Avaliação de microalgas verdes isoladas nas costas central e norte de São Paulo como fonte de óleos

Microalgae strains, newly isolated from freshwater in mangrove areas of Central and North Coasts of Sao Paulo State (Brazil), were evaluated regarding total protein and lipid content, and fatty acids profile. The biochemical composition was compared with that observed in strains obtained by UTEX Culture Collection (USA). Among seven identified green algae, Monoraphidium contortum (CCMA-UFSCar-701) presented the highest lipid content (43.60%), close to that observed in Botryococcus braunii (UTEX-2441; 48.85%). Protein content in isolated strains varied in the range of 13.90~23.60%. Finally, the most abundant fatty acids were palmitic acid (C16:0), oleic acid (C18:1), linoleic acid (C18:2), and y-linolenic acid (C18:3).Chlorella vulgaris (CCMA- UFSCar-704) may be highlighted for its high linoleic acid content (49%). On the other hand, Elakatothrix sp (CCMA- UFSCar-702) and Scenedesmus obliquus (UTEX-B2630) presented the highest content of oleic acid (41% and 43%, respectively), which is preferable for oils to be used as feedstock for biodiesel.Microalgas de água doce, isoladas em áreas de mangue nas costas central e norte do estado de São Paulo (Brasil), foram avaliadas considerando conteúdo de lipídios, perfil de ácidos graxos e conteúdo de proteí-nas. Essa composição bioquímica foi comparada com cepas obtidas da Coleção de Culturas da UTEX (EUA). Entre as sete algas verdes identificadas, Monoraphidium contortum (CCMA-UFSCar-701) apre-sentou o maior conteúdo lipídio (43,60%), valor próximo ao observado em Botryococcus braunii (UTEX-2441, 48,85%). O conteúdo de proteínas nos isolados variou entre 13,90 e 23,60%. Os ácidos graxos mais abundantes foram ácido palmítico (C16:0), ácido oleico (C18:1), ácido linoleico (C18:2) e ácido y-linolénico (C18:3).Chlorella vulgaris (CCMA-UFSCar-704) destacou-se por seu alto conteúdo de ácido linoleico (49%), enquanto Elakatothrix sp (CCMA-UFSCar-702) e Scenedesmus obliquus (UTEX-B2630) apresentaram o maior conteúdo de ácido oleico (41% e 43%, respectivamente), sendo que este ácido se destaca como matéria prima para produção de biodiesel

Tertiary treatment of dairy industry wastewater with production of Chlorella vulgaris biomass: evaluation of effluent dilution

Efluentes secundários da indústria de laticínios, quando não tratados adequadamente, podem provocar eutrofização de corpos d’água, principalmente por conter nutrientes como fósforo e nitrogênio. O tratamento terciário empregando microalgas poderia ser uma solução adequada para o estado de Minas Gerais, maior produtor brasileiro de leite, contribuindo na redução de impactos ambientais, bem como fornecendo biomassa para extração de óleos e obtenção de compostos ativos e insumos (incluindo proteínas) para nutrição animal. Neste trabalho, avaliaram-se diluições (com água destilada) do efluente secundário da indústria de laticínios para cultivo de Chlorella vulgaris em fotobiorreator tubular em escala de bancada. Os resultados encontrados indicam a viabilidade do uso de efluente de indústria de laticínios, pós tratamento secundário, para o cultivo de microalgas, apresentando crescimento similar àquele obtido em cultivos padrões (meio basal Bold). O efluente secundário sem diluição (100% efluente) foi o que apresentou melhor desempenho na produção de biomassa. Além disso, a biomassa obtida em efluentes não apresentou diferenças em relação àquela obtida em meio basal Bold (controle), no que se refere a teores de proteínas, lipídios ou perfil de ácidos graxos.Secondary wastewaters from the dairy industry may cause eutrophication of water bodies when not properly treated, mainly because they contain nutrients such as phosphorus and nitrogen. Tertiary treatment using microalgae could be an adequate solution for Minas Gerais State, the largest Brazilian milk producer, contributing to the reduction of environmental impacts, as well as providing biomass for oil extraction, and obtaining active compounds and inputs (including proteins) for animal feeding. In this work, dilutions (with distilled water) of the secondary wastewater from the dairy industry were evaluated to cultivate Chlorella vulgaris in a bench-scale tubular photobioreactor. Theresults indicate the feasibility of using wastewater from the dairy industry, after secondary treatment, to cultivate microalgae, showing cell growth like that obtained in control cultures (Bold basal medium). The secondary wastewater without dilution (100% wastewater) provided the best condition for biomass production. The biomass obtained in wastewater showed no differences from the biomass obtained in the Bold basal medium (control) in terms of protein, lipid content, or fatty acid profile

Cultivation of \' Spirulina platensis \' by repeated fed-batch, using urea as nitrogen source

