The goal of this research is to identify and characterize enzymes involved in bilin attachment to the phycobiliprotein allophycocyanin in the cyanobacterium Synechococcus sp. PCC 7002. Candidates for lyases responsible for attachment of phycocyanobilin to allophycocyanin are two cpeS-like genes termed cpcS and cpcU, and one cpeT-like gene termed cpcT. In vitro bilin attachment reactions were conducted in the presence of the recombinant substrate apo-allophycocyanin (HT-ApcAB). Size exclusion HPLC showed that CpcS and HT-CpcU form a 1:1 heterodimeric complex and that HT-ApcAB is present as a monomer (áâ). Absorbance and fluorescence spectroscopy illustrated that both CpcS and HT-CpcU were required to get holo-allophycocyanin with phycocyanobilin attached to the cysteine-81 residue. Absorbance of the product at 615 nm was consistent with holo-monomeric allophycocyanin. Experiments were performed with HT-ApcD ApcB and HT-ApcF ApcA, but size exclusion HPLC showed they were in aggregated form.

Phycoerythrin (PE) present on the outer phycobilisome (PBS) rods in Fremyella diplosiphon contains covalently attached phycoerythrobilin (PEB) chromophores for efficient photosynthetic light capture. Chromophore ligation on phycobiliprotein subunits occurs through bilin lyase catalyzed reactions. The cpeY and cpeZ genes in F. diplosiphon were shown to attach PEB on alph-82 of PE. To better understand the individual functions of cpeY and cpeZ in native cyanobacteria, we characterized PBS and PE purified from cpeY and cpeZ deletion mutants and compared them with wild type (WT). Both cpeY and cpeZ mutants generated much less PE than WT as well as assembling much less PE into the PBS. PE purified from cpeY mutant had phycocyanobilin on alpha-PE in place of PEB. The mutation of cpeZ affected the biosynthesis and accumulation of beta-PE with a red-shifted absorbance compared to WT PE. CpeY was shown to function as a bilin lyase, and CpeZ possibly functions as a chaperone.

CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / The phycocyanins are water-soluble proteins that function as accessory pigments and exhibit various properties, as immunostimulatin, cholesterol lowering effect, anti-inflammatory, antiviral, anticancer and antioxidant action, in addition to application as a natural dye. The focus of the commercial production of phycocyanin has fallen in most of the microalgae Arthrospira platensis. This cyanophyceae is rich in compounds as proteins, vitamins, essential amino acids, minerals, essential fatty acids, antioxidants, pigments, among others. Aquaculture is an activity of great importance, generating income and producing quality protein for human consumption. However, their activity generates large amounts of effluents with high nutrient load. The use of microalgae for aquaculture waste production is quite used, yielding good results in the cultivation of several species. This study aimed to evaluate the production of phycocyanin by A. platensis microalgae grown in fish effluent. For this, the microalgae was exposed to growing in Venkataraman modified medium and effluent from the Nile tilapia farming, in indoor and outdoor systems. After the end of the crop, the biomass obtained was exposed to phycocyanin extraction process, which consisted of freezing and thawing of wet biomass obtained from the culture in indoor system and subsequent extraction in sodium acetate buffer pH 5.0 for 48 h. The biomass produced in the outdoor system was dried at 60  C for 24 h in an oven with recirculating air. The dried biomass was resuspended in sodium acetate buffer pH 5.0 for 48 h. After that, the extracts were centrifuged at 4,700 rpm at 4 ÂC for 30 min. The supernatant was collected and evaluated in a spectrophotometer at 280 nm wavelength for proteins, 615 nm for phycocyanin,and and 652 nm for allophycocyanin. After this process, the crude extracts obtained from phycocyanin were subjected to purification by ion exchange chromatography. There wasnt significant difference between the performance of algae grown under the same conditions. However, algae exposed to outdoor system showed superior results. The phycocyanin concentrations were higher in the treatments that used Venkataraman medium, while the proportions of the pigment found in indoor systems were higher. The process of purification by ion exchange chromatography resulted in higher concentrations of pigment for fractions eluted with 0.2 M NaCl to all crude extracts of phycocyanin. / As ficocianinas sÃo proteÃnas solÃveis em Ãgua que funcionam como pigmentos acessÃrios e apresentam diversas