In situ/Operando Synchrotron Radiation Analytical Techniques for CO2/CO Reduction Reaction: From Atomic Scales to Mesoscales.

Electrocatalytic carbon dioxide/carbon monoxide reduction reaction (CO(2)RR) has emerged as a prospective and appealing strategy to realize carbon neutrality for manufacturing sustainable chemical products. Developing highly active electrocatalysts and stable devices has been demonstrated as effective approach to enhance the conversion efficiency of CO(2)RR. In order to rationally design electrocatalysts and devices, a comprehensive understanding of the intrinsic structure evolution within catalysts and micro-environment change around electrode interface, particularly under operation conditions, is indispensable. Synchrotron radiation has been recognized as a versatile characterization platform, garnering widespread attention owing to its high brightness, elevated flux, excellent directivity, strong polarization and exceptional stability. This review systematically introduces the applications of synchrotron radiation technologies classified by radiation sources with varying wavelengths in CO(2)RR. By virtue of in situ/operando synchrotron radiationanalytical techniques, we also summarize relevant dynamic evolution processes from electronic structure, atomic configuration, molecular adsorption, crystal lattice and devices, spanning scales from the angstrom to the micrometer. The merits and limitations of diverse synchrotron characterization techniques are summarized, and their applicable scenarios in CO(2)RR are further presented. On the basis of the state-of-the-art fourth-generation synchrotron facilities, a perspective for further deeper understanding of the CO(2)RR process using synchrotron radiation analytical techniques is proposed.

Tuning the Microenvironment in Monolayer MgAl Layered Double Hydroxide for CO2 -to-Ethylene Electrocatalysis in Neutral Media.

The electrocatalytic reduction of carbon dioxide provides a feasibility to achieve a carbon-neutral energy cycle. However, there are a number of bottleneck issues to be resolved before industrial application, such as the low conversion efficiency, selectivity and reaction rate, etc. Engineering local environment is a critical way to address these challenges. Here, a monolayer MgAl-LDH was proposed to optimize the local environment of Cu for stimulating industrial-current-density CO2 -to-C2 H4 electroreduction in neutral media. In situ spectroscopic results and theoretical study demonstrated that the Cu electrode modified by MgAl-LDH (MgAl-LDH/Cu) displayed a much higher surface pH value compared to the bare Cu, which could be attributed to the decreased energy barrier for hydrolysis on MgAl-LDH sites with more OH- ions on the surface of the electrode. As a result, MgAl-LDH/Cu achieved a C2 H4 Faradaic efficiency of 55.1 % at a current density up to 300 mA cm-2 in 1.0 M KHCO3 electrolyte.

Facial Skin Microbiota-Mediated Host Response to Pollution Stress Revealed by Microbiome Networks of Individual.

Urban living has been reported to cause various skin disorders. As an integral part of the skin barrier, the skin microbiome is among the key factors associated with urbanization-related skin alterations. The role of skin microbiome in mediating the effect of urban stressors (e.g., air pollutants) on skin physiology is not well understood. We generated 16S sequencing data and constructed a microbiome network of individual (MNI) to analyze the effect of pollution stressors on the microbiome network and its downstream mediation effect on skin physiology in a personalized manner. In particular, we found that the connectivity and fragility of MNIs significantly mediated the adverse effects of air pollution on skin health, and a smoking lifestyle deepened the negative effects of pollution stress on facial skin microbiota. This is the first study that describes the mediation effect of the microbiome network on the skin's physiological response toward environmental factors as revealed by our newly developed MNI approach and conditional process analysis. IMPORTANCE The association between the skin microbiome and skin health has been widely reported. However, the role of the skin microbiome in mediating skin physiology remains a challenging and yet priority subject in the field. Through developing a novel MNI method followed by mediation analysis, we characterized the network signature of the skin microbiome at an individual level and revealed the role of the skin microbiome in mediating the skin's responses toward environmental stressors. Our findings may shed new light on microbiome functions in skin health and lay the foundation for the design of a microbiome-based intervention strategy in the future.

Induction of ganoderic acid biosynthesis by Mn2+ in static liquid cultivation of Ganoderma lucidum.

Metal ions affect cell physiology and metabolism significantly, but the role of Mn(2+) in the secondary metabolism of mushrooms is yet unclear. In static liquid cultivation of Ganoderma lucidum for producing antitumor ganoderic acids (GAs), the Mn(2+) addition was performed. Addition of 10 mM Mn(2+) at the start of the static liquid cultivation resulted in 2.2-fold improvement of total GAs production. The expression levels of GA biosynthetic and Ca(2+) sensors' genes were up-regulated with Mn(2+) induction while down-regulated by adding cyclosporin A (calcineurin inhibitor), suggesting that higher GA production might result from calcineurin signal regulation. Intracellular Ca(2+) imaging and calcineurin inhibitor study revealed that addition of Mn(2+) led to Ca(2+) influx from medium to the cells to trigger calcineurin signals. Mn(2+) addition was therefore an efficient induction strategy for improving GAs production, whose regulation mechanism was via calcineurin signaling transduction.

