Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 46
Filtrar
Más filtros













Base de datos
Intervalo de año de publicación
1.
FEMS Yeast Res ; 242024 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-38444195

RESUMEN

In this study, we explored the sphingolipid (SL) landscape in Candida auris, which plays pivotal roles in fungal biology and drug susceptibility. The composition of SLs exhibited substantial variations at both the SL class and molecular species levels among clade isolates. Utilizing principal component analysis, we successfully differentiated the five clades based on their SL class composition. While phytoceramide (PCer) was uniformly the most abundant SL class in all the isolates, other classes showed significant variations. These variations were not limited to SL class level only as the proportion of different molecular species containing variable number of carbons in fatty acid chains also differed between the isolates. Also a comparative analysis revealed abundance of ceramides and glucosylceramides in fluconazole susceptible isolates. Furthermore, by comparing drug-resistant and susceptible isolates within clade IV, we uncovered significant intraclade differences in key SL classes such as high PCer and low long chain base (LCB) content in resistant strains, underscoring the impact of SL heterogeneity on drug resistance development in C. auris. These findings shed light on the multifaceted interplay between genomic diversity, SLs, and drug resistance in this emerging fungal pathogen.


Asunto(s)
Antifúngicos , Candida , Antifúngicos/farmacología , Candida auris , Esfingolípidos , Farmacorresistencia Fúngica , Pruebas de Sensibilidad Microbiana
2.
Microb Cell Fact ; 22(1): 201, 2023 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-37803395

RESUMEN

BACKGROUND: Xylitol has a wide range of applications in the pharmaceuticals, cosmetic, food and beverage industry. Microbial xylitol production reduces the risk of contamination and is considered as environment friendly and sustainable compared to the chemical method. In this study, random mutagenesis and genetic engineering approaches were employed to develop Candida tropicalis strains with reduced xylitol dehydrogenase (XDH) activity to eliminate co-substrate requirement for corn cob-based xylitol-ethanol biorefinery. RESULTS: The results suggest that when pure xylose (10% w/v) was fermented in bioreactor, the Ethyl methane sulfonate (EMS) mutated strain (C. tropicalis K2M) showed 9.2% and XYL2 heterozygous (XYL2/xyl2Δ::FRT) strain (C. tropicalis K21D) showed 16% improvement in xylitol production compared to parental strain (C. tropicalis K2). Furthermore, 1.5-fold improvement (88.62 g/L to 132 g/L) in xylitol production was achieved by C. tropicalis K21D after Response Surface Methodology (RSM) and one factor at a time (OFAT) applied for media component optimization. Finally, corncob hydrolysate was tested for xylitol production in biorefinery mode, which leads to the production of 32.6 g/L xylitol from hemicellulosic fraction, 32.0 g/L ethanol from cellulosic fraction and 13.0 g/L animal feed. CONCLUSIONS: This work, for the first time, illustrates the potential of C. tropicalis K21D as a microbial cell factory for efficient production of xylitol and ethanol via an integrated biorefinery framework by utilising lignocellulosic biomass with minimum waste generation.


Asunto(s)
Candida tropicalis , Xilitol , Candida tropicalis/genética , Zea mays , Fermentación , Etanol , Hidrólisis , Xilosa
3.
Res Microbiol ; 174(7): 104087, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37328042

RESUMEN

Sphingolipids (SLs) are essential to fungal survival and represent a major class of structural and signaling lipids. Unique SL structures and their biosynthetic enzymes in filamentous fungi make them an ideal drug target. Several studies have contributed towards the functional characterization of specific SL metabolism genes, which have been complemented by advanced lipidomics methods which allow accurate identification and quantification of lipid structures and pathway mapping. These studies have provided a better understanding of SL biosynthesis, degradation and regulation networks in filamentous fungi, which are discussed and elaborated here.

