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1.
Adv Exp Med Biol ; 1398: 53-64, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36717486

RESUMO

Aquaporins (AQP) are a class of the integral membrane proteins. The main physiological function of AQPs is to facilitate the water transport across plasma membrane of cells. However, the transport of various kinds of small molecules by AQPs is an interesting topic. Studies using in vitro cell models have found that AQPs mediated transport of small molecules, including glycerol, urea, carbamides, polyols, purines, pyrimidines and monocarboxylates, and gases such as CO2, NO, NH3, H2O2 and O2, although the high intrinsic membrane permeabilities for these gases make aquaporin-facilitated transport not dominant in physiological mechanism. AQPs are also considered to transport silicon, antimonite, arsenite and some ions; however, most data about transport characteristics of AQPs are derived from in vitro experiments. The physiological significance of AQPs that are permeable to various small molecules is necessary to be determined by in vivo experiments. This chapter will provide information about the transport characteristics of AQPs.


Assuntos
Aquaporinas , Peróxido de Hidrogênio , Peróxido de Hidrogênio/metabolismo , Água/metabolismo , Aquaporinas/genética , Aquaporinas/metabolismo , Transporte Biológico , Gases/metabolismo
2.
Int J Mol Sci ; 23(21)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36362091

RESUMO

Short-term gaseous treatments improve rachis quality during table grape postharvest, but little is known about the mechanisms involved. In this work, we observed that the application of a 3-day CO2 treatment at 0 °C improved rachis browning of Superior Seedless and Red Globe bunches, affecting the non-enzymatic antioxidant system by reducing the total phenolic content, the antioxidant activity and the expression of different stilbene synthase genes. Lipid peroxidation levels revealed lower oxidative stress in CO2-treated rachis of both cultivars linked to the activation of the enzymatic antioxidant system. Furthermore, whereas a positive correlation was denoted between rachis browning and the accumulation of key ABA regulatory genes in Red Globe bunches, this effect was restricted to ACS1, a key synthetic ethylene gene, in Superior Seedless clusters. This work also corroborated the important role of ethylene-responsive factors in the beneficial effect of the gaseous treatment, not only in the berries but also in the rachis. Finally, the application of the gaseous treatment avoided the induction of cell wall-degrading enzyme-related genes in both cultivars, which could favor the maintenance of rachis quality. This work provides new insight into specific responses modulated by the gaseous treatment focused on mitigating rachis browning independently of the cultivar.


Assuntos
Vitis , Vitis/genética , Gases/metabolismo , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Dióxido de Carbono/metabolismo , Temperatura , Frutas/metabolismo , Etilenos/farmacologia , Etilenos/metabolismo
3.
Nutrients ; 14(19)2022 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-36235628

RESUMO

This research examined the effects of single-dose molecular hydrogen (H2) supplements on acid-base status and local muscle deoxygenation during rest, high-intensity intermittent training (HIIT) performance, and recovery. Ten healthy, trained subjects in a randomized, double-blind, crossover design received H2-rich calcium powder (HCP) (1500 mg, containing 2.544 µg of H2) or H2-depleted placebo (1500 mg) supplements 1 h pre-exercise. They performed six bouts of 7 s all-out pedaling (HIIT) at 7.5% of body weight separated by 40 s pedaling intervals, followed by a recovery period. Blood gases' pH, PCO2, and HCO3- concentrations were measured at rest. Muscle deoxygenation (deoxy[Hb + Mb]) and tissue O2 saturation (StO2) were determined via time-resolved near-infrared spectroscopy in the vastus lateralis (VL) and rectus femoris (RF) muscles from rest to recovery. At rest, the HCP group had significantly higher PCO2 and HCO3- concentrations and a slight tendency toward acidosis. During exercise, the first HIIT bout's peak power was significantly higher in HCP (839 ± 112 W) vs. Placebo (816 ± 108 W, p = 0.001), and HCP had a notable effect on significantly increased deoxy[Hb + Mb] concentration during HIIT exercise, despite no differences in heart rate response. The HCP group showed significantly greater O2 extraction in VL and microvascular (Hb) volume in RF during HIIT exercise. The HIIT exercise provided significantly improved blood flow and muscle reoxygenation rates in both the RF and VL during passive recovery compared to rest in all groups. The HCP supplement might exert ergogenic effects on high-intensity exercise and prove advantageous for improving anaerobic HIIT exercise performance.


