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1.
Mycorrhiza ; 30(1): 63-77, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32062707

RESUMO

Arbuscular mycorrhizal (AM) fungi establish symbiotic associations with many plant species, transferring significant amounts of soil nutrients such as phosphorus to plants and receiving photosynthetically fixed carbon in return. Functioning of AM symbiosis is thus based on interaction between two living partners. The importance of dead AM fungal biomass (necromass) in ecosystem processes remains unclear. Here, we applied either living biomass or necromass (0.0004 potting substrate weight percent) of monoxenically produced AM fungus (Rhizophagus irregularis) into previously sterilized potting substrate planted with Andropogon gerardii. Plant biomass production significantly improved in both treatments as compared to non-amended controls. Living AM fungus, in contrast to the necromass, specifically improved plant acquisition of nutrients normally supplied to the plants by AM fungal networks, such as phosphorus and zinc. There was, however, no difference between the two amendment treatments with respect to plant uptake of other nutrients such as nitrogen and/or magnesium, indicating that the effect on plants of the AM fungal necromass was not primarily nutritional. Plant growth stimulation by the necromass could thus be either due to AM fungal metabolites directly affecting the plants, indirectly due to changes in soil/root microbiomes or due to physicochemical modifications of the potting substrate. In the necromass, we identified several potentially bioactive molecules. We also provide experimental evidence for significant differences in underground microbiomes depending on the amendment with living or dead AM fungal biomass. This research thus provides the first glimpse into possible mechanisms responsible for observed plant growth stimulation by the AM fungal necromass.


Assuntos
Andropogon , Glomeromycota , Micorrizas , Biomassa , Raízes de Plantas , Simbiose
2.
Microorganisms ; 7(10)2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31658718

RESUMO

Slowly melting snowfields in mountain and polar regions are habitats of snow algae. Orange blooms were sampled in three European mountain ranges. The cysts within the blooms morphologically resembled those of Chloromonas nivalis (Chlorophyceae). Molecular and morphological traits of field and cultured material showed that they represent a new species, Chloromonas hindakii sp. nov. The performance of photosystem II was evaluated by fluorometry. For the first time for a snow alga, cyst stages collected in a wide altitudinal gradient and the laboratory strain were compared. The results showed that cysts were well adapted to medium and high irradiance. Cysts from high light conditions became photoinhibited at three times higher irradiances (600 µmol photons m-2 s-1) than those from low light conditions, or likewise compared to cultured flagellates. Therefore, the physiologic light preferences reflected the conditions in the original habitat. A high content of polyunsaturated fatty acids (about 60% of total lipids) and the accumulation of the carotenoid astaxanthin was observed. They are regarded as adaptations to cope with extreme environmental conditions of snow that include low temperatures, freeze-thaw cycles, and variable light intensity. The intraspecific ability of adaptation of the photosynthetic apparatus to different irradiance regimes seems to be advantageous for thriving in different snow habitats.

3.
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
4.
Phytochemistry ; 164: 243-251, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31128818

RESUMO

Lipid-like compounds containing a dimethylarsinoyl group, i.e. Me2As(O)-, have been identified by liquid chromatography/inductively coupled plasma mass spectrometry (LC/ICP-MS) and non-aqueous reversed-phase high-performance liquid chromatography (positive and/or negative high-resolution tandem electrospray ionization mass spectrometry (NARP-HPLC/HR-ESI+(-)-MS/MS) from three strains of green algae of the genus Coccomyxa (Trebouxiophyceae, Chlorophyta). The algae were cultivated in a medium containing 10 g arsenic/L, i.e. 133.5 mmol/L of Na2HAsO4.7H2O. After extraction by methyl-tert-butyl ether (MTBE), total lipids were analyzed by ICP-MS or ESI-MS without any further separation or fractionation. A total of 39 molecular species of arsenic triacylglycerols (AsTAG), 15 arsenic phosphatidylcholines (AsPC), 8 arsenic phosphatidylethanolamines (AsPE), 6 arsenic phosphatidylinositols (AsPI), 2 arsenic phosphatidylglycerols (AsPG) and 5 unknown lipids (probably ceramides) were identified. The structures of all molecular species were confirmed by tandem MS. Dry matter of the individual strains contained different amounts of total arsenolipids, i.e. C. elongata CCALA 427 (0.32 mg/g), C. onubensis (1.48 mg/g), C. elongata S3 (2.13 mg/g). On the other hand, there were only slight differences between strains in the relative abundances of individual molecular species. Possible biosynthesis of long-chain lipids with the end group Me2As(O) has also been suggested.