propriedades, como aÃÃo imunoestimulante, efeito redutor do colesterol, efeitos anti-inflamatÃrio, antiviral, anticÃncer, antioxidante, alÃm de aplicaÃÃo como corante natural. O foco da produÃÃo comercial de ficocianina tem caÃdo em maior parte sobre a microalga Arthrospira platensis. Essa cianofÃcea à rica em proteÃnas, vitaminas, aminoÃcidos essenciais, minerais, Ãcidos graxos essenciais, pigmentos antioxidantes, dentre outros. A aquicultura à uma atividade de grande importÃncia, geradora de renda e produtora de proteÃna de qualidade para alimentaÃÃo humana. No entanto, sua atividade gera grandes quantidades de efluentes com alta carga de nutrientes. O uso de efluentes aquÃcolas para a produÃÃo de microalgas à bastante empregado, gerando bons resultados no cultivo de diversas espÃcies. Este trabalho teve como objetivo avaliar a produÃÃo de ficocianina pela microalga A. platensis cultivada em efluente piscÃcola. Para isto a microalga foi exposta à cultivo em meio Venkataraman modificado e efluente, proveniente de cultivo de tilÃpias do Nilo, em sistemas indoor e outdoor. ApÃs o tÃrmino dos cultivos a biomassa obtida foi exposta a processo de extraÃÃo de ficocianina que consistiu no congelamento e descongelamento da biomassa Ãmida obtida do cultivo em sistema indoor e posterior extraÃÃo em tampÃo acetato de sÃdio pH 5,0 durante 48 h. A biomassa produzida no sistema outdoor foi seca a 60 ÂC durante 24 h em estufa com recirculaÃÃo de ar. A biomassa seca foi ressuspendida em tampÃo acetato de sÃdio pH 5,0 durante 48 h. ApÃs isso, os extratos foram centrifugados a 4.700 rpm a 4 ÂC durante 30 min. O sobrenadante foi coletado e avaliado em espectrofotÃmetro nos comprimentos de onda de 280 nm, para proteÃnas, 615 nm, para ficocianina e 652, para aloficocianina. ApÃs esse processo, os extratos brutos de ficocianina obtidos foram submetidos a purificaÃÃo por cromatografia de troca iÃnica. NÃo houve diferenÃa significativa entre o desempenho das algas cultivadas nas mesmas condiÃÃes. No entanto, as algas expostas ao sistema outdoor mostraram resultados superiores. As concentraÃÃes de ficocianina foram superiores para os tratamentos que utilizaram o meio Venkataraman, enquanto que as proporÃÃes do pigmento encontradas nos tratamentos expostos ao sistema indoor foram maiores. O processo de purificaÃÃo por cromatografia de troca iÃnica resultou em maiores concentraÃÃes do pigmento para as fraÃÃes eluÃdas com NaCl 0,2 M para todos os extratos brutos de ficocianina.

A multi-plasmid, co-expression system was used to recreate the biosynthetic pathway for phycobiliproteins from the cyanobacterium Synechococcus sp. PCC 7002 in E. coli. This system efficiently produced chromophorylated allophycocyanin (ApcA/ApcB), -phycocyanin, and -phycocyanin. This system was used to demonstrate that CpcS-I and CpcU proteins are both required attaching PCB to allophycocyanin subunits ApcD (AP-B) and ApcF (18). The N-terminal, AP-like domain of ApcE (LCM99) was produced in soluble form and shown to have intrinsic bilin lyase activity. In addition, this system was used to chromophorylated CpcA from Synechococystis sp. PCC 6803 with a non-cognate bilin; PEB with the aid of CpcEF type bilin lyase. However, the CpcSU type lyase displays much higher specificity for PCB (the native bilin in these species) than PEB. Next, using a heterologous, co-expression system in E. coli, the PEB ligation activity of putative lyase subunits CpeY, CpeZ, and CpeS was tested on the CpeA and CpeB subunits from F. diplosiphon. CpeY/CpeZ was found to ligate PEB on CpeA, although CpeY alone had only 60% chromophorylation activity compared to CpeYZ together. Studies with site-directed variants of CpeA (C82S and C139S), revealed that CpeY/CpeZ attached PEB at Cys-82 on HT-CpeA. The CpeS bilin lyase ligated PEB at both Cys-82 and Cys-139 of CpeA, but the yield of attached PEB at Cys 82 was much lower than observed with CpeY or CpeY/CpeZ. However, CpeS efficiently attached PEB to Cys-82 of CpeB. Purified PE from cpeY deletion mutants in F. diplosiphon was found to have PCB added on α-PE instead of PEB, which was likely performed by CpcEF in vivo. However, a cpeZ knock-out mutant is affected in chromophorylation of both  and  subunits of PE with a red-shifted absorbance compared to wild type PE probably due to missing PEB on PE subunits. Next a new type of bilin lyase isomerase for PEII ( subunit) named MpeZ from Synechococcus sp. RS 9916, was analyzed using the E. coli heterologous coexpression system. MpeZ acted as bilin lyase/isomerase chromophorylating α-PEII (MpeA) with PUB on Cys 83.