Assuntos
Treinamento Intervalado de Alta Intensidade , Substâncias para Melhoria do Desempenho , Cálcio/metabolismo , Gases/metabolismo , Humanos , Hidrogênio/metabolismo , Músculo Esquelético/metabolismo , Consumo de Oxigênio/fisiologia , Substâncias para Melhoria do Desempenho/metabolismo , Pós
4.
mBio ; 13(5): e0188822, 2022 10 26.
Artigo em Inglês | MEDLINE | ID: mdl-36154443

RESUMO

The obligate intracellular protozoan pathogen Toxoplasma gondii infects a wide range of vertebrate hosts and frequently causes zoonotic infections in humans. Whereas infected immunocompetent individuals typically remain asymptomatic, toxoplasmosis in immunocompromised individuals can manifest as a severe, potentially lethal disease, and congenital Toxoplasma infections are associated with adverse pregnancy outcomes. The protective immune response of healthy individuals involves the production of lymphocyte-derived cytokines such as interferon gamma (IFN-γ), which elicits cell-autonomous immunity in host cells. IFN-γ-inducible antiparasitic defense programs comprise nutritional immunity, the production of noxious gases, and the ubiquitylation of the Toxoplasma-containing parasitophorous vacuole (PV). PV ubiquitylation prompts the recruitment of host defense proteins to the PV and the consequential execution of antimicrobial effector programs, which reduce parasitic burden. However, the ubiquitin E3 ligase orchestrating these events has remained unknown. Here, we demonstrate that the IFN-γ-inducible E3 ligase RNF213 translocates to Toxoplasma PVs and facilitates PV ubiquitylation in human cells. Toxoplasma PVs become decorated with linear and K63-linked ubiquitin and recruit ubiquitin adaptor proteins in a process that is RNF213 dependent but independent of the linear ubiquitin chain assembly complex (LUBAC). IFN-γ priming fails to restrict Toxoplasma growth in cells lacking RNF213 expression, thus identifying RNF213 as a potent executioner of ubiquitylation-driven antiparasitic host defense. IMPORTANCE Globally, approximately one out of three people become infected with the obligate intracellular parasite Toxoplasma. These infections are typically asymptomatic but can cause severe disease and mortality in immunocompromised individuals. Infections can also be passed on from mother to fetus during pregnancy, potentially causing miscarriage or stillbirth. Therefore, toxoplasmosis constitutes a substantial public health burden. A better understanding of mechanisms by which healthy individuals control Toxoplasma infections could provide roadmaps toward novel therapies for vulnerable groups. Our work reveals a fundamental mechanism controlling intracellular Toxoplasma infections. Cytokines produced during Toxoplasma infections instruct human cells to produce the enzyme RNF213. We find that RNF213 labels intracellular vacuoles containing Toxoplasma with the small protein ubiquitin, which functions as an "eat-me" signal, attracting antimicrobial defense programs to fight off infection. Our work therefore identified a novel antiparasitic protein orchestrating a central aspect of the human immune response to Toxoplasma.


Assuntos
Toxoplasma , Toxoplasmose , Humanos , Adenosina Trifosfatases/metabolismo , Antiparasitários/metabolismo , Antivirais/metabolismo , Citocinas/metabolismo , Gases/metabolismo , Interferon gama , Interferons/metabolismo , Toxoplasma/metabolismo , Toxoplasmose/parasitologia , Ubiquitina/metabolismo , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Vacúolos/metabolismo
5.
Fungal Genet Biol ; 163: 103739, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36089227

RESUMO

Fungal biofilm founder cells experience self-generated hypoxia leading to dramatic changes in their cell biology. For example, during Aspergillus nidulans biofilm formation microtubule (MT) disassembly is triggered causing dispersal of EB1 from MT tips. This process is dependent on SrbA, a sterol regulatory element-binding transcription factor required for adaptation to hypoxia. We show that SrbA, an ER resident protein prior to activation, is proteolytically activated during early stages of biofilm formation and that, like SrbA itself, its activating proteases are also required for normal biofilm MT disassembly. In addition to SrbA, the AtrR transcription factor is also found to be required to modulate cellular responses to gaseous signaling during biofilm development. Using co-cultures, we further show that cells lacking srbA or atrR are capable of responding to biofilm generated gaseous microenvironments but are actually more sensitive to this signal than wild type cells. SrbA is a regulator of ergosterol biosynthetic genes and we find that the levels of seven GFP-tagged Erg proteins differentially accumulate during biofilm formation with various dependencies on SrbA for their accumulation. This uncovers a complex pattern of regulation with biofilm accumulation of only some Erg proteins being dependent on SrbA with others accumulating to higher levels in its absence. Because different membrane sterols are known to influence cell permeability to gaseous molecules, including oxygen, we propose that differential regulation of ergosterol biosynthetic proteins by SrbA potentially calibrates the cell's responsiveness to gaseous signaling which in turn modifies the cell biology of developing biofilm cells.