Assuntos
Arsenicais/isolamento & purificação , Chlorella/química , Lipídeos/isolamento & purificação , Arsenicais/química , Arsenicais/metabolismo , Chlorella/metabolismo , Lipídeos/química , Estrutura Molecular
5.
Lipids ; 54(2-3): 177-187, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30843230

RESUMO

Four bacterial isolates, which produced polyunsaturated fatty acids (PUFA), were isolated from water samples of radioactive springs collected from Jáchymov spa. Jáchymov (Sankt Joachimsthal) is a city in northwestern Bohemia, where Marie and Pierre Curie isolated radium in 1898 from the mineral uraninite. To date, four springs (Agricola, Behounek, C1, and Curie) have been used for spa purposes, that is for the treatment of nervous and rheumatic disorders by constantly produced radioactive gas radon (222 Rn) dissolved in the water. The radioactivity reaches 24 kBq/L. Using 16S rRNA gene sequence analysis, all four isolates were identified as members of the genus Kocuria, with two isolates designated 208 and 401 affiliated with Kocuria kristinae, while isolates 101 and 301 most likely with K. rhizophila. The content of fatty acids in polar lipids was determined by gas chromatography-mass spectrometry (GC-MS) and two PUFA, that is arachidonic and eicosapentaenoic, were identified. The position of double bonds was confirmed by GC-MS of 3-pyridylcarbinol (formerly picolinyl) esters. We assume that all four isolates of Kocuria produce PUFA to increase the stability of cell membranes, which may be impaired by the reaction of the reactive oxygen species. These can arise, for example, because of α radiation during 222 Rn decay.


Assuntos
Ácidos Graxos Insaturados/metabolismo , Micrococcaceae/genética , Micrococcaceae/isolamento & purificação , Composição de Bases , Micrococcaceae/metabolismo , Nascentes Naturais/microbiologia , RNA Ribossômico 16S/genética , Microbiologia da Água
6.
Lipids ; 53(6): 627-639, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-30206958

RESUMO

Mass spectrometry-based shotgun lipidomics was applied to the analysis of sphingolipids of 11 yeast strains belonging to four genera, that is Cryptococcus, Saccharomyces, Schizosaccharomyces, and Wickerhamomyces. The analysis yielded comprehensive results on both qualitative and quantitative representation of complex sphingolipids of three classes-phosphoinositol ceramide (PtdInsCer), mannosyl inositol phosphoceramide (MInsPCer), and mannosyl diinositol phosphoceramide (M(InsP)2 Cer). In total, nearly 150 molecular species of complex sphingolipids were identified. Individual strains were cultured at five different temperatures, that is 5, 10, 20, 30, and 40 °C (Wickerhamomyces genus only up to 30 °C), and the change in the culture temperature was found to affect the representation of both the sphingolipid classes and the length of the long-chain bases (LCB). Individual classes of sphingolipids differing in polar heads differed in the temperature response. The relative content of PtdInsCer increased with increasing temperature, whereas that of M(InsP)2 Cer decreased. Molecular species having C18-LCB were associated with low cultivation temperature, and a higher proportion of C20-LCB molecular species was produced at higher temperatures regardless of the type of polar head. On the other hand, the influence of temperature on the representation of very long-chain fatty acids (VLCFA) was less noticeable, the effect of the taxonomic affiliation of the strains being more pronounced than the cultivation temperature. For example, lignoceric and 2-hydrocylo-lignoceric acids were characteristic of the genera Cryptococcus and Schizosaccharomyces, and of Saccharomyces genus cultivated at high temperatures.


