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Controlling crystal growth kinetics using different reductants is an efficient strategy to modulate the surficial chemistry micro-circumstance of Cu aerogels, enabling the creation of efficient surface sites for increasing C2+ product selectivity.

The regulation of morphology and wettability of Zn films is an efficient strategy for producing syngas with a wide CO/H2ratio range from electrochemical CO2and H2O reduction.

Guided by first-principles calculations, it was found that Cd single-atom catalysts (SACs) have excellent performance in activating CO2 , and the introduction of axial coordination structure to Cd SACs cannot only further decrease the free energy barrier of CO2 reduction, but also suppress the hydrogen evolution reaction (HER). Based on the above discovery, we designed and synthesized a novel Cd SAC that comprises an optimized CdN4 S1 moiety incorporated in a carbon matrix. It was shown that the catalyst exhibited outstanding performance in CO2 electroreduction to CO. The faradaic efficiency (FE) of CO could reach up to 99.7 % with a current density of 182.2 mA cm-2 in a H-type electrolysis cell, and the turnover frequency (TOF) value could achieve 73000 h-1 , which was much higher than that reported to date. This work shows a successful example of how to design highly efficient catalysts guided by theoretical calculations.

The thermotolerant yeast Kluyveromyces marxianus has great potential for high-temperature ethanol fermentation, but it produces excess acetic acid during high-temperature fermentation, which inhibits ethanol production. The mechanisms of K. marxianus’s responses to acetic acid have not been fully understood. In this study, the transcriptomic changes of K. marxianus DMKU3-1042 resulted from acetic acid stress during high-temperature ethanol fermentation were investigated based on high-throughput RNA sequencing. We identified 611 differentially expressed genes (DEGs) under acetic acid stress (fold change > 2 or < 0.5, P-adjust K. marxianus and led to the decrease of ethanol production. The findings in this study provide a better understanding of the response mechanism of K. marxianus to acetic acid stress, and provide a basis for subsequent increase of ethanol production by K. marxianus.

The thermotolerant yeast Kluyveromyces marxianus is a promising bioethanol producer, but its fermentation arrested earlier at high temperatures. Untargeted metabolomic analysis was used to explore K. marxianus’s stress responses during high-temperature fermentation. Fermentation experiments were conducted at 45 °C, with a group conducted at 30 °C as control. Samples were collected from both groups at 14 and 22 h and were subjected to metabolomic analysis. The results show that pathways related to biosynthesis of amino acids, metabolism of purine, pyridoxine and riboflavin, etc. were induced at high temperature. More oleic acid, less palmitic acid and less palmitoleic acid were synthesized at 45 °C than at 30 °C, indicating that K. marxianus can adapt to high temperature by increasing the mean fatty acid chain length. In addition, most of the metabolic pathways stopped after the fermentation arrest, but pathways related to amino acids metabolism, riboflavin metabolism, etc. were still active. This is the first study about comprehensive metabolomic profiling of K. marxianus during high-temperature fermentation. The findings in this study offer deeper insight in mechanisms of K. marxianus’s stress responses during high-temperature fermentation at the metabolome level, and provide potential target pathways for further metabolic engineering towards improved stress tolerance and efficient bioethanol production.

The electrocatalytic oxygen evolution reaction (OER) is a critical half-cell reaction for hydrogen production via water electrolysis. However, the practical OER suffers from sluggish kinetics and thus requires efficient electrocatalysts. Transition metal-based layered double hydroxides (LDHs) represent one of the most active classes of OER catalysts. An in-depth understanding of the activity of LDH based electrocatalysts can promote further rational design and active site regulation of high-performance electrocatalysts. In this review, the fundamental understanding of the structural characteristics of LDHs is demonstrated first, then comparisons and in-depth discussions of recent advances in LDHs as highly active OER catalysts in alkaline media are offered, which include both experimental and computational methods. On top of the active site identification and structural characterization of LDHs on an atomic scale, strategies to promote the OER activity are summarised, including doping, intercalation and defect-making. Furthermore, the concept of superaerophobicity, which has a profound impact on the performance of gas evolution electrodes, is explored to enhance LDHs and their derivatives for a large scale OER. In addition, certain operating standards for OER measurements are proposed to avoid inconsistency in evaluating the OER activity of LDHs. Finally, several key challenges in using LDHs as anode materials for large scale water splitting, such as the issue of stability and the adoption of membrane-electrode-assembly based electrolysers, are emphasized to shed light on future research directions.