A cianobactéria \' Spirulina platensis \' possui alto teor de proteína e vem sendo cultivada fotoautotroficamente para a produção de biomassa microbiana. Embora as fontes convencionais de nitrogênio utilizadas para a produção de Spirulina spp. sejam os nitratos, há a possibilidade do emprego de uréia, utilizando o processo descontínuo alimentado, com diminuição do custo de produção. O emprego do processo descontínuo alimentado repetitivo para o cultivo desta microalga utilizando a uréia como fonte de nitrogênio poderia facilitar os cultivos em escala de produção, pois não haveria a necessidade de preparo de inóculo para cada ciclo de produção, além de possibilitar o aumento da produtividade do sistema. Este trabalho tem o objetivo de verificar o comportamento do cultivo microbiano com este processo, visto que não foram encontrados na literatura tais estudos para o cultivo de \'S. platensis\'. Foi verificada a influência dos parâmetros fração de corte, tempo de alimentação de uréia e ciclos de cultivo neste tipo de processo, tendo como variáveis dependentes a concentração celular máxima (Xm), a produtividade em células (Px) e o fator de conversão de nitrogênio em células (Yx/n), bem como a composição protéica e lipídica da biomassa obtida. Os resultados obtidos permitem concluir que, de uma forma geral, uma fração de corte de 80% associada a um tempo de alimentação de 6 dias leva a melhores condições de cultivo com bons resultados nos três parâmetros cinéticos (em média, 2101 mg.L?¹, 219 mg.L?¹.d?¹ e 10,3 mg.mg?¹ para Xm, Px e Yx/n, respectivamente), que foram reprodutíveis ao longo de 3 ciclos.\' Spirulina platensis \', with high protein content, can be cultivated photoautotrophically for the microbial biomass production. Although nitrates are the conventional source of nitrogen for the Spirulina spp. production, there is a possibility of the use of urea, in a fed-batch process, leading to a cost reduction. The application of repeated fed-batch process, using urea as nitrogen source, could propitiate the cultivation of this microorganism in a production scale, since it would not need to prepare the inoculum for each production cycle. Moreover, there is a possibility to improve the productivity of this process. The aim of this work was to verify the behavior of the microbial cultivation employing this process, since this kind of study for \' Spirulina platensis \' production was not found in literature. The influence of withdrawn rate, urea feeding time and cultivation cycles were studied, considering maximum cell concentration (Xm), cell productivity (Px), nitrogen-to-cell conversion (Yx/n), and protein and total fat contents as dependent variables. The results show that in general a 80% of withdrawn rate associated with 6 days of feeding time leads to the best cultivation conditions with satisfactory results of Xm, Px and Yx/n (2101 mg.L?¹, 219 mg.L?¹.d?¹ and 10.3 mg.mg?¹, in average, respectively), that could be reproduced through the three cycles

Continuous cultivation of Arthrospira (Spirulina) platensis in tubular photobioreactor using urea as nitrogen source and CO2 from cylinder or produced by alcoholic fermentation