Cyanobacteria are photosynthetic prokaryotes that able to produce oxygen. They have light harvesting complexes called phycobilisomes (PBS). PBS are generally composed of an allophycocyanin core with phycocyanin and phycoerythrin rods connected to the core. PBS are able to efficiently harvest light energy from different wavelengths of visible light due to the evolution of PBP. Phycoerythrin has five chromophores that are attached to six cysteine residues and is essential for efficient green light capture and transfer of energy for use in photosynthesis. The attachment of these chromophores to PBP is facilitated by enzymes known as bilin lyases. In this study, we characterize and explore the role of enzymes that are involved in the biosynthesis of phycoerythrin in cyanobacteria. Biochemical and molecular techniques were used in the characterization of these proteins to gain a better understanding of their roles in the post-translational modification of phycobiliprotein. In F. diplosipohon, the lyase activity of CpeT was characterized and studied using a heterologous, co-expression system in E. coli. It was determined that CpeT was able to ligate PEB to Cys-165 of CpeB in the presence of CpeZ, a chaperone-like protein. Next, the roles of three proteins, MpeY from RS9916 and MpeQ and MpeW from A15-62, were analyzed using a combination of gene-interruption mutants and recombinant protein expression techniques. The absence of mpeY resulted in the reduction of PEB chromophorylation of MpeA in green light conditions, and recombinant protein coexpression confirmed that MpeY was responsible for PEB attachment to Cys-83 of MpeA. The interruption of mpeQ in A15-62 resulted in a reduced PUB phenotype in MpeA in blue light. Recombinant protein expressions revealed that MpeQ was a lyase-isomerase responsible for the attachment of PUB to Cys-83 of MpeA. Two regulatory proteins located in two conserved configurations of a genomic island present in species that are able to change their phycobilin content in response to different light environments, known as Type-IV chromatic acclimation (CA4), were investigated. FciA and FciB from RS9916 were studied using gene interruption mutants from RS9916 and they were found to be responsible for the CA4 response in CA4-A containing species of Synechococcus.

NOBRE, Clareane Avelino Simplicio Nobre. Isolamento, purificação e caracterização parcial da estrutura primária de uma ficobiliproteína da alga marinha vermelha Hypnea musciformis (Wulfen) Lamouroux. 2015. 55 f. : Dissertação (mestrado) - Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Engenharia de Pesca, Fortaleza-CE, 2015 / Submitted by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-12T12:16:54Z No. of bitstreams: 1 2015_dis_casnobre.pdf: 1293747 bytes, checksum: ef415f9b1a75c524f87b2a6e87d52332 (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-07-12T12:17:27Z (GMT) No. of bitstreams: 1 2015_dis_casnobre.pdf: 1293747 bytes, checksum: ef415f9b1a75c524f87b2a6e87d52332 (MD5) / Made available in DSpace on 2016-07-12T12:17:27Z (GMT). No. of bitstreams: 1 2015_dis_casnobre.pdf: 1293747 bytes, checksum: ef415f9b1a75c524f87b2a6e87d52332 (MD5) Previous issue date: 2015 / Seaweeds are a rich reserve of substances with biotechnological interest, among these substances it is possible to highlight the phycobiliproteins. These molecules are water-soluble proteins covalently linked to pigments with linear tetrapyrrole structure called bilin, also known as accessory pigment. Thus, the phycobiliproteins form a complex named phycobilisomes, which is a primary structure of light-gathering, showing photosynthetic function. These structures are found in red and Cyanophyceae seaweed. Phycobiliproteins isolated and purified, when structuraly analised, present subunits characterized as alpha, beta and gamma. These proteins can be used as colorants and stabilizers for food, markers of biomolecules, antioxidants and anti-inflammatory agents. In view of the importance of these molecules, this work aimed to isolate, purify and determine the partial primary structure of the beta chain phycobiliprotein present in the red marine algae Hypnea musciformis. The phycobiliprotein (HMp) was isolated by precipitation of proteins with ammonium sulphate and purified by ion-exchange chromatography. The polyacrylamide gel electrophoresis revealed that the HMp has two chains around 20 kDa and 22 kDa. The 22 kDa chain was excised from the gel and digested with proteolytic enzyme trypsin. The peptides from digestion underwent fragmentation in mass spectrometer. The generated fragments were used for sequencing peptides and