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1.
PLoS Pathog ; 17(4): e1009478, 2021 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-33798244

RESUMO

Despite considerable reduction of mother-to-child transmission (MTCT) of HIV through use of maternal and infant antiretroviral therapy (ART), over 150,000 infants continue to become infected with HIV annually, falling far short of the World Health Organization goal of reaching <20,000 annual pediatric HIV cases worldwide by 2020. Prior to the widespread use of ART in the setting of pregnancy, over half of infants born to HIV-infected mothers were protected against HIV acquisition. Yet, the role of maternal immune factors in this protection against vertical transmission is still unclear, hampering the development of synergistic strategies to further reduce MTCT. It has been established that infant transmitted/founder (T/F) viruses are often resistant to maternal plasma, yet it is unknown if the neutralization resistance profile of circulating viruses predicts the maternal risk of transmission to her infant. In this study, we amplified HIV-1 envelope genes (env) by single genome amplification and produced representative Env variants from plasma of 19 non-transmitting mothers from the U.S. Women Infant Transmission Study (WITS), enrolled in the pre-ART era. Maternal HIV Env variants from non-transmitting mothers had similar sensitivity to autologous plasma as observed for non-transmitting variants from transmitting mothers. In contrast, infant variants were on average 30% less sensitive to paired plasma neutralization compared to non-transmitted maternal variants from both transmitting and non-transmitting mothers (p = 0.015). Importantly, a signature sequence analysis revealed that motifs enriched in env sequences from transmitting mothers were associated with broadly neutralizing antibody (bnAb) resistance. Altogether, our findings suggest that circulating maternal virus resistance to bnAb-mediated neutralization, but not autologous plasma neutralization, near the time of delivery, predicts increased MTCT risk. These results caution that enhancement of maternal plasma neutralization through passive or active vaccination during pregnancy may potentially drive the evolution of variants fit for vertical transmission.

2.
Environ Res ; : 111074, 2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33798516

RESUMO

This work reports synthesis of a dual-function facile heterojunction and investigation of role of the charge transfer dynamism between individual semiconductor components for superior photocatalytic and electrochemical sensing application. The bio-benevolent and sturdy ZnO/Fe2O3 heterojunctions were utilized for visible light facilitated photo-degradation of sulfamethoxazole (SMX) antibiotic and electrochemical sensing of dopamine drug (DA). The fabricated heterojunction were characterized for structural, optical, and magnetic properties. Structural studies revealed the formation of nano heterojunction containing both phases. Magnetic studies confirmed the highly pure magnetic nature of photocatalysts. ZnO/30wt%Fe2O3 heterojunction (S2) shows 95.2% SMX degradation under visible light and high retention of performance under solar light. The scavenging experiments infer that OH radicals are the active species responsible for degradation. A Z-scheme photocatalytic mechanism was predicted for higher performance with protection of high potential VB of ZnO and CB of Fe2O3 for high generation of reactive oxygen species. LC-MS was employed to predict a plausible degradation route. The sample modified glassy carbon electrodes (GCE) were used for electrochemical sensing of dopamine via cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The S2 junction exhibited 0.18 µM limit of detection with concentration range of 1 µM to 50 µM. The stability test was successfully carried out at room temperature for 15 days. In addition, the S2 modified electrodes were spiked in real urine samples and good results were obtained. DPV reveals that S2 modified electrode is best sensor for dopamine sensing among all synthesized heterojunctions. The detection mechanism was also discussed in detail. The in-built metal redox i.e Zn2+/Zn+ and Fe3+/Fe2+ facilitate the Z-scheme transfer, improve the charge transfer capacity and reduce the recombination. This study is beneficial because it reports utilization of popular and well-tested semiconductor metal oxides to form heterojunctions with dual capabilities of environmental detoxification and cost-effective electrochemical detection of biomolecules.

