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1.
J Chromatogr A ; 1605: 460365, 2019 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-31402108

RESUMO

The analysis of triacylglycerols and phospholipids - phosphatidylcholines allowed the use of shotgun lipidomics to identify very long-chain fatty acids and very long-chain polyunsaturated fatty acids in microalgae. These fatty acids were determined in triacylglycerols by positive electrospray ionization of neutral loss scans of different fatty acids, e.g. 24:0, 24:1ω9, 24:6ω3, 26:0, 26:1ω9, 28:0, 28:1ω9, 28:2ω6, and 28:8ω3. Likewise, very long-chain fatty acids in phosphatidylcholines were identified by negative electrospray ionization mass spectrometry in the selected ion-monitoring of the two most important ions (R1COO- and R2COO-). The limit of detection was determined at 10 nmol/L (∼11 pg/µL) in triacylglycerols and 8.6 nmoles/L (∼8 pg/µL) in phosphatidylcholines. The use of liquid chromatography-mass spectrometry is suitable for very long-chain polyunsaturated fatty acids with up to 8 double bonds due to the time of analysis as well as for reasons of lower thermal stability of polyunsaturated fatty acids towards saturated fatty acids, but gas chromatography-mass spectrometry is better suited for the analysis of saturated very long-chain fatty acids.


Assuntos
Bactérias/metabolismo , Ácidos Graxos/análise , Clorófitas/metabolismo , Ácidos Graxos Insaturados/análise , Cromatografia Gasosa-Espectrometria de Massas , Limite de Detecção , Fosfatidilcolinas/análise , Padrões de Referência , Triglicerídeos/análise
2.
Extremophiles ; 23(1): 35-48, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30284641

RESUMO

Genotypic and morphological diversity of cyanobacteria in the Rupite hot spring (Bulgaria) was investigated by means of optical microscopy, cultivation, single-cell PCR, and 16S rRNA gene amplicon sequencing. Altogether, 34 sites were investigated along the 71-39 °C temperature gradient. Analysis of samples from eight representative sites shown that Illumina, optical microscopy, and Roche 454 identified 72, 45 and 19% respective occurrences of all cumulatively present taxa. Optical microscopy failed to detect species of minor occurrence; whereas, amplicon sequencing technologies suffered from failed primer annealing and the presence of species with extensive extracellular polysaccharides production. Amplicon sequencing of the 16S rRNA gene V5-V6 region performed by Illumina identified the cyanobacteria most reliably to the generic level. Nevertheless, only the combined use of optical microscopy, cultivation and sequencing methods allowed for reliable estimate of the cyanobacterial diversity. Here, we show that Rupite hot-spring system hosts one of the richest cyanobacterial flora reported from a single site above 50 °C. Chlorogloeopsis sp. was the most abundant at the highest temperature (68 °C), followed by Leptolyngbya boryana, Thermoleptolyngbya albertanoae, Synechococcus bigranulatus, Oculatella sp., and Desertifilum sp. thriving above 60 °C, while Leptolyngbya geysericola, Geitlerinema splendidum, and Cyanobacterium aponinum were found above 50 °C.


Assuntos
Cianobactérias/genética , Fontes Termais/microbiologia , Microbiota , Cianobactérias/classificação , Cianobactérias/citologia , Cianobactérias/isolamento & purificação , RNA Ribossômico 16S/genética
3.
Int J Biol Macromol ; 121: 1254-1263, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30342124

RESUMO

Many microalgal species produce a wide range of highly-value products which are interesting for biotechnological applications. Cultivation of microalgal species Dictyosphaerium pulchellum and Dictyosphaerium tetrachotomum, strains Ruzicka and Fott resulted yields of 0.2, 0.7 and 1.8 g/L of extracellular biopolymers (EPSs), respectively. All biopolymers were shown to be anionic proteoglycans. The sugar composition analyses of all EPSs showed high contents of hexoses and the presence of partially methylated monosaccharide residues, i.e. hexoses, and deoxy hexoses. The dominant sugar component of all EPSs was found to be galactose. Extracellular microalgal biopolymers were subjected to immunobiological and immunotoxicological evaluation using murine melanoma cancer cells B16, murine fibroblast cell line NIH-3T3, murine macrophages cell line RAW 264.7 and skin construct EpiDerm™ (EPI-200). The EPSs exerted the antiproliferative effectivity; treatment of EPS induced proinflammatory cytokines TNF-α, IL-6, IL-12, IL-1ß and IL-17, also engaged in anti-cancer immunity. Immunotoxicological studies revealed their non-toxic character and safe application on EpiDerm™.