have identified in databases. Primers were designed to amplify the beta chain gene bhmp from the genomic DNA of the algae. The amplified gene was sequenced and the tool Phred/Phrap/Consed processed the raw data. The final gene sequence has been translated to obtain the partial primary structure of bHMp. The translation resulted in a sequence with 87 amino acid residues and HMp presented identity with various phycoerythrins of red algae. / As algas marinhas constituem uma rica reserva de substância de interesse biotecnológico, dentre essas substâncias podemos destacar as ficobiliproteínas. Essas moléculas são proteínas solúveis em água ligadas covalentemente a pigmentos com estrutura tetrapirrólica linear denominado bilina, também conhecido como pigmento acessório. Dessa forma, as ficobiliproteínas formam um complexo denominado ficobilissomos, que constitui uma estrutura primordial de captação de luz, apresentando função fotossintética. Essas estruturas são encontradas nas algas marinhas vermelhas e cianofíceas. Ficobiliproteínas isoladas e purificadas, quando caracterizadas, apresentaram subunidades estruturais, como subunidades alfa, beta e gama. Quanto a suas aplicações, essas proteínas foram utilizadas como corantes e estabilizantes de alimentos, marcadores de biomoléculas, agentes antioxidantes e anti-inflamatórios. Tendo em vista a importância destas moléculas, este trabalho teve como objetivo isolar, purificar e determinar a estrutura primária parcial da cadeia beta de uma ficobiliproteína presente na alga marinha vermelha Hypnea musciformis. A ficobiliproteína (HMp) foi isolada através da precipitação do extrato proteico com sulfato de amônio e purificada por cromatografia de troca iônica. A eletroforese em gel de poliacrilamida revelou que a HMp possui duas bandas proteicas em torno de 20 kDa e 22 kDa. A banda de 22 kDa foi excisada do gel e digerida com a enzima proteolítica tripsina. Os peptídeos oriundos da digestão foram submetidos à fragmentação em espectrômetro de massas. Os fragmentos gerados foram utilizados para sequenciar os peptídeos e estes na identificação de proteínas a partir dos bancos de dados existentes. A partir dessas informações, iniciadores foram desenhados para amplificar o gene da cadeia beta da ficobiliproteína de Hypnea musciformis (bhmp) a partir do DNA genômico da alga. O gene amplificado foi sequenciado e os dados brutos foram processados pela ferramenta Phred/Phrap/Consed. A sequência processada foi traduzida para obtenção da estrutura primária parcial de bhmp. A tradução resultou em uma sequência de 87 resíduos de aminoácidos e HMp apresentou identidade com diversas ficoeritrinas de algas vermelhas.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Seaweeds are a rich reserve of substances with biotechnological interest, among these substances it is possible to highlight the phycobiliproteins. These molecules are water-soluble proteins covalently linked to pigments with linear tetrapyrrole structure called bilin, also known as accessory pigment. Thus, the phycobiliproteins form a complex named phycobilisomes, which is a primary structure of light-gathering, showing photosynthetic function. These structures are found in red and Cyanophyceae seaweed. Phycobiliproteins isolated and purified, when structuraly analised, present subunits characterized as alpha, beta and gamma. These proteins can be used as colorants and stabilizers for food, markers of biomolecules, antioxidants and anti-inflammatory agents. In view of the importance of these molecules, this work aimed to isolate, purify and determine the partial primary structure of the beta chain phycobiliprotein present in the red marine algae Hypnea musciformis. The phycobiliprotein (HMp) was isolated by precipitation of proteins with ammonium sulphate and purified by ion-exchange chromatography. The polyacrylamide gel electrophoresis revealed that the HMp has two chains around 20 kDa and 22 kDa. The 22 kDa chain was excised from the gel and digested with proteolytic enzyme trypsin. The peptides from digestion underwent fragmentation in mass spectrometer. The generated fragments were used for sequencing peptides and have identified in databases. Primers were designed to amplify the beta chain gene bhmp from the genomic DNA of the algae. The amplified gene was sequenced and the tool Phred/Phrap/Consed processed the raw data. The final gene sequence has been translated to obtain the partial primary structure of bHMp. The translation resulted in a sequence with 87 amino acid residues and HMp presented identity with various phycoerythrins of red algae. / As algas marinhas constituem uma