4.
Molecules ; 27(24)2022 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-36558055

RESUMEN

This research work focuses on the potential application of an organic compound, santalol, obtained from santalum album, in the inhibition of the enzyme tyrosinase, which is actively involved in the biosynthesis of melanin pigment. Over-production of melanin causes undesirable pigmentation in humans as well as other organisms and significantly downgrades their aesthetic value. The study is designed to explain the purification of tyrosinase from the mushroom Agaricus bisporus, followed by activity assays and enzyme kinetics to give insight into the santalol-modulated tyrosinase inhibition in a dose-dependent manner. The multi-spectroscopic techniques such as UV-vis, fluorescence, and isothermal calorimetry are employed to deduce the efficiency of santalol as a potential candidate against tyrosinase enzyme activity. Experimental results are further verified by molecular docking. Santalol, derived from the essential oils of santalum album, has been widely used as a remedy for skin disorders and a potion for a fair complexion since ancient times. Based on enzyme kinetics and biophysical characterization, this is the first scientific evidence where santalol inhibits tyrosinase, and santalol may be employed in the agriculture, food, and cosmetic industries to prevent excess melanin formation or browning.


Asunto(s)
Melaninas , Monofenol Monooxigenasa , Humanos , Simulación del Acoplamiento Molecular , Sesquiterpenos Policíclicos , Inhibidores Enzimáticos/química
5.
ACS Omega ; 7(48): 44241-44250, 2022 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-36506193

RESUMEN

The constant rise in energy demands, costs, and concerns about global warming has created a demand for new renewable alternative fuels that can be produced sustainably. Lignocellulose biomass can act as an excellent energy source and various value-added compounds like xylitol. In this research study, we have explored the xylose reductase that was obtained from the genome of a thermophilic fungus Thermothelomyces thermophilus while searching for an enzyme to convert xylose to xylitol at higher temperatures. The recombinant thermostable TtXR histidine-tagged fusion protein was expressed in Escherichia coli and successfully purified for the first time. Further, it was characterized for its function and novel structure at varying temperatures and pH. The enzyme showed maximal activity at 7.0 pH and favored  d-xylose over other pentoses and hexoses. Biophysical approaches such as ultraviolet-visible (UV-visible), fluorescence spectrometry, and far-UV circular dichroism (CD) spectroscopy were used to investigate the structural integrity of pure TtXR. This research highlights the potential application of uncharacterized xylose reductase as an alternate source for the effective utilization of lignocellulose in fermentation industries at elevated temperatures. Moreover, this research would give environment-friendly and long-term value-added products, like xylitol, from lignocellulosic feedstock for both scientific and commercial purposes.

6.
Curr Pharm Des ; 28(43): 3478-3485, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36415093

RESUMEN

Colorectal cancer is the second leading cause of cancer deaths worldwide and has engrossed researchers' attention toward its detection and prevention at early stages. Primarily associated with genetic and environmental risk factors, the disease has also shown its emergence due to dysbiosis in microbiota. The microbiota not only plays a role in modulating the metabolisms of metastatic tissue but also has a keen role in cancer therapy. The immune cells are responsible for secreting various chemokines and cytokines, and activating pattern recognition receptors by different microbes can lead to the trail by which these cells regulate cancer. Furthermore, mixed immune reactions involving NK cells, tumor-associated macrophages, and lymphocytes have shown their connection with the microbial counterpart of the disease. The microbes like Bacteroides fragilis, Fusobacterium nucleatum, and Enterococcus faecalis and their metabolites have engendered inflammatory reactions in the tumor microenvironment. Hence the interplay between immune cells and various microbes is utilized to study the changing metastasis stage. Targeting either immune cells or microbiota could not serve as a key to tackling this deadly disorder. However, harnessing their complementation towards the disease can be a powerful weapon for developing therapy and diagnostic/prognostic markers. In this review, we have discussed various immune reactions and microbiome interplay in CRC, intending to evaluate the effectiveness of chemotherapy and immunotherapy and their parallel relationship.


Asunto(s)
Neoplasias del Colon , Neoplasias Colorrectales , Microbioma Gastrointestinal , Microbiota , Humanos , Neoplasias Colorrectales/tratamiento farmacológico , Microbioma Gastrointestinal/fisiología , Sistema Inmunológico , Microambiente Tumoral
7.
J Fungi (Basel) ; 8(7)2022 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-35887407

