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1.
Chemosphere ; 250: 126199, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32092568

RESUMO

As stand-alone approaches, chromatographic separations of arsenic in lichen using HPLC-ICP-MS or the use of sequential extractions have historically been shown to have low analyte recoveries and poor analyte selectivity respectively. This study modifies the first step of a sequential extraction with a chromatographic separation of five arsenic species using HPLC-ICP-MS, followed by a three-step sequential extraction and analysis with ICP-MS. The method was applied to lichens from a rural and urban site to demonstrate the applicability thereof, and the sum of arsenic concentrations from the extraction steps were compared to the total arsenic concentrations. Short term species stability of the As species in the lichen matrix was also evaluated over 1 month in the water-extractable fraction, where As species concentrations changed week by week, providing insight into biotransformation mechanisms. In the modified extraction step, dimethylarsinic acid (DMA) and arsenobetaine and an unknown As species (AsB + U1) were statistically (p < 0.05) higher in the urban site than the rural site. Analyte recoveries using the combined method were higher than other studies reported in literature, with percentage recoveries of 104% and 111% of As in the urban and rural sites respectively. Arsenic concentrations were found in the following order of abundance at both sites: oxidizable > reducible > water-extractable > residual. Concentrations of total As in the oxidizable and non-bioavailable fraction were statistically lower (p < 0.05) in the rural site than in the urban site. Based upon the information gained from this study, we could draw concise conclusions regarding the source apportionment, timing and the magnitude of the pollution event.


Assuntos
Arsênico/metabolismo , Poluentes Ambientais/metabolismo , Líquens/metabolismo , Arsênico/análise , Arsenicais , Ácido Cacodílico/análise , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos
2.
Ecotoxicol Environ Saf ; 190: 110128, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31891838

RESUMO

Over the last few decades, the threat posed to biodiversity and ecosystem function by atmospheric nitrogen (N) deposition has been increasingly recognized. The disturbed nutrient balance and species composition of plants induced by higher N deposition can impact the biodiversity of the organisms that consume the plants. In this research, we implemented several experiments to estimate the effects of increased N deposition on the growth, survival, and nutrients of the dominant epiphytic lichens in the subtropical mountains in Central China to assess the lichen food amount and nutritional quality for two endangered primates endemic to China. Our results indicated that the thallus growth and propagule survival of the lichens were significantly decreased when nitrogen addition changed from 6.25 to 50.0 kg N·ha-1·y-1; it was also shown that lichen biomass could be decreased by 11.2%-70.2% when the deposition addition exceeded 6.25 kg N·ha-1·y-1. Further, our study revealed that increased nitrogen deposition also reduced the nutritional quality of the lichens via reducing the soluble protein and soluble sugar levels and increasing the fiber content, which would substantially affect the diet selection of the plants consumers in the region, particularly the populations of the two lichen-eating endangered primate species, Rhinopithecus roxellana and R. bieti. Our experimental study suggested that the nitrogen pollution derived from anthropogenic activities could cause cascading effects for the whole forest ecosystem of Central China; thus, more studies about nitrogen deposition in this region are required.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental , Líquens/química , Nitrogênio/análise , Animais , Atmosfera , Biodiversidade , Biomassa , China , Ecossistema , Poluição Ambiental , Abastecimento de Alimentos , Florestas , Líquens/metabolismo , Nitrogênio/metabolismo , Primatas
3.
Chem Biodivers ; 17(1): e1900465, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31701649

RESUMO

We performed comparative profiling of four specialized metabolites in the lichen Evernia prunastri, collected at three different geographic locations, California and Maine, USA, and Yoshkar Ola, Mari El, Russia. Among the compounds produced at high concentrations that were identified in all three specimens, evernic acid, usnic acid, lecanoric acid and chloroatranorin, evernic acid was the most abundant. Two depsidones, salazinic acid and physodic acid, were detected in the Yoshkar-Ola collection only. The crystalline structure of evernic acid (2-hydroxy-4-[(2-hydroxy-4-methoxy-6-methylbenzoyl)oxy]-6-methylbenzoate) (hmb) revealed two crystallographically and conformationally distinct hmb anions, along with two monovalent sodium atoms. One hmb moiety contained an exotetradentate binding mode to sodium, whereas the other exhibited an exohexadentate binding mode to sodium. Embedded edge-sharing {Na2 O8 }n sodium-oxygen chains connected the hmb anions into the full three-dimensional crystal structure of the title compound. The crystal used for single-crystal X-ray diffraction exhibited non-merohedral twinning. The data suggest the importance of the acetyl-polymalonyl pathway products to processes of maintaining integrity of the lichen holobiont community.


