Exploring microalgal and cyanobacterial metabolites with antiprotozoal activity against Leishmania and Trypanosoma parasites.

Neglected tropical diseases (NTD) like Leishmaniasis and trypanosomiasis affect millions of people annually, while currently used antiprotozoal drugs have serious side effects. Drug research based on natural products has shown that microalgae and cyanobacteria are a promising platform of biochemically active compounds with antiprotozoal activity. These unicellular photosynthetic organisms are rich in polyunsaturated fatty acids, pigments including phycocyanin, chlorophylls and carotenoids, polyphenols, bioactive peptides, terpenes, alkaloids, which have proven antioxidant, antimicrobial, antiviral, antiplasmodial and antiprotozoal properties. This review provides up-to-date information regarding ongoing studies on substances synthesized by microalgae and cyanobacteria with notable activity against Leishmania spp., Trypanosoma cruzi, and Trypanosoma brucei, the causative agents of Leishmaniasis, Chagas disease, and human African trypanosomiasis, respectively. Extracts of several freshwater or marine microalgae have been tested on different strains of Leishmania and Trypanosoma parasites. For instance, ethanolic extract of Chlamydomonas reinhardtii and Tetraselmis suecica have biological activity against T. cruzi, due to their high content of carotenoids, chlorophylls, phenolic compounds and flavonoids that are associated with trypanocidal activity. Halophilic Dunaliella salina showed moderate antileishmanial activity that may be attributed to the high ß-carotene content in this microalga. Peptides such as almiramides, dragonamides, and herbamide that are biosynthesized by marine cyanobacteria Lyngbya majuscula were found to have increased activity in micromolar scale IC50 against L. donovani, T. Cruzi, and T. brucei parasites. The cyanobacterial peptides symplocamide and venturamide isolated from Symploca and Oscillatoria species, respectively, and the alkaloid nostocarbonile isolated from Nostoc have shown promising antiprotozoal properties and are being explored for pharmaceutical and medicinal purposes. The discovery of new molecules from microalgae and cyanobacteria with therapeutic potential against Leishmaniasis and trypanosomiasis may address an urgent medical need: effective and safe treatments of NTDs.

Light induces peridinin and docosahexaenoic acid accumulation in the dinoflagellate Durusdinium glynnii.

Peridinin is a light-harvesting carotenoid present in phototrophic dinoflagellates and has great potential for new drug applications and cosmetics development. Herein, the effects of irradiance mediated by light-emitting diodes on growth performance, carotenoid and fatty acid profiles, and antioxidant activity of the endosymbiotic dinoflagellate Durusdinium glynnii were investigated. The results demonstrate that D. glynnii is particularly well adapted to low-light conditions; however, it can be high-light-tolerant. In contrast to other light-harvesting carotenoids, the peridinin accumulation in D. glynnii occurred during high-light exposure. The peridinin to chlorophyll-a ratio varied as a function of irradiance, while the peridinin to total carotenoids ratio remained stable. Under optimal irradiance for growth, there was a peak in docosahexaenoic acid (DHA) bioaccumulation. This study contributes to the understanding of the photoprotective role of peridinin in endosymbiont dinoflagellates and highlights the antioxidant activity of peridinin-rich extracts. KEY POINTS: • Peridinin has a protective role against chlorophyll photo-oxidation • High light conditions induce cellular peridinin accumulation • D. glynnii accumulates high amounts of DHA under optimal light supply.

An overview on microalgae as renewable resources for meeting sustainable development goals.

The increased demands and dependence on depleted oil reserves, accompanied by global warming and climate change have driven the world to explore and develop new strategies for global sustainable development. Among sustainable biomass sources, microalgae represent a promising alternative to fossil fuel and can contribute to the achievement of important Sustainable Development Goals (SDGs). This article has reviewed the various applications of microalgal biomass that includes (i) the use in aquaculture and its sustainability; (ii) commercial value and emerging extraction strategies of carotenoids; (iii) biofuels from microalgae and their application in internal combustion engines; (iv) the use and reuse of water in microalgae cultivation; and (v) microalgae biotechnology as a key factor to assist SDGs. The future prospects and challenges on the microalgae circular bio economy, issues with regard to the scale-up and water demand in microalgae cultivation are also highlighted.

Advances in Microalgal Research in Brazil

Abstract Microalgae research has attracted interest worldwide and in order to advance algal biotechnology in Brazil, government has been funding several projects. In the last 10 years, two main funds were provided by the National Council of Scientific and Technological Development (CNPq) agency to researchers in Brazil, who study the potential uses of microalgae for biomass, bioproducts and biofuels production. These funded projects addressed aspects of algal strain identification, development of algal cultivation techniques, designing photobioreactors and raceway ponds, modeling harvesting and dewatering process, maximizing biomass and oil productivities, characterizing chemical composition with different extractions systems and determining physiochemical properties of biodiesel. This review presents the state of art of algal research conducted by Brazilian institutions. Special attention is given to the recent progress on microalgal cultivation, high-value products extracted from microalgae and potential biofuels production. This review may serve as a policy instrument for planning next steps for algal research in Brazil as well as for attracting attention from international researchers who work with microalgae and would like to pursue a future partnership on algal research with Brazilian research institutions.