Assuntos
Biopolímeros/química , Biopolímeros/farmacologia , Clorófitas/química , Espaço Extracelular/química , Fatores Imunológicos/química , Fatores Imunológicos/farmacologia , Animais , Biopolímeros/toxicidade , Fatores Imunológicos/toxicidade , Camundongos , Microalgas/química , Células NIH 3T3 , Células RAW 264.7 , Pele/efeitos dos fármacos
4.
Carbohydr Polym ; 198: 215-224, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30092993

RESUMO

Microalgae occupy all territories and their products represent a rich source of phytochemicals for human being. Green microalga Dictyosphaerium chlorelloides was found to be a significant producer of the extracellular biopolymer. Dominant components of the biopolymer were found to be Gal (39 wt%) with its methyl derivatives (15 wt%), Rha (19 wt%) and Man (14 wt%). 2-OMe-Gal was found to be the major derivative while other sugars, namely 3-OMe-, 6-OMe- and 2,3-di-OMe-Gal, 3-OMe-Glc and 4-OMe-Xyl were in smaller amounts. NMR spectroscopy revealed complex structure with galactan backbone branched by sugars in furano and pyrano forms in alpha and beta configurations. NMR data of 2-OMe, 3-OMe, 2,3-OMe and 6-OMe galactoses afforded characteristic values for O-methyls in each position. Biopolymer antitussive effect was similar to that of centrally acting antitussive drugs, indicating its relatively good antitussive potential.


Assuntos
Biopolímeros/análise , Clorófitas/metabolismo , Resistência das Vias Respiratórias/efeitos dos fármacos , Animais , Antitussígenos/farmacologia , Biopolímeros/química , Biopolímeros/metabolismo , Biopolímeros/farmacologia , Tosse/tratamento farmacológico , Cobaias , Espectroscopia de Ressonância Magnética , Masculino , Peso Molecular
6.
Lipids ; 53(4): 413-427, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29709080

RESUMO

Freshwater bryozoan Pectinatella magnifica was collected from a sand pit (South Bohemia). The total lipids after extraction from lyophilized bryozoans were analyzed using high-performance liquid chromatography/high-resolution negative tandem electrospray mass spectrometry. A total of 19 lipid classes were identified, including N-acyl-substituted phospholipids, that is, N-acylphosphatidylethanolamine and N-acylphosphatidylserine in their plasmenyl forms. Based on gas chromatography/mass spectrometry of 3-pyridylcarbonyl (picolinyl) esters, a very unusual fatty acid was identified, namely 24:7n-3 (all-cis-3,6,9,12,15,18,21-tetracosaheptaenoic acid). The presence of polyunsaturated fatty acids in individual classes is very specific: arachidonic and eicosapentaenoic acids being predominantly bound as amides in N-acyl phospholipids, that is, diacyl-N-acylphosphatidylethanolamines (NAPtdEtn), plasmenyl-N-acylphosphatidyl ethanolamines (PlsNAPtdEtn), diacyl-N-acylphosphatidylserines (NAPtdSer), and plasmenyl-N-acylphosphatidylserines (PlsNAPtdSer). While 24:6n-3 was identified in the sn-2 position of several phospholipids, 24:7n-3 was identified in only two plasmalogens, that is, PlsNAPtdEtn and PlsNAPtdSer. Thanks to the tandem mass spectrometry, we managed to identify the position of all acyl groups in both diacyl- and also in alkenyl-acyl-(plasmenyl) molecular species of N-acylphospholipids. The identification of the molecular species of N-acyl-substituted phosphatidylethanolamine and phosphatidylserine, including their plasmalogen forms, in the freshwater bryozoan P. magnifica has enabled the identification of endogenous cannabinoid precursors.