Assuntos
Benzofuranos/análise , Hidroxibenzoatos/análise , Líquens/química , Salicilatos/análise , Benzofuranos/metabolismo , Hidroxibenzoatos/metabolismo , Líquens/metabolismo , Modelos Moleculares , Salicilatos/metabolismo
4.
J Microbiol Biotechnol ; 29(7): 1155-1164, 2019 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-31280524

RESUMO

Lichens contain diverse bioactive secondary metabolites with various chemical and biological properties, which have been widely studied. However, details of the inhibitory mechanisms of their secondary metabolites against influenza A virus (IAV) have not been documented. Here, we investigated the antiviral effect of lichen extracts, obtained from South Korea, against IAV in MDCK cells. Of the lichens tested, Nipponoparmelia laevior (LC24) exhibited the most potent inhibitory effect against IAV infection. LC24 extract significantly increased cell viability, and reduced apoptosis in IAV-infected cells. The LC24 extract also markedly reduced (~ 3.2 logfold) IAV mRNA expression after 48 h of infection. To understand the antiviral mechanism of LC24 against IAV, proteomic (UPLC-HDMSE) analysis was performed to compare proteome modulation in IAV-infected (V) vs. mock (M) and LC24+IAV (LCV) vs. V cells. Based on Ingenuity Pathway Analysis (IPA), LC24 inhibited IAV infection by modulating several antiviral-related genes and proteins (HSPA4, HSPA5, HSPA8, ANXA1, ANXA2, HIF-1α, AKT1, MX1, HNRNPH1, HNRNPDL, PDIA3, and VCP) via different signaling pathways, including HIF-1α signaling, unfolded protein response, and interferon signaling. These molecules were identified as the specific biomarkers for controlling IAV in vitro and further confirmation of their potential against IAV in vivo is required. Our findings provide a platform for further studies on the application of lichen extracts against IAV.


Assuntos
Antivirais/farmacologia , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Líquens/química , Infecções por Orthomyxoviridae/metabolismo , Animais , Antivirais/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Cães , Líquens/metabolismo , Células Madin Darby de Rim Canino , Infecções por Orthomyxoviridae/virologia , Proteômica , RNA Mensageiro/metabolismo , República da Coreia , Transdução de Sinais/efeitos dos fármacos , Proteínas Virais/genética
5.
Environ Sci Pollut Res Int ; 26(26): 27002-27013, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31313231

RESUMO

Biological materials play a significant role in the treatment of heavy metal-contaminated soil and wastewater. In this study, the Pb2+ biosorption potential of lichen Evernia prunastri, extensively available at a forest in Bilecik-Turkey, was investigated at batch-scale level. The optimal conditions were determined and the adsorption isotherms, kinetics, and thermodynamic calculations were also done. In order to have detailed knowledge about metal biosorption, SEM, FTIR, and BET analyses were carried out before and after the biosorption process. The optimal pH was found pH 4 and the maximum metal uptake capacity was found as 0.067 mol kg-1. The results of this study indicate that the lichen was effectively applied to the removal of Pb2+ process as an inexpensive biosorbent from industrial wastewater.