Assuntos
Saccharomyces cerevisiae/química , Esfingolipídeos/análise , Temperatura Ambiente , Estabilidade Proteica
7.
Folia Microbiol (Praha) ; 63(5): 569-579, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29926340

RESUMO

Cyanobacteria are one of the most successful and oldest forms of life that are present on Earth. They are prokaryotic photoautotrophic microorganisms that colonize so diverse environments as soil, seawater, and freshwater, but also stones, plants, or extreme habitats such as snow and ice as well as hot springs. This diversity in the type of environment they live in requires a successful adaptation to completely different conditions. For this reason, cyanobacteria form a wide range of different secondary metabolites. In particular, the cyanobacteria living in both freshwater and sea produce many metabolites that have biological activity. In this review, we focus on metabolites called siderophores, which are low molecular weight chemical compounds specifically binding iron ions. They have a relatively low molecular weight and are produced by bacteria and also by fungi. The main role of siderophores is to obtain iron from the environment and to create a soluble complex available to microbial cells. Siderophores play an important role in microbial ecology; for example, in agriculture they support the growth of many plants and increase their production by increasing the availability of Fe in plants. The aim of this review is to demonstrate the modern use of physico-chemical methods for the detection of siderophores in cyanobacteria and the use of these methods for the detection and characterization of the siderophore-producing microorganisms. Using high-performance liquid chromatography-mass spectrometry (LC-MS), it is possible not only to discover new chemical structures but also to identify potential interactions between microorganisms. Based on tandem mass spectrometry (MS/MS) analyses, previous siderophore knowledge can be used to interpret MS/MS data to examine both known and new siderophores.


Assuntos
Cianobactérias/metabolismo , Sideróforos/química , Sideróforos/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Ferro/metabolismo , Estrutura Molecular , Processos Fotoquímicos , Água do Mar/microbiologia , Sideróforos/metabolismo , Espectrometria de Massas em Tandem
8.
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
9.
Eur J Phycol ; 53(2): 230-243, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29755214

RESUMO

Based on analyses of multiple molecular markers (18S rDNA, ITS1, ITS2 rDNA, rbcL), an alga that causes red snow on the melting ice cover of a high-alpine lake in the High Tatras (Slovakia) was shown to be identical with Chlainomonas sp. growing in a similar habitat in the Tyrolean Alps (Austria). Both populations consisted mostly of smooth-walled quadriflagellates. They occurred in slush, and shared similar photosynthetic performances (photoinhibition above 1300 µmol photons m-2 s-1), very high levels of polyunsaturated fatty acids (PUFA, 64% and 74% respectively) and abundant astaxanthin accumulation, comparable to the red spores of Chlamydomonas nivalis (Bauer) Wille. Physiological differences between the Slovak and Austrian populations included higher levels of α-tocopherol and a 13Z-isomer of astaxanthin in the former. High accumulation of secondary pigments in the Slovak population probably reflected harsher environmental conditions, since the collection was made later in the growing season when cells were exposed to higher irradiance at the surface. Using a polyphasic approach, we compared Chlainomonas sp. with Chlamydomonas nivalis. The latter causes 'conventional' red snow, and shows high photophysiological plasticity, with high efficiency under low irradiance and no photoinhibition up to 2000 µmol photons m-2 s-1. Its PUFA content was significantly lower (50%). An annual cycle of lake-to-snow colonization by Chlainomonas sp. from slush layers deeper in the ice cover is proposed. Our results point to an ecologically highly specialized cryoflora species, whose global distribution is likely to be more widespread than previously assumed.