3.
Nanomaterials (Basel) ; 11(3)2021 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-33802059

RESUMO

One-dimensional metal nanowires, with novel functionalities like electrical conductivity, optical transparency and high mechanical stiffness, have attracted widespread interest for use in applications such as transparent electrodes in optoelectronic devices and active components in nanoelectronics and nanophotonics. In particular, silver nanowires (AgNWs) have been widely researched owing to the superlative thermal and electrical conductivity of bulk silver. Herein, we present a detailed review of the synthesis of AgNWs and their utilization in fabricating improved transparent conducting electrodes (TCE). We discuss a range of AgNW synthesis protocols, including template assisted and wet chemical techniques, and their ability to control the morphology of the synthesized nanowires. Furthermore, the use of scalable and cost-effective solution deposition methods to fabricate AgNW based TCE, along with the numerous treatments used for enhancing their optoelectronic properties, are also discussed.

4.
Artigo em Inglês | MEDLINE | ID: mdl-33817919

RESUMO

Heme-like metal-chelating macrocycles, including expanded and contracted porphyrins, are of everlasting interest as drug candidates for numerous diseases. Still, all reported corrole derivatives (and most other heme analogs) do not fulfill the most basic standards expected for oral drug administration: a combination of low molecular weight and reasonable water solubility. We now disclose a very facile synthetic methodology that relies on surprisingly easy trifluoromethyl hydrolysis for gaining access to a new class of corroles that do satisfy all druglikeness criteria. The relevance is briefly exemplified for the iron corroles by demonstrating the ability to affect their association to plasma proteins and their performance for catalase-like decomposition of hydrogen peroxide.

5.
Artigo em Inglês | MEDLINE | ID: mdl-33830736

RESUMO

A technology for systemic and repeated administration of osteogenic factors for orthopedic use is an unmet medical need. Lactoferrin (∼80 kDa), present in milk, is known to support bone growth. We discovered a lactoferrin-mimetic peptide, LP2 (an 18-residue fragment from the N-terminus of the N-lobe of human lactoferrin), which self-assembles into a nano-globular assembly with a ß-sheet structure in an aqueous environment. LP2 is non-hemolytic and non-cytotoxic against human red blood cells and 3T3 fibroblasts, respectively, and appreciably stable in the human serum. LP2 through the bone morphogenetic protein-dependent mechanism stimulates osteoblast differentiation more potently than the full-length protein as well as the osteoblastic production of osteoprotegerin (an anti-osteoclastogenic factor). Consequently, daily subcutaneous administration of LP2 to rats and rabbits with osteotomy resulted in faster bone healing and stimulated bone formation in rats with a low bone mass more potently than that with teriparatide, the standard-of-care osteogenic peptide for osteoporosis. LP2 has skeletal bioavailability and is safe at the 15× osteogenic dose. Thus, LP2 is a novel peptide that can be administered systemically for the medical management of hard-to-heal fractures.

6.
Artigo em Inglês | MEDLINE | ID: mdl-33829315

RESUMO

Decalepis salicifolia (Bedd. ex. Hook.f.) Venter is a potential natural source of the vanillin isomer, 2-hydroxy-4-methoxybenzaldehyde (2H4MB), an aromatic compound. However, the utilization of the plant is hindered especially due to its critically endangered status and the root-specific accumulation of the compound. The use of in vitro culture techniques offers a sustainable means for the production of valuable metabolites. In this study, an efficient system was established for the production of 2H4MB in the adventitious root cultures of D. salicifolia. Leaf explants of in vitro grown plants produced on an average 4.33 ± 2.07 number of roots with root initiation frequency of 95.69 ± 3.74% in woody plant medium supplemented with 0.5 mg/L α-naphthalene acetic acid (NAA) and 1.0 mg/L kinetin (Kn). The adventitious root biomass accumulation of 10.61 ± 0.89 g fresh weight (FW) was obtained in woody plant liquid media containing 0.5 mg/L NAA and 0.3 mg/L indole-3-butyric acid (IBA) in 60 days of inoculation. Field-grown plants of the same age produced 0.30 ± 0.02 g FW, which was 35-fold lower than the adventitious root culture. The total production of 2H4MB in the same growth period was 4.9-fold higher in adventitious root culture (139.54 µg) as compared to field-grown plants (28.62 µg). Furthermore, sucrose concentration of 2% was favorable for biomass accumulation, whereas 5% was favorable for 2H4MB production. On the other hand, media pH 5.0 was suitable for biomass production and pH 7.0 was best suited for accumulation of 2H4MB. The adventitious roots also showed stable production of biomass and 2H4MB over 2 years. The established adventitious root culture system is suitable for further large-scale production of 2H4MB for flavor and fragrance industrial applications. KEY POINTS: • Biomass accumulation was higher in adventitious root cultures than in field-grown plants. • Manipulation of sucrose concentration and media pH led to increased 2H4MB production. • Adventitious roots showed stable biomass and 2H4MB production over 2 years.