Assuntos
Chumbo/isolamento & purificação , Líquens/metabolismo , Parmeliaceae/metabolismo , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Biodegradação Ambiental , Concentração de Íons de Hidrogênio , Cinética , Chumbo/metabolismo , Líquens/química , Microscopia Eletrônica de Varredura , Modelos Teóricos , Parmeliaceae/química , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Turquia , Poluentes Químicos da Água/metabolismo
6.
Plant Cell Physiol ; 60(8): 1880-1891, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31127294

RESUMO

Oxidative stress is a crucial challenge for lichens exposed to cyclic desiccation and rehydration (D/R). However, strategies to overcome this potential stress are still being unraveled. Therefore, the physiological performance and antioxidant mechanisms of two lichen microalgae, Trebouxia sp. (TR9) and Coccomyxa simplex (Csol), were analyzed. TR9 was isolated from Ramalina farinacea, a Mediterranean fruticose epiphytic lichen adapted to xeric habitats, while Csol is the phycobiont of Solorina saccata, a foliaceous lichen that grows on humid rock crevices. The tolerance to desiccation of both species was tested by subjecting them to different drying conditions and to four consecutive daily cycles of D/R. Our results show that a relative humidity close to that of their habitats was crucial to maintain the photosynthetic rates. Concerning antioxidant enzymes, in general, manganese superoxide dismutases (MnSODs) were induced after desiccation and decreased after rehydration. In TR9, catalase (CAT)-A increased, and its activity was maintained after four cycles of D/R. Ascorbate peroxidase activity was detected only in Csol, while glutathione reductase increased only in TR9. Transcript levels of antioxidant enzymes indicate that most isoforms of MnSOD and FeSOD were induced by desiccation and repressed after rehydration. CAT2 gene expression was also upregulated and maintained at higher levels even after four cycles of D/R in accordance with enzymatic activities. To our knowledge, this is the first study to include the complete set of the main antioxidant enzymes in desiccation-tolerant microalgae. The results highlight the species-specific induction of the antioxidant system during cyclic D/R, suggesting a priming of oxidative defence metabolism.


Assuntos
Antioxidantes/metabolismo , Líquens/metabolismo , Microalgas/metabolismo , Dessecação , Estresse Oxidativo/fisiologia , Superóxido Dismutase/metabolismo
7.
Ecotoxicol Environ Saf ; 180: 679-685, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31146154

RESUMO

Two lichen species, Usnea aciculifera and Usnea luridorufa, were used as biomonitors for the deposition of traffic-related metals in China's Shennongjia National Nature Reserve. The suitability of the two lichen species for use as biomonitors was compared. The health threat to the Sichuan snub-nosed (aka golden) monkey (Rhinopithecus roxellana) from consuming lichen with elevated metal concentrations due to vehicular traffic was then assessed. Lichens, with large surface areas and neither roots nor stomata, efficiently absorb both particulate and gaseous air pollutants. The resulting data was used to assess the effect of heavy metal accumulation on the lichens as well as the health risk imposed on the monkeys as lichen is a primary food source. Lichen samples were collected in the core area of the reserve at three locations of varying traffic intensity. A forth site in the reserve, with no proximate traffic, was used as the control. Results show: (1) lichen from high traffic sites has significantly higher concentrations of Fe, Cd, Pb Zn, and Cr than lichen collected from the control site; (2) vehicular traffic is the primary source of metals in lichen; (3) U. luridorufa collected at high traffic sites displayed decreased photosynthetic efficiency, an indication of stress; (4) intake of Cd and Pb from vehicle emissions in the Shennongjia National Nature Reserve could adversely affect snub-nosed monkey health. This research advances the science of biomonitoring, contributes to environmental protection efforts in China's nature reserves and helps improve food safety for Sichuan snub-nosed monkey, a national treasure of China.


Assuntos
Colobinae/fisiologia , Biomarcadores Ambientais/efeitos dos fármacos , Líquens/efeitos dos fármacos , Metais Pesados/toxicidade , Emissões de Veículos/toxicidade , Poluentes Atmosféricos/metabolismo , Poluentes Atmosféricos/toxicidade , Animais , China , Conservação dos Recursos Naturais , Líquens/metabolismo , Metais Pesados/metabolismo , Medição de Risco
8.
J Vis Exp ; (145)2019 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-30958472

RESUMO

Communities of nonvascular cryptogams, such as mosses or lichens, are an important part of the Earth's biodiversity, contributing to the regulation of the carbon and nitrogen cycles in many ecosystems. Being poikilohydric organisms, they do not actively control their internal water content and need a humid environment to activate their metabolism. Therefore, studying water relationships of nonvascular cryptogams is crucial to understand both their diversity patterns and their functions in the ecosystems. We present the BtM datalogger, a low-cost open-source platform for the study of the water content of nonvascular cryptogams. The datalogger is designed to measure ambient temperature, humidity, and conductance from up to eight samples simultaneously. We provide a design for a printed circuit board (PCB), a detailed protocol to assemble the components, and the required source code. All this makes the assembly of the BtM datalogger accessible to any research group, even to those without previous specialized knowledge. Therefore, the design presented here has the potential to help popularize the use of this type of device among ecologists and field biologists.