RESUMEN

In this study, we have specifically blocked a key step of sphingolipid (SL) biosynthesis in Candida glabrata by disruption of the orthologs of ScIpt1 and ScSkn1. Based on their close homology with S. cerevisiae counterparts, the proteins are predicted to catalyze the addition of a phosphorylinositol group onto mannosyl inositolphosphoryl ceramide (MIPC) to form mannosyl diinositolphosphoryl ceramide (M(IP)2C), which accounts for the majority of complex SL structures in S. cerevisiae membranes. High throughput lipidome analysis confirmed the accumulation of MIPC structures in ΔCgipt1 and ΔCgskn1 cells, albeit to lesser extent in the latter. Noticeably, ΔCgipt1 cells showed an increased susceptibility to azoles; however, ΔCgskn1 cells showed no significant changes in the drug susceptibility profiles. Interestingly, the azole susceptible phenotype of ΔCgipt1 cells seems to be independent of the ergosterol content. ΔCgipt1 cells displayed altered lipid homeostasis, increased membrane fluidity as well as high diffusion of radiolabeled fluconazole (3H-FLC), which could together influence the azole susceptibility of C. glabrata. Furthermore, in vivo experiments also confirmed compromised virulence of the ΔCgipt1 strain. Contrarily, specific functions of CgSkn1 remain unclear.

8.
Environ Technol ; : 1-15, 2022 Jul 06.
Artículo en Inglés | MEDLINE | ID: mdl-35762251

RESUMEN

HIGHLIGHTSCandia tropicalis K2 isolate was screened from natural sites of biomass degradation and characterized for xylitol production.Non-detoxified Albizia pod and corncob hydrolysates were explored for xylitol production using selected C. tropicalis K2 isolate.A maximum of 0.90 g/g yield and 1.07 g/L.h xylitol productivity was achieved with pure xylose.A >10% increase in xylitol yield was achieved using glycerol as a co-substrate.

9.
Bioresour Technol ; 351: 127067, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35351564

RESUMEN

Dependency on fossil fuels raises an economic and ecological concern that has urged to look for alternative sources of energy. Bio-refinery concept is one of the alternate frameworks for the biomass conversion into biofuel and other value-added by-products. The present work illustrates importance of an oleaginous yeast Rhodotorula pacifica INDKK in an integrated bio-refinery field by utilizing renewable sugars generated from lignocellulosic biomass. The maximum 11.8 g/L lipid titer, 210.4 mg/L ß-carotene and 7.1 g animal feed were produced by R. pacifica INDKK in bioreactor containing 5% (v/v) molasses supplemented with enzymatically hydrolyzed and alkali-pretreated sugarcane bagasse hydrolysate (35% v/v). Furthermore, xylooligosaccharides (20.6 g/L), a beneficial prebiotics were also produced from the hemicellulosic fraction separated after alkali pretreatment of bagasse. This novel concept of integrated yeast bio-refinery for concomitant production of biodiesel and multiple value-added products with minimum waste generation is proposed as a sustainable and profitable process.


Asunto(s)
Rhodotorula , Saccharum , Álcalis , Biocombustibles , Biomasa , Celulosa , Melaza , beta Caroteno
10.
Biotechnol Adv ; 56: 107925, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35151789

RESUMEN

Lignocellulosic biomass, a rich and inexpensive source of fermentable and renewable carbon, is the most abundant material on earth. Microbial bioprocessing of lignocellulosic biomass to produce biofuels (bioethanol, biobutanol, biodiesel) is a sustainable blueprint to reduce our depleting energy reserves and carbon footprint. Saccharomyces cerevisiae, being an excellent industrial ethanologenic organism, is an ideal candidate to engineer as a consolidated bio-processing (CBP) host, a concept that integrates the different steps of cellulosic ethanol production, from hydrolysis of cellulose to glucose and fermentation of glucose to ethanol in one step. Owing to the developments in the field of genetic engineering and sequencing technologies, research in the past two decades have made pivotal achievements to realize CBP enabling yeast suited for industrial applications. However, overcoming major limitations such as incomplete substrate catabolism, low titres of heterologous protein expression, sub-optimal operational conditions and impediment due to toxic inhibitors/by-products accumulation is still challenging. This review focuses on the progress achieved in constructing S. cerevisiae to produce bioethanol in a CBP framework. The different techniques of developing cellulolytic yeast strains are initially explained followed by relevant strategies to tackle the key bottlenecks associated with the process. Additionally, engineering efforts towards designing hemicellulose-derived sugar utilizing yeast strains are discussed.