A aplicabilidade do processo de produção de microrganismos fotossintetizantes depende da obtenção de altas concentrações de biomassa e para isso seria interessante o emprego de fotobiorreatores tubulares. Eles permitem redução da área de cultivo e menor perda de CO2 e nitrogênio amoniacal por volatilização. Em uma primeira etapa deste trabalho, Arthrospira platensis foi cultivada por processo contínuo, avaliando-se diferentes valores de vazão específica de alimentação (D = 0,2 a 1,0 dia-1) e diferentes intensidades luminosas (I = 60 e 120 µmol fótons.m-2.s-1). Verificou-se que 120 µmol fótons.m-2.s-1 associada a D igual a 0,2 dia-1 resultou em maior valor de concentração celular em regime permanente (XP = 2446 ± 74 mg.L-1.d-1), mas o mesmo I associado a maior valor de D (0,6 dia-1) levou ao melhor valor de produtividade em células (PX = 938,73 mg.L-1.d-1). Foi possível a obtenção do regime permanente em quase todos os ensaios, o que indica que o cultivo contínuo de A. platensis em fotobiorreator tubular, usando uréia como fonte de nitrogênio, pode levar a resultados satisfatórios. Considerando a preocupação em relação à substituição de combustíveis fósseis por biocombustíveis, é iminente o crescente aumento da produção de etanol ainda nos próximos anos, e esse trabalho propõe o uso do CO2 liberado pela fermentação alcoólica na produção de microrganismos fotossintetizantes como A. platensis. Para isso, em uma segunda etapa, A. platensis foi cultivada por processo contínuo, com I igual a 120 µmol fótons.m-2.s-1, empregando uréia e CO2 proveniente de fermentação alcoólica para manutenção de pH e reposição da fonte de carbono. O uso desse CO2, sem tratamento prévio, associado a D igual a 0,6 dia-1 e concentração de uréia de 3,2 mM no meio de alimentação, permitiu a obtenção de PX igual a 839 ± 25 mg.L-1.d-1, o que está próximo de 938 ± 30mg.L-1.d-1, obtido com CO2 puro de cilindro. Estes resultados mostram que o uso de CO2 de fermentação alcoólica, associado a uréia, é adequado para cultivo contínuo de biomassa fotossintetizante de potencial interesse na área farmacêutica, alimentícia e de cosméticos, promovendo não só a redução no custo de produção mas também outros benefícios relacionados a questões ambientais e sociais.Appropriately designed tubular photobioreactors seem to be suitable for photosynthetic biomass production. It can reduce the cultivation area and provide lower loss of CO2 and ammoniacal nitrogen by volatilization. In a first step of this study, Arthrospira platensis was cultivated by continuous process, testing different values of dilution rate (D = 0.2 to 1.0 d-1) and light intensities (I = 60 and 120 µmol photons.m-2.s-1). The results of these runs showed that the maximum steady-state cell concentration (XS = 2446 ± 74 mg.L-1.d-1) was achieved at 120 µmol photons.m-2.s-1 and D of 0.2 d-1, but the same light intensity associated to higher dilution rate (0.6 d-1) provided the highest cell productivity (PX = 938 ± 30 mg.L-1.d-1), a value appreciably higher than that reported in other studies. Besides, steady-state conditions were achieved in most of the runs indicating that A. platensis continuous cultivation in the tubular photobioreactor, using urea as nitrogen source, can be performed effectively, thus appearing an interesting alternative for the large scale fixation of carbon dioxide to mitigate the green house effect. Taking into account the concern about the substitution of fossil fuel with biofuels, its evident that the ethanol production is going to increase even more in the next years, and this study propose the use of the CO2 released by the alcoholic fermentation for the production of photosynthetic microorganism such as A. platensis. For this purpose, in a second step, cultivations of A. platensis were carried out with 120 µmol photons.m-2.s-1 by continuous process, using urea and CO2 from Alcoholic fermentation for pH maintenance and carbon source replacement. The use of this CO2, without any treatment, associated with a D of 0.6 d-1 and feed urea concentration of 3.2 mM provide us a PX of 839 ± 25 mg.L-1.d-1, which is slightly lower than 938 ±30 mg.L-1.d-1, obtained with pure CO2 from cylinder. Our results showed that the use of CO2 from alcoholic fermentation, associated with urea, is suitable for the continuous cultivation cyanobacterial biomass, providing not only the production cost reduction but also other benefits related to environmental and social issues

Effects of photobioreactor configuration, nitrogen source and light intensity on the fed-batch cultivation of Arthrospira (Spirulina) platensis. Bioenergetic aspects

Bioenergetic analysis may be applied in order to predict microbial growth yields, based on the Gibbs energy dissipation and mass conservation principles of the overall growth reaction. The bioenergetics of the photoautotrophic growth of the cyanobacterium Arthrospira (Spirulina) platensis was investigated in different bioreactor configurations (tubular photobioreactor and open ponds) using different nitrogen sources (nitrate and urea) and under different light intensity conditions to determine the best growing conditions in terms of Gibbs energy dissipation, number of photons to sustain cell growth and phototrophic energy yields distribution in relation to the ATP and NADPH formation, and release of heat. Although an increase in the light intensity increased the Gibbs energy dissipated for cell growth and maintenance with both nitrogen sources, it did not exert any appreciable influence on the moles of photons absorbed by the system to produce one C-mol biomass. On the other hand, both bioenergetic parameters were higher in cultures with nitrate than with urea, likely because of the higher energy requirements needed to reduce the former nitrogen source to ammonia. They appreciably increased also when open ponds were substituted by the tubular photobioreactor, where a more efficient light distribution ensured a remarkably higher cell mass concentration. The estimated percentages of the energy absorbed by the cell showed that, compared with nitrate, the use of urea as nitrogen source allowed the system to address higher energy fractions to ATP production and light fixation by the photosynthetic apparatus, as well as a lower fraction released as heat. The best energy yields values on Gibbs energy necessary for cell growth and maintenance were achieved in up to 4-5 days of cultivation, indicating that it would be the optimum range to maintain cell growth. Thanks to this better bioenergetic situation, urea appears to be a quite promising low-cost, alternative nitrogen source for Arthrospira platensis cultures in photobioreactors. (C) 2011 Elsevier Ltd. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), BrazilFundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Sao Paulo, Brazil [06/54959-3, 06/56976-2]Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), Brazil [3978/08-7, 0350-11/2010]Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), BrazilItalian Ministry of Education, University and Research (MIUR)Italian Ministry of Education, University and Research (MIUR) [200744HMBN, RBIP06993E]Vigoni Program (Deutsch-Italienisches Hochschulzentrum)Vigoni Program (DeutschItalienisches Hochschulzentrum