Assuntos
Aspergillus nidulans , Aspergillus nidulans/genética , Aspergillus nidulans/metabolismo , Aspergillus fumigatus/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Esteróis/metabolismo , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Gases/metabolismo , Proteínas de Ligação a Elemento Regulador de Esterol/genética , Hipóxia , Biofilmes , Ergosterol/metabolismo
6.
J Dairy Sci ; 105(11): 8879-8897, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36085109

RESUMO

To investigate the effects of acetate, propionate, and pH on thermodynamics of volatile fatty acids (VFA) in the rumen, a dual-flow continuous culture study was conducted to quantify production of major VFA, interconversions among the VFA, and H2 and CH4 emissions in a 4 × 4 Latin square design. The 4 treatments were (1) control: pH buffered to an average of 6.75; (2) control plus 20 mmol/d of infused acetate (InfAc); (3) control plus 7 mmol/d of infused propionate (InfPr); and (4) a 0.5-unit decline in pH elicited by adjustment of the buffer (LowpH). All fermentors were fed 40 g of a pelleted diet containing whole alfalfa pellets and concentrate mix pellets (50:50) once daily. After 7 d of treatment, sequential, continuous infusions of [2-13C] sodium acetate (3.5 mmol/d), [U-13C] sodium propionate (2.9 mmol/d), and [1-13C] sodium butyrate (0.22 mmol/d) were carried out from 12 h before feeding for 36 h. Filtered liquid effluent (4 mL) was sampled at 0, 2, 4, 6, 8, 12, 16, and 22 h after feeding, and assessed for VFA concentrations, with another filtered sample (20 mL) used to quantify aqueous concentrations of CH4 and H2. Headspace CH4 and H2 gases were monitored continuously. Ruminal microbes were isolated from the mixed effluent samples, and the microbial community structure was analyzed using the 16S rRNA amplicon sequencing technique. The digestibility of neutral detergent fiber, acid detergent fiber, and starch and microbial C sequestrated from VFA were not affected by treatments. The LowpH treatment increased net propionate production and decreased H2 and CH4 headspace emissions, primarily due to shifts in metabolic pathways of VFA formation, likely due to the observed changes in bacterial community structure. Significant interconversions occurred between acetate and butyrate, whereas interconversions of other VFA with propionate were relatively small. The InfAc and InfPr treatments increased net acetate and propionate production, respectively; however, interconversions among VFA were not affected by pH, acetate, or propionate treatments, suggesting that thermodynamics might not be a primary influencer of metabolic pathways used for VFA formation.


Assuntos
Propionatos , Rúmen , Animais , Rúmen/metabolismo , Propionatos/metabolismo , RNA Ribossômico 16S/metabolismo , Ácido Butírico/metabolismo , Acetato de Sódio , Detergentes/metabolismo , Fermentação , Ácidos Graxos Voláteis/metabolismo , Acetatos/metabolismo , Dieta , Amido/metabolismo , Concentração de Íons de Hidrogênio , Termodinâmica , Gases/metabolismo , Digestão , Ração Animal
7.
Biomed Pharmacother ; 155: 113666, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36099790

RESUMO

Acute lung injury (ALI) and its more serious form; acute respiratory distress syndrome are major causes of COVID-19 related mortality. Finding new therapeutic targets for ALI is thus of great interest. This work aimed to prepare a biocompatible nanoformulation for effective pulmonary delivery of the herbal drug; tanshinone-IIA (TSIIA) for ALI management. A nanoemulsion (NE) formulation based on bioactive natural ingredients; rhamnolipid biosurfactant and tea-tree oil, was developed using a simple ultrasonication technique, optimized by varying oil concentration and surfactant:oil ratio. The selected TSIIA-NE formulation showed 105.7 nm diameter and a PDI âˆ¼ 0.3. EE exceeded 98 % with biphasic sustained drug release and good stability over 3-months. In-vivo efficacy was evaluated in lipopolysaccharide (LPS)-induced ALI model. TSIIA-NE (30 µg/kg) was administered once intratracheally 2 h after LPS instillation. Evaluation was performed 7days post-treatment. Pulmonary function assessment, inflammatory, oxidative stress and glycocalyx shedding markers analysis in addition to histopathological examination of lung tissue were performed. When compared to untreated rats, in-vivo efficacy study demonstrated 1.4 and 1.9-fold increases in tidal volume and minute respiratory volume, respectively, with 32 % drop in wet/dry lung weight ratio and improved levels of arterial blood gases. Lung histopathology and biochemical analysis of different biomarkers in tissue homogenate and bronchoalveolar lavage fluid indicated that treatment may ameliorate LPS-induced ALI symptoms thorough anti-oxidative, anti-inflammatory effects and inhibition of glycocalyx degradation. TSIIA-NE efficacy was superior to free medication and blank-NE. The enhanced efficacy of TSIIA bioactive nanoemulsion significantly suggests the pharmacotherapeutic potential of bioactive TSIIA-NE as a promising nanoplatform for ALI.


