The characteristics of solid-phase substrate during the co-fermentation of lignite and straw.

Co-fermentation of lignite and biomass has been considered as a new approach in achieving clean energy. Moreover, the study of the characteristics of solid phase in the synergistic degradation process is of great significance in revealing their synergistic relationship. Accordingly, in order to produce biogas, lignite, straw, and the mixture of the two were used as the substrates, the solid phase characteristics of which were analyzed before and after fermentation using modern analytical methods. The results revealed that the mixed fermentation of lignite and straw promoted the production of biomethane. Moreover, the ratios of C/O and C/H were found to be complementary in the co-fermentation process. Furthermore, while the relative content of C-C/C-H bonds was observed to be significantly decreased, the aromatics degree of lignite was weakened. Also, while the degree of branching increased, there found to be an increase in the content of cellulose amorphous zone, which, consequently, led to an increase in the crystallinity index of the wheat straw. Hence, the results provide a theoretical guidance for the efficient utilization of straw and lignite.

Metagenomic insight of corn straw conditioning on substrates metabolism during coal anaerobic fermentation.

Increasing methane production from anaerobic digestion of coal is challenging. This study shows that the combined fermentation of coal and corn straw greatly enriched the substrates available to microorganisms. This was mainly manifested in the increased types and abundance of organic matter in the fermentation liquid, which enhanced methane production by 61%. Metagenomic analysis showed that the addition of corn straw enriched the abundance of Methanosarcina in the combined fermentation system and promoted the complementary advantages of the microorganisms. At the same time, the abundance of genes that convert glucose into acetic acid (K00927, K01689, K01905, etc.) in the combined fermentation system increased, which is conducive to acidification process and biomethane production. In addition, there were the two key methanogenic pathways, namely aceticlastic (57.1%-63.5%) and hydrogenotrophic (23.4%-25.1%) methanogenesis, identified in the single coal fermentation system and the combined coal and corn straw fermentation system. Combined fermentation enhanced the hydrogenotrophic and methylotrophic methanogenic pathways by increasing the gene abundance of K00200 (methane production from CO2 and oxidation of coenzyme M to CO2), K00440 (participates in the binding to other known physiological receptors with hydrogen as a donor), and K00577 (methyltransferase).

In silico/computational analysis of mevalonate pyrophosphate decarboxylase gene families in Campanulids.

Mevalonate pyrophosphate decarboxylase (MPD) is a key enzyme in terpenoid biosynthesis. MPD plays an important role in the upstream regulation of secondary plant metabolism. However, studies on the MPD gene are relatively very few despite its importance in plant metabolism. Currently, no systematic analysis has been conducted on the MPD gene in plants under the order Apiales, which comprises important medicinal plants such as Panax ginseng and Panax notoginseng. This study sought to explore the structural characteristics of the MPD gene and the effect of adaptive evolution on the gene by comparing and analyzing MPD gene sequences of different campanulids species. For that, phylogenetic and adaptive evolution analyses were carried out using sequences for 11 Campanulids species. MPD sequence characteristics of each species were then analyzed, and the collinearity analysis of the genes was performed. As a result, a total of 21 MPD proteins were identified in 11 Campanulids species through BLAST analysis. Phylogenetic analysis, physical and chemical properties prediction, gene family analysis, and gene structure prediction showed that the MPD gene has undergone purifying selection and exhibited highly conserved structure. Analysis of physicochemical properties further showed that the MPD protein was a hydrophilic protein without a transmembrane region. Moreover, collinearity analysis in Apiales showed that MPD gene on chromosome 2 of D. carota and chromosome 1 of C. sativum were collinear. The findings showed that MPD gene is highly conserved. This may be a common characteristic of all essential enzymes in the biosynthesis pathways of medicinal plants. Notably, MPD gene is significantly affected by environmental factors which subsequently modulate its expression. The current study's findings provide a basis for follow-up studies on MPD gene and key enzymes in other medicinal plants.

A simple "turn-on" fluorescence sensor for salicylaldehyde skeleton based on switch of PET-AIE effect.

The selective detection of salicylaldehyde skeleton is of great significance in phytochemistry and biological research but rarely reported. In this research, a simple and highly selective "turn-on" fluorescence sensor (CDB-Am) for salicylaldehyde skeleton was developed based on switch of photoinduced electron transfer (PET) and aggregation-induced emission (AIE). CDB-Am bearing amino-cyanodistyrene structure responded to salicylaldehyde in the range of 3.1 to 40 µM with a detection limit of 0.94 µM. The sensing process of formation of Schiff-base adduct CDB-SA was confirmed by 1H NMR, MS, and FT-IR spectra, revealing that a recovered AIE property accounted for the turn-on fluorescence response of CDB-Am and the intramolecular hydrogen bonding played a crucial role in the disruption of PET process. This sensing ability was successfully applied for both fluorescence qualitative test of salicylaldehyde skeleton on TLC analysis and quantitative detection of salicylaldehyde skeleton with good accuracy in the root bark of Periploca sepium, suggesting the extensive applications in phytochemistry and traditional Chinese herbal medicine. Furthermore, CDB-Am exhibited the first excellent fluorescence imaging ability in detecting salicylaldehyde skeleton in a living system. This work supplied a new strategy of preparing a novel "turn-on" fluorescence probe for detecting salicylaldehyde skeleton in complex environments and living bodies.

Identification of Parthenolide Dimers as Activators of Pyruvate Kinase M2 in Xenografts of Glioblastoma Multiforme in Vivo.

