation is considered viable for reducing emissions of this pollutant. These processes are based on the use of reactors used to develop photosynthetic reactions in which microalgae are used as biocatalysts in a series of biochemical reactions responsible for the conversion of CO2 into photosynthetic metabolic products (Jacob-Lopes et al., 2010). With this in mind, the objectives of this present chapter are to present an overview of a potential technology for carbon dioxide transformation into biomolecules and to describe the current state of the art in the biological conversion of CO2 in photobioreactors thereby facilitating worldwide advances in this research area.

Why does the Photobioreactors Fail

Luis G Ramírez-Mérida1,2, Leila Queiroz Zepka2 and Eduardo Jacob-Lopes2* 1Applied Biotechnology Center, Department of Biology, University of Carabobo, Universidad Avenue, 2002, Valencia, Edo. Carabobo, Venezuela 2Food Science and Technology Department, Federal University of Santa Maria, UFSM, Roraima Avenue 1000, 97105-900, Santa Maria, RS, Brazil *Corresponding author: Eduardo Jacob-Lopes, Food Science and Technology Department, Federal University of Santa Maria, UFSM, Roraima Avenue 1000, 97105-900, Santa Maria, RS, Brazil, Tel: +55-553-220-8822; E-mail: jacoblopes@pq.cnpq.br

Producción de pigmentos por Aphanothece microscopica Nägeli a partir de residuos industriales lácteos

espanolLos sistemas basados en el uso de microalgas para la obtencion de bioproductos son considerados un area prometedora para aplicaciones industriales. El objetivo del trabajo fue evaluar la produccion de ficobiliproteinas y clorofila-a cuando Aphanothece microscopica Nageli es cultivada en sistemas autotroficos y heterotroficos. Para ello, se desarrollaron sistemas de cultivos heterotroficos (en ausencia de luz) y autotroficos (2 klux de intensidad luminosa) en biorreactores a pH 7,6, 20 °C, 1 vvm de aireacion, empleando como medios de cultivo un efluente de industria lactea con relacion C/N 20 y N/P 10, y BG11. Inoculo inicial 200 mg/L. Se efectuo el monitoreo de concentraciones de clorofila-a y ficobiliproteinas en fase logaritmica y estacionaria. Se observaron las mayores concentraciones de pigmento en la fase logaritmica: mayores concentraciones de clorofila-a en cultivos autotroficos y predominio de aloficocianina y ficoeritrina en cultivos heterotroficos. Los resultados mostraron el efecto de las variables en estudio para la produccion de pigmentos, en la fase de crecimiento logaritmico, lo que indica la posibilidad de producir en sistemas heterotroficos de Aphanothece microscopica Nageli, aproximadamente 3.185 ton/ ano de biomasa, para 3.127 kg/ano clorofila, 232.825 kg/ano ficocianina, 47.775 kg/ano aloficocianina y 7.008 kg/ano ficoeritrina, cuando se utiliza efluente de industria lactea como medio de cultivo. EnglishThe systems that use microalgae to obtain bioproducts are considered a promising area for industrial applications. The objective of this work was to evaluate the production of phycobiliproteins and chlorophyll-a by Aphanothece microscopica Nageli, when it is cultivated in autotrophic and heterotrophic systems. Thus, the cultures were grown in heterotrophic (absence of light) and autotrophic (2 klux of light intensity) system, in bioreactors at pH 7.6, 20 oC, 1 vvm aeration, using a dairy industry effluent, with C/N 20 and N/P 10, and BG11 as culture media. Initial inoculum 200 mg/L. The concentrations of chlorophyll-a-andphycobiliproteins in logarithmic and stationary phase were monitored. The highest concentrations of pigment were observed in logarithmic phase: The highest concentrations of chlorophyll-a in autotrophic cultures, and predominance of allophycocyanin and phycoerythrin in heterotrophic cultures. The results show the effect of the variables under study for pigment production, bearing in mind the logarithmic growth phase, suggesting the possibility of producing in heterotrophic systems by Aphanothece microscopica Nageli, around 3,185 ton/year of biomass, and 3,127 kg/year of chlorophyll, 232,825 kg/year of phycocyanin, 47,775 kg/year of allophycocyanin and 7,008 kg/year of phycoerythrin, when dairy effluent is used as culture medium