Assuntos
Briófitas/metabolismo , Custos e Análise de Custo , Equipamentos e Provisões Elétricas/economia , Monitoramento Ambiental/instrumentação , Líquens/metabolismo , Água/metabolismo , Monitoramento Ambiental/economia , Umidade , Temperatura
9.
Environ Monit Assess ; 191(5): 260, 2019 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-30949767

RESUMO

In bioaccumulation studies, the interpretation of pollutant contents in the target biomonitor has to be performed by assessing a deviation from an unaltered reference condition. A common strategy consists in the comparison with background element content (BEC) values, often built up by uncritically merging methodologically heterogeneous data. In this respect, the acid digestion of samples was identified as a major step affecting BEC data. Here, the analytical outcomes of two acid mixtures were compared on a set of matched paired samples of the lichen Pseudevernia furfuracea, a widely used biomonitor for which BEC values based on partial digestion were previously provided. The standard reference material BCR 482 (P. furfuracea) was used to validate analytical procedures consisting of either a HF total mineralization or an aqua regia partial one, both associated to ICP-MS multi-element analysis. In particular, the performance of the procedures was evaluated by comparing analytical results of field samples with the accuracy obtained on BCR aliquots (measured-to-expected percentage ratio). The total digestion showed a better performance for Al, As, Ba, Ca, Cd, Cu, Fe, Mn, Ni, Se, Sn, and Zn, whereas the opposite was found for Cr, Co, P, and S. Moreover, new BEC values were provided for P. furfuracea using a consolidated statistical approach, after a total sample digestion with hydrofluoric acid. The multivariate investigation of the background variability of 43 elements in 57 remote Italian sites led to the identification of geographically homogeneous areas for which BEC values are provided for use as reference in biomonitoring applications.


Assuntos
Poluentes Ambientais/análise , Ácido Clorídrico/análise , Líquens/metabolismo , Ácido Nítrico/análise , Oligoelementos/análise , Monitoramento Ambiental , Itália
10.
Environ Sci Pollut Res Int ; 26(14): 14689-14692, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30937743

RESUMO

An important factor affecting acquisition of pollution elements could be the lichen growth form. The Brunauer-Emmett-Teller theory approach has been used to determinate the specific area surface (BET-area) of solids by gas multilayer adsorption. Taking this standard method as a new tool, we measure the specific thallus area in foliose and fruticose lichens to evaluated area/volume relation for bioaccumulation prospects. Some preliminary results of elemental contents such as REEs (La, Sc, Sr) and pollutants (Cd, Co, Pb) were also measured to support the importance to use for the analysis of these thallus attributes.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Líquens/metabolismo , Metais Pesados/análise , Poluentes Atmosféricos/farmacocinética , Argentina , Líquens/efeitos dos fármacos , Líquens/crescimento & desenvolvimento , Metais Pesados/farmacocinética
11.
Ecotoxicol Environ Saf ; 174: 26-34, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30818257