Obtaining Bioproducts from the Studies of Signals and Interactions between Microalgae and Bacteria

The applications of microalgae biomass have been widely studied worldwide. The classical processes used in outdoor cultivations of microalgae, in closed or open photobioreactors, occur in the presence of bacteria. Understanding how communication between cells occurs through quorum sensing and evaluating co-cultures allows the production of microalgae and cyanobacteria to be positively impacted by bacteria, in order to guarantee safety and profitability in the production process. In addition, the definition of the effects that occur during an interaction, promotes insights to improve the production of biomolecules, and to develop innovative products. This review presents the interactions between microalgae and bacteria, including compounds exchanges and communication, and addresses the development of new pharmaceutical, cosmetic and food bioproducts from microalgae based on these evaluations, such as prebiotics, vegan skincare products, antimicrobial compounds, and culture media with animal free protein for producing vaccines and other biopharmaceutical products. The use of microalgae as raw biomass or in biotechnological platforms is in line with the fulfillment of the 2030 Agenda related to the Sustainable Development Goals (SDGs)

Semicontinuous system for the production of recombinant mCherry protein in Chlamydomonas reinhardtii

Biotechnology advances have allowed bacteria, yeasts, plants, mammalian and insect cells to function as heterologous protein expression systems. Recently, microalgae have gained attention as an innovative platform for recombinant protein production, due to low culture media cost, compared to traditional systems, as well as the fact that microalgae such as Chlamydomonas reinhardtii are considered safe (GRAS) by the Food and Drug Administration (FDA). Previous studies showed that recombinant protein production in traditional platforms by semicontinuous process increased biomass and bio product productivity, when compared to batch process. As there is a lack of studies on semicontinuous process for recombinant protein production in microalgae, the production of recombinant mCherry fluorescent protein was evaluated by semicontinuous cultivation of Chlamydomonas reinhardtii in bubble column photobioreactor. This semicontinuous cultivation process was evaluated in the following conditions: 20%, 40%, and 60% culture portion withdrawal. The highest culture withdrawal percentage (60%) provided the best results, as an up to 161% increase in mCherry productivity (454.5 RFU h−1 – Relative Fluorescence Unit h−1), in comparison to batch cultivation (174.0 RFU h−1) of the same strain. All cultivations were carried out for 13 days, at pH 7, temperature 25°C and, by semicontinuous process, two culture withdrawals were taken during the cultivations. Throughout the production cycles, it was possible to obtain biomass concentration up to 1.36 g L−1

Phycoremediation Processes for Secondary Effluent from Sewage Treatment Plants Using Photosynthetic Microorganisms: A Review

Taking into account the worrying scenario of water scarcity, it is essential to enable more efficient technologies for wastewater treatment. Wastewater may be treated by conventional biological processes that remove pathogenic organisms, particulate and soluble organic compounds, and other components. However, secondary effluents from treatment plants may still contain toxic elements or high concentrations of inorganic nutrients (mainly nitrogen and phosphorus), which enable the growth of photosynthetic microorganisms in water bodies, resulting in eutrophication. In this context, cultivation of photosynthetic microorganisms in secondary wastewater from sewage treatment allows the removal of nutrients from such wastewater, reducing the possibility of eutrophication. Moreover, microalgal biomass, produced in this tertiary wastewater treatment, may be harvested by different methods with the potential for different applications, such as fertilizer and biofuel

Fed-batch cultivation of Arthrospira platensis using carbon dioxide from alcoholic fermentation and urea as carbon and nitrogen sources

It was evaluated the Arthrospira platensis cultivation using CO2 from alcoholic fermentation and either urea or nitrate as nitrogen source at different light intensities (60 64 I 64 240 \u3bcmol photons m-2 s-1). Whereas the CO2 source (pure CO2 or from alcoholic fermentation) did not influence the maximum cell concentration (Xm), cell productivity (PX) and nitrogen-to-cell conversion factor (YX/N), the use of urea instead of nitrate led to higher YX/N values. Xm and PX increased when I was increased from 60 to 120-240 \u3bcmol photons m-2 s-1. Using CO2 from alcoholic fermentation, the best performance (Xm = 2952 \ub1 35 mg L-1, PX = 425 \ub1 5.9 mg L-1 d-1 and YX/N = 15 \ub1 0.20 mg mg-1) was obtained at I = 120 \u3bcmol photons m-2 s-1 with urea. The results obtained in this work demonstrate that urea and CO2 from alcoholic fermentation could be simultaneously used in large-scale cultivations to reduce the environmental impact associated to the release of this greenhouse gas as well as the production cost of cyanobacteria