16 research outputs found
Time-resolved transcriptomic and proteomic profiling of Heyndrickxia coagulans during NaOH-buffered L-lactic acid production
The L-lactic acid (L-LA) fermentation process, based on sodium hydroxide neutralization, demonstrates environmental friendliness during product extraction. However, lactate fermentation is hindered by the pronounced stress effect of sodium lactate on the strain compared with calcium lactate. In this study, we performed time-resolved transcriptomic and proteomic analyses of Heyndrickxia coagulans DSM1 during NaOH-buffered L-LA production. The expression levels of the glycolytic genes demonstrated an initial increase followed by a subsequent decrease, whereas the tricarboxylic acid cycle genes exhibited an initial decrease followed by a subsequent increase throughout the fermentation process. Moreover, we identified clusters of genes consisting of transcription factors and ATP-binding cassette (ABC) transporters that demonstrate a progressive elevation of expression levels throughout the fermentation process, with significant upregulation observed at later stages. This investigation yields valuable insights into the response mechanisms of H. coagulans during NaOH-buffered L-LA fermentation and presents potential targets for metabolic engineering
The Global Search for Liquid Water on Mars from Orbit: Current and Future Perspectives
Due to its significance in astrobiology, assessing the amount and state of liquid water present on Mars today has become one of the drivers of its exploration. Subglacial water was identified by the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) aboard the European Space Agency spacecraft Mars Express through the analysis of echoes, coming from a depth of about 1.5 km, which were stronger than surface echoes. The cause of this anomalous characteristic is the high relative permittivity of water-bearing materials, resulting in a high reflection coefficient. A determining factor in the occurrence of such strong echoes is the low attenuation of the MARSIS radar pulse in cold water ice, the main constituent of the Martian polar caps. The present analysis clarifies that the conditions causing exceptionally strong subsurface echoes occur solely in the Martian polar caps, and that the detection of subsurface water under a predominantly rocky surface layer using radar sounding will require thorough electromagnetic modeling, complicated by the lack of knowledge of many subsurface physical parameters. Higher-frequency radar sounders such as SHARAD cannot penetrate deep enough to detect basal echoes over the thickest part of the polar caps. Alternative methods such as rover-borne Ground Penetrating Radar and time-domain electromagnetic sounding are not capable of providing global coverage. MARSIS observations over the Martian polar caps have been limited by the need to downlink data before on-board processing, but their number will increase in coming years. The Chinese mission to Mars that is to be launched in 2020, Tianwen-1, will carry a subsurface sounding radar operating at frequencies that are close to those of MARSIS, and the expected signal-to-noise ratio of subsurface detection will likely be sufficient for identifying anomalously bright subsurface reflectors. The search for subsurface water through radar sounding is thus far from being concluded
Barley TAPETAL DEVELOPMENT and FUNCTION1 (HvTDF1) gene reveals conserved and unique roles in controlling anther tapetum development in dicot and monocot plants
•The anther tapetum helps control microspore release and essential components for pollen wall formation. TAPETAL DEVELOPMENT and FUNCTION1 (TDF1) is an essential R2R3 MYB tapetum transcription factor in Arabidopsis thaliana; however, little is known about pollen development in the temperate monocot barley.•Here, we characterize the barley (Hordeum vulgare L.) TDF1 ortholog using reverse genetics and transcriptomics.•Spatial/temporal expression analysis indicates HvTDF1 has tapetum-specific expression during anther stage 7/8. Homozygous barley hvtdf1 mutants exhibit male sterility with retarded tapetum development, delayed tapetum endomitosis and cell wall degeneration, resulting in enlarged, vacuolated tapetum surrounding collapsing microspores. Transient protein expression and dual-luciferase assays show TDF1 is a nuclear-localized, transcription activator, that directly activates osmotin proteins. Comparison of hvtdf1 transcriptome data revealed several pathways were delayed, endorsing the observed retarded anther morphology. Arabidopsis tdf1 mutant fertility was recovered by HvTDF1, supporting a conserved role for TDF1 in monocots and dicots.•This indicates that tapetum development shares similarity between monocot and dicots; however, barley HvTDF1 appears to uniquely act as a modifier to activate tapetum gene expression pathways, which are subsequently also induced by other factors. Therefore, the absence of HvTDF1 results in delayed developmental progression rather than pathway failure, although inevitably still results in pollen degeneration
Performance evaluation and microbial community analysis of microaerobic pretreatment on thermophilic dry anaerobic digestion