rica reserva de substÃncia de interesse biotecnolÃgico, dentre essas substÃncias podemos destacar as ficobiliproteÃnas. Essas molÃculas sÃo proteÃnas solÃveis em Ãgua ligadas covalentemente a pigmentos com estrutura tetrapirrÃlica linear denominado bilina, tambÃm conhecido como pigmento acessÃrio. Dessa forma, as ficobiliproteÃnas formam um complexo denominado ficobilissomos, que constitui uma estrutura primordial de captaÃÃo de luz, apresentando funÃÃo fotossintÃtica. Essas estruturas sÃo encontradas nas algas marinhas vermelhas e cianofÃceas. FicobiliproteÃnas isoladas e purificadas, quando caracterizadas, apresentaram subunidades estruturais, como subunidades alfa, beta e gama. Quanto a suas aplicaÃÃes, essas proteÃnas foram utilizadas como corantes e estabilizantes de alimentos, marcadores de biomolÃculas, agentes antioxidantes e anti-inflamatÃrios. Tendo em vista a importÃncia destas molÃculas, este trabalho teve como objetivo isolar, purificar e determinar a estrutura primÃria parcial da cadeia beta de uma ficobiliproteÃna presente na alga marinha vermelha Hypnea musciformis. A ficobiliproteÃna (HMp) foi isolada atravÃs da precipitaÃÃo do extrato proteico com sulfato de amÃnio e purificada por cromatografia de troca iÃnica. A eletroforese em gel de poliacrilamida revelou que a HMp possui duas bandas proteicas em torno de 20 kDa e 22 kDa. A banda de 22 kDa foi excisada do gel e digerida com a enzima proteolÃtica tripsina. Os peptÃdeos oriundos da digestÃo foram submetidos à fragmentaÃÃo em espectrÃmetro de massas. Os fragmentos gerados foram utilizados para sequenciar os peptÃdeos e estes na identificaÃÃo de proteÃnas a partir dos bancos de dados existentes. A partir dessas informaÃÃes, iniciadores foram desenhados para amplificar o gene da cadeia beta da ficobiliproteÃna de Hypnea musciformis (bhmp) a partir do DNA genÃmico da alga. O gene amplificado foi sequenciado e os dados brutos foram processados pela ferramenta Phred/Phrap/Consed. A sequÃncia processada foi traduzida para obtenÃÃo da estrutura primÃria parcial de bhmp. A traduÃÃo resultou em uma sequÃncia de 87 resÃduos de aminoÃcidos e HMp apresentou identidade com diversas ficoeritrinas de algas vermelhas.

Cyanobacteria are photosynthetic organisms that efficiently capture light by utilizing the light-harvesting complexes called phycobilisomes. In many cyanobacteria, phycobilisomes are composed of an allophycocyanin core with phycocyanin and phycoerythrin (PE) rods radiating from the core. These phycobiliproteins have multiple bilin chromophores, such as phycoerythrobilin (PEB), covalently attached to specific cysteine (Cys) residues for efficient photosynthetic light capture. Chromophore ligation on phycobiliprotein subunits occurs through bilin lyase catalyzed reactions. This study mainly focuses on characterizing the roles of enzymes that are involved in the biosynthetic pathway of the phycobiliproteins within two cyanobacteria Thermosynechococcus elongatus and Fremyella diplosiphon. A combination of molecular and biochemical techniques were used to better understand the roles of these proteins in the post-translational modification and/or stability of phycobiliproteins. Using a heterologous plasmid coexpression system in E. coli, recombinant CpcS-III from T. elongatus was shown to ligate three different bilins to both subunits of allophycocyanin and to the beta subunit of phycocyanin, thus, acting as a bilin lyase. The crystal structure of CpcS-III was also solved, the first bilin lyase structure. Next, the roles of three proteins from F. diplosiphon CpeY, CpeZ, and CpeF were analyzed using a combination of gene knock-out mutants and recombinant protein expression techniques. In the absence of cpeY, chromophorylation to the alpha subunit of PE at Cys-82 was reduced, coinciding with the recombinant data that CpeY is the lyase that attaches PEB to this site. Removing cpeZ from the genome resulted in the destabilization and reduced accumulation of PE, especially the beta subunit CpeB. Recombinant CpeZ was shown to act like a chaperone-like protein and increased the solubility and fluorescence of both recombinant and native CpeB by increasing the stability of the phycobiliprotein and/or by increasing the activities of other lyases. The deletion of cpeF resulted in a reduced-PE phenotype with the doubly attached PEB missing from CpeB at Cys-48/Cys-59. Recombinant CpeF was shown to ligate PEB to CpeB-Cys-48/Cys-59 in the presence of recombinant CpeS (lyase attaches PEB to CpeB-Cys-80) and CpeZ. CpeF also showed a chaperone-like function by stabilizing CpeB, but its main role appears to be as a bilin lyase.