10.
J Chromatogr A ; 1557: 9-19, 2018 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-29729864

RESUMO

Enantiomers of triacylglycerols (TAGs) containing any combination of very long chain fatty acids (VLCFAs) and/or very long chain polyunsaturated fatty acids (VLCPUFAs) with diolein, dilinolein and didocosahexaenoin were synthesized. Gradient non-aqueous reversed-phase high-performance liquid chromatography/high resolution atmospheric pressure chemical ionization-tandem mass spectrometry (NARP-HPLC/HRMS2-APCI) and chiral liquid chromatography were used for the separation and identification of molecular species of these TAGs. Further, NARP-LC and chiral LC were used to separate natural mixtures of TAGs obtained from four natural sources, i.e. ximenia oil (Ximenia americana), green alga (Botryococcus braunii), brewers yeast (Saccharomyces pastorianus) and a dinoflagellate (Amphidinium carterae). The ratio of regioisomers and enantiomers in individual samples was determined and a hypothesis has been confirmed on the biosynthetic pathway of natural TAGs, which is based on the preferential representation of VLCFAs and VLCPUFAs in the sn-1 position of the glycerol backbone.


Assuntos
Ácidos Graxos não Esterificados/química , Ácidos Graxos Insaturados/química , Triglicerídeos/isolamento & purificação , Pressão Atmosférica , Clorófitas/química , Clorófitas/metabolismo , Cromatografia Líquida de Alta Pressão , Cromatografia de Fase Reversa , Dinoflagelados/química , Dinoflagelados/metabolismo , Saccharomyces/química , Saccharomyces/metabolismo , Estereoisomerismo , Espectrometria de Massas em Tandem , Triglicerídeos/análise , Triglicerídeos/química
11.
Lipids ; 53(1): 5-25, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29446847

RESUMO

Lipids are among the most important organic compounds found in all living cells, from primitive archaebacteria to flowering plants or mammalian cells. They form part of cell walls and constitute cell storage material. Their biosynthesis and metabolism play key roles in faraway topics such as biofuel production (third-generation biofuels produced by microorganisms, e.g. algae) and human diseases such as adrenoleukodystrophy, Zellweger syndrome, or Refsum disease. Current lipidomic analysis requires fast and accurate processing of samples and especially their characterization. Because the number of possible lipids and, more specifically, molecular species of lipids is of the order of hundreds to thousands, it is necessary to process huge amounts of data in a short time. There are two basic approaches to lipidomic analysis: shotgun and liquid chromatography-mass spectometry. Both methods have their pros and cons. This review deals with lipidomics not according to the type of ionization or the lipid classes analyzed but according to the types of samples (organisms) under study. Thus, it is divided into lipidomic analysis of archaebacteria, bacteria, yeast, fungi, algae, plants, and animals.


Assuntos
Archaea/genética , Metabolismo dos Lipídeos/genética , Lipídeos/genética , Metabolômica/métodos , Animais , Archaea/química , Cromatografia Líquida de Alta Pressão , Cromatografia Líquida , Humanos , Lipídeos/química , Mamíferos/genética
12.
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
13.
Fottea (Praha) ; 18(1): 1-18, 2018 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-30976329

RESUMO

Melting snow fields populated by aplanozygotes of the genus Chloromonas (Chlamydomonadales, Chlorophyta) are found in polar and alpine habitats. In the High Tatra Mountains (Slovakia), cells causing blooms of brownish-red snow designated as Scotiella tatrae kol turned out to be genetically (18S, ITS1 and ITS2 rDNA, rbcL) very closely related to Chloromonas nivalis (Chodat) Hoham et Mullet from the Austrian Alps. Therefore, Sc. tatrae is transferred into the latter taxon and reduced to a subspecies as Cr. nivalis subsp. tatrae. Both exhibit a similar photosynthetic performance, thrive in similar habitats at open sites above timberline, but differ in astaxanthin accumulation and number of aplanozygote cell wall flanges. In a field sample of Cr. nivalis subsp. tatrae, polyunsaturated fatty acids formed nearly 50 % of total lipids, dominating in phospholipids and glycolipids. Cr. nivalis subsp. tatrae represents likely a variation of a common cryoflora species with distinct morphology.