Asunto(s)
Etanol , Saccharomyces cerevisiae , Biocombustibles , Biomasa , Etanol/metabolismo , Fermentación , Glucosa/metabolismo , Lignina/metabolismo , Ingeniería Metabólica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
11.
mBio ; 13(1): e0354521, 2022 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-35038899

RESUMEN

In this study, 18 predicted membrane-localized ABC transporters of Candida glabrata were deleted individually to create a minilibrary of knockouts (KO). The transporter KOs were analyzed for their susceptibility toward antimycotic drugs. Although CgYOR1 has previously been reported to be upregulated in various azole-resistant clinical isolates of C. glabrata, deletion of this gene did not change the susceptibility to any of the tested azoles. Additionally, Cgyor1Δ showed no change in susceptibility toward oligomycin, which is otherwise a well-known substrate of Yor1 in other yeasts. The role of CgYor1 in azole susceptibility only became evident when the major transporter CgCDR1 gene was deleted. However, under nitrogen-depleted conditions, Cgyor1Δ demonstrated an azole-susceptible phenotype, independent of CgCdr1. Notably, Cgyor1Δ cells also showed increased susceptibility to target of rapamycin (TOR) and calcineurin inhibitors. Moreover, increased phytoceramide levels in Cgyor1Δ and the deletions of regulators downstream of TOR and the calcineurin signaling cascade (Cgypk1Δ, Cgypk2Δ, Cgckb1Δ, and Cgckb2Δ) in the Cgyor1Δ background and their associated fluconazole (FLC) susceptibility phenotypes confirmed their involvement. Collectively, our findings show that TOR and calcineurin signaling govern CgYor1-mediated azole susceptibility in C. glabrata. IMPORTANCE The increasing incidence of Candida glabrata infections in the last 40 years is a serious concern worldwide. These infections are usually associated with intrinsic azole resistance and increasing echinocandin resistance. Efflux pumps, especially ABC transporter upregulation, are one of the prominent mechanisms of azole resistance; however, only a few of them are characterized. In this study, we analyzed the mechanisms of azole resistance due to a multidrug resistance-associated protein (MRP) subfamily ABC transporter, CgYor1. We demonstrate for the first time that CgYor1 does not transport oligomycin but is involved in azole resistance. Under normal growing conditions its function is masked by major transporter CgCdr1; however, under nitrogen-depleted conditions, it displays its azole resistance function independently. Moreover, we propose that the azole susceptibility due to removal of CgYor1 is not due to its transport function but involves modulation of TOR and calcineurin cascades.


Asunto(s)
Azoles , Candidiasis , Antifúngicos/farmacología , Transportadoras de Casetes de Unión a ATP/genética , Azoles/farmacología , Calcineurina/metabolismo , Candida glabrata/genética , Farmacorresistencia Fúngica/genética , Fluconazol/farmacología , Proteínas de Transporte de Membrana/metabolismo , Pruebas de Sensibilidad Microbiana , Nitrógeno/metabolismo , Oligomicinas/farmacología , Sirolimus/farmacología , Proteínas Fúngicas/metabolismo
12.
Curr Drug Targets ; 23(1): 2-20, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34165406

RESUMEN

Parkinson's disease (PD) is one of the most common types of neurological disorder prevailing worldwide and is rapidly increasing in the elderly population across the globe. The cause of PD is still unknown, but a number of genetic as well as environmental factors contributing to the pathogenesis of Parkinson's disease have been identified. The hallmark of PD includes dopamine deficiency (neurotransmitter imbalance) due to the gradual loss of dopaminergic nerves in the substantia nigra in the midbrain. Studying the mutation of associated genes is particularly informative in understanding the fundamental molecular and pathogenic changes in PD. Intracellular accumulation of misfolded or degraded protein due to mutated genes leading to the manifestation of mitochondrial dysfunction, oxidative stress followed by multifaceted patho-physiologic symptoms. Other studies include the appearance of both motor and non-motor responses like resting tremor, muscle stiffness, slow movement and anxiety, anaemia, constipation, rapid eye movement sleep behaviour disorder. Many bioactive natural compounds have shown positive pharmacological results in treating a number of extensive disease models of PD. Despite the availability of end number of potent medicinal plants around the world, limited research has been done associated with various neurological disorders, including PD. The currently available dopamine-based drug treatments have several side-effects, further, not effective enough to combat PD completely. Therefore, various plant-based compounds with medicinal benefits have grabbed lots of attention of researchers to deal with various life-threatening neurodegenerative disorders like PD. On the basis of literature available till date, here, we have discussed and addressed the molecular basis, current scenario, and the best possible treatment of PD for the future with minimal or no side-effects using various key bioactive compounds from natural origin/medicinal plants.