Assuntos
Lesão Pulmonar Aguda , Ratos , Animais , Lipopolissacarídeos/farmacologia , Glicocálix/patologia , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/tratamento farmacológico , Lesão Pulmonar Aguda/patologia , Pulmão , Anti-Inflamatórios/farmacologia , Tensoativos/farmacologia , Gases/efeitos adversos , Gases/metabolismo , Chá/metabolismo
8.
Sci Total Environ ; 848: 157653, 2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-35926596

RESUMO

This study investigated the impacts of lime addition and further microbial inoculum on gaseous emission and humification during kitchen waste composting. High-throughput sequencing was integrated with Linear Discriminant Analysis Effect Size (LEfSe) and Functional Annotation of Prokaryotic Taxa (FAPROTAX) to decipher bacterial dynamics in response to different additives. Results showed that lime addition enriched bacteria, such as Taibaiella and Sphingobacterium as biomarkers, to strengthen organic biodegradation toward humification. Furthermore, lime addition facilitated the proliferation of thermophilic bacteria (e.g. Bacillus and Symbiobacterium) for aerobic chemoheterotrophy, leading to enhanced organic decomposition to trigger notable gaseous emission. Such emission profile was further exacerbated by microbial inoculum to lime-regulated condition given the rapid enrichment of bacteria (e.g. Caldicoprobacter and Pusillimonas as biomarkers) for fermentation and denitrification. In addition, microbial inoculum slightly hindered humus formation by narrowing the relative abundance of bacteria for humification. Results from this study show that microbial inoculum to feedstock should be carefully regulated to accelerate composting and avoid excessive gaseous emission.


Assuntos
Compostagem , Bactérias/metabolismo , Compostos de Cálcio , Compostagem/métodos , Gases/metabolismo , Óxidos , Solo
9.
Sci Total Environ ; 848: 157735, 2022 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-35926625

RESUMO

This study evaluated the effects of supplementing feed with arazyme and dietary carbohydrolases derived from invertebrate gut-associated symbionts on the noxious gas emissions, gut microbiota, and host-microbiome interactions of pigs. Here, 270 and 260 growing pigs were assigned to control and treatment groups, respectively. The tested feed additives contained a mixture of arazyme (2,500,000 Unit/kg) and synergetic enzymes, xylanase (200,000 Unit/kg) and mannanase (200,000 Unit/kg), derived from insect gut-associated symbionts in a 7.5:1:1 ratio. The control group was fed a basal diet and the treatment group was fed the basal diet supplemented with 0.1 % enzyme mixture (v/v) for 2 months. Odorous gases were monitored in ventilated air from tested houses. Fecal samples were collected from steel plate under the cage at the completion of the experiment to determine chemical composition, odor emissions, and bacterial communities. There was a significant decrease in the concentration of NH3 (22.5 vs. 11.2 ppm; P < 0.05), H2S (7.35 vs. 3.74 ppm; P < 0.05), trimethylamine (TMA) (0.066 vs. 0.001 ppm; P < 0.05), and p-cresol (0.004 ppm vs. 0 ppm; P < 0.05) at 56 d in treatment group compared with the control group. Moreover, fecal analysis results showed that exogenous enzyme supplementation caused a reduction in VFAs and indole content with approximately >60 % and 72.7 %, respectively. The result of gas emission analysis showed that NH3 (9.9 vs. 5.3 ppm; P < 0.05) and H2S (5.8 vs. 4.1 ppm; P < 0.05) were significantly reduced in the treatment group compared to the control group. The gut microbiota of the treatment group differed significantly from that of the control group, and the treatment group altered predicted metabolic pathways, including sulfur and nitrogen related metabolism, urea degradation. The results demonstrated that supplementing feed with arazyme with dietary carbohydrolases effectively controls noxious gas emissions and improves health and meat quality of pigs.