Herein we detail the discovery of a series of parthenolide dimers as activators of PKM2 and evaluation of their anti-GBM activities. The most promising compound 5 showed high potency to activate PKM2 with an AC50 value of 15 nM, inhibited proliferation and metastasis, and induced apoptosis of GBM cells. Compound 5 could promote tetramer formation of PKM2 and reduce nucleus translocation of PKM2 in GBM cells without influence on the expression of total PKM2, thereby inhibiting the STAT3 signal pathway in vitro and in vivo. PKM2 knockdown assay demonstrated that the anti-GBM effect of 5 mainly depended on the expression of PKM2 in vitro and in vivo. Compound 16, a prodrug of 5, markedly suppressed U118 tumor xenograft growth and reduced the weight of tumor. On the basis of these investigations, we propose that 16 might be considered as a promising lead compound for discovery of anti-GBM drugs.

The mechanisms of biogenic methane metabolism by synergistic biodegradation of coal and corn straw.

The mechanisms associated with the biomethane metabolism through the synergistic biodegradation of both coal and corn straw were explored to improve the utilization rate of corn straw. This applies to the filling of the goaf with corn straw and the production of biomethane using indigenous bacteria in the mine water with coal. The results showed that new macromolecular substances (e.g., Tetracosane and Pentacosane) were produced on the third day. A lower coal rank leads to a lower biodegradation rate of low-molecular-weight substances (e.g., butyric acid and valeric acid). Under the addition of coal samples, the biodegradation rate of cellulose, hemicellulose and lignin in corn straw could reached up to 29.82%, 35.79% and 6.16%, respectively. The addition of corn straw promoted the complementary advantages of archaeal genera (such as Methanosarina and Methanospirillum) and decreased the adverse bacterial genera (such as Desulfovibrio and Pseudomonas) in the fermentation system of single coal.

Genome-Wide Identification of WRKY Transcription Factors in the Asteranae.

The WRKY transcription factors family, which participates in many physiological processes in plants, constitutes one of the largest transcription factor families. The Asterales and the Apiales are two orders of flowering plants in the superorder Asteranae. Among the members of the Asterales, globe artichoke (Cynara cardunculus var. scolymus L.), sunflower (Helianthus annuus L.), and lettuce (Lactuca sativa L.) are important economic crops worldwide. Within the Apiales, ginseng (Panax ginseng C. A. Meyer) and Panax notoginseng (Burk.) F.H. Chen are important medicinal plants, while carrot (Daucus carota subsp. carota L.) has significant economic value. Research involving genome-wide identification of WRKY transcription factors in the Asterales and the Apiales has been limited. In this study, 490 WRKY genes, 244 from three species of the Apiales and 246 from three species of the Asterales, were identified and categorized into three groups. Within each group, WRKY motif characteristics and gene structures were similar. WRKY gene promoter sequences contained light responsive elements, core regulatory elements, and 12 abiotic stress cis-acting elements. WRKY genes were evenly distributed on each chromosome. Evidence of segmental and tandem duplication events was found in all six species in the Asterales and the Apiales, with segmental duplication inferred to play a major role in WRKY gene evolution. Among the six species, we uncovered 54 syntenic gene pairs between globe artichoke and lettuce. The six species are thus relatively closely related, consistent with their traditional taxonomic placement in the Asterales. This study, based on traditional species classifications, was the first to identify WRKY transcription factors in six species from the Asteranae. Our results lay a foundation for further understanding of the role of WRKY transcription factors in species evolution and functional differentiation.

Enzyme-induced in vivo assembly of gold nanoparticles for imaging-guided synergistic chemo-photothermal therapy of tumor.

This article describes a nanoplatform based on matrix metalloproteinase (MMP)-responsive gold nanoparticles (AuNPs) for tumor-targeted photoacoustic (PA) imaging-guided photothermal therapy and drug delivery. AuNPs were grafted with complementary DNA strands, tethered with doxorubicin and coated with poly(ethylene glycol) via a thermal-labile linker and a MMP-cleavable peptide, respectively. The nanoprobes remained well-isolated in healthy tissues, but formed aggregates rapidly under MMP-abundant conditions. The DNA hybridization-induced assembly of the nanoprobes led to prolonged tumor retention and strong near-infrared (NIR) absorption, which is beneficial to deep-tissue imaging and therapy. Compared with MMP-inert nanoprobes, our platform demonstrated significantly enhanced efficiency in PA imaging and photothermal conversion upon NIR irradiation. Meanwhile, doxorubicin could be released rapidly in response to the localized elevation of temperature, leading to synergistic chemo-photothermal therapy. The unique nanoplatform may find applications in effective disease control by delivering imaging and therapy to tumors with high specificity, safety, and universality.

Effect of acidic, neutral and alkaline conditions on product distribution and biocrude oil chemistry from hydrothermal liquefaction of microalgae.

Hydrothermal liquefaction (HTL) of microalgae produces high amount of water-insoluble organic compounds, the biocrude oil. Using high-growth-rate Spirulina platensis as feedstock, product fraction distribution and biocrude oil chemistry from HTL at a temperature of 240-300 °C under acidic, neutral and alkaline condition were studied. Positive effects on biocrude oil yield were only found with KOH and acetic acid, and these effects were stronger under milder HTL conditions. FT-ICR MS showed that O2 class in the biocrude was high due to higher carbohydrate in the biomass, numbers of N3O5-6 species present in the sample from acetic acid run, indicating its less decarboxylation ability. GC-MS showed more ketones and amides were formed from fatty acids in catalytic HTL, and this effect was sensitive toward reaction temperature. GPC suggested more light volatiles were in biocrude from KOH run, while analysis from NMR, FT-IR and elemental confirmed its high oil quality.