7.
Environ Dev Sustain ; : 1-19, 2021 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-33782633

RESUMO

The study aims to examine the CO2 emissions by considering the implication of COVID-19 under strict lockdown in India. The nonlinear (asymmetric) relationship is investigated between CO2 emission and COVID-19 with its specific determinants. The positive and negative asymmetries of COVID-19 determinants are also captured by using econometric techniques. The daily data series of CO2 emission, new confirmed cases, confirmed deaths, and lockdown as dummy variables from January 30, 2020, to December 1, 2020, for India is analyzed by employing the nonlinear autoregressive distributed lag model. This research revealed a significant nonlinear relationship between CO2 emission and COVID-19. The bound test and asymmetric coefficients are confirmed by the variables' long- and short-run relationships. The dynamic multiplier graphs present that India's strict lockdown due to the rapid increase in COVID-19 patients significantly reduces toxic gas emissions, especially CO2 emissions. This asymmetric relationship has been proficiently declared that unhealthy public routine, extra traffic, and unhygienic gases released in the air become the reason for environmental destruction. The lockdown is practically imposed for specific periods and reasons, contributing to reducing toxic emissions, but it is not a permanent solution for environmental sustainability. The government of India, policymakers, and environmentalists should make people aware of unhealthy and environmentally envying activities and policies and long-term applicable strategies should be designed to upgrade the environment's quality.

8.
J Am Med Dir Assoc ; 2021 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-33775597

RESUMO

OBJECTIVES: The COVID-19 pandemic has disproportionately affected racial and ethnic minorities in the United States and has been devastating for residents of nursing homes (NHs). However, evidence on racial and ethnic disparities in COVID-19-related mortality rates within NHs and how that has changed over time has been limited. This study examines the impact of a high proportion of minority residents in NHs on COVID-19-related mortality rates over a 30-week period. DESIGN: Longitudinal study. SETTING AND PARTICIPANTS: Centers for Medicare & Medicaid Services Nursing Home COVID-19 Public Use File data from 50 states from June 1, 2020, to December 27, 2020. METHODS: We linked data from 11,718 NHs to (1) Nursing Home Compare data, (2) the Long-Term Care: Facts on Care in the U.S., and (3) US county-level data on COVID cases and deaths. Our primary independent variable was proportion of minority residents (blacks and Hispanics) in NHs and its association with mortality rate over time. RESULTS: During the first 6 weeks from June 1, 2020, NHs with a higher proportion of black residents reported more COVID-19 deaths per 1000 followed by NHs with a higher proportion of Hispanic residents. Between 7 and 12 weeks, NHs with a higher proportion of Hispanic residents reported more deaths per 1000, followed by NHs with a higher proportion of black residents. However, after 23 weeks (mid-November 2020), NHs serving a higher proportion of white residents reported more deaths per 1000 than NHs serving a high proportion of black and Hispanic residents. CONCLUSIONS AND IMPLICATIONS: The disparities in COVID-19-related mortality for nursing homes serving minority residents is evident for the first 12 weeks of our study period. Policy interventions and the equitable distribution of vaccine are required to mitigate the impact of systemic racial injustice on health outcomes of people of color residing in NHs.

9.
Plant Physiol Biochem ; 162: 110-123, 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33667964

RESUMO

Salt stress limits plant growth and productivity by severely impacting the fundamental physiological processes. Silicon (Si) supplementation is considered one of the promising methods to improve plant resilience under salt stress. Here, the role of Si in modulating physiological and biochemical processes that get adversely affected by high salinity, is discussed. Although numerous reports show the beneficial effects of Si under stress, the precise molecular mechanism underlying this is not well understood. Questions like whether all plants are equally benefitted with Si supplementation despite having varying Si uptake capability and salinity tolerance are still elusive. This review illustrates the Si uptake and accumulation mechanism to understand the direct or indirect participation of Si in different physiological processes. Evaluation of plant responses at transcriptomics and proteomics levels are promising in understanding the role of Si. Integration of physiological understanding with omics scale information highlighted Si supplementation affecting the phytohormonal and antioxidant responses under salinity as a key factor defining improved resilience. Similarly, the crosstalk of Si with lignin and phenolic content under salt stress also seems to be an important phenomenon helping plants to reduce the stress. The present review also addressed various crucial mechanisms by which Si application alleviates salt stress, such as a decrease in oxidative damage, decreased lipid peroxidation, improved photosynthetic ability, and ion homeostasis. Besides, the application and challenges of using Si-nanoparticles have also been addressed. Comprehensive information and discussion provided here will be helpful to better understand the role of Si under salt stress.