Assuntos
Microbioma Gastrointestinal , Ração Animal/análise , Animais , Dieta/veterinária , Gases/metabolismo , Indóis , Nitrogênio/metabolismo , Odorantes/análise , Aço , Enxofre , Suínos , Ureia
10.
Bioresour Technol ; 361: 127711, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35907600

RESUMO

Gas fermentation is a well-established process for the conversion of greenhouse gases from industrial wastes into valuable multi-carbon chemicals. Here, a two-stage process was developed to expand the product range of gas fermentation and synthesized the versatile biopolymer bacterial cellulose (BC). In the first stage, the acetogen Clostridium autoethanogenum was cultivated with H2:CO:CO2 and produced ethanol and acetate. In the second stage, BC-synthesizing Komagataeibacter sucrofermentans was grown in the spent medium from gas fermentation. K. sucrofermentans was able to produce BC autotrophically from gas-derived metabolites alone as well as mixotrophically with the addition of exogenous glucose. In these circumstances, 1.31 g/L BC was synthesized with a major energetic contribution from C1 gas fermentation products. Mixotrophic BC characterization reveals unique properties including augmented mechanical strength, porosity, and crystallinity. This proof-of-concept process demonstrates that BC can be produced from gases and holds good potential for the efficient conversion of C1 wastes.


Assuntos
Celulose , Gases , Processos Autotróficos , Ciclo do Carbono , Celulose/química , Fermentação , Gases/metabolismo
11.
Bioresour Technol ; 361: 127656, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35872277

RESUMO

The sustainable production of chemicals and biofuels from non-fossil carbon sources is considered key to reducing greenhouse gas (GHG) emissions. Clostridium sp. can convert various substrates, including the 1st-generation (biomass crops), the 2nd-generation (lignocellulosic biomass), and the 3rd-generation (C1 gases) feedstocks, into high-value products, which makes Clostridia attractive for biorefinery applications. However, the complexity of lignocellulosic catabolism and C1 gas utilization make it difficult to construct efficient production routes. Accordingly, this review highlights the advances in the development of three generations of feedstocks with Clostridia as cell factories. At the same time, more attention was given to using agro-industrial wastes (lignocelluloses and C1 gases) as the feedstocks, for which metabolic and process engineering efforts were comprehensively analyzed. In addition, the challenges of using agro-industrial wastes are also discussed. Lastly, several new synthetic biology tools and regulatory strategies are emphasized as promising technologies to be developed to address the aforementioned challenges in Clostridia and realize the efficient utilization of agro-industrial wastes.


Assuntos
Biocombustíveis , Resíduos Industriais , Biomassa , Clostridium/metabolismo , Gases/metabolismo , Engenharia Metabólica
12.
Biomed Phys Eng Express ; 8(4)2022 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-35594846

RESUMO

The transport of gases across cell membranes plays a key role in many different cell functions, from cell respiration to pH control. Mathematical models play a central role in understanding the factors affecting gas transport through membranes, and are the tool needed for testing the novel hypothesis of the preferential crossing through specific gas channels. Since the surface pH of cell membrane is regulated by the transport of gases such as CO2and NH3, inferring the membrane properties can be done indirectly from pH measurements. Numerical simulations based on recent models of the surface pH support the hypothesis that the presence of a measurement device, a liquid-membrane pH sensitive electrode on the cell surface may disturb locally the pH, leading to a systematic bias in the measured values. To take this phenomenon into account, it is necessary to equip the model with a description of the micro-environment created by the pH electrode. In this work we propose a novel, computationally lightweight numerical algorithm to simulate the surface pH data. The effect of different parameters of the model on the output are investigated through a series of numerical experiments with a physical interpretation.


Assuntos
Gases , Oócitos , Gases/metabolismo , Concentração de Íons de Hidrogênio , Modelos Teóricos , Oócitos/metabolismo
13.
Int J Mol Sci ; 23(8)2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35457090

RESUMO

Hydrogen sulfide (H2S) serves as an important gaseous signaling molecule that is involved in intra- and intercellular signal transduction in plant-environment interactions. In plants, H2S is formed in sulfate/cysteine reduction pathways. The activation of endogenous H2S and its exogenous application has been found to be highly effective in ameliorating a wide variety of stress conditions in plants. The H2S interferes with the cellular redox regulatory network and prevents the degradation of proteins from oxidative stress via post-translational modifications (PTMs). H2S-mediated persulfidation allows the rapid response of proteins in signaling networks to environmental stimuli. In addition, regulatory crosstalk of H2S with other gaseous signals and plant growth regulators enable the activation of multiple signaling cascades that drive cellular adaptation. In this review, we summarize and discuss the current understanding of the molecular mechanisms of H2S-induced cellular adjustments and the interactions between H2S and various signaling pathways in plants, emphasizing the recent progress in our understanding of the effects of H2S on the PTMs of proteins. We also discuss future directions that would advance our understanding of H2S interactions to ultimately mitigate the impacts of environmental stresses in the plants.


