Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences
Not a member yet
3266 research outputs found
Sort by
Genome-wide characterization of GRAS family genes in Medicago truncatula reveals their evolutionary dynamics and functional diversification
No full textThe GRAS gene family is a large plant-specific family of transcription factors that are involved in diverse processes during plant development. Medicago truncatula is an ideal model plant for genetic research in legumes, and specifically for studying nodulation, which is crucial for nitrogen fixation. In this study, 59 MtGRAS genes were identified and classified into eight distinct subgroups based on phylogenetic relationships. Motifs located in the C-termini were conserved across the subgroups, while motifs in the N-termini were subfamily specific. Gene duplication was the main evolutionary force for MtGRAS expansion, especially proliferation of the LISCL subgroup. Seventeen duplicated genes showed strong effects of purifying selection and diverse expression patterns, highlighting their functional importance and diversification after duplication. Thirty MtGRAS genes, including NSP1 and NSP2, were preferentially expressed in nodules, indicating possible roles in the process of nodulation. A transcriptome study, combined with gene expression analysis under different stress conditions, suggested potential functions of MtGRAS genes in various biological pathways and stress responses. Taken together, these comprehensive analyses provide basic information for understanding the potential functions of GRAS genes, and will facilitate further discovery of MtGRAS gene functions
Bifunctional catalyst Pd-Al-MCM-41 for efficient dimerization-hydrogenation of beta-pinene in one pot
No full textA new type of bimetallic palladium and aluminum incorporated mobile crystalline materials (Pd-Al-MCM-41) as bifunctional catalysts has been hydrothermally synthesized. Characterization shows that these molecular materials exhibit an ordered mesoporous structure, high surface area and a good dispersion of palladium in the frame. The catalytic activity of the Pd-Al-MCM-41 for the dimerization-hydrogenation reaction system of beta-pinene in one pot has been systematically studied. Pd-0.5-Al-30-MCM-41 (SiO2/Al2O3 = 30, 0.5 wt% palladium content) was found to be the best catalyst which gave a dimer yield of up to 64.7%. It is worth noting that palladium shows a good synergic catalytic effect with aluminum in the dimerization reaction and enhances the dimerization yield. Furthermore, the bifunctional catalyst displayed a good activity over 4 runs
The diversity of CO2-concentrating mechanisms in marine diatoms as inferred from their genetic content
No full texte Marine diatoms are one of the most ecologically significant primary producers in the ocean. Most diatoms use a CO2-concentrating mechanism (CCM) to overcome the scarcity of CO2 in the ocean and limitations of the carbon-fixing enzyme Rubisco. However, the CCMs in model diatoms differ substantially in their genetic make-up and structural organization. To assess the extent of CCM diversity in marine diatoms more generally, we analyzed genome and transcriptome data from 31 diatom strains to identify putative CCM genes, examine the overall CCM architecture, and study CCM development in the context of the evolutionary history of these diatoms. Key CCM genes [carbonic anhydrases (CAs) and solute carrier 4 (SLC4) bicarbonate transporters] identified in the diatoms were placed into groups of likely orthologs by sequence similarity (OrthoMCL) and phylogenetic methods. These analyses indicated that diatoms seem to share similar HCO3- transporters, but possess a variety of CAs that have either undergone extensive diversification within the diatom lineage or have been acquired through horizontal gene transfer. Hierarchical clustering of the diatom species based on their CCM gene content suggests that CCM development is largely congruent with evolution of diatom species, despite some notable differences in CCM genes even among closely related species
A Rechargeable Li-Air Fuel Cell Battery Based on Garnet Solid Electrolytes
No full textNon-aqueous Li-air batteries have been intensively studied in the past few years for their theoretically super-high energy density. However, they cannot operate properly in real air because they contain highly unstable and volatile electrolytes. Here, we report the fabrication of solid-state Li-air batteries using garnet (i.e., Li6.4La3Zr1.4Ta0.6O12, LLZTO) ceramic disks with high density and ionic conductivity as the electrolytes and composite cathodes consisting of garnet powder, Li salts (LiTFSI) and active carbon. These batteries run in real air based on the formation and decomposition at least partially of Li2CO3. Batteries with LiTFSI mixed with polyimide (PI: LiTFSI) as a binder show rechargeability at 200 degrees C with a specific capacity of 2184 mAh g(-1) (carbon) at 20 mu A cm(-2). Replacement of PI: LiTFSI with LiTFSI dissolved in polypropylene carbonate (PPC: LiTFSI) reduces interfacial resistance, and the resulting batteries show a greatly increased discharge capacity of approximately 20300 mAh g(-1) carbon and cycle 50 times while maintaining a cutoff capacity of 1000 mAh g(-1) carbon at 20 mu A cm(-2) and 80 degrees C. These results demonstrate that the use of LLZTO ceramic electrolytes enables operation of the Li-air battery in real air at medium temperatures, leading to a novel type of Li-air fuel cell battery for energy storage
Effects of two different high-fidelity DNA polymerases on genetic analysis of the cyanobacterial community structure in a subtropical deep freshwater reservoir
No full textThe use of molecular methods to investigate the community structure and diversity of microalgae has largely replaced the previous morphological methods that were routinely carried out by microscopy. Different DNA polymerases can lead to bias in PCR amplification and affect the downstream community and diversity analysis. In this study, two clone libraries were constructed with two different DNA polymerases, Q5 high-fidelity DNA polymerase and exTaq polymerase, to compare the differences in their capability to accurately reflect the cyanobacterial community structure and diversity in a subtropical deep freshwater reservoir, Dongzhen reservoir. The results indicated that the two cyanobacterial clone libraries constructed by using Q5 high-fidelity DNA polymerase and exTaq DNA polymerase did not show significant differences, although a slightly higher community diversity was revealed by using Q5 high-fidelity DNA polymerase. It is noteworthy that so far Q5 high-fidelity DNA polymerase was the first time to be employed in the genetic analysis of cyanobacterial community. And it is for the first time that the cyanobacterial community structure in Dongzhen reservoir was analyzed using molecular methods. Phylogenetic analysis revealed that most of the clones belonged to Cyanophyta and chloroplast, among which Cyanobium sp. Suigetsu-CR5 made up the largest fraction of cyanobacteria in winter