10.
ACS Appl Mater Interfaces ; 13(12): 14569-14576, 2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33724775

RESUMO

Cinnamate-based polyesters were synthesized, including poly(4-hydroxycinnamic acid), poly(4-hydroxy-3-methoxycinnamic acid), poly(3-hydroxycinnamic acid) (P3HCA), and hyperbranched poly(3,4-dihydroxycinnamic acid) (PdHCA). These materials were further processed into hard and dry membranes by casting and underwent photoreactions by ultraviolet (UV) light. The photodeformation behavior of the linear and hyperbranched polyester containing membranes with cinnamate derivatives in the main chain was observed macroscopically and microscopically. The PdHCA and P3HCA membranes were amorphous and exhibited photodeformations. The PdHCA surface visibly contracts, which is a typically observed phenomenon in photoresponsive polymers; however, the P3HCA surface showed a unique photoexpansion behavior. Time-resolution infrared spectroscopy of the P3HCA film revealed trans-to-cis isomerism in the polymer main chains that bent convexly as a result of photoexpansion of the UV-irradiated regions. Furthermore, photomasking created a micropattern on the P3HCA film, which supported the photoexpansion mechanism of the P3HCA film.

11.
Indian Pediatr ; 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33772534

RESUMO

OBJECTIVES: We assessed agreement between non-invasive (Oscillatory) blood pressure (NIBP) measurements and invasive intra-arterial blood pressure (IBP) in the pediatric cardiac critical care unit. METHODS: Children with intra-arterial lines as per standard management protocol were enrolled. NIBP was measured every 4 hourly and the corresponding IBP reading was recorded. RESULTS: A total of 839 brachial NIBP, 834 IBP Femoral (IF), and 137 IBP Radial (IR) readings were noted on 45 participants. The mean difference (95% CI) for agreement between NIBP and IF was -2.3 (-27.1, 22.5) mmHg for systolic, 0.9 (-21.3, 23.1) mmHg for diastolic and 0.3 (-23.3, 23.9) mmHg for mean BP. Similar results were found between NIBP and IR and between IF and IR. The interrater agreement [Kappa (95% CI)] was fair between NIBP and IF [0.54 (0.48, 0.61)], and IF and IR [0.62 (0.48, 0.76)] but lower between NIBP and IR [0.37(0.20, 0.55)] when values were classified as hypotensive, normotensive, and hypertensive. CONCLUSIONS: NIBP cannot replace but can supplement IBP in the pediatric cardiac critical care setting.

12.
Phys Chem Chem Phys ; 23(10): 5963-5968, 2021 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-33666599

RESUMO

The present work investigates the effect of confinement on the hydrogen bonding interactions in H2S dimers. The interiors of different sized fullerenes (C60, C70, C84, and C120) have been used to model the effect of confinement. It was found that as the degree of confinement increases, the hydrogen bonding between H2S molecules disappears and sulphur-sulphur interactions appear. We obtained clear computational evidence that, inside C60, the H2S dimer is bound by a covalent bond between two sulphur atoms. It was also found that the strength of the S-S bond inside fullerenes is linked to the amount of charge transfer from the H2S dimer to the fullerene.