Made available in DSpace on 2014-12-17T14:01:58Z (GMT). No. of bitstreams: 1 DinaelzaCP.pdf: 982597 bytes, checksum: 8505a456042640660a4eeec39570774f (MD5) Previous issue date: 2009-03-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The seaweed Gracilaria domingensis is a common species in the coast of Rio Grande do Norte. This species lives in the intertidal zone, where colour strains (red, green and brown) co-occur during the whole year. Seaweeds that live in this region are exposed to daily changes and to the rhythm of the tide. During the low tide they are exposed to dissection, hiper-or hipo-osmotic shock, high temperatures and high irradiance. The aim of this study was to analyze whether the pigment and protein content of the colour strains of G. domingensis is affected by some environmental parameters in a temporal scale. The seaweeds were collected during 10 months in the seashore of Rio do Fogo (RN). The total soluble proteins and the phycobiliprotein were extracted in phosphate buffer and the carotenoids were analyzed by a standardized method through HPLC-UV. The pigments analysis showed that phycoerithrin is the most abundant pigment in the three strains. This pigment was strongly correlated with nitrogen and the photosynthetically active radiation. Chlorophyll presented higher concentrations than carotenoids during the whole, but the ratio carotenoid/chlorophyll-a was modified by incident radiation. The most abundant carotenoid was ?-carotene and zeaxanthin, which had higher concentrations in the higher radiation months. The concentration increase of zeaxanthin in this period indicated a photoprotective response of the seaweed. The three strains presented a pigment profile that indicates different radiation tolerance profile. Our results pointed that the green strain is better adapted to high irradiance levels than the red and brown strains / A macroalga Gracilaria domingensis ? comumente encontrada no litoral do Rio Grande do Norte. Esta esp?cie habita a zona intertidal, onde linhagens crom?ticas (vermelha, verde e marrom) co-ocorrem durante todo o ano. Algas que vivem nesta regi?o est?o submetidas a mudan?as diurnas e ao ritmo da mar?. Durante a mar? baixa elas ficam expostas a disseca??o, choque hiper ou hipo-osm?tico, altas temperaturas e elevada irradi?ncia. Este trabalho teve como objetivo geral o estudo do perfil prot?ico e pigmentar das variantes crom?ticas de G. domingensis e a altera??o deste perfil em fun??o dos par?metros ambientais em uma escala temporal. As algas foram coletadas mensalmente, durante 10 meses, nas parias de Rio do Fogo-RN. As prote?nas totais sol?veis e as ficobiliprote?nas foram extra?das em tamp?o fosfato e os caroten?ides foram analisados em um m?todo padronizado por HPLC-UV. A an?lise dos pigmentos mostrou que a ficoeritrina ? o pigmento mais abundante nas tr?s linhagens. Este pigmento esteve fortemente correlacionado com o nitrog?nio e a PAR. Os pigmentos caroten?ides apresentaram concentra??es inferiores as da clorofila-a durante todos os meses, mas a raz?o caroten?ides/clorofila-a foi modificada com o aumento da radia??o. O caroten?ide mais abundante foi o ?-caroteno, seguido da zeaxantina, que esteve em maiores concentra??es nos meses de maior radia??o. O aumento na concentra??o da zeaxantina nesse per?odo indicou uma resposta fotoprotetora da alga. As tr?s linhagens apresentaram um perfil pigmentar que remete a diferentes padr?es de toler?ncia a radia??o. A linhagem verde mostrou ser melhor adaptada a elevados n?veis de irradi?ncias do que a vermelha e a marrom