In order to explore the microbial diversity in industrial effluents, and on this basis, to verify the feasibility of tracking industrial effluents in sewer networks based on sequencing data, we collected 28 sewage samples from the industrial effluents relative to four factories in Shenzhen, China, and sequenced the 16S rRNA genes to profile the microbial compositions. We identified 5413 operational taxonomic units (OTUs) in total, and found that microbial compositions were highly diverse among samples from different locations in the sewer system, with only 107 OTUs shared by 90% of the samples. These shared OTUs were enriched in the phylum of Proteobacteria, the families of Comamonadaceae and Pseudomonadaceae, as well as the genus of Pseudomonas, with both degradation related and pathogenic bacteria. More importantly, we found differences in microbial composition among samples relevant to different factories, and identified microbial markers differentiating effluents from these factories, which can be used to track the sources of the effluents. This study improved our understanding of microbial diversity in industrial effluents, proved the feasibility of industrial effluent source tracking based on sequencing data, and provided an alternative technique solution for environmental surveillance and management.

Bioelectrochemical CO2 reduction is a promising method for biogas upgrading. However, the CO2 reduction efficiency in these bioelectrical systems is always relatively low and limits their applicati...

The bubbles electrochemically generated by gas evolution reactions are commonly driven off the electrode by buoyancy, a weak force used to overcome bubble adhesion barriers, leading to low gas-transporting efficiency. Herein, a Janus electrode with asymmetric wettability has been prepared by modifying two sides of a porous stainless-steel mesh electrode, with superhydrophobic polytetrafluoroethylene (PTFE) and Pt/C (or Ir/C) catalyst with well-balanced hydrophobicity, respectively, affording unidirectional transportation of as-formed gaseous hydrogen and oxygen from the catalyst side to the gas-collecting side during water splitting. "Bubble-free" electrolysis was realized while "floating" the Janus electrode on the electrolyte. Antibuoyancy through-mesh bubble transportation was observed while immersing the electrode with the PTFE side downward. The wettability gradient within the electrode endowed sticky states of bubbles on the catalyst side, resulting in efficient bubble-free gas transportation with 15-fold higher current density than submerged states.

Bacteria have evolved several mechanisms to resist Cd toxicity, which are crucial for Cd detoxication and have the potential to be used for bioremediation of Cd. Geobacter species are widely found in anaerobic environments and play important roles in natural biogeochemical cycles. However, the transcriptomic responses of Geobacter sulfurreducens under Cd stress have not been fully elucidated. This project aims to uncover a global view of mRNA changes in Cd-induced cellular processes.

Bacteria have evolved several mechanisms to resist Cd toxicity, which are crucial for Cd detoxication and have the potential to be used for bioremediation of Cd. Geobacter species are widely found in anaerobic environments and play important roles in natural biogeochemical cycles. However, the transcriptomic response of Geobacter sulfurreducens under Cd stress have not been fully elucidated. Through integrated analysis of transcriptomic and protein-protein interaction (PPI) data, we uncovered a global view of mRNA changes in Cd-induced cellular processes in this study. We identified 182 differentially expressed genes (|log

Methanol is a highly desirable product of CO

Guided by first-principles calculations, it was found that Cd single-atom catalysts (SACs) have excellent performance in activating CO

Development of highly active electrocatalysts for oxygen evolution reaction (OER) is one of the critical issues for water splitting, and most reported catalysts operate at overpotentials above 190 mV. Here we present a multiphase nickel iron sulfide (MPS) hybrid electrode with a hierarchical structure of iron doped NiS and Ni3S2, possessing a benchmark OER activity in alkaline media with a potential as low as 1.33 V ( vs . reversible hydrogen electrode) to drive an OER current density of 10 mA cm−2. The Fe doped NiS, combined with highly conductive disulfide phase on porous Ni foam, is believed to be responsible for the ultrahigh activity. Furthermore, density functional theory simulation reveals that partially oxidized sulfur sites in Fe doped NiS could dramatically lower the energy barrier for the rate-determining elementary reaction, thus contributing to the active oxygen evolution.