13.
Adv Mater ; : e2008068, 2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33734520

RESUMO

During switching, the microstructure of a ferroelectric normally adapts to align internal dipoles with external electric fields. Favorably oriented dipolar regions (domains) grow at the expense of those in unfavorable orientations and this is manifested in a predictable field-induced motion of the walls that separate one domain from the next. Here, the discovery that specific charged 90°domain walls in copper-chlorine boracite move in the opposite direction to that expected, increasing the size of the domain in which polarization is anti-aligned with the applied field, is reported. Polarization-field (P-E) hysteresis loops, inferred from optical imaging, show negative gradients and non-transient negative capacitance, throughout the P-E cycle. Switching currents (generated by the relative motion between domain walls and sensing electrodes) confirm this, insofar as their signs are opposite to those expected conventionally. For any given bias, the integrated switching charge due to this anomalous wall motion is directly proportional to time, indicating that the magnitude of the negative capacitance component should be inversely related to frequency. This passes Jonscher's test for the misinterpretation of positive inductance and gives confidence that field-induced motion of these specific charged domain walls generates a measurable negative capacitance contribution to the overall dielectric response.

14.
Indian J Public Health ; 65(1): 67-70, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33753694

RESUMO

Tobacco-Free Educational Institution (ToFEI) guidelines are required to be followed by the schools. This cross-sectional study conducted in the year 2019 assessed the accordance with ToFEI guidelines among all the 84 schools of Raipur Rani educational block, Haryana. Investigators collected data from all the government (71) and private (13) schools during school working days. Tobacco sales within 100 yards of the school premises was covertly observed. None of the schools thoroughly complied with the tobacco-free school policy, though the compliance score for private schools (26.77 ± 19.15) was better than the government schools (13.65 ± 4.38). Only two private schools achieved the mandatory score of 50. All private schools and few government schools (42.3%) had successfully implemented the ban on tobacco sale within 100 yards of the school. None of the schools could achieve a ToFEI status in the present study. The policymakers and implementers should prioritize ToFEI agenda & support schools in achieving tobacco-free status.

16.
Materials (Basel) ; 14(4)2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33671941

RESUMO

The primary objective of this research was to develop a finite element model specifically designed for electron beam additive manufacturing (EBAM) of Ti-6Al-4V to understand metallurgical and mechanical aspects of the process. Multiple single-layer and 10-layer build Ti-6Al-4V samples were fabricated to validate the simulation results and ensure the reliability of the developed model. Thin wall plates of 3 mm thickness were used as substrates. Thermocouple measurements were recorded to validate the simulated thermal cycles. Predicted and measured temperatures, residual stresses, and distortion profiles showed that the model is quite reliable. The thermal predictions of the model, when validated experimentally, gave a low average error of 3.7%. The model proved to be extremely successful for predicting the cooling rates, grain morphology, and the microstructure. The maximum deviations observed in the mechanical predictions of the model were as low as 100 MPa in residual stresses and 0.05 mm in distortion. Tensile residual stresses were observed in the deposit and the heat-affected zone, while compressive stresses were observed in the core of the substrate. The highest tensile residual stress observed in the deposit was approximately 1.0 σys (yield strength). The highest distortion on the substrate was approximately 0.2 mm.

17.
Chemosphere ; 275: 129996, 2021 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-33647680

RESUMO

Nickel (Ni) has been a subject of interest for environmental, physiological, biological scientists due to its dual effect (toxicity and essentiality) in terrestrial biota. In general, the safer limit of Ni is 1.5 µg g-1 in plants and 75-150 µg g-1 in soil. Litreature review indicates that Ni concentrations have been estimated up to 26 g kg-1 in terrestrial, and 0.2 mg L-1 in aquatic resources. In case of vegetables and fruits, mean Ni content has been reported in the range of 0.08-0.26 and 0.03-0.16 mg kg-1. Considering, Ni toxicity and its potential health hazards, there is an urgent need to find out the suitable remedial approaches. Plant vascular (>80%) and cortical (<20%) tissues are the major sequestration site (cation exchange) of absorbed Ni. Deciphering molecular mechanisms in transgenic plants have immense potential for enhancing Ni phytoremediation and microbial remediation efficiency. Further, it has been suggested that integrated bioremediation approaches have a potential futuristic path for Ni decontamination in natural resources. This systematic review provides insight on Ni effects on terrestrial biota including human and further explores its transportation, bioaccumulation through food chain contamination, human health hazards, and possible Ni remediation approaches.

