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Natural compounds produced by cyanobacteria have a large structural variety and several biotechnologic al applications, such as biofertilization, bioremediat ion, biofuels, food and feed. Some compounds have properties in antiviral, antibacterial, antifungal and anticancer activities. Aphano thece halophytica is a halotolerant cyanobacteria which can grow at a wide range of salt concentration and ph values. Due the adaptation strategies to live on these extreme envi ronments, they can be a rich source of bioactive co mpounds. The salt production in salines consists in the use of different water reservoirs, where natural water evaporation gradually increases salt concentration in each rese rvoir until salt precipitation. In this study, we c ollected Aphanothece halophytica strains at the crystallizer reservoir, where the s alinity was 225, at a saline in Cabo Frio, RJ. The cyanobacteria was identified by micro scopic analysis following Komarek and Anagnostidis (1988) method. Four extracts were obtained using so lvents with different polarities . The methanol extract was evaluated for antibacterial activity on micro assay s using P seudomonas sp ., Vibrio sp . and Pseudoalteromonas sp .. These bacteria are involved both in health and e nvironmental issues, due to their participation on some pathologies and on the formation of biofilms, one o f the first steps of biofouling. The extract affect ed the growth of some of the assayed bacteria with differe nt intensities, showing that it may have antibacter ial compounds. Other extractions methods and biological assays must be tested to elucidate which compounds are responsible for this activity and their mechanism o f action. These preliminary results corroborates th e biotechnological potential of cyanobacteria from hy persaline environments. The relatively low cost and fast grow of this organisms may facilitate furthers stud ies and commercial exploitation.

Glioblastoma is the most malignant brain tumor of the central nervous system, having a high rate of proliferation and invasive growth, which limits its treatment. Cyanobacteria are photoautotrophic prokaryote organisms, which are recognized as being large producers of secondary metabolites with unique structural characteristics, many of them with biological activities known with the antibacterial, anti-inflammatory and antitumor. To evaluate the possible antitumoral effect of crude extracts from different species of cyanobacteria collected in different hypersaline environment against human glioblastoma cells. The collection of cyanobacteria of the genus Oscilatorium sp., Phormidium sp., Lyngbya sp. and Aphanothece sp. was made in the Lagoon of Araruama and salines. The collected material was lyophilized and extracted 3 times by static maceration in Ethyl Acetate:Methanol (1:1) over a period of 2h. MTT cell viability assay was performed with two human glioblastoma cell lines U251 and T98G. The cells were incubated with the crudes extracts at concentrations of 62,5μg/mL, 125μg/mL, 250μg/mL, 500μg/mL and 1000μg/mL maintained for 72h in 5% CO2 at 37°C. The control condition consisted of cells cultured with the extract dilution vehicle (0.5% DMSO). The percent viability calculation was performed from the ratio: [(A570nm of treated cells/A570nm of untreated cells)x100]. Thin layer chromatography was performed on flexible aluminum plates having silica gel as adsorbent material; two different elution systems were used (Hex:CH2Cl2 1.5:8.5) and (AcOEt 100%). Each of the plates was revealed by the Dragendorff, KMnO4, FeCl3, EtOH 5%H2SO4 and Ninhyndrin reagents. In order of response in lineage U251 the crude extracts Oscilatorium sp. demonstrated IC50=51,91μg/ml, followed by Phormidium sp. with IC50=197,5μg/ml and the Lyngbya sp. with IC50=299,2μg/ml. In the T98G cell line the crude extracts Oscilatorium sp. demonstrated IC50=124.9μg/mL, followed by Phormidium sp. with IC50=261,8μg/ml. The crude extract of Aphanothece sp. did not present cytotoxic activity in any of the studied cell lines. The analysis of the thin layer chromatography allowed the visualization of the presence different classes of secondary metabolites of cyanobacteria Article extracts, showing a great chemical diversity. The results suggest that the secondary metabolites of cyanobacteria Oscilatorium sp., Phormidium sp., And Lyngbya sp. of hypersaline systems can present bioactive compounds with antitumor effect in vitro and that these extracts present a diversity of chemical substances.