Assuntos
Briozoários/química , Endocanabinoides/análise , Endocanabinoides/química , Animais , Cromatografia Líquida de Alta Pressão , Água Doce , Espectrometria de Massas em Tandem
8.
Phytochemistry ; 148: 29-38, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29366853

RESUMO

Very long chain fatty acids (VLCFAs) were identified in four strains of the green alga Botryococcus braunii (Trebouxiophyceae). The algae contained a series of monoenoic fatty acids up to triacontenoic acid and further VLCFAs in amounts around 1% of total fatty acids. The separation of lipid classes using hydrophilic interaction chromatography revealed that the most abundant VLCFAs (28:2, 28:1 and 28:0) were contained in neutral lipids (triacylglycerols and/or diacylglycerols) and in phospholipids (phosphatidic acid and/or phosphatidylcholine). Using non-aqueous reversed-phase liquid chromatography tandem mass spectrometry (NARP-LC/MS2) of the appropriate collected fractions, molecular species of triacylglycerols containing one or two VLCFAs were described and phosphatidylcholines containing VLCFAs were separated for the first time. Because the presence of Botryosphaerella sudetica (Chlorophyceae) as contaminant of Botryococcus braunii strain Droop 1950/807-1 placed some doubts on the results of previous studies, a strain of this green alga of was also analyzed. In contrast to Botryococcus, C16, a substantially lower proportion of C18 polyunsaturated fatty acids and no VLCFAs were detected in Botryosphaerella.


Assuntos
Clorófitas/química , Ácidos Graxos/análise , Fosfolipídeos/análise , Cromatografia Líquida , Ácidos Graxos Insaturados/química
9.
Int J Biol Macromol ; 103: 863-869, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28528945

RESUMO

Microalgae organisms are of interest for many biotechnology applications due to the production of a wide range of biologically active compounds. Incubation of Wollea saccata in a large scale afforded a mucilaginous, high molecular weight biopolymer composed of carbohydrate, protein and phenolic compounds. Sugar moiety was rich in hexoses (60%) and 6-deoxyhexoses (31%), while only 9% of pentoses was identified. Methylation analysis revealed about 40 types of methylated sugar derivatives, suggesting a very complex structure of Wollea biopolymer. Pharmacological studies revealed new pharmacodynamic properties of cyanobacteria biopolymer, i.e. antitussive and bronchodilatory. Biopolymer was able to suppress the cough reflex induced by chemical tussigen, but its effect was lower than that of codeine, the strongest antitussive agent. The bronchodilatory effect was similar or higher than the effect of salbutamol, a bronchodilatory drug used in a clinical practice. In pharmacological studies, there were no signs of toxicity or side effects in the animals following administration of Wollea biopolymer.


Assuntos
Biopolímeros/química , Biopolímeros/farmacologia , Cianobactérias/citologia , Espaço Extracelular/química , Animais , Antitussígenos/química , Antitussígenos/farmacologia , Broncodilatadores/química , Broncodilatadores/farmacologia , Cobaias , Masculino
10.
Phytochemistry ; 139: 88-97, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28433954