RESUMO

The epigeic lichens Cladonia rei and Diploschistes muscorum are effective heavy-metal-tolerant colonisers of highly polluted and disturbed sites. In this study we compare their bioaccumulation capacities, accumulation patterns, and responses to heavy-metal stress, as expressed in terms of cell membrane damage. We also aim at verifying the relationships between cell membrane damage and levels of soil pollution with heavy metals, and thereby to identify the bioindicative value of this physiological parameter. Total and intracellular concentrations of Zn, Pb, Cd, As, Cu, and Ni were measured in 140 samples of lichens and corresponding soil, collected from variously contaminated sites. Relative electrical conductivity (EC%) values were determined concurrently in the lichen samples. The studied lichens differ considerably in intracellular uptake susceptibility and the related reduction in membrane integrity. In C. rei thalli, more than half of Zn, Pb, Cd, and As loads are accumulated extracellularly, whereas D. muscorum exhibits a tendency towards intracellular accumulation of the same elements. This property is clearly reflected in cell membrane damage, which is considerably greater in the latter species irrespective of study site. This indicates that intracellular heavy-metal accumulation affects the level of cell membrane damage. Two soil pollution classes were distinguished for both lichens based on element contents in host-substrate samples. The losses of cell membrane integrity in lichen thalli are related to these classes. EC% values above 16 in C. rei and above 20 in D. muscorum suggest elevated levels of heavy metals in the soil. Consequently, this physiological parameter can serve as an early warning indicator for detection of elevated metal concentrations in soil. The biomonitoring method proposed here involves common and widespread lichen species and can be widely applied in post-industrial areas.


Assuntos
Líquens/metabolismo , Metais Pesados/metabolismo , Poluentes do Solo/metabolismo , Ascomicetos/efeitos dos fármacos , Ascomicetos/metabolismo , Membrana Celular/efeitos dos fármacos , Condutividade Elétrica , Monitoramento Ambiental , Líquens/efeitos dos fármacos , Metais Pesados/análise , Metais Pesados/toxicidade , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
12.
Environ Sci Pollut Res Int ; 26(11): 10562-10575, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30762185

RESUMO

The aim of this study was to assess the temporal change of atmospheric deposition patterns of persistent organic pollutants (POPs) and polycyclic aromatic hydrocarbons (PAHs) in Switzerland between 1995 and 2014 by a passive biomonitoring with lichens. Lichen tissues sampled at 16 representative sites in the same season of 1995 and 2014 were analyzed for a total of 94 individual and 27 sum parameters of POPs and PAHs by means of gas chromatography-mass spectrometry (GC/MS). The comparative analyses showed a decrease of 40 to 80% (medians) for most of the POPs and PAHs concentration in lichens at all site categories. Reduction in tissue concentration of the polychlorinated dibenzo-p-dioxins/furans (PCDD/PCDFs), such as the highly toxic 2,3,7,8-TetraCDD and the TEQ according to WHO (2005) were 66% and 73%, respectively. For the dioxin- and non-dioxin-like PCBs, a decrease of 67% and 58% was found. The average decrease of 30 organochlorine pesticides and insecticides (OCPs) was 65%, with a 94% decrease for lindane. For the 27 PAHs and for benzo(a)pyrene, an average decrease of 58% and 59% was found. Polybrominated diphenyl ethers (PBDE) showed reduced concentrations in lichens at rural and agglomeration sites, but an increase of contamination was observed at industrial and road traffic sites. The direct comparison of changes of POPs and PAHs concentrations in lichens and of emissions between 1995 and 2014 revealed consistent results. The results of this study highlight for the first time in biota the positive effect of emission regulation of POPs in Switzerland.


Assuntos
Poluentes Ambientais/análise , Éteres Difenil Halogenados/análise , Hidrocarbonetos Clorados/análise , Líquens/química , Praguicidas/análise , Dibenzodioxinas Policloradas/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Monitoramento Ambiental/métodos , Poluentes Ambientais/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Éteres Difenil Halogenados/metabolismo , Hidrocarbonetos Clorados/metabolismo , Líquens/metabolismo , Praguicidas/metabolismo , Bifenilos Policlorados/análise , Bifenilos Policlorados/metabolismo , Dibenzodioxinas Policloradas/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Suíça
13.
Photosynth Res ; 141(2): 245-257, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30729446