18.
Artigo em Inglês | MEDLINE | ID: mdl-33653246

RESUMO

BACKGROUND: In this study, Near-field electrospinning (NFES) technique used with a cylindrical collector to fabricate a large area permanent piezoelectric micro and nanofibers by a prepared solution. NFES requires a small electric field to fabricate fibers. OBJECTIVE: The objective of this paper to investigate silver nanoparticle (Ag-NP)/ Polyvinylidene fluoride (PVDF) composite as the best piezoelectric material with improved properties to produced tremendously flexible and sensitive piezoelectric material with pertinent conductance. METHOD: In this paper we used controllable electrospinning technique based on Near-field electrospinning (NFES)The process parameter for Ag-NP/PVDF composite electrospun fiber based on pure PVDF fiber. A PVDF solution concentration of 18 wt.% and 6 wt.% silver nitrate which is relative to the weight of PVDF wt.% with 1058 µS conductivity fibers have been directly written on a rotating cylindrical collector for aligned fiber PVDF/Ag-NP fibers are patterned on fabricated copper (Cu) interdigitated electrodes were implemented on a thin flexible polyethylene terephthalate (PET) substrate and Polydimethylsiloxane (PDMS) used as a package to enhance the durability of the PVDF/ Ag-NP device. RESULTS: A notable effect on the piezoelectric response has been observed after Ag-NP addition confirmed by XRD characterization and tapping test of Ag-NP/PVDF composite fiber. The morphology of the PVDF/Ag-NP fibers and measure diameter by scanning electron microscopy (SEM) and Optical micrograph (OM), of fiber. Finally, The result shows that diameter of PVDF/Ag-NP fibers up to ~7 µm. The. High diffraction peak at 2θ = 20.5˚ was investigated by X-ray diffraction (XRD) in the piezoelectric crystal ß-phase structure. While the electromechanical conversion is found enhance from ~0.1 V to ~1 V by the addition of silver nanoparticles (Ag-NPs) in the PVDF solution. CONCLUSION: In conclusion, we can say that confirmed and validated the addition of Ag-NP in PVDF could enhance the piezoelectric property by using NFES technique with improved crystalline phase content can be useful for a wide range of power and sensing applications like biomedical devices and energy harvesting, among others.

19.
J Bacteriol ; 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33649149

RESUMO

DNA strand consisting of multiple runs of guanines can adopt the non-canonical, four-stranded DNA secondary structure known as G-quadruplex or G4 DNA. G4 DNA is thought to play an important role in transcriptional and translational regulation of genes, DNA replication, genome stability, and oncogene expression in eukaryotic genomes. In other organisms including several bacterial pathogens and some plant species, the biological role of G4 DNA and G4 RNA is starting to be explored. Recent investigation showed that G4 DNA and G4 RNA are generally conserved across plant species. In silico analyses of several bacterial genomes identified the putative guanine-rich, G4 DNA-forming sequences in the promoter regions. They were particularly abundant in certain gene classes, suggesting that these highly diverse structures can be employed to regulate expression of genes involved in secondary metabolite synthesis and signal transduction. Furthermore, in the pathogen Mycobacterium tuberculosis, the distribution of G4 motifs and their potential role in the regulation of gene transcription advocate for the use of G4 ligands to develop novel antitubercular therapies. In this review, we discuss the various roles of G4 structures in bacterial DNA and the application of G4 DNA as an inhibitor or therapeutic agent to tackle the bacterial pathogens.

20.
FEMS Microbiol Lett ; 2021 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-33713123

RESUMO

Several fungi have been shown to harbor microorganisms that regulate the key components of fungal metabolism. We explored the symbiotic association of an endophyte, Aspergillus terreus which led to the isolation of a yeast, Meyerozyma caribbica as its symbiont. An axenic fungal culture, free of the symbiont, was developed to study the effect of this association on the endophytic fungus. The symbiotic yeast partner was found to play an important role in the adaptation of A. terreus to thermal as well as osmotic stress. Under these stress conditions, the symbiont enhanced the production of lovastatin and the growth of the host fungus. The symbiotic yeast was found to induce the expression of the global regulator gene, the key genes involved in the lovastatin biosynthetic pathway as well as those involved in general growth and development, under stress conditions, in the fungal partner. Analysis by PCR and FISH microscopy indicated that the yeast may be present inside the hyphae of the fungus. However, a direct method like transmission electron microscopy may help to better understand the dynamics of this association including the distribution of the yeast cells in/on the fungal hyphae and spores.

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