Immobilization of proline-specific endoprotease on nonporous silica nanoparticles functionalized with amino group
No full textEnzyme immobilization is believed to provide an excellent base for increasing environmental tolerance of enzyme and considerable period of time. In this work, a kind of nonporous silica nanoparticles functionalized with amino group was synthesized to immobilize proline-specific endoprotease (PSEP). PSEP is known to specifically cleave peptides (or esters) at the carboxyl side of proline, thus can prevent the formation of haze and prolong the shelf life of beer. After immobilization, the environmental tolerance (temperature and pH, respectively) was obviously improved, and the immobilized enzyme can retain above 90 % of its original activity after 6 uses. Moreover, the immobilized enzyme can effectively prevent the formation of chill-haze using fresh beer fermentation liquid
Lignification of Sheepgrass Internodes at Different Developmental Stages and Associated Alteration of Cell Wall Saccharification Efficiency
No full textSheepgrass (Leymus chinensis) is a high-quality cool-season forage crop used as pasture and hay for livestock feeds. The presence of lignin in cell walls, however, impairs forage digestibility of such lignocellulosic feedstock. Here, the structural characterization and cell wall composition of sheepgrass internodes were studied, and a progressive increase in cell wall lignification was observed with internode maturation. Lignin composition analysis further revealed a gradual accumulation of guaiacyl and syringyl lignin units during internode development. Consistently, the transcript abundance of lignin-related genes was upregulated in mature internodes, suggesting their potential roles in lignin biosynthesis. Furthermore, the effects of cell wall composition and lignification extent on biomass saccharification efficiency were examined in sheepgrass. The results showed that lignin content, guaiacyl and syringyl lignin unit levels inversely correlated with cell wall digestibility, indicating that lignin is a crucial obstacle for utilizing sheepgrass feedstock. The baseline information obtained in this work will facilitate establishment, grazing management, harvesting and feedstock utilization of sheepgrass in future
Aerobic Water-based Oxidation of 2,3,6-Trimethylphenol to Trimethyl-1,4-benzoquinone over Copper(II) Nitrate Catalyst
No full textA catalytic method for aerobic water-based oxidation of 2,3,6-trimethylphenol to trimethyl-1,4-benzoquinone catalysed by copper(II) nitrate was achieved under mild conditions using dioxygen as an oxidant and water as a solvent. The catalyst shows high activity and selectivity in the direct oxidation of 2,3,6-trimethylphenol into trimethyl-1,4-benzoquinone. Since components used in the present system are cheap and available, our method offers a safe system in the synthesis of trimethyl-1,4-benzoquinone under halogen ions-free conditions
Catalytically active metal organic framework based on a porphyrin modified by electron-withdrawing groups
No full textOne metal-free porphyrin, modified by electron-withdrawing groups, was synthesized by introduction of two peripheral pyridyl substituents and two metal coordination polymers, {[Zn(C42H16F10N6)]2C(2)H(7)N}(n) (1) and {[Co(C42H16F10N6)]C2H7N}(n) (2), were synthesized solvothermally. In 1, each porphyrin connected four other porphyrin molecules to construct a 2-D network through coordination bonds. Similarly, in 2 every Co(II) porphyrin coordinated with four adjacent molecules to form a 2-D framework. Thermogravimetric analyses indicate that both 1 and 2 show high-thermal stabilities. The fluorescence data of 1 and 2 show that 1 may be a candidate for potential inorganic-organic photoactive materials. Catalytic oxidation results show that 2 displays high activity with the only product acetophenone quantitatively in 81.4%, and after six cycles, the catalytic activity slightly decreases. These features of 2, including the exceptional stability, and high catalytic activity, make it outstanding among MOFs reported in the literature
Core-shell and concentration-gradient cathodes prepared via co-precipitation reaction for advanced lithium-ion batteries
No full textThe core-shell structure has been extensively utilized to develop new functional materials and become a research focus in materials science recently. Over the past decades, the requirements of high-capacity, high-rate, long cycle-life and superior safety have been the main driving force for the advance of cathode materials for lithium-ion batteries (LIBs). Correspondingly, the concept of the core-shell structure is introduced to prepare the above desired cathodes. After that, the concentration-gradient structure is further exploited to overcome the drawbacks of the core-shell structure. The co-precipitation route is more suitable for synthesizing core-shell and concentration-gradient structures compared with other methods, such as sol-gel and spray-drying. More importantly, it is capable of producing large-scale cathodes in the domain of LIBs. In this review, we first illustrate the design principles and formation mechanism of core-shell and concentration-gradient cathode materials; then the recent advances in co-precipitation preparation core-shell and concentration-gradient cathodes for high-energy, high-power, long-life and safe LIBs are summarized. Moreover the structural evolution during cycles to uncover the origin of these improved performances is also analysed. Based on these achievements thus gained, we propose a new strategy to enhance the performances of cathodes. Finally, the remaining challenges including fundamental investigation, commercialized application and present possible solutions are also discussed