Assuntos
Sulfeto de Hidrogênio , Reguladores de Crescimento de Plantas , Gases/metabolismo , Sulfeto de Hidrogênio/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Plantas/metabolismo , Transdução de Sinais , Estresse Fisiológico
14.
ISME J ; 16(7): 1798-1808, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35396347

RESUMO

Lost Hammer Spring, located in the High Arctic of Nunavut, Canada, is one of the coldest and saltiest terrestrial springs discovered to date. It perennially discharges anoxic (<1 ppm dissolved oxygen), sub-zero (~-5 °C), and hypersaline (~24% salinity) brines from the subsurface through up to 600 m of permafrost. The sediment is sulfate-rich (1 M) and continually emits gases composed primarily of methane (~50%), making Lost Hammer the coldest known terrestrial methane seep and an analog to extraterrestrial habits on Mars, Europa, and Enceladus. A multi-omics approach utilizing metagenome, metatranscriptome, and single-amplified genome sequencing revealed a rare surface terrestrial habitat supporting a predominantly lithoautotrophic active microbial community driven in part by sulfide-oxidizing Gammaproteobacteria scavenging trace oxygen. Genomes from active anaerobic methane-oxidizing archaea (ANME-1) showed evidence of putative metabolic flexibility and hypersaline and cold adaptations. Evidence of anaerobic heterotrophic and fermentative lifestyles were found in candidate phyla DPANN archaea and CG03 bacteria genomes. Our results demonstrate Mars-relevant metabolisms including sulfide oxidation, sulfate reduction, anaerobic oxidation of methane, and oxidation of trace gases (H2, CO2) detected under anoxic, hypersaline, and sub-zero ambient conditions, providing evidence that similar extant microbial life could potentially survive in similar habitats on Mars.


Assuntos
Metano , Microbiota , Anaerobiose , Archaea/genética , Archaea/metabolismo , Gases/metabolismo , Sedimentos Geológicos/microbiologia , Metano/metabolismo , Oxirredução , Oxigênio/metabolismo , Filogenia , RNA Ribossômico 16S/genética , Sulfatos/metabolismo , Sulfetos/metabolismo
15.
ISME J ; 16(7): 1705-1716, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35319019

RESUMO

Natural gas seeps release significant amounts of methane and other gases including ethane and propane contributing to global climate change. In this study, bacterial actively consuming short-chain alkanes were identified by cultivation, whole-genome sequencing, and stable-isotope probing (SIP)-metagenomics using 13C-propane and 13C-ethane from two different natural gas seeps, Pipe Creek and Andreiasu Everlasting Fire. Nearly 100 metagenome-assembled genomes (MAGs) (completeness 70-99%) were recovered from both sites. Among these, 16 MAGs had genes encoding the soluble di-iron monooxygenase (SDIMO). The MAGs were affiliated to Actinobacteria (two MAGs), Alphaproteobacteria (ten MAGs), and Gammaproteobacteria (four MAGs). Additionally, three gaseous-alkane degraders were isolated in pure culture, all of which could grow on ethane, propane, and butane and possessed SDIMO-related genes. Two Rhodoblastus strains (PC2 and PC3) were from Pipe Creek and a Mycolicibacterium strain (ANDR5) from Andreiasu. Strains PC2 and PC3 encoded putative butane monooxygenases (MOs) and strain ANDR5 contained a propane MO. Mycolicibacterium strain ANDR5 and MAG19a, highly abundant in incubations with 13C-ethane, share an amino acid identity (AAI) of 99.3%. We show using a combination of enrichment and isolation, and cultivation-independent techniques, that these natural gas seeps contain a diverse community of active bacteria oxidising gaseous-alkanes, which play an important role in biogeochemical cycling of natural gas.