Asunto(s)
Enfermedad de Parkinson , Anciano , Dopamina , Humanos , Estrés Oxidativo , Enfermedad de Parkinson/tratamiento farmacológico , Enfermedad de Parkinson/metabolismo
13.
J Fungi (Basel) ; 7(11)2021 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-34829254

RESUMEN

Oleaginous yeast Rhodosporidium toruloides has great biotechnological potential and scientific interest, yet the molecular rationale of its cellular behavior to carbon and nitrogen ratios with concurrent lipid agglomeration remains elusive. Here, metabolomics adaptations of the R. toruloides in response to varying glucose and nitrogen concentrations have been investigated. In preliminary screening we found that 5% glucose (w/v) was optimal for further analysis in Rhodosporidium toruloides 3641. Hereafter, the effect of complementation to increase lipid agglomeration was evaluated with different nitrogen sources and their concentration. The results obtained illustrated that the biomass (13 g/L) and lipid (9.1 g/L) production were maximum on 5% (w/v) glucose and 0.12% (NH4)2SO4. Furthermore, to shed lights on lipid accumulation induced by nitrogen-limitation, we performed metabolomic analysis of the oleaginous yeast R. toruloides 3641. Significant changes were observed in metabolite concentrations by qualitative metabolomics through gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS), which were mapped onto the governing metabolic pathways. Notable finding in this strain concerns glycerol and CDP-DAG metabolism wherein reduced production of glycerol and phospholipids induced a bypass leading to enhanced de-novo triacylglyceride synthesis. Collectively, our findings help in understanding the central carbon metabolism of R. toruloides which may assist in developing rationale metabolic models and engineering efforts in this organism.

14.
Pathogens ; 10(11)2021 Nov 11.
Artículo en Inglés | MEDLINE | ID: mdl-34832620

RESUMEN

Reduced sensitivity of the human malaria parasite, Plasmodium falciparum, to Artemisinin and its derivatives (ARTs) threatens the global efforts towards eliminating malaria. ARTs have been shown to cause ubiquitous cellular and genetic insults, which results in the activation of the unfolded protein response (UPR) pathways. The UPR restores protein homeostasis, which otherwise would be toxic to cellular survival. Here, we interrogated the role of DNA-damage inducible protein 1 (PfDdi1), a unique proteasome-interacting retropepsin in mediating the actions of the ARTs. We demonstrate that PfDdi1 is an active A2 family protease that hydrolyzes ubiquitinated proteasome substrates. Treatment of P. falciparum parasites with ARTs leads to the accumulation of ubiquitinated proteins in the parasites and blocks the destruction of ubiquitinated proteins by inhibiting the PfDdi1 protease activity. Besides, whereas the PfDdi1 is predominantly localized in the cytoplasm, exposure of the parasites to ARTs leads to DNA fragmentation and increased recruitment of the PfDdi1 into the nucleus. Furthermore, we show that Ddi1 knock-out Saccharomycescerevisiae cells are more susceptible to ARTs and the PfDdI1 protein robustly restores the corresponding functions in the knock-out cells. Together, these results show that ARTs act in multiple ways; by inducing DNA and protein damage and might be impairing the damage recovery by inhibiting the activity of PfDdi1, an essential ubiquitin-proteasome retropepsin.

15.
Biol Futur ; 72(3): 325-337, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34554551

RESUMEN

Plasmodial resistance to a variety of plant-based antimalarial drugs has led toward the discovery of more effective antimalarial compounds having chemical or biological origin. Since natural compounds are considered as safer drugs, in this study, yeast strains were identified and compared for the production of carotenoids that are well-known antioxidants and this metabolite was tested for its antiparasitic activity. Plasmodium falciparum 3D7 strain was selected as the target parasite for evaluation of antimalarial activity of yeast carotenoids using in vitro studies. Data were analyzed by FACS (fluorescence-activated cell sorter) and counted via gold standard Giemsa-stained smears. The extracted yeast carotenoids showed a profound inhibitory effect at a concentration of 10-3 µg/µl and 10-4 µg/µl when compared to ß- carotene as control. SYBR Green1 fluorescent dye was used to confirm the decrease in parasitaemia at given range of concentration. Egress assay results suggested that treated parasite remained stalled at schizont stage with constricted morphology and were darkly stained. Non-toxicity of carotenoids on erythrocytes and on human liver hepatocellular carcinoma cells (HepG2 cells) was shown at a given concentration. This report provides strong evidence for antimalarial effects of extracted yeast carotenoids, which can be produced via a sustainable and cost-effective strategy and may be scaled up for industrial application.