Induced effect of Na(+) on ganoderic acid biosynthesis in static liquid culture of Ganoderma lucidum via calcineurin signal transduction.

Na(+)/Ca(2+) exchange is important to cell physiology and metabolism, but its role in the secondary metabolite biosynthesis by fungi is yet unclear. In this work, in static liquid cultures of Ganoderma lucidum, which is an efficient process for hyper-production of anti-tumor ganoderic acids (GAs), it was interestingly found that Na(+) addition could enhance the GAs production, but K(+) did not. Further investigation by intracellular Ca(2+) imaging and using a calcineurin inhibitor (i.e., cyclosporin A) revealed that addition of Na(+) led to the influx of Ca(2+) from culture broth to the cells and calcineurin signals were also triggered. Addition of 100 mM Na(+) at the beginning of the static liquid cultivation, in which the addition dosage and timing were optimized, resulted in 2.8-fold improvement of total GAs production. Quantitative gene transcription analysis indicated that the expression levels of the genes of Ca(2+) sensors and GA biosynthesis were upregulated with Na(+) induction while downregulated by using the calcineurin inhibitor, implying that higher GA production might result from higher expression of those genes. This work not only provided a simple and efficient induction strategy by Na(+) addition for the improved GAs production but also suggested the regulation mechanism of Na(+) on the GA biosynthesis through calcineurin signaling transduction.

Enhancement of ganoderic acid accumulation by overexpression of an N-terminally truncated 3-hydroxy-3-methylglutaryl coenzyme A reductase gene in the basidiomycete Ganoderma lucidum.

Ganoderic acids produced by Ganoderma lucidum, a well-known traditional Chinese medicinal mushroom, exhibit antitumor and antimetastasis activities. Genetic modification of G. lucidum is difficult but critical for the enhancement of cellular accumulation of ganoderic acids. In this study, a homologous genetic transformation system for G. lucidum was developed for the first time using mutated sdhB, encoding the iron-sulfur protein subunit of succinate dehydrogenase, as a selection marker. The truncated G. lucidum gene encoding the catalytic domain of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR) was overexpressed by using the Agrobacterium tumefaciens-mediated transformation system. The results showed that the mutated sdhB successfully conferred carboxin resistance upon transformation. Most of the integrated transfer DNA (T-DNA) appeared as a single copy in the genome. Moreover, deregulated constitutive overexpression of the HMGR gene led to a 2-fold increase in ganoderic acid content. It also increased the accumulation of intermediates (squalene and lanosterol) and the upregulation of downstream genes such as those of farnesyl pyrophosphate synthase, squalene synthase, and lanosterol synthase. This study demonstrates that transgenic basidiomycete G. lucidum is a promising system to achieve metabolic engineering of the ganoderic acid pathway.

Isolation and analysis of differentially expressed genes during asexual sporulation in liquid static culture of Ganoderma lucidum by suppression subtractive hybridization.

Ganoderma lucidum differentiates in liquid static culture by forming aerial mycelia and asexual spores, and this differentiation process is accompanied by higher production of anti-tumor compounds ganoderic acids. To gain an insight into the molecular events during asexual sporulation of G. lucidum, comparative transcriptome analysis using suppression subtractive hybridization (SSH) technique was performed to identify preferentially expressed genes in liquid static culture vs. in traditional shaking culture. After macroarray analysis of 1920 cDNAs from SSH library, 147 unigenes which exhibited high expression in static culture were identified. Among these sequences, putative translations of 88 unigenes possessed much similarity to known proteins involved in cell organization, signal transduction, cell metabolism, protein biosynthesis and transcription regulation; 13 had significant similarity to hypothetical proteins; the remaining 46 showed little or no similarity to GenBank sequences. RT-qPCR analysis confirmed increases in transcripts of selected genes under liquid static culture condition. The results of this study present the useful application of EST analysis on G. lucidum and provide preliminary indication of gene expression putatively involved in asexual sporulation process.

Impacts of calcium signal transduction on the fermentation production of antitumor ganoderic acids by medicinal mushroom Ganoderma lucidum.

Recently signal transduction engineering of secondary metabolism is receiving great interest as a powerful tool towards efficient production of valuable secondary metabolites. This work found that the calcineurin-signal transduction was significant to triterpene biosynthesis by higher fungus (mushroom). Addition of calcium ion (at 10mM) to static liquid cultures of Ganoderma lucidum, a famous traditional medicinal mushroom, was proved as a useful strategy to enhance the production of antitumor ganoderic acids (GAs), which resulted in 3.7-, 2.6-, 4.5-, 3.2- and 3.8-fold improvement of total GAs, individual GA-Mk, -T, -S, and -Me, respectively. Experiments using Ca2+ sensor inhibitors indicated the involvement of calcineurin signal in regulating GAs biosynthesis. Quantitative gene transcription analysis revealed that the expression levels of genes of GAs biosynthesis and Ca2+ sensor were up-regulated with calcium addition while down-regulated under the inhibitors addition, suggesting that higher GAs production may be resulted from higher expressions of those genes. Based on the results obtained, a possible model on the effect of external calcium ion on the GAs biosynthesis via calcineurin signal transduction pathway was proposed.