Assuntos
Alcanos , Gás Natural , Alcanos/metabolismo , Bactérias/genética , Bactérias/metabolismo , Butanos/metabolismo , Etano/metabolismo , Gases/metabolismo , Oxigenases de Função Mista/genética , Filogenia , Propano/metabolismo
16.
Environ Sci Pollut Res Int ; 29(37): 56579-56591, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35338463

RESUMO

Urban afforestation can mitigate the effects of air pollution, but the suitability of plant species for this purpose needs to be determined according to pollution intensity and climate change. The goal of this study was to evaluate the sensitivity of different phytotoxicity endpoints using two native Brazilian plant species as models, Aroeira (Schinus terebinthifolius) and Cuvatã (Cupania vernalis). The sensitivity parameters evaluated could help in selecting the most air-pollution-tolerant plant species for use in urban afforestation programs. The two plant species were exposed, in a greenhouse, to the combustion gases of a diesel engine for 120 days, with daily intermittent gas exposure. Every 30 days, leaf injury (chlorosis and necrosis), biomass, and physiological/biochemical parameters (proteins, chlorophyll, and peroxidase enzyme activity) were evaluated for both plant species. For the two selected species, the endpoints studied can be ranked according to their sensitivity (or inversely the tolerance) to diesel oil combustion gases in the following order: peroxidase > biomass ≈ chlorophyll > protein > leaf injury. The endpoint responses of higher plants can be used to assess the suitability of particular plant species for use in urban afforestation areas with relatively intense vehicle traffic.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Alcaloides , Anacardiaceae , Poluentes Atmosféricos/análise , Alcaloides/farmacologia , Anacardiaceae/metabolismo , Brasil , Clorofila/metabolismo , Gases/metabolismo , Peroxidases/metabolismo , Plantas/metabolismo , Sapindaceae
17.
Int J Mol Sci ; 23(3)2022 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-35163659

RESUMO

Rice crops are often subject to multiple abiotic stresses simultaneously in both natural and cultivated environments, resulting in yield reductions beyond those expected from single stress. We report physiological changes after a 4 day exposure to combined drought, salt and extreme temperature treatments, following a 2 day salinity pre-treatment in two rice genotypes-Nipponbare (a paddy rice) and IAC1131 (an upland landrace). Stomata closed after two days of combined stresses, causing intercellular CO2 concentrations and assimilation rates to diminish rapidly. Abscisic acid (ABA) levels increased at least five-fold but did not differ significantly between the genotypes. Tandem Mass Tag isotopic labelling quantitative proteomics revealed 6215 reproducibly identified proteins in mature leaves across the two genotypes and three time points (0, 2 and 4 days of stress). Of these, 987 were differentially expressed due to stress (cf. control plants), including 41 proteins that changed significantly in abundance in all stressed plants. Heat shock proteins, late embryogenesis abundant proteins and photosynthesis-related proteins were consistently responsive to stress in both Nipponbare and IAC1131. Remarkably, even after 2 days of stress there were almost six times fewer proteins differentially expressed in IAC1131 than Nipponbare. This contrast in the translational response to multiple stresses is consistent with the known tolerance of IAC1131 to dryland conditions.


Assuntos
Oryza/fisiologia , Estresse Fisiológico/fisiologia , Ácido Abscísico/metabolismo , Gases/metabolismo , Regulação da Expressão Gênica de Plantas , Genótipo , Oryza/genética , Fotossíntese , Folhas de Planta/metabolismo , Proteínas de Plantas/metabolismo , Proteoma/metabolismo , Proteômica , Estresse Fisiológico/genética
18.
Int J Mol Sci ; 23(3)2022 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-35163669

RESUMO

Arabidopsis thaliana SYNAPTOTAGMIN 1 (AtSYT1) was shown to be involved in responses to different environmental and biotic stresses. We investigated gas exchange and chlorophyll a fluorescence in Arabidopsis wild-type (WT, ecotype Col-0) and atsyt1 mutant plants irrigated for 48 h with 150 mM NaCl. We found that salt stress significantly decreases net photosynthetic assimilation, effective photochemical quantum yield of photosystem II (ΦPSII), stomatal conductance and transpiration rate in both genotypes. Salt stress has a more severe impact on atsyt1 plants with increasing effect at higher illumination. Dark respiration, photochemical quenching (qP), non-photochemical quenching and ΦPSII measured at 750 µmol m-2 s-1 photosynthetic photon flux density were significantly affected by salt in both genotypes. However, differences between mutant and WT plants were recorded only for qP and ΦPSII. Decreased photosynthetic efficiency in atsyt1 under salt stress was accompanied by reduced chlorophyll and carotenoid and increased flavonol content in atsyt1 leaves. No differences in the abundance of key proteins participating in photosynthesis (except PsaC and PsbQ) and chlorophyll biosynthesis were found regardless of genotype or salt treatment. Microscopic analysis showed that irrigating plants with salt caused a partial closure of the stomata, and this effect was more pronounced in the mutant than in WT plants. The localization pattern of AtSYT1 was also altered by salt stress.