RESUMO

This study describes the identification of very long chain polyunsaturated fatty acids (VLCPUFAs) in three strains of dinoflagellates (Amphidinium carterae, Cystodinium sp., and Peridinium aciculiferum). The strains were cultivated and their lipidomic profiles were obtained by high resolution mass spectrometry with the aid of positive and negative electrospray ionization (ESI) mode by Orbitrap apparatus. Hydrophilic interaction liquid chromatography (HILIC/ESI) was used to separate major lipid classes of the three genera of dinoflagellates by neutral loss scan showing the ion [M + H-28:8]+, where 28:8 was octacosaoctaenoic acid, and by precursor ion scanning of ions at m/z 407, which was an ion corresponding to the structure of acyl of 28:8 acid (C27H39COO-). Based on these analyzes, it was found that out of more than a dozen lipid classes present in the total lipids, only two classes of neutral lipids, i.e. major triacylglycerols and minor diacylglycerols contain VLCPUFAs. In polar lipids, VLCPUFAs were identified only in phosphatidic acid (PA) and phosphatidyl choline (PC) or in their lyso-forms (LPA and LPC). Further analysis of individual lipid classes by reversed-phase high-performance liquid chromatography (RP-HPLC) showed the presence of triacylglycerols (TAGs) containing VLCPUFAs, i.e. molecular species of the sn-28:7/28:8/28:8, sn-26:7/28:7/28:8, or sn-26:7/28:8/28:8 types. These TAGs are the longest and most unsaturated TAGs isolated from a natural source that have yet been synthesized. In the case of PA and PC, tandem MS identified sn-28:8/16:0-PA and sn-28:8/16:0-PC and the corresponding lyso-forms (28:8-LPC and 28:8-LPA). All these results indicate that TAGs containing VLCPUFAs are biosynthesized in dinoflagellates in the same manner as in higher eukaryotic organisms, which means that the PA, after conversion to DAG, serves as a precursor in the biosynthesis of other phospholipids, e.g. PC, and, after further acylation, also of TAG.


Assuntos
Dinoflagelados/química , Ácidos Graxos Insaturados/isolamento & purificação , Cromatografia Líquida/métodos , Cromatografia de Fase Reversa , Ácidos Graxos Insaturados/química , Interações Hidrofóbicas e Hidrofílicas , Morfinanos , Fosfatidilcolinas/análise , Fosfolipídeos , Quinolinas
11.
PLoS One ; 10(3): e0120768, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25789995

RESUMO

Trebouxia aggregata (Archibald) Gärtner (phylum Chlorophyta, family Trebouxiaceae), a lichen symbiotic alga, has been identified as host of the well-known herbaceous plant virus Cauliflower mosaic virus (CaMV, family Caulimoviridae). The alga had been isolated from Xanthoria parietina more than 70 years ago and has been maintained in a collection since that time. The CaMV detected in this collection entry has now been completely sequenced. The virus from T. aggregata is mechanically transmissible to a herbaceous host and induces disease symptoms there. Its genome differs by 173 nt from the closest European CaMV-D/H isolate from cauliflower. No site under positive selection was found on the CaMV genome from T. aggregata. We therefore assume that the virus's presence in this alga was not sufficiently long to fix any specific changes in its genome. Apart from this symbiotic alga, CaMV capsid protein sequences were amplified from many other non-symbiotic algae species maintained in a collection (e.g., Oonephris obesa, Elliptochloris sp., Microthamnion kuetzingianum, Chlorella vulgaris, Pseudococcomyxa sp.). CaMV-free Chlorella vulgaris was treated with CaMV to establish virus infection. The virus was still detected there after five passages. The virus infection is morphologically symptomless on Chlorella algae and the photosynthesis activity is slightly decreased in comparison to CaMV-free alga culture. This is the first proof as to the natural presence of CaMV in algae and the first demonstration of algae being artificially infected with this virus.


Assuntos
Caulimovirus/genética , Clorófitas/virologia , Aniversários e Eventos Especiais , Sequência de Bases , Caulimovirus/classificação , Caulimovirus/isolamento & purificação , DNA Viral/química , DNA Viral/isolamento & purificação , Ouro/química , Microscopia Eletrônica , Dados de Sequência Molecular , Alinhamento de Sequência
12.
Phytochemistry ; 110: 37-45, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25564261

RESUMO

This study describes the identification of regioisomers and enantiomers of triacylglycerols of C20 polyunsaturated fatty acids (PUFAs) in the alga Trachydiscus minutus cultivated at different temperatures using reversed- and chiral-phase liquid chromatography-mass spectrometry. The use of the two different phases contributes to ready identification, both qualitative and semiquantitative, of regioisomers and enantiomers of triacylglycerols containing eicosapentaenoic and arachidonic in the molecule. The ratio of regioisomers and enantiomers of triacylglycerols (TAG) depends on the temperature of cultivation; with lowering temperature the proportion of the achiral TAG increases and the enantiomer ratio diverges from 1:1.