Synthetic Biology Category Wins the 350th Anniversary Merck Innovation Cup.

Over the past 350 years, Merck has developed science and technology especially in health care, life sciences, and performance materials. To celebrate so many productive years, Merck conducted a special expanded anniversary edition of the Innovation Cup in combination with the scientific conference Curious2018 - Future Insight in Darmstadt, Germany.

Effects of different photoperiod and trophic conditions on biomass, protein and lipid production by the marine alga Nannochloropsis gaditana at optimal concentration of desalination concentrate.

This study investigated the cultivation of the marine alga Nannochloropsis gaditana in a medium based on desalination concentrate (DC) with an optimal concentration of 75% DC, under three trophic conditions and four photoperiod schedules. N. gaditana produced a peak biomass concentration (1.25gL-1) under mixotrophic culture condition and a photoperiod of 16L:08D. N. gaditana cells compensate to different light-dark regimes producing different amounts of protein (17.9-44.8%). The intracellular lipid content in N. gaditana cells increased both under autotrophic conditions with a 16L:08D cycle (16.7%), and under mixotrophic conditions with a 08L:16D cycle (15.7%). In heterotrophic culture, N. gaditana cells were rich in polyunsaturated fatty acids (46.0%). This study demonstrates an alternative approach to enhancing intracellular lipid content of the marine alga N. gaditana by modifying the photoperiod, trophic conditions and stress-salinity-conductivity with the use of a DC-based medium.

Intensive care management of patients with liver disease: proceedings of a single-topic conference sponsored by the Brazilian Society of Hepatology

ABSTRACT Survival rates of critically ill patients with liver disease has sharply increased in recent years due to several improvements in the management of decompensated cirrhosis and acute liver failure. This is ascribed to the incorporation of evidence-based strategies from clinical trials aiming to reduce mortality. In order to discuss the cutting-edge evidence regarding critical care of patients with liver disease, a joint single topic conference was recently sponsored by the Brazilian Society of Hepatology in cooperation with the Brazilian Society of Intensive Care Medicine and the Brazilian Association for Organ Transplantation. This paper summarizes the proceedings of the aforementioned meeting and it is intended to guide intensive care physicians, gastroenterologists and hepatologists in the care management of patients with liver disease.

RESUMO A sobrevida de pacientes cirróticos críticos aumentou significantemente nos últimos anos devido a inúmeros avanços obtidos no manejo do paciente com cirrose descompensada e com insuficiência hepática aguda grave, particularmente após a incorporação na prática clínica de uma série de estratégias baseadas em evidencias com impacto reconhecido na redução de mortalidade. Com o intuito de discutir as principais evidencias disponíveis na literatura médica sobre o assunto, a Sociedade Brasileira de Hepatologia, em conjunto com a Associação de Medicina Intensiva Brasileira e a Associação Brasileira de Transplantes de Órgãos promoveu uma reunião monotemática sobre o manejo do paciente hepatopata crítico, que ocorreu em 21 de maio de 2014 na cidade do Rio de Janeiro. O relatório da reunião foi resumido no presente manuscrito com o objetivo de nortear a prática clínica de intensivistas, gastroenterologistas e hepatologistas no manejo do paciente hepatopata em ambiente de terapia intensiva.

Biomass, lipid productivities and fatty acids composition of marine Nannochloropsis gaditana cultured in desalination concentrate.

In this study the feasibility of growing marine Nannochloropsis gaditana in desalination concentrate (DC) was explored and the influence of the DC concentration on the biomass growth, lipid productivities and fatty acids composition was assessed. The reuse of the medium with the optimum DC concentration in successive algal cultivation cycles and the additional of a carbon source to the optimized medium were also evaluated. On varying the DC concentration, the maximum biomass concentration (0.96gL(-1)) and lipid content (12.6%) were obtained for N. gaditana in the medium with the optimum DC concentration (75%). Over the course of the reuse of the optimum DC medium, three cultivation cycles were performed, observing that the biomass productivity is directly correlated to lipid productivity. Palmitic acid was the major fatty acid found in N. gaditana cells. The saturated fatty acids content of the algae enhanced significantly on increasing the DC concentration.