Assuntos
Arabidopsis/fisiologia , Fotossíntese/fisiologia , Estresse Salino/fisiologia , Sinaptotagmina I/deficiência , Arabidopsis/efeitos da radiação , Proteínas de Arabidopsis/metabolismo , Clorofila A/metabolismo , Fluorescência , Gases/metabolismo , Luz , Fotossíntese/efeitos da radiação , Pigmentos Biológicos/metabolismo , Estômatos de Plantas/citologia , Estômatos de Plantas/fisiologia , Estômatos de Plantas/efeitos da radiação , Estresse Salino/efeitos da radiação , Sinaptotagmina I/metabolismo
19.
J Dairy Sci ; 105(1): 231-241, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34696908

RESUMO

The physiological function of the reticulorumen plays an essential role in ruminant nutrition, and detailed knowledge of rumen motility can further advance understanding of ruminant nutrition and physiology. Rumen motility was simulated by setting different stirrer rotation speeds in a rumen simulation technique (RUSITEC) system. The aim of this study was to investigate the effects of rotation speeds on rumen fermentation, saturation factor of dissolved gases, hydrogen (H2) and methane (CH4) emissions, microbial protein synthesis, and selected microbial population using RUSITEC. The experiment was performed according to a balanced 3 × 3 Latin square design, and each period included 7 d for adaptation and 3 d for sampling. Three motility treatments included 5, 15, and 25 rpm rotation speeds. Daily total gas and H2 and CH4 emissions had quadratic responses to the increasing rotation speed and were highest at 15 rpm. Quadratic and linear responses (highest at 5 rpm) to increasing rotation speed were observed for saturation factors of H2 and CH4, liquid-dissolved H2 and CH4 concentrations, and headspace concentration of H2 in the gas phase, whereas increasing rotation speed linearly decreased saturation factors of CO2 and liquid-dissolved CO2 concentration. Quadratic and linear responses to increasing rotation speed were observed for molar percentages of acetate, ammonia, and microbial protein concentration, whereas increasing rotation speed quadratically increased pH and decreased total volatile fatty acid concentration and acetate-to-propionate ratio. The 15-rpm rotation speed had the highest values of total volatile fatty acids, acetate molar percentage, and microbial protein concentration. Quadratic and linear responses to increasing rotation speed were observed for copy numbers of solid-associated fungi and fluid-associated bacteria, fungi, and protozoa, while increasing rotation speed linearly increased copy numbers of solid-associated protozoa. Rotation at 15 rpm increased populations of fungi and protozoa in the solid rumen contents and the population of bacteria and fungi in the liquid rumen contents. In summary, this study provides insights on the biofunction of proper rumen motility (i.e., at a rotation speed of 15 rpm), such as improving feed fermentation, increasing gas emissions with decreased dissolved gas concentrations and saturation factors, and promoting microbial colonization and microbial protein synthesis, although further increase in rotation speed (i.e., to 25 rpm) decreases feed fermentation and microbial protein synthesis.


Assuntos
Gases , Rúmen , Ração Animal/análise , Animais , Dieta , Digestão , Fermentação , Gases/metabolismo , Metano/metabolismo , Rúmen/metabolismo
20.
Adv Biochem Eng Biotechnol ; 180: 1-32, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34894287

RESUMO

Aerobic carboxydotrophic bacteria are a group of microorganisms which possess the unique trait to oxidize carbon monoxide (CO) as sole energy source with molecular oxygen (O2) to produce carbon dioxide (CO2) which subsequently is used for biomass formation via the Calvin-Benson-Bassham cycle. Moreover, most carboxydotrophs are also able to oxidize hydrogen (H2) with hydrogenases to drive the reduction of carbon dioxide in the absence of CO. As several abundant industrial off-gases contain significant amounts of CO, CO2, H2 as well as O2, these bacteria come into focus for industrial application to produce chemicals and fuels from such gases in gas fermentation approaches. Since the group of carboxydotrophic bacteria is rather unknown and not very well investigated, we will provide an overview about their lifestyle and the underlying metabolic characteristics, introduce promising members for industrial application, and give an overview of available genetic engineering tools. We will point to limitations and discuss challenges, which have to be overcome to apply metabolic engineering approaches and to utilize aerobic carboxydotrophs in the industrial environment.


Assuntos
Biotecnologia , Dióxido de Carbono , Bactérias/genética , Bactérias/metabolismo , Dióxido de Carbono/metabolismo , Gases/metabolismo , Hidrogênio/metabolismo , Engenharia Metabólica
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