In this study, micmaembic pretreatment (MP) was used to improve the system stability and biogas production performance of the thermophilic dry anaerobic digestion (AD). The results showed that proper MP made the AD have better methane-producing performance and the maximum cumulative methane production was 108.31 mL/g VS with an oxygen load of 5 mL/g VS, which was 13.20 % higher than that of control group (G1, 95.68 mL/g VS). Specific micmaerobic conditions promoted the generation of volatile fatty acid (VFA) and reduced propionic acid content in the digestive system. In addition, the volatile solid (VS) removal rate of the digestive substrates was improved in the presence of limited oxygen, which can reduce environmental risks. Microbial community diversity indicated that MP increased the relative abundance of Firmicutes to promote substrate hydrolysis and accelerated the growth of hydrogenotrophic methanogens to improve AD performance
Effect of Phase Change Materials and Phase Change Temperature on Optimization of Design Parameters of Anaerobic Reactor Thermal Insulation Structure
Direct-absorption anaerobic reactors can maintain the fermentation process of microorganisms by utilizing solar absorption and scattering media in the biogas reactor to improve the slurry temperature. Direct-absorption heating alone can save the corresponding electric energy and ensure the normal fermentation process of the biogas slurry in the reactor, but there is still the problem of temperature fluctuation. In order to improve the stability of the fermentation process, it is proposed to optimize the design of this kind of reactor by adding paraffin phase change material. This article mainly studies the influence of paraffin phase change material added on the top and side of the reactor in the fermentation process and gives the corresponding design parameters for different climatic conditions, which lays a theoretical reference for the design process of this kind of reactor
Ratiometric and Turn-On Luminescence Detection of Water in Organic Solvents Using a Responsive Europium-Organic Framework
The development of simple, rapid-response sensors for water detection in organic solvents is highly desirable in the chemical industry. Here we demonstrate a unique luminescence water sensor based on a dual-emitting europium-organic framework (Eu-MOF), which is assembled from a purposely selected 2-aminoterephthalic acid ligand with responsive fluorescence inherent in its intramolecular charge transfer (ICT) process. This ICT process can be rapidly switched-on in the presence of water owing to its ability to boost and stabilize the ICT state. In contrast, the Eu 3+ emission within the framework is insensitive to water and can serve as a reference, thus enabling highly sensitive water detection in a turn-on and ratiometric way. In addition, the significant ratiometric luminescence response induced by water makes Eu-MOF undergo a distinct change of emitting color from red to blue, which is favorable for visual analysis with the naked eye. Sensitive determination of water content (0.05-10% v/v) in various organic solvents is achieved in multiple readouts including ratiometric emission intensity, emission color, or the Commission Internationale de l\u27Eclairage (CIE) chromaticity coordinate. The present Eu-MOF sensor featuring high sensitivity and reusability, self-calibration, simple fabrication and operation, and capability for real-time and in situ detection is expected to have practical applications in water analysis for industrial processes
Quantitative SERS Analysis by Employing Janus Nanoparticles with Internal Standards
Abstract Surface‐enhanced Raman scattering (SERS), a powerful analysis technique featuring ultrahigh sensitivity and the ability in chemically specific detection, has encountered intrinsic challenges in quantitative analysis due to the signal heterogeneity arising from sample preparation, molecular distribution, and experimental conditions. Herein, the plasmonic Janus nanoparticle, which is curved on one side and flat on the other, as a universal platform for quantitative analysis is proposed. The probe molecules are adsorbed on the curved side as internal standards to correct the signal fluctuation while the target molecules are adsorbed on the flat side for SERS measurement, and thus competitive adsorption between different molecules is prevented. Moreover, the Janus nanoparticles are partially embedded in a flexible and transparent membrane, enabling liquid‐state SERS measurement which is favorable to form a uniform self‐assembly molecular monolayer for quantitative SERS analysis. The quantitation of different biochemical molecules including Rhodamine 6G, crystal violet, and adenine are demonstrated, and an extension in linear response region for quantitative analysis is observed. The findings suggest a robust approach toward quantitative analysis
Supplemental data Movie 1
Microtomographic reconstruction and rendering of the holotype specimen CUBar90-
Supplemental data Movie 2
3D reconstructions of Septuconularia yanjiaheensis n. gen. n. sp