Assuntos
Ácidos Graxos Insaturados/análise , Estramenópilas/química , Triglicerídeos/isolamento & purificação , Estereoisomerismo , Temperatura Ambiente , Triglicerídeos/química , Triglicerídeos/metabolismo
13.
Phytochemistry ; 104: 95-104, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24833034

RESUMO

Structured triacylglycerols (TAGs) were isolated from nine cultivated strains of microalgae belonging to different taxonomic groups, i.e. Audouinella eugena, Balbiania investiens, Myrmecia bisecta, Nannochloropsis limnetica, Palmodictyon varium, Phaeodactylum tricornutum, Pseudochantransia sp., Thorea ramosissima, and Trachydiscus minutus. They were separated and isolated by means of NARP-LC/MS-APCI and chiral LC and the positional isomers and enantiomers of TAGs with two polyunsaturated, i.e. arachidonic (A) and eicosapentaenoic (E) acids and one saturated, i.e. palmitic acid (P) were identified. Algae that produce eicosapentaenoic acid were found to biosynthesize more asymmetrical TAGs, i.e. PPE or PEE, whereas algae which produced arachidonic acid give rise to symmetrical TAGs, i.e. PAP or APA, irrespective of their taxonomical classification. Nitrogen and phosphorus starvation consistently reversed the ratio of asymmetrical and symmetrical TAGs.


Assuntos
Clorófitas/química , Microalgas/química , Rodófitas/química , Estramenópilas/química , Triglicerídeos/metabolismo , Ácido Araquidônico/metabolismo , Ácido Eicosapentaenoico/metabolismo , Ácidos Graxos/análise , Ácidos Graxos/isolamento & purificação , Ácidos Graxos/metabolismo , Nitrogênio/metabolismo , Fósforo/metabolismo , Triglicerídeos/análise , Triglicerídeos/isolamento & purificação
14.
Phytochemistry ; 80: 17-27, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22704815

RESUMO

The diatom Phaeodactylum tricornutum was cultivated in a standard medium and under sulfur, silicon, nitrogen and phosphorus starvation and its triacylglycerols (TAGs) were analyzed by RP-HPLC/MS-APCI. Nearly 100 molecular species of polyunsaturated TAGs were identified. RP-HPLC was used to isolate positional isomers of TAGs, which were further separated by chiral HPLC. First eluted were those TAGs that have an eicosapentaenoic acid moiety in the sn-1 position. The ratios of symmetrical to asymmetrical TAGs in P. tricornutum were affected under sulfur-, nitrogen-, phosphorus- and silica-starvation, i.e. in cultivations involving cells in nutrient stress. The ratios of positional TAGs and also the proportions of enantiomers were changed. The ratios of symmetrical to asymmetrical TAGs in the control and under N- and P-starvation were very close. In the control, the ratio of 1,2-dipalmitoyl-3-eicosapentaenoyl-rac-glycerol to 1,3-dipalmitoyl-2-eicosapentaenoyl-rac-glycerol was 3:1 and the ratio of 1,2-dieicosapentaenoyl-3-palmitoyl-rac-glycerol to 1,3-dieicosapentaenoyl-2-palmitoyl-rac-glycerol was 9:1. Under N-starvation the ratios were reversed irrespective of the presence or absence of silicate in the medium. A similar pattern was found in P- and S-starvation.