The recent estimated incidence was 600,000 new cases of cancer each year in Brazil. Cyanobacterias are photoautotrophic prokaryote organisms, which are recognized as producers of secondary metabolites with unique structural characteristics, presenting antibacterial and anti-inflammatory effects. The aim of this study is to evaluate the anticancer effect of the Aphanothece halophytica´s extracts (A.halophytica) in different human cancer cells. The cyanobacteria extratcs were collected in a specific hypersaline microenvironment during the 2019’s spring. The material was extracted in 1:1 Ethyl Acetate:MetOH for 2h. After reconstitution in dimethyl sulfoxide, increasing concentrations were used in MTT assay with cancer cell lines, T98G (glioblastoma), MDA (breast), A549(lung), K562 (leukemia) and a healthy human fibroblast for 72h. The cytostatic effect was analyzed by flow cytometry as well as DNA fragmentation. For chemical basic profile the thin layer chromatography was performed, using Hex: CH2Cl2 1.5:8.5 and AcOEt 100% elutions and revealed by Dragendorff, KMnO4, FeCl3, EtOH 5% H2SO4 and Ninhyndrin. It was observed a variation in the cyanobacteria species between the 3 collections, being mostly composed by A. halophytica (extract 2) and presenting 10% and 15% of A. clathrata in extracts 1 and 3, respectively. The extract 1 showed a significant cytotoxic effect in MDA (IC50=690.8μg/mL) and A549 (IC50=1,827μg/mL) cells. The cytotoxic effect of extract 2 was only saw in the MDA (IC50 = 597.9g/mL) cells and T98G, MDA and K562 cells presented significant S and G2/M arrest. The extract 3 didn’t have cytotoxic effect. Extracts 1 and 3 demonstrated significant S and G2/M arrest only in T98G and MDA cells. The chemical analysis exhibited different classes of secondary metabolites between collections. All extracts didn´t have effect in healthy cells. We suggest that cyanobacteria’s extract present bioactive compounds as source of marine biopharmaceuticals in the future.

As cianobactérias marinhas são organismos procariontes capazes de realizar fotossíntese, assim como as algas. Possuem metabólitos secundários (ou produtos naturais), que possuem um amplo espectro de atividade biológica como antivirais, antibacteriano, antifúngicos e cosméticos. A demanda de alimentos no mundo é cada vez maior em função do crescimento populacional e o aumento do uso de insumos como fertilizantes e agrotóxicos tem causado graves impactos ambientais e a saúde humana. A necessidade do uso de substâncias mais eficazes e menos tóxicas é iminente o que faz com que os estudos de produtos naturais sejam incentivados. O objetivo deste trabalho é avaliar o potencial de cianobactérias marinhas das salinas da Região dos Lagos do Rio de Janeiro, e seus produtos naturais como biofertilizantes e antifúngicos. Para tal, os organismos foram coletados nas salinas de Cabo Frio, RJ, triados e uma parte separada para identificação taxonômica. O restante foi liofilizado e extraído com metanol e acetato de etila (1:1). Os perfis químicos foram obtidos por Cromatografia em Camada Delgada e Cromatografia Gasosa acoplada a Espectrometria de Massas (CG-EM). Os extratos foram inicialmente avaliados quanto à sua atividade fungicida frente ao fungo Colletrotrichum Musae em teste de crescimento em placa. O manejo inadequado dos frutos causa lesões que propiciam o aparecimento de doenças, levando a perda do fruto. A antracnose, causada pelo fungo Colletrotrichum Musae, é considerada a principal doença pós-colheita da banana. De uma forma geral, as análises cromatográficas mostraram uma elevada complexidade de metabólitos, com a predominância de ácidos graxos e seus derivados, pigmentos fotossintetizantes e esteróis. Dos 15 extratos avaliados, 3 inibiram significativamente o crescimento do fungo em relação ao controle. mostrando o potencial desses organismos para a descoberta de antifúngicos de origem natural.