A novel bioenergy-producing green alga (lab ID.: XNY8011) was isolated from a local mountain in Beijing, China, and was identified as a strain belonging to the genus of Coelastrum on the basis of morphological and molecular characterization. Physiological analyses of photobiological H 2 and lipid production suggested that XNY8011 could be a candidate for biofuels production. This strain could accumulate considerable biomass and produce massive chlorophylls in water diluted waste molasses. Three concentrations of molasses (0.1, 0.2 and 0.5%, w/v) were studied to optimize the cell growth and chlorophylls synthesis of XNY8011, and 0.2% was proved to be the optimum, in which XNY8011 could reach A600 of 1.55 ± 0.06 and produce 11.35 ± 0.93 μg/mL of chlorophylls. It was found that 25 °C is the most preferable temperature for the cell growth of XNY8011 in molasses. Interestingly, the strain XNY8011 exhibited significant low temperature adaptability when growing in waste molasses compared to typical bioenergy green algae. It produced 5.73 and 3.05 folds of cell densities in molasses than that Chlamydomonas reinhardtii CC503 and Chlorella vulgaris did under 20 °C, respectively, and even obtained 13.51 and 2.72 folds of cell densities under 15 °C, respectively. The dynamic analysis suggested that the sugar in waste molasses was utilized as carbon source for cell growth and biomass accumulation. The present study isolated a novel bioenergy-producing green alga from the native environment which could convert waste molasses to biomass and bioenergy with significant temperature adaptability.

Sustainable water-splitting hydrogen production has long been considered one of the most promising energy conversion technologies, but enormous challenges remain: for instance, water electrolysis suffers from high overpotential and over energy consumption under neutral pH conditions. Here, taking advantage of the memory effect of layered double hydroxide (LDH), we report an energy-efficient neutral water electrolyzer material based on LDH with multiple vacancy defects. Benefiting from the improved electrical conductivity, larger electrochemical surface area (ECSA), and faster charge transfer, the NiFe LDH with O, Ni, and Fe vacancies exhibits a low overpotential of 87 mV at 10 mA/cm2 for hydrogen evolution reaction (HER) in a pH 7 buffer electrolyte. Impressively, the as-fabricated vacancy-containing NiFe LDH (v-NiFe LDH) splits water with a current density of 10 mA/cm2 at ∼1.60 V in a two-electrode device, outperforming most other water-splitting catalysts in neutral media. Such an electrolyzer setup cou...

In this study, an

High salinity organic wastewater (HSOW) contains both organic pollutants and high concentration of inorganic salts. If it is discharged into the environment without proper treatment, it will cause adverse consequences such as dehydration and death of aquatic organisms, and soil salinization. Bioelectrochemical systems (BESs) have been applied in various wastewater treatment processes. To assess the feasibility of using BESs to treat HSOW, the effect of applying potential on anaerobic digestion of HSOW was explored in an up-flow anaerobic sludge blanket (UASB) reactor poised at -0.6 V (vs. Ag/AgCl). When organic loading rate (OLR) was 2.16-2.88 kg chemical oxygen demand/(m

Here, an engineered Saccharomyces cerevisiae strain SFA1OE was constructed by overexpressing SFA1 in a reported WXY70 with effective six-gene clusters. Under simulated maize hydrolysate, SFA1OE produced an ethanol yield of 0.492 g/g total sugars within 48 h. The productivity of SFA1OE was comprehensively evaluated in typical hydrolysates from stalks of maize, sweet sorghum, wheat and Miscanthus. Within 48 h, SFA1OE achieved an ethanol yield of 0.489 g/g total sugars in the optimized hydrolysate of alkaline-distilled sweet sorghum bagasse derived from Advanced Solid-State Fermentation process. By crossing SFA1OE with a DQ1-derived haploid strain, we obtained an evolved diploid strain SQ-2, exhibiting improved ethanol production and thermotolerance. This study demonstrates that overexpressing SFA1 enables efficient fermentation performance in different lignocellulosic hydrolysates, especially in the hydrolysate of alkaline-distilled sweet sorghum bagasse. The increased cellulosic bioethanol production of SFA1OE provides a promising platform for efficient biorefineries.