14.
Folia Microbiol (Praha) ; 63(3): 273-282, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29127620

RESUMO

The bacterial strain KDF8 capable of growth in the presence of diclofenac and codeine analgesics was obtained after chemical mutagenesis of nature isolates from polluted soils. The strain KDF8 was identified as Raoultella sp. based on its morphology, biochemical properties, and 16S rRNA gene sequence. It was deposited in the Czech Collection of Microorganisms under the number CCM 8678. A growing culture efficiently removed diclofenac (92% removal) and partially also codeine (about 30% degradation) from culture supernatants within 72 h at 28 °C. The degradation of six analgesics by the whole cell catalyst was investigated in detail. The maximum degradation of diclofenac (91%) by the catalyst was achieved at pHINI of 7 (1 g/L diclofenac). The specific removal rate at high concentrations of diclofenac and codeine increased up to 16.5 mg/gCDW per h and 5.1 mg/gCDW per h, respectively. HPLC analysis identified 4'-hydroxydiclofenac as a major metabolite of diclofenac transformation and 14-hydroxycodeinone as codeine transformation product. The analgesics ibuprofen and ketoprofen were also removed, albeit to a lower extent of 3.2 and 2.0 mg/gCDW per h, respectively. Naproxen and mefenamic acid were not degraded.


Assuntos
Analgésicos/metabolismo , Enterobacteriaceae/metabolismo , Poluentes Químicos da Água/metabolismo , Analgésicos/toxicidade , Codeína/metabolismo , Codeína/toxicidade , DNA Bacteriano/genética , Diclofenaco/metabolismo , Diclofenaco/toxicidade , Enterobacteriaceae/classificação , Enterobacteriaceae/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Viabilidade Microbiana/efeitos dos fármacos , Filogenia , RNA Ribossômico 16S/genética , Microbiologia do Solo , Temperatura Ambiente
15.
Int J Anal Chem ; 2017: 8195329, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29129976

RESUMO

We investigated the possibility of utilizing unusual carbon sources by three yeast strains: Candida krusei DBM 2136, Trichosporon cutaneum CCY 30-5-10, and Yarrowia lipolytica CCY 30-26-36. These strains are characterized by high biomass yield, ability to accumulate high amounts of lipids, and their potential as producers of dietetically important fatty acids. The aim of this work was the production of nutritionally important fatty acids by utilization of n-alkanes with an odd number of carbon atoms, alone and in combination with glucose and subsequent analysis of microbial lipids accumulation and fatty acid profile. All three yeast strains were able to grow and produce high amounts of the fatty acids of interest. Yarrowia lipolytica was found as the most suitable strain for the growth on n-alkanes (n-pentadecane and n-heptadecane) as the only source of carbon. The addition of biosurfactants rhamnolipids into the cultivation increased the ratio of heptadecenoic acid (up to 17.9% of total FAs in Y. lipolytica CCY 30-26-36, 14.9% in T. cutaneum CCY 30-5-10, and 17.5% in C. krusei DBM 2136) and the total biomass yield. The results show that, by manipulation of the initial cultivation conditions, the ratio of important fatty acids may be increased.

16.
World J Microbiol Biotechnol ; 33(11): 205, 2017 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-29101483

RESUMO

Mid-exponential cultures of two traditional biotechnological yeast species, winery Saccharomyces cerevisiae and the less ethanol tolerant bottom-fermenting brewery Saccharomyces pastorianus, were exposed to different concentrations of added ethanol (3, 5 and 8%) The degree of ethanol-induced cell stress was assessed by measuring the cellular activity of superoxide dismutase (SOD), level of lipid peroxidation products, changes in cell lipid content and fatty acid profile. The resveratrol as an antioxidant was found to decrease the ethanol-induced rise of SOD activity and suppress the ethanol-induced decrease in cell lipids. A lower resveratrol concentration (0.5 mg/l) even reduced the extent of lipid peroxidation in cells. Resveratrol also alleviated ethanol-induced changes in cell lipid composition in both species by strongly enhancing the proportion of saturated fatty acids and contributing thereby to membrane stabilization. Lower resveratrol concentrations could thus diminish the negative effects of ethanol stress on yeast cells and improve their physiological state. These effects may be utilized to enhance yeast vitality in high-ethanol-producing fermentations or to increase the number of yeast generations in brewery.