Microalgae as Nanofactory for Production of Antimicrobial Molecules

In recent decades, due to increasing bacterial resistance, have been developed researches to find molecules with antimicrobial activity. The searches for new compounds, especially unexplored sources such as microalgae are a potential alternative. Microalgae are microorganisms extremely diverse and ubiquitous; they have advantages to become a powerful nanofactory due to the variety of metabolic compounds as the ability to form metallic nanoparticles with antimicrobial effect. This mini-review shows the importance of integrating nanotechnology with microalgae and/ or their products for the preservation and formation of molecules to be applied in prophylactic therapy and infectious.

Single-Cell Protein as a Source of Biologically Active Ingredients for the Formulation of Antiobesity Foods

Abstract The World Health Organization has defined obesity as a global public health problem. Several factors are responsible for the development of obesity; however, diets containing excessive macronutrients seem to play an important role in controlling body weight. Some authors have demonstrated the ability of proteins to affect food intake and appetite in humans, thus increased protein intake might promote weight loss and act against the development of obesity. However, the scarcity of protein-rich food has forced mankind to search for alternative protein sources that can replace conventional ones. Microalgae-based processing is a field of food bioengineering and is considered to be key to producing novel food ingredients with potential health benefits. This is largely due to the high-protein levels found in the biomass, in addition to the other components, such as fatty acids and pigments. The purpose of this chapter is to elucidate the use of microalgae biomass as a food ingredient, emphasize the ability of single-cell proteins to be used as antiobesity factors, and evaluate the feasibility of their inclusion in foods for the control of obesity.

Insights in cyanobacteria lipidomics: A sterols characterization from Phormidium autumnale biomass in heterotrophic cultivation

Sterol profiles were obtained from cyanobacteria Phormidium autumnale, cultivated in a heterotrophic system using three distinct sources of carbon: glucose, sucrose, and agroindustrial slaughterhouse wastewater. A simultaneous saponification-extraction ultrasound-assisted method was performed to determine sterol and other non-saponified compounds in the dry biomasses. A total of 24 compounds were observed in the biomasses, including hope-22,29-en-3-one, squalene, and 22 other sterols. Using wastewater as a carbon source, the microalgae biomass produced a diversity of sterols such as stigmasterol (455.3u202fμgu202fg-1) and β-sitosterol (279.0u202fμgu202fg-1). However, with glucose it is possible to produce ergosterol (1033.3u202fμgu202fg-1). Squalene was found in all the cultures, with 1440.4u202fμgu202fg-1, 225.4u202fμgu202fg-1, and 425.6u202fμgu202fg-1 for glucose, sucrose, and slaughterhouse wastewater biomasses, respectively. Several intermediate compounds from those sterols were found. These data provide the construction of the sterol metabolism according to the literature for P. autumnale heterotrophically cultured.

INFLUÊNCIA DAS CONDIÇÕES DE SECAGEM NAS PROPRIEDADES FUNCIONAIS DA Aphanothece microscopica Nägeli CULTIVADA NO EFLUENTE DA PARBOILIZAÇÃO DO ARROZ

O objetivo deste trabalho foi caracterizar a solubilidade e a capacidade emulsificante da biomassa da cianobacteria Aphanothece microscopica Nageli em diferentes condicoes de secagem. Produziu-se a biomassa na agua residuaria do processo de parboilizacao do arroz, inoculando 100 mg.L -1 de Aphanothece microscopica Nageli na fase exponencial de crescimento em reator cilindrico de mistura completa, na ausencia de luz, pH 8,0, 30oC, razao C/N 50 e tempo de detencao hidraulica de 72h. A biomassa foi separada do efluente por centrifugacao e desidratada em secador descontinuo de bandejas nas condicoes de 40, 50 e 60oC em espessuras de biomassa de 3, 5 e 7 mm. A solubilidade proteica 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 proteicas ocorreram em pH 10, havendo incremento da capacidade emulsificante nas camadas de biomassa de 3 mm de espessura.