Assuntos
Meios de Cultura/química , Diatomáceas/crescimento & desenvolvimento , Diatomáceas/metabolismo , Triglicerídeos/química , Triglicerídeos/metabolismo , Ácido Eicosapentaenoico/metabolismo , Estereoisomerismo
15.
Phytochemistry ; 78: 147-55, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22445652

RESUMO

Reversed phase liquid chromatography-atmospheric pressure chemical ionization mass spectrometry (RP-HPLC/APCI-MS) was used for direct analysis of triacylglycerols (TAGs) from different strains of the cyanobacteria Mastigocladus laminosus, Tolypothrix cf. tenuis and Tolypothrix distorta. This technique enabled us to identify and quantify the specific molecular species of TAGs directly from lipid extracts of the cyanobacteria. The regioisomeric series of TAGs having α-linolenic and γ-linolenic and also oleic and cis-vaccenic acids were separated by RP-HPLC and identified by APCI-MS. M. laminosus produced only a few molecular species of TAGs, including both isomers of octadecenoic (oleic and vaccenic) acid, while T. distorta contained tens of molecular species of TAGs having FAs with up to four double bonds (stearidonic acid and including also its positional isomer, i.e. 3,6,9,12-octadecatetraenoic acid) and both positional isomers (α and γ) of linolenic acids. Individual strains of both cyanobacteria exhibited different contents of polyunsaturated fatty acids (Tolypothrix sp.) and different distribution of positional isomers of monoenoic fatty acids in TAGs (M. laminosus).


Assuntos
Cianobactérias/química , Ácidos Oleicos/análise , Triglicerídeos/análise , Ácido gama-Linolênico/análise , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia Gasosa-Espectrometria de Massas , Isomerismo , Estrutura Molecular
16.
J Phycol ; 48(1): 231-42, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27009667

RESUMO

The traditional order Mischococcales (Xanthophyceae) is polyphyletic with some original members now classified in a separate class, Eustigmatophyceae. However, most mischococcalean species have not yet been studied in detail, raising the possibility that many of them still remain misplaced. We established an algal culture (strain CCALA 838) determined as one such species, Trachydiscus minutus (Bourr.) H. Ettl, and studied the morphology, ultrastructure, life cycle, pigment composition, and phylogeny using the 18S rRNA gene. We discovered a zoosporic part of the life cycle of this alga. Zoospore production was induced by darkness, suppressed by light, and was temperature dependent. The zoospores possessed one flagellum covered with mastigonemes and exhibited a basal swelling, but a stigma was missing. Ultrastructural investigations of vegetative cells revealed plastids lacking both a connection to the nuclear envelope and a girdle lamella. Moreover, we described biogenesis of oil bodies on the ultrastructural level. Photosynthetic pigments of T. minutus included as the major carotenoids violaxanthin and vaucheriaxanthin (ester); we detected no chl c. An 18S rRNA gene-based phylogenetic analysis placed T. minutus in a clade with species of the genus Pseudostaurastrum and with Goniochloris sculpta Geitler, which form a sister branch to initially studied Eustigmatophyceae. In summary, our results are inconsistent with classifying T. minutus as a xanthophycean and indicate that it is a member of a novel deep lineage of the class Eustigmatophyceae.

17.
Phytochemistry ; 72(18): 2342-51, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21911235

RESUMO

The yellow-green alga Trachydiscus minutus (Eustigmatophyceae, Heterocontophyta) was cultivated in a standard medium and under nitrogen- and phosphorus-starvation and its triacylglycerols were analyzed by RP-HPLC/MS-APCI. The molecular species of triacylglycerols included a total of 74 triacylglycerols having at least one polyunsaturated fatty acid. Polyunsaturated triacylglycerols were identified for the first time in a yellow-green alga. N-starvation brought about a nearly 50% drop in TAGs containing EPA, and also decreased TAGs containing ARA, while P-starvation had a sizable effect on those TAGs that contain two or three arachidonic acids. In four TAGs containing PUFA, i.e. EEE, EEA, EAA and AAA, N-starvation caused a rapid fivefold increase in ARA content and the ratio of TAGs containing ARA, i.e. AEE to AAA increased tenfold relative to control. Regioisomeric characterization of triacylglycerols containing palmitic, arachidonic (ARA) and eicosapentaenoic acids (EPA) showed that the proportion of positional isomers is affected by N- and P-starvation. N- and P-starvation also changed the ratio of symmetrical to asymmetrical TAGs. Positional isomers exhibited identical ratios of symmetrical and asymmetrical TAGs irrespective of the type of FAs. In control cultivation the major TAGs with a single PUFA were symmetrical ones (PEP or PAP) whose ratio to asymmetrical counterparts (PPE or PPA) was about 3:1, whereas N- and P-starvation yielded opposite ratios, 1:3-1:5. The control cultivation yielded ~90% asymmetrical TAGs with two PUFAs (i.e. PEE and PAA), whereas with N- and P-starvation the ratio of symmetrical to asymmetrical TAGs increased to 2:1 and 3:2, respectively.