Glioblastoma é o tumor cerebral mais maligno do sistema nervoso central, tendo uma alta taxa de proliferação e crescimento invasivo, o que limita seu tratamento. As cianobactérias são reconhecidas por serem grandes produtoras de metabólitos secundários com características estruturais únicas, muitos deles com atividades biológicas conhecidas como antibacteriano, anti-inflamatório e antitumoral. Objetivos: Avaliar o efeito antitumoral dos extratos brutos de diferentes espécies de cianobactérias coletadas em ambiente hipersalino em células de glioblastoma humano. Metodologia: A coleta das cianobactérias Oscilatorium sp., Phormidium sp., Lyngbya sp. e Aphanothece sp. foi feita na Lagoa de Araruama e salineiras. O material coletado foi liofilizado e extraído 3 vezes por maceração estática em Acetato de Etila:Metanol 1:1, durante um período de 2h. Foi realizado ensaio de viabilidade celular por MTT com duas linhagens de glioblastoma humanos U251 e T98G. As células foram incubadas com os extratos brutos nas concentrações de 62,5μg/mL, 125μg/mL, 250μg/ mL, 500μg/mL e 1000μg/mL mantidas por 72h em 5% de CO2 a 37o C. A condição controle consistiu das células cultivadas com o veículo de diluição dos extratos (DMSO 0,5%). O cálculo do percentual de viabilidade foi realizado a partir da razão: [(A570nm das células tratadas/A570nm das células não tratadas) x 100]. Resultados Parciais: Em ordem de resposta na linhagem U251 os extratos brutos Oscilatorium sp. demonstrou IC50=51,91μg/mL, seguido da Phormidium sp. com IC50=197,5μg/mL e da Lyngbya sp. com IC50=299,2μg/mL. E na linhagem T98G os extratos brutos Oscilatorium sp. demonstrou IC50=124,9μg/mL, seguido da Phormidium sp. com IC50=261,8μg/mL. O extrato bruto da Aphanothece sp. não apresentou atividade citotóxica em nenhuma das linhagens estudadas. Considerações finais: Os resultados sugerem que os metabólitos secundários das cianobactérias Oscilatorium sp., Phormidium sp., e Lyngbya sp. de sistemas hipersalinos podem apresentar compostos bioativos com efeito antitumoral in vitro.

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Bibliografia: p.145 Resumos em português e inglês

A guerra química quando comparada as guerras biológicas e nucleares é provavelmente uma das mais brutais. As armas químicas utilizadas, são consideradas armas de destruição em massa, construídas com relativo baixo custo e fáceis de se produzir. Devido a sua aplicação destrutiva, simples produção, alta toxicidade, ação rápida e letal mesmo em baixas concentrações, vêm atraindo um amplo interesse de militares e grupos terroristas. Alguns agentes neurotóxicos, são compostos organofosforados (OP´s) semelhantes a muitos pesticidas comercialmente disponíveis. Os OP´s podem ser considerados armas de destruição em massa, pois são simples e facilmente fabricados, dispersam-se com facilidade na atmosfera, são de difícil detecção e têm potencial para matar centenas de pessoas em um único ataque. Atuam inibindo a colinesterase (ChE), enzima do sistema nervoso que controla impulsos e transmissões dos estímulos nervosos. Estas, podem ser obtidas respectivamente de extratos brutos de vários tecidos, como tecido cerebral e muscular de peixes, mamíferos e aves. O objetivo deste trabalho foi Imobilizar em sílica mesoporosa SBA-15, ChE, de extrato bruto de cérebros de Paralichthys patagonicus (linguado branco), avaliando a atividade enzimática sem a presença do inibidor Paraoxon-etil (análogo ao Sarin) e com a presença do inibidor. Detectar e quantificar o substrato de Iodeto de Acetiltiocolina, utilizando a técnica de voltametria de onda quadrada. Como resultado da revisão bibliográfica, três artigos utilizaram a sílica mesoporosa como matriz de imobilização, porém não foram identificados na literatura pesquisada, biossensores construídos com ChE imobilizadas em Sílica mesoporosa SBA-15, utilizados para detecção do agente nervoso Paraoxon-etil (análogo ao Sarin). A presente pesquisa concluiu que a sílica mesoporosa SBA-15, mostrou ser uma matriz confiável e estável para imobilização por adsorção de ChE, contidas no extrato bruto. Os testes de inibição da enzima IC50, detectaram o Paraoxon-etil em uma concentração de 2,18 x 10-4 mmol.L-1, demonstrando quanto sensível pode ser a detecção do inibidor em meio aquoso. O método voltamétrico desenvolvido e aplicado apresentou-se eficaz para detecção e quantificação na faixa de 1,25 x 10-4 a 1,32 x 10-3 