Catalytic electrodes with the capability to directly convert atmospheric CO 2 into value‐added products are of potential environmental and economic benefit, but entail an effective CO 2 selection strategy to impede the competing O 2 reduction reaction. In this work, we have developed a new generation of hybrid electrodes with improved O 2 tolerance and unprecedented capability of CO 2 conversion to liquid products in the presence of O 2 . We introduce aniline molecules into the pore structure of a polymer of intrinsic microporosity to expand its gas separation functionality beyond pure physical sieving. The chemical interaction between the acidic CO 2 molecule and the basic amino group of aniline renders enhanced CO 2 separation from O 2 . Loaded with a cobalt phthalocyanine‐based cathode catalyst, our hybrid electrode achieves a CO Faradaic efficiency of 71% with 10% O 2 in the CO 2 feed gas. The electrode can still perform CO production at an O 2 /CO 2 ratio as high as 9:1. Switching to a Sn‐based catalyst, we for the first time realize O 2 ‐tolerant CO 2 electroreduction to liquid products, generating formate with nearly 100% selectivity and a current density of 56.7 mA/cm 2 in the presence of 5% O 2 .

Developing efficient seawater-electrolysis system for mass production of hydrogen is highly desirable due to the abundance of seawater. However, continuous electrolysis with seawater feeding boosts the concentration of sodium chloride in the electrolyzer, leading to severe electrode corrosion and chlorine evolution. Herein, the common-ion effect was utilized into the electrolyzer to depress the solubility of NaCl. Specifically, utilization of 6 M NaOH halved the solubility of NaCl in the electrolyte, affording efficient, durable, and sustained seawater electrolysis in NaCl-saturated electrolytes with triple production of H 2 , O 2 , and crystalline NaCl. Ternary NiCoFe phosphide was employed as a bifunctional anode and cathode in simulative and Ca/Mg-free seawater-electrolysis systems, which could stably work under 500 mA/cm 2 for over 100 h. We attribute the high stability to the increased Na + concentration, which reduces the concentration of dissolved Cl - in the electrolyte according to the common-ion effect, resulting in crystallization of NaCl, eliminated anode corrosion, and chlorine oxidation during continuous supplementation of Ca/Mg-free seawater to the electrolysis system.

Summary CRISPR/Cas‐based (clustered regularly interspaced short palindromic repeats/CRISPR‐associated) screening has been proved to be an efficient method to study functional genomics from yeast to human. In this study, we report the development of a focused CRISPR/Cas‐based gene activation library in Saccharomyces cerevisiae and its application in gene identification based on functional screening towards improved thermotolerance. The gene activation library was subjected to screening at 42°C, and the same library cultured at 30°C was set as a control group. After five successive subcultures, five clones were randomly picked from the libraries cultured at 30 and 42°C, respectively. The five clones selected at 30°C contain the specificity sequences of five different single guide RNAs, whereas all the five clones selected at 42°C contain the specificity sequence of one sgRNA that targets the promoter region of OLE1. A crucial role of OLE1 in thermotolerance was identified: the overexpression of OLE1 increased fatty acid unsaturation, and thereby helped counter lipid peroxidation caused by heat stress, rendering the yeast thermotolerant. This study described the application of CRISPR/Cas‐based gene activation screening with an example of thermotolerant yeast screening, demonstrating that this method can be used to identify functional genes in yeast.

Bioethanol production based on solid-state fermentation (SSF) of sweet sorghum stalks has been demonstrated to have great potential due to the its low pollution and low cost. A novel S. cerevisiae strain TSH3 exhibited better SSF performance compared with BY4743 during SSF of sweet sorghum stalks. High-quality total RNA of S. cerevisiae was extracted from SSF mixture and the global gene expression profiles during SSF were studied using RNA-Seq. Compared with BY4743, TSH3’s genes related to ribosome biogenesis, amino acid and coenzyme metabolism during early fermentation stage, secondary metabolite biosynthesis, metabolism in diverse environment during middle fermentation stage, and lipid metabolism during late fermentation stage were up-regulated; while the genes involved in fatty acid metabolism and peroxisome during early fermentation stage, ribosome biogenesis during middle fermentation stage, and mitotic cell cycle during late fermentation stage were down-regulated. Further dynamic analysis of TSH3’s transcriptome reveals its three different metabolic stages: 1) ribosome biogenesis and respiration-fermentation transition; 2) biosynthesis of secondary metabolites and stress resistance; 3) plasma membrane related metabolism for stress resistance. These findings provided insight into the S. cerevisiae transcriptome during SSF of sweet sorghum stalks and suggest that TSH3 would be an ideal candidate for SSF-based bioethanol production.