Assuntos
Nitrogênio , Fósforo , Estramenópilas/metabolismo , Triglicerídeos/metabolismo , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Triglicerídeos/química
18.
Z Naturforsch C J Biosci ; 66(5-6): 267-76, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21812344

RESUMO

Fatty acids of twelve species of cyanobacteria grown under different photoautotrophic conditions were studied and their composition was compared with literature data of many other species. We have come to the conclusion that the lipids of cyanobacteria do not contain fatty acids with a chain longer than 18 carbon atoms. In our opinion, omission of an analytical procedure, i.e. purification of fatty acid methyl esters before gas chromatography, leads to incorrect interpretation of the results. Absence or presence of fatty acids was suggested as a useful taxonomic marker and a proper diagnostic indicator in the commercial application of cyanobacterial biomass.


Assuntos
Cianobactérias/química , Ácidos Graxos/análise , Lipídeos/química , Biomassa , Cromatografia Gasosa , Ácidos Graxos/química
19.
Environ Toxicol ; 26(4): 345-58, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20082446

RESUMO

Extensive selection of cyanobacterial strains (82 isolates) belonging to the genus Nostoc, isolated from different climatic regions and habitats, were screened for both their secondary metabolite content and their cytotoxic effects to mammalian cell lines. The overall occurrence of cytotoxicity was found to be 33%, which corresponds with previously published data. However, the frequency differs significantly among strains, which originate from different climatic regions and microsites (particular localities). A large fraction of intensely cytotoxic strains were found among symbiotic strains (60%) and temperate and continental climatic isolates (45%); compared with the less significant incidences in strains originating from cold regions (36%), deserts (14%), and tropical habitats (9%). The cytotoxic strains were not randomly distributed; microsites that clearly had a higher occurrence of cytotoxicity were observed. Apparently, certain natural conditions lead to the selection of cytotoxic strains, resulting in a high cytotoxicity occurrence, and vice versa. Moreover, in strains isolated from a particular microsite, the cytotoxic effects were caused by different compounds. This result supports our hypothesis for the environmental dependence of cytotoxicity. It also contradicts the hypothesis that clonality and lateral gene transfer could be the reason for this phenomenon. Enormous variability in the secondary metabolites was detected within the studied Nostoc extracts. According to their molecular masses, only 26% of these corresponded to any known structures; thus, pointing to the high potential for the use of many terrestrial cyanobacteria in both pharmacology and biotechnology.


Assuntos
Clima , Citotoxinas/metabolismo , Nostoc/metabolismo , Ecossistema , Nostoc/classificação , Nostoc/genética , Filogenia , Microbiologia do Solo , Especificidade da Espécie , Simbiose
20.
Cryo Letters ; 29(1): 27-8, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18392286

RESUMO

Polar isolates of four chlorococcal microalgae originating from the Arctic and Antarctica withstand cryopreservation using encapsulation-dehydration. Viability assessments, which initially used chloroplhyll fluorescence (Kautsky) induction kinetics, revealed that all strains suffered photosynthetic impairment during early post-cryopreservation recovery. This cryoinjury was reversible, as indicated by cell regrowth in three of the four strains. Lack of growth in the fourth isolate was due to contaminating bacteria rather than cryogenic factors.


Assuntos
Clima Frio , Criopreservação/métodos , Eucariotos
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