mol.L-1 deste substrato enzimático em solução aquosa, podendo ser utilizado para mensurar a inibição enzimática de ChE, no eletrodo de carbono vítreo. Palavras-chave: Biossesor. Acetilcolinesterases. Armas Químicas. Paraoxon etil (análogo Sarin). When the chemical war is compared to the biological and nuclear wars, it is probably one of the most brutal ones. The chemical weapons utilized are constructed cheaply and easily produced, weapons of mass destruction. Due to its destructive application, high toxicity, simple production, and quick and lethal action even in low concentrations, it is attracting a huge military and terrorist interest. Some neurotoxic are organophosphates compounds similar to many commercially available pesticides. The OP’s can be considered as weapons of mass destruction because they are simple easily fabricated, disperse well in the atmosphere, it is difficult to detect, and has the potential to kill hundreds of people in a single attack. They act inhibiting the cholinesterase (ChE), which are enzymes from the nervous system, which control the impulses and transmissions of the nervous stimuli. Those can be obtained, respectively, from crude extracts of many tissues, like the fish’s, mammal’s and bird’s cerebral and muscular tissue. This project objective was to immobilize in mesoporous silica SBA-15, ChE, from Paralichthys patagonicus (white sole), brains crude extract, rating the enzymatic activity without the presence of the Paraoxon-ethyl xenobiotic (similar to Sarin) inhibitor, and with its presence. Detect and quantify the Cholinesterase iodide substrate in potentiostat, utilizing the square wave voltammetry technique. As a result of the literature review, three articles used the mesoporous silica as immobilization matrix but were not identified in the searched literature, biosensors built with ChE immobilized in mesoporous silica SBA-15, utilized for the nervous agent Paraoxon-ethyl (similar to Sarin) detection. The mesoporous silica SBA-15 has shown to be a reliable and stable matrix for the immobilization by ChE adsorption, contained in the crude extract. The tests of IC50, enzyme inhibition have detected the Paraoxon-ethyl in a 2,18 x 10-4 mmol.L-1 concentration, showing how sensible can be the inhibitor detection in an aqueous medium. The method developed and applied in the potentiostat was effective for the detection and quantification in the 1,25 x 10-4 1,32 x 10-3 mol.L-1 rage of the enzymatic substrate in an aqueous medium, willing to be used for measure the ChE enzymatic inhibition, in the carbon glassy carbon electrode. Key words: Biosensor. Cholinesterase. Chemical weapons. Paraoxon-ethyl (similar to Sarin).

Dissertação (mestrado) - Programa Associado de Pós-Graduação em Biotecnologia Marinha IEAPM/UFF, Arraial do Cabo, 2018. Bibliografia: p. 77-81. As macroalgas constituem um habitat bastante favorável à formação de comunidade acompanhante e produzem uma gama de moléculas que podem ser utilizadas na área biomédica, cosmétic a, indústria alimentar e farmacêutica, o que faz destes organismos marinhos um alvo de estudo muito interessante em termos biotecnológicos. O gênero Sargassum está entre as macroalgas marinhas mais ricas em termos de comunidade acompanhante. Além disso, es te gênero está entre os detentores de compostos antioxidantes, antibacterianos, antitumorais, antimaláricos, anti - herbivoria e propriedades anti - incrustantes. Considerando a importante relação entre os bancos de algas e a comunidade epibionte, além da impo rtância das algas no campo da biotecnologia marinha, o presente estudo visou a ampliação do conhecimento da espécie S. furcatum e seus epibiontes, caracterizando as espécies em termos ecológicos no que diz respeito a seus parâmetros populacionais e sua com unidade acompanhante, bem como as propriedades antibacterianas de S. furcatum e a influência de seus epibiontes sobre bactérias marinhas atuantes no processo de bioincrustação. O presente estudo mostrou o primeiro crescimento do banco após cinco anos de co lapso. Os resultados indicaram que no verão de 2015, o banco de S. furcatum voltou a apresentar um crescimento e aumento de biomassa significativo e que suas epífitas acompanharam o padrão de crescimento e senescência do banco. Em termos de atividade antib acteriana, o presente estudo mostrou que os extratos brutos de S.furcatum nos diferentes solventes de extração testados (aquoso, etanol e diclorometano) apresentaram atividade inibitória. O epifitismo influenciou, de forma negativa, a ação dos extratos sob re as cepas de bactéria utilizadas. Este estudo mostrou que extratos não epifitados de S. furcatum , cujo solvente de extração utilizado seja diclorometano apresentaram maior poder inibitório sobre o crescimento bacteriano. Conhecendo o importante papel que o crescimento de bactérias e a formação do biofilme tem na fase inicial da bioincrustação, tal extrato deve possuir compostos bioativos antibacterianos promissores para a síntese de anti - incrustantes para o desenvolvimento de tintas a base de produtos nat urais. M acroalgae constitute a favorable habitat for a rich and diverse associated community . They are able to produce a wide range of biomolecules with applicat ion in biomedicine, cosmetics, food, and pharmaceutical industries and because of those properties, these organisms have been studied for biotechnological applications. The genus Sargassum is one of the richest marine macroalgae regarding associated commun ity. Furthermore , th e algae of this genus ha ve compounds with antioxidant, antitumoral, antimalarial, antiherbivore and antifouling properties. Considering the important relation between algal beds and epibiont community, as well as the ir importance to mar ine biotechnology research , the present study aim ed to increase the knowledge about Sargassum furcatum (Küetzing,1843) and its epibionts. Population parameters and their associated fauna were studied. Moreover , we tested the antibacterial properties of S. furcatum and its epibionts on marine bacteria present in biofouling growth . The present study was performed after five years of a collapse in the seasonal growth of the bed . Our results indicated that in the summer of 2015, the S. furcatum b ed showed a re markable growth and biomass increase , followed by the growth of epiphytes until the senescence of the host algae, despite the years of negligible growth. In terms of antibacterial activity, the present study showed that the crude extracts of S.furcatum sho wed inhibitory activity using different extraction solvents (aqueous, ethanol and dichloromethane). Epiphy tism influenced negatively the action of the extracts on the bacterial strains used. Our findings indicated that extracts of S. furcatum in dichlorome thane ( without epiphytes) showed superior inhibit ion on bacterial growth. Considering the important role of bacteria l growth and the formation of the biofilm to the initial phase of biofouling, the extract s obtained from the algae might have promising anti bacterial compounds that could be used for the development of a natural product - based antifouling paint.

Infection of marine dinoflagellates by the parasitic dinoflagellate Amoebophrya spp. plays an important role in population dynamics and carbon flow in marine food webs. It has been extensively reported that Amoebophrya parasitoids occur in temperate coastal areas of the northern hemisphere; however, little is known about their distribution and importance in tropical areas and southern oceans. We used an rRNA-based, fluorescent in situ hybridization assay to detect Amoebophrya spp. infections during the decline of a late-summer dinoflagellate population dominated by Ceratium falcatiforme in a tropical coastal area of the southern Atlantic Ocean subjected to recurrent upwelling―downwelling cycles. Conditions during our survey were typical of downwelling when oligotrophic waters dominate the area. C. falcatiforme was the most infected host, with a prevalence averaging 2 % over the study area at the beginning of sampling. At a fixed sampling station monitored over 4 wk, Amoebophrya prevalence escalated from 1 to 7 % over a 6 d period, concomitant to a 94 % decrease in host cell numbers. Infection by Amoebophrya was estimated to have killed ca. 11 % of the host cell population within this period; thus, parasitism was not the main factor behind the C. falcatiforme population decline. Estimates based on biovolume calculations indicate that ca. 6.5 % of the carbon in the decaying C. falcatiforme population was transformed into parasitoid dinospores, which became available to tintinnid ciliates that were abundant during our survey. Such a trophic link might be relevant in tropical oligotrophic waters when the system is characterized by a microbial food web structure.