Assuntos
Etanol/farmacologia , Ácidos Graxos/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos , Estilbenos/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Antioxidantes/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipídeos/fisiologia , Resveratrol , Vinho/microbiologia
17.
Lipids ; 52(12): 1007-1017, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28905226

RESUMO

Yeast lipids and fatty acids (FA) were analyzed in Saccharomyces pastorianus from seven breweries and in the dietary yeast supplement Pangamin. GC-MS identified more than 30 FA, half of which were very-long chain fatty acids (VLCFA) with hydrocarbon chain lengths of ≥22 C atoms. Positional isomers ω-9 and ω-7 were identified in FA with C18-C28 even-numbered alkyl chains. The most abundant ω-7 isomer was cis-vaccenic acid. The structure of monounsaturated FA was proved by dimethyl disulfide adducts (position of double bonds and cis geometric configuration) and by GC-MS of pyridyl carbinol esters. Ultra-high performance liquid chromatography-tandem mass spectrometry with negative electrospray ionization identified the phospholipids phosphatidylethanolamine, phosphatidylinositol and phosphatidylcholine, with more than 150 molecular species. Wild-type unmutated brewer's yeast strains conventionally used for the manufacture of food supplements were found to contain VLCFA.


Assuntos
Fosfolipídeos/análise , Saccharomyces/metabolismo , Ácidos Graxos/química , Ácidos Graxos Monoinsaturados , Cromatografia Gasosa-Espectrometria de Massas , Estrutura Molecular , Fosfolipídeos/química , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem
18.
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
19.
Anal Biochem ; 524: 3-12, 2017 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-27318242

RESUMO

A survey of useful methods for separation and identification of regioisomers and enantiomers of triacylglycerols. Gas chromatography, gas chromatography-mass spectrometry, 13C NMR determination of regioisomers by enzymatic methods, and supercritical fluid chromatography are briefly surveyed, whereas a detailed description is given of the analysis of triacylglycerols by liquid chromatography, especially with silver ion (Ag+; argentation), and nonaqueous reversed phase liquid chromatography. Special attention is paid to chiral chromatography. Details of mass spectrometry of triacylglycerols are also described, especially the identification of important triacylglycerol ions such as [M + H-RCOOH]+ in atmospheric pressure chemical ionization mass spectra.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Triglicerídeos/análise , Prata/química
20.
Extremophiles ; 21(1): 187-200, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27888351

RESUMO

The aim of this study was to assess the phylogenetic relationships, ecology and ecophysiological characteristics of the dominant planktic algae in ice-covered lakes on James Ross Island (northeastern Antarctic Peninsula). Phylogenetic analyses of 18S rDNA together with analysis of ITS2 rDNA secondary structure and cell morphology revealed that the two strains belong to one species of the genus Monoraphidium (Chlorophyta, Sphaeropleales, Selenastraceae) that should be described as new in future. Immotile green algae are thus apparently capable to become the dominant primary producer in the extreme environment of Antarctic lakes with extensive ice-cover. The strains grew in a wide temperature range, but the growth was inhibited at temperatures above 20 °C, indicating their adaptation to low temperature. Preferences for low irradiances reflected the light conditions in their original habitat. Together with relatively high growth rates (0.4-0.5 day-1) and unprecedently high content of polyunsaturated fatty acids (PUFA, more than 70% of total fatty acids), it makes these isolates interesting candidates for biotechnological applications.


Assuntos
Biodiversidade , Clorófitas/classificação , Camada de Gelo , Fitoplâncton/isolamento & purificação , Adaptação Fisiológica , Regiões Antárticas , Clorófitas/genética , Clorófitas/metabolismo , Ácidos Graxos Insaturados/metabolismo , Lagos , Fitoplâncton/classificação , Fitoplâncton/genética , Fitoplâncton/metabolismo , RNA Ribossômico 18S/genética
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