RESUMO

Chlorophyll content in lichens is routinely used as an accurate indicator of lichen vigor, interspecific differences, and the effect of site-related environmental parameters. Traditional methods of chlorophyll extraction are destructive, time-consuming, expensive, and inoperable, especially when measuring large quantities of chlorophyll. However, non-destructive methods of measurement using portable chlorophyll meters are rarely used for lichens. Considering the characteristics of lichens such as rough blade surface and absence of chlorophyll b in cyanolichens, we compared the non-destructive methods with traditional methods and evaluated their applicability in studying lichen pigment content. Two instruments, SPAD-502 and CCM-300, were used to measure the pigment content of seven foliose lichen species. These pigment readings were compared with those determined using the dimethyl sulphoxide (DMSO) extraction method. Significant correlations were observed between SPAD/CCM values and pigments (chlorophyll and total carotenoids) extracted from chlorolichens, especially species with a smooth surface. The CCM-300 was more accurate in detecting the pigment content of foliose chlorolichens. However, both instruments showed certain limitations in the determination of pigment content in cyanolichens, especially gelatinous species. For example, CCM-300 often failed to give specific values for some cyanolichen samples, and both instruments showed low measurement accuracy for cyanolichens. Based on the high correlation observed between chlorophyll meter readings and pigments extracted from chlorolichens, equations obtained in this study enabled accurate prediction of pigment content in these lichens.


Assuntos
Líquens/metabolismo , Pigmentos Biológicos/análise , Carotenoides/análise , Clorofila/análise
14.
Artigo em Inglês | MEDLINE | ID: mdl-30744810

RESUMO

Usnic acid, which is the most widespread and well-studied secondary lichen compound, has antibacterial and cytotoxic effects. Usnic acid is present in lichens as the (+)- and (-)-enantiomers, which have different biological activities. We used a DNA-comet assay to determine the genotoxic effect of (+)- and (-)-usnic acid in the liver and kidney cells of mice. The genotoxic effect of usnic acid was only observed 1 h after oral administration. Usnic acid doses of 100 and 50 mg/kg resulted in DNA damage in the liver and kidney cells. The genotoxic effect of usnic acid is associated with oxidative stress in cells. There were no significant differences in the effects of (+)- and (-)-enantiomers.


Assuntos
Anti-Infecciosos/toxicidade , Benzofuranos/toxicidade , Dano ao DNA , Rim/patologia , Líquens/metabolismo , Fígado/patologia , Estresse Oxidativo , Animais , Rim/metabolismo , Fígado/metabolismo , Masculino , Camundongos , Estereoisomerismo
15.
Biomolecules ; 9(2)2019 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-30769763

RESUMO

Silver-based nanostructures are suitable for many biomedical applications, but to be useful therapeutic agents, the high toxicity of these nanomaterials must be eliminated. Here, we biosynthesize nontoxic and ultra-small silver nanoclusters (rsAg@NCs) using metabolites of usnioid lichen (a symbiotic association of algae and fungi) that exhibit excellent antimicrobial activity against fluconazole (FCZ)-resistant Candida albicans that is many times higher than chemically synthesized silver nanoparticles (AgNPs) and FCZ. The rsAg@NCs trigger apoptosis via reactive oxygen species accumulation that leads to the loss of mitochondrial membrane potential, DNA fragmentation, chromosomal condensation, and the activation of metacaspases. The proteomic analysis clearly demonstrates that rsAg@NCs exposure significantly alters protein expression. Most remarkable among the down-regulated proteins are those related to glycolysis, metabolism, free radical scavenging, anti-apoptosis, and mitochondrial function. In contrast, proteins involved in plasma membrane function, oxidative stress, cell death, and apoptosis were upregulated. Eventually, we also established that the apoptosis-inducing potential of rsAg@NCs is due to the activation of Ras signaling, which confirms their application in combating FCZ-resistant C. albicans infections.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Farmacorresistência Fúngica/efeitos dos fármacos , Fluconazol/farmacologia , Nanopartículas Metálicas/química , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Prata/metabolismo , Antifúngicos/química , Candida albicans/citologia , Morte Celular , Sobrevivência Celular/efeitos dos fármacos , Fluconazol/química , Líquens/química , Líquens/metabolismo , Tamanho da Partícula , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Prata/química , Propriedades de Superfície
16.
Nitric Oxide ; 83: 11-18, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30529156

RESUMO

Metabolic responses of epiphytic lichen Ramalina farinacea to cadmium (Cd) and/or nitric oxide (NO) scavenger (cPTIO) were studied. Accumulation of Cd and other metallic nutrients was not affected by cPTIO while total and absorbed amounts differed. Cd-induced NO formation was suppressed by cPTIO but ROS signal was synergistically enhanced, confirming that NO is essential to keep ROS under control. This excessive ROS generation could be a reason for depleted amount of all fatty acids, including SFAs, MUFAs and PUFAs. Total content of fatty acids reached 3.89 mg/g DW in control with linoleic (40%), palmitic (24%), oleic (12.8%) and stearic (8%) acids as major compounds: interestingly, shift in relative ratio of saturated (from 40 to 35% of total FAs) versus polyunsaturated fatty acids (from 42 to 48% of total FAs) was observed. Glutathione was suppressed by all treatments but Krebs acids were almost unaffected by cPTIO, indicating no regulatory role of NO in their accumulation. On the contrary, Cd-induced elevation in NO signal was related to increase in ascorbate and proline content while cPTIO suppressed it, indicating a tight relation between NO and these metabolites. Data are compared also with algae and vascular plants to show similarities between various life lineages.


Assuntos
Cádmio/farmacologia , Líquens/efeitos dos fármacos , Óxido Nítrico/metabolismo , Depuradores de Radicais Livres/farmacologia , Líquens/metabolismo , Microscopia de Fluorescência , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese
17.
Artigo em Inglês | MEDLINE | ID: mdl-30282060

RESUMO

Lichens are successful colonizers in extreme environments worldwide, and they are considered to have played an important role during the evolution of life. Here, we have used a correlative approach, combining three optical signals (chlorophyll a fluorescence (ChlF), reflectance, and Raman spectra), to monitor hydration induced changes in photosynthetic properties of an Antarctic chlorolichen Dermatocarpon polyphyllizum. We measured these three signals from this lichen at different stages (after 4 h, 24 h, and 48 h) of hydration, and compared the data obtained from this lichen in "dry state" as well as in different "hydrated state". We found that dry state of this lichen has: (1) no variable ChlF, (2) high reflectance, with no red-edge and almost zero photochemical reflectance index (PRI), and (3) low-intensity Raman bands of their carotenoids. Furthermore, 4 h of hydration, increased its relative water content (RWC) by 93%, showed red-edge in reflectance spectra, and changed the maximum quantum yield of PSII photochemistry (Fv/Fm) from 0 to 0.57 ±â€¯0.01. We found that reflectance indices, normalized difference index (NDVI) and PRI, significantly differed between brown and black/green surface areas, at all hydration stages; whereas, a shift in the Raman ν1(CC) band, between brown and black/green surface areas, occurred in 24 h or 48 h hydrated samples. These data indicate that hydration shortly (within 4 h) activated functions of photosynthetic apparatus, and the de novo synthesis of carotenoids occured in 24 h or 48 h. Furthermore, exposure to high irradiance (2000 µmol photons m-2 s-1), in 48 h hydrated lichen, significantly reduced Fv/Fm (signifies photoinhibition) and increased PRI (represents changes in xanthophyll pigments). We conclude that the implication of such a correlative approach is highly useful for understanding survival and protective mechanisms on extremophile photosynthetic organisms.


Assuntos
Clorofila A/análise , Líquens/metabolismo , Análise Espectral Raman , Água/química , Fluorescência , Fotossíntese , Processamento de Sinais Assistido por Computador
18.
J Biosci Bioeng ; 127(3): 388-393, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30201527

RESUMO

Densitometric high performance thin layer chromatography (HPTLC) quantification method was developed to validate the decolorization/biotransformation of Disperse Orange ERL and dye mixture by lichen Parmelia sp. which release several colored compounds during decolorization process, hence unable to use colorimetric estimation. Percent decolorization of Disperse Orange ERL and dye mixture by lichen Parmelia sp. was observed when estimated using developed HPTLC method. Limit of detection and limit of quantification for both dyes in mixture were obtained as 0.3 and 1 µg/µl, respectively. Area of peak of control Disperse Orange ERL was reduced by 43% after 12 h, 71% after 48 h and upto 82% after 72 h of incubation. Precision and repeatability of data elucidated the % relative standard deviation less than 3 for all the values thus indicating statistically acceptable. Biodegradation of dye and mixture was confirmed with Fourier transform infrared spectroscopy analysis, i.e., altered fingerprinting spectral pattern.


Assuntos
Compostos Azo/metabolismo , Corantes/metabolismo , Líquens/metabolismo , Compostos Azo/isolamento & purificação , Biodegradação Ambiental , Biotransformação , Cor , Corantes/isolamento & purificação
19.
Microb Ecol ; 77(1): 201-216, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29922904

RESUMO

Arid ecosystems constitute 41% of land's surface and play an important role in global carbon cycle. In particular, biological soil crusts (BSC) are known to be a hotspot of carbon fixation as well as mineralization in arid ecosystems. However, little information is available on carbon decomposition and microbes in BSC and key controlling variables for microbial activities in arid ecosystems. The current study, carried out in South Mediterranean arid ecosystem, aimed to evaluate the effects of intact and removed cyanobacteria/lichen crusts on soil properties, soil enzyme activities, and microbial abundances (bacteria and fungi). We compared five different treatments (bare soil, soil with intact cyanobacteria, soil with cyanobacteria removed, soil with intact lichens, and soil with lichens removed) in four different soil layers (0-5, 5-10, 10-15, and 15-20 cm). Regardless of soil treatments, activities of hydrolases and water content increased with increasing soil depth. The presence of lichens increased significantly hydrolase activities, which appeared to be associated with greater organic matter, nitrogen, and water contents. However, phenol oxidase was mainly controlled by pH and oxygen availability. Neither fungal nor bacterial abundance exhibited a significant correlation with enzyme activities suggesting that soil enzyme activities are mainly controlled by edaphic and environmental conditions rather than source microbes. Interestingly, the presence of lichens reduced the abundance of bacteria of which mechanism is still to be investigated.


Assuntos
Clima Desértico , Ecossistema , Ativação Enzimática , Microbiota , Microbiologia do Solo , Solo/química , Bactérias/enzimologia , Bactérias/metabolismo , Biodiversidade , Carbono/metabolismo , Ciclo do Carbono , Cianobactérias/crescimento & desenvolvimento , Cianobactérias/metabolismo , Monitoramento Ambiental , Fungos/enzimologia , Fungos/metabolismo , Concentração de Íons de Hidrogênio , Hidrolases/metabolismo , Líquens/crescimento & desenvolvimento , Líquens/metabolismo , Monofenol Mono-Oxigenase , Nitrogênio/metabolismo , Tunísia , Água
20.
Molecules ; 23(11)2018 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-30355963

RESUMO

Lichens are a symbiotic association between a fungus and a green alga or a cyanobacterium, or both. They can grow in practically any terrestrial environment and play crucial roles in ecosystems, such as assisting in soil formation and degrading soil organic matter. In their thalli, they can host a wide diversity of non-photoautotrophic microorganisms, including bacteria, which play important functions and are considered key components of the lichens. In this work, using the BioLog® EcoPlate system, we studied the consumption kinetics of different carbon-sources by microbial communities associated with the thallus and the substrate of Peltigera lichens growing in a Chilean temperate rain forest dominated by Nothofagus pumilio. Based on the similarity of the consumption of 31 carbon-sources, three groups were formed. Among them, one group clustered the microbial metabolic profiles of almost all the substrates from one of the sampling sites, which exhibited the highest levels of consumption of the carbon-sources, and another group gathered the microbial metabolic profiles from the lichen thalli with the most abundant mycobiont haplotypes. These results suggest that the lichen thallus has a higher impact on the metabolism of its microbiome than on the microbial community of its substrate, with the latter being more diverse in terms of the metabolized sources and whose activity level is probably related to the availability of soil nutrients. However, although significant differences were detected in the microbial consumption of several carbon-sources when comparing the lichen thallus and the underlying substrate, d-mannitol, l-asparagine, and l-serine were intensively metabolized by both communities, suggesting that they share some microbial groups. Likewise, some communities showed high consumption of 2-hydroxybenzoic acid, d-galacturonic acid, and itaconic acid; these could serve as suitable sources of microorganisms as bioresources of novel bioactive compounds with biotechnological applications.


Assuntos
Carbono/metabolismo , Florestas , Líquens/metabolismo , Líquens/microbiologia , Microbiota , Chile , Metaboloma , Metabolômica
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