Teores de proteínas e lipídeos de Chlorella sp. cultivada em concentrado de dessalinização residual / Protein and lipid contents from Chlorella sp. Cultivated in residual concentrated desalination

A dessalinização é um método de obtenção de água potável limitado pelos problemas ambientais, causados pelo resíduo gerado em seu processo. O objetivo deste estudo foi avaliar o cultivo de Chlorella sp., em meio de cultura a base de concentrado de dessalinização, e determinar os teores de proteínas e lipídeos ao longo dos ciclos de cultivo. Os cultivos foram desenvolvidos em fotobiorreatores cônicos invertidos (4L) e mantidos durante 28 dias resultando em quatro ciclos de cultivo. Para cada ciclo de cultivo, os valores de biomassa (peso seco, g L-1) resultaram em 1º ciclo, 1,55; 2º ciclo, 0,96; 3º ciclo, 0,62, e 4º ciclo em 0,42. Os teores de proteínas e lipídeos variaram entre 45,2 a 48,8% e 8,5 a 11,4%, respectivamente. O primeiro ciclo de cultivo apresentou a maior produtividade em biomassa (PB = 200 mg L-1 dia-1) e produtividade lipídica (PL = 19,6 mg L-1 dia-1), bem como o maior teor de proteínas (48,8%). O maior teor de lipídeos (11,4%) foi obtido no segundo ciclo de cultivo. Foi observado, nos quatro ciclos de cultivo, que a produtividade em biomassa está diretamente correlacionada com a produtividade lipídica, indicando que quanto maior a PB maior será a PL. Os resultados da cultura de Chlorella sp. demonstraram que é possível utilizar o concentrado de dessalinização residual como meio de cultura alternativo e obter biomassa ao longo de quatro ciclos de cultivo, sem comprometer os teores de proteínas e lipídeos na célula microalgal.

Desalination process is a method of obtaining potable drinking water which is limited by environmental problems caused by the waste generated in the process. The aim of this study was to evaluate the cultivation of Chlorella sp. in a culture medium based on residual concentrated desalination and determines the protein and lipid contents along the cultivation cycles. The cultures were developed in a reverse conical photobioreactors (4L) during 28 days resulting in four cultivation cycles. For each cultivation cycle, the value of biomass (dry weight g L-1) resulted: 1st cycle, 1.55 g; 2nd cycle, 0.96; 3rd cycle, 0.62 and 4th cycle, 0.42. The protein and lipid levels ranged from 45.2 to 48.8% and 8.5 to 11.4%, respectively. The first cultivation cycle showed the highest biomass productivity (PB = 200 mg L-1 dia-1) and lipid productivity (PL = 19.6 mg L-1 dia-1), as well as the highest protein content (48.8%). The highest lipid content (11.4%) was observed on second cultivation cycle. It was observed during the four cultivation cycles that the biomass productivity is directly correlated to lipid productivity, indicating that higher PB higher will be PL. The results from this study showed that it is possible to growth Chlorella sp. in a culture medium based on residual concentrated desalination for biomass production along the four cultivation cycles and also, without compromise the protein and lipid contents into the microalgal cell.

Leptospirose: reflexöes sobre o espectro grave / Leptospirosis: observations on the severe spectrum

Säo estudados 30 enfermeiros com espectro grave de leptospirose, retirados de um total de 69 observados no Hospital dos Servidores do Estado, durante surto epidêmico conseqüente as chuvas torrenciais e enchentes ocorridas no Rio de Janeiro e "Grande Rio" em 1988. As formas graves foram definidas pela presença de icterícia e de insuficiência renal aguda. Distúrbios hemorrágicos, cardiovasculares, respiratórios, neurológicos e metabólicos foram outros achado clínicos importantes neste grupo. A heterogeneidade de evoluçäo clínica permitiu-nos a caracterizaçäo de três subgrupos: 1) evoluçöes para o óbito; 2) recuperaçöes com evoluçäo arrastada e tormentosa; e 3) formas brandas, dialisadas ou näo. Dez enfermos cursaram com anúria, 15 com oligúria e dois com poliúria. A mortalidade foi maior nos que tiveram anúria. Dos 30 estudados, 13 apresentaram arritmias cardíacas, 8/20 tiveram alteraçöes de ondas T e, em 5/20, houve alteraçöes de segmento ST. Dos dois casos necropsiados, ambos tinham miocardite. O estudo ecocardiográfico näo demonstrou alteraçöes significativas. Treze tiveram alteraçöes hemorrágicas e, entre os 10 com hemorragia digestiva, cinco (50%) faleceram. Foi assinalada plaquetopenia entre 12 entre 22 estudados. Dois casos fatais mostraram padräo radiológico de angústia respiratória, porém a morte näo pode ser atribuída exclusivamente ao envolvimento pulmonar, porque havia concomitância de lesöes graves em outros setores. Os dois casos necropsiados mostraram broncopneumonial hemorragica bilateral. As principais alteraçöes neurológicas descritas foram torpor, convulsöes e coma. Oito dos 30 enfermos tiveram infecçäo hospitalar, como conseqüência da própria gravidade do espectro e da utilizaçäo de terapêuticas invasivas (broncopneumonia, infecçäo urinária, sepsis, parotidite e contaminaçäo de catéter de bexiga e de hemodiálise). Houve concordância entre prognóstico pior e maior número de órgäos acometidos; nos que tiveram evoluçäo fatal, o acometimento foi de 4,3% de órgäos (4 a 6 órgäos). Houve ainda relaçäo direta entre o tipo de evoluçäo, mortalidade e faixa etária. Dez doentes tiveram evoluçäo fatal (33,3%) de mortalidade