Asunto(s)
Antimaláricos/normas , Carotenoides/análisis , Carotenoides/aislamiento & purificación , Plasmodium falciparum/efectos de los fármacos , Levaduras/metabolismo , Antimaláricos/farmacología , Antimaláricos/uso terapéutico , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/fisiopatología , Levaduras/aislamiento & purificación
17.
Fungal Genet Biol ; 150: 103550, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33675986

RESUMEN

The ATP binding cassette (ABC) transporters, first discovered as high-affinity nutrient importers in bacteria, rose to prominence when their ability to confer multidrug resistance (MDR) to cancer cells was realized. The most characterized human permeability glycoprotein (P-gp) is a dominant exporter of anti-cancer drugs and its overexpression is directly linked to MDR. The overexpression of drug efflux pumps belonging to the ABC superfamily is also a frequent cause of resistance to antifungals. Fungi has a battery of ABC proteins, but in variable numbers and at different subcellular locations. These proteins perform many critical functions, from serving as gatekeepers for xenobiotic cleansing to translocating various structurally unrelated cargoes, including lipids, fatty acids, ions, peptides, sterols, metabolites and toxins. Their emerging additional roles in cellular physiology and virulence call for attention to analyze and re-examine their divergent functions in yeast. In brief, this review traces the history of ABC transporters in yeast and discusses their typical physiological functions that go beyond their well-known role as antifungal drug efflux pumps.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Antifúngicos , Resistencia a Múltiples Medicamentos , Proteínas de Transporte de Membrana/metabolismo , Saccharomyces cerevisiae/efectos de los fármacos , Saccharomyces cerevisiae/genética
18.
Artículo en Inglés | MEDLINE | ID: mdl-32942047

RESUMEN

Independent studies from our group and others have provided evidence that sphingolipids (SLs) influence the antimycotic susceptibility of Candida species. We analyzed the molecular SL signatures of drug-resistant clinical isolates of Candida auris, which have emerged as a global threat over the last decade. This included Indian hospital isolates of C. auris, which were either resistant to fluconazole (FLCR) or amphotericin B (AmBR) or both drugs. Relative to Candida glabrata and Candida albicans strains, these C. auris isolates were susceptible to SL pathway inhibitors such as myriocin and aureobasidin A, suggesting that SL content may influence azole and AmB susceptibilities. Our analysis of SLs confirmed the presence of 140 SL species within nine major SL classes, namely the sphingoid bases, Cer, αOH-Cer, dhCer, PCer, αOH-PCer, αOH-GlcCer, GlcCer, and IPC. Other than for αOH-GlcCer, most of the SLs were found at higher concentrations in FLCR isolates as compared to the AmBR isolates. SLs were at intermediate levels in FLCR + AmBR isolates. The observed diversity of molecular species of SL classes based on fatty acyl composition was further reflected in their distinct specific imprint, suggesting their influence in drug resistance. Together, the presented data improves our understanding of the dynamics of SL structures, their synthesis, and link to the drug resistance in C. auris.


Asunto(s)
Anfotericina B/farmacología , Antifúngicos/farmacología , Candida/metabolismo , Farmacorresistencia Fúngica Múltiple/fisiología , Fluconazol/farmacología , Glucosilceramidas/metabolismo , Candida/efectos de los fármacos , Candida/aislamiento & purificación , Candida albicans/efectos de los fármacos , Candida albicans/aislamiento & purificación , Candida albicans/metabolismo , Candida glabrata/efectos de los fármacos , Candida glabrata/aislamiento & purificación , Candida glabrata/metabolismo , Candidiasis/microbiología , Cromatografía Liquida , Depsipéptidos/farmacología , Farmacorresistencia Fúngica Múltiple/efectos de los fármacos , Ácidos Grasos Monoinsaturados/farmacología , Glucosilceramidas/clasificación , Glucosilceramidas/aislamiento & purificación , Humanos , Lipidómica/métodos , Espectrometría de Masas en Tándem
19.
Biotechnol Biofuels ; 13: 175, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33088345

RESUMEN

BACKGROUND: To meet the present transportation demands and solve food versus fuel issue, microbial lipid-derived biofuels are gaining attention worldwide. This study is focussed on high-throughput screening of oleaginous yeast by microwave-aided Nile red spectrofluorimetry and exploring pongamia shell hydrolysate (PSH) as a feedstock for lipid production using novel oleaginous yeast Rhodotorula pacifica INDKK. RESULTS: A new oleaginous yeast R. pacifica INDKK was identified and selected for microbial lipid production. R. pacifica INDKK produced maximum 12.8 ± 0.66 g/L of dry cell weight and 6.78 ± 0.4 g/L of lipid titre after 120 h of growth, showed high tolerance to pre-treatment-derived inhibitors such as 5-hydroxymethyl furfural (5-HMF), (2 g/L), furfural (0.5 g/L) and acetic acid (0.5 g/L), and ability to assimilate C3, C5 and C6 sugars. Interestingly, R. pacifica INDKK showed higher lipid accumulation when grown in alkali-treated saccharified PSH (AS-PSH) (0.058 ± 0.006 g/L/h) as compared to acid-treated detoxified PSH (AD-PSH) (0.037 ± 0.006 g/L/h) and YNB medium (0.055 ± 0.003 g/L/h). The major fatty acid constituents are oleic, palmitic, linoleic and linolenic acids with an estimated cetane number (CN) of about 56.7, indicating the good quality of fuel. CONCLUSION: These results suggested that PSH and R. pacifica INDKK could be considered as potential feedstock for sustainable biodiesel production.

20.
mSphere ; 5(4)2020 08 12.
Artículo en Inglés | MEDLINE | ID: mdl-32817456

RESUMEN

Alternative splicing (AS)-a process by which a single gene gives rise to different protein isoforms in eukaryotes-has been implicated in many basic cellular processes, but little is known about its role in drug resistance and fungal pathogenesis. The most common human fungal pathogen, Candida albicans, has introns in 4 to 6% of its genes, the functions of which remain largely unknown. Here, we report AS regulating drug resistance in C. albicans Comparative RNA-sequencing of two different sets of sequential, isogenic azole-sensitive and -resistant isolates of C. albicans revealed differential expression of splice isoforms of 14 genes. One of these was the superoxide dismutase gene SOD3, which contains a single intron. The sod3Δ/Δ mutant was susceptible to the antifungals amphotericin B (AMB) and menadione (MND). While AMB susceptibility was rescued by overexpression of both the spliced and unspliced SOD3 isoforms, only the spliced isoform could overcome MND susceptibility, demonstrating the functional relevance of this splicing in developing drug resistance. Furthermore, unlike AMB, MND inhibits SOD3 splicing and acts as a splicing inhibitor. Consistent with these observations, MND exposure resulted in increased levels of unspliced SOD3 isoform that are unable to scavenge reactive oxygen species (ROS), resulting in increased drug susceptibility. Collectively, these observations suggest that AS is a novel mechanism for stress adaptation and overcoming drug susceptibility in C. albicansIMPORTANCE The emergence of resistance in Candida albicans, an opportunistic pathogen, against the commonly used antifungals is becoming a major obstacle in its treatment. The necessity to identify new drug targets demands fundamental insights into the mechanisms used by this organism to develop drug resistance. C. albicans has introns in 4 to 6% of its genes, the functions of which remain largely unknown. Using the RNA-sequencing data from isogenic pairs of azole-sensitive and -resistant isolates of C. albicans, here, we show how C. albicans uses modulations in mRNA splicing to overcome antifungal drug stress.


Asunto(s)
Empalme Alternativo , Antifúngicos/farmacología , Candida albicans/efectos de los fármacos , Candida albicans/genética , Farmacorresistencia Fúngica/genética , Estrés Fisiológico/genética , Azoles/farmacología , Candida albicans/patogenicidad , Candidiasis/microbiología , Proteínas Fúngicas/genética , Humanos , ARN Mensajero/genética , RNA-Seq
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA