Preparation and characterization of furfural residue derived char-based catalysts for biomass tar cracking.

This study proposed an innovative strategy of catalytic cracking of tar during biomass pyrolysis/gasification using furfural residue derived biochar-based catalysts. Fe, Co, and Ni modified furfural residue char (FRC-Fe, FRC-Co, and FRC-Ni) were prepared by one-step impregnation method. The influences of cracking temperature and metal species on the tar cracking characteristics were investigated. The results showed that the tar conversion efficiency for all catalysts were improved with the cracking temperature increasing, the higher tar conversion efficiency achieved at 800 °C were 66.72 %, 89.58 %, 84.58 %, and 94.70 % for FRC, FRC-Fe, FRC-Co, and FRC-Ni respectively. FRC-Ni achieved the higher gas (H2, CO, CH4, CO2) yield 681.81 mL/g. At 800 °C, the catalyst (FRC-Ni) still reached a high tar conversion efficiency over 85.90 % after 5 cycles. SEM-EDS results showed that the distribution of Ni particles on the biochar support was uniform. TGA results demonstrated that FRC-Ni exhibited better thermal stability. XRD results indicated that there was no significant change in the grain size of Ni before and after the reaction. The FRC-Ni catalyst was reasonably stable due to its better anti-sintering and coke-resistant capabilities.

Environmental risk of ion-absorbed rare earth ores: concentration of leaching agent and fractionation of Pb.

Rare earth (RE) is an important strategic resource; however, there has been a growing concern about the environmental problems caused by RE mining, such as ammonia nitrogen pollution and heavy metal pollution. There is a limited research about the behavior of leaching agents and the fractionation of RE and heavy metal during the mining process for ion adsorption of rare earth ore (IRE-ore) in the previously available papers. In this study, (NH4)2SO4 solution, which commonly used in the production of mining IRE-ore, was used as a leaching agent. The adsorption behavior of ore soils on ammonium ions was explored by batch experiments. The adsorption process of IRE-ore on ammonium ions followed a pseudo-second-order equation and was controlled by the kinetics of surface adsorption and intra-particle diffusion; the ammonium ion adsorption isotherm conformed to the Freundlich isotherm equilibrium equation, and the higher concentration advantage made the ore soils possess a higher adsorption capacity of ammonium ion. In addition, the fractionation characteristics of lanthanum (La), cerium (Ce), and lead (Pb) in the ore soil during the leaching process were simulated based on the batch and column leaching experiments. The results demonstrated that the exchangeable states of La and Ce in IRE-ore were high, and the exchangeable, carbonate-bound La and Ce were almost all leached out by (NH4)2SO4 leaching agent, while the most of exchangeable Pb flowed out along with leaching agent, and a small amount of leached Pb in the ore soil was converted to iron and manganese oxide-bound Pb and enriched in the direction of migration of the leaching solution, and when the environment (e.g., pH and Eh) changed, this part of Pb may be re-activated. Our research might serve as crucial baseline knowledge for the adsorption of ammonium ions by ore soils, and provide a data reference for reducing the use of leaching agents and developing sustainable technologies for green mining of ion-adsorption RE ores.

Synergistic Effect of Cation Composition Engineering of Hybrid Cs1-x FAx PbBr3 Nanocrystals for Self-Healing Electronics Application.

Mixed-cation hybrid perovskite nanocrystal (HPNC) with high crystallinity, color purity, and tunable optical bandgap offers a practical pathway toward next-generation displays. Herein, a two-step modified hot-injection combined with cation compositional engineering and surface treatment to synthesize high-purity cesium/formamidinium lead bromide HPNCs(Cs1-x FAx PbBr3 ) is presented. The optimized Cs0.5 FA0.5 PbBr3 light-emitting devices (LEDs) exhibit uniform luminescence of 3500 cd m-2 and a prominent current efficiency of 21.5 cd A-1 . As a proof of concept, a self-healing polymer (SHP) integrated with white LED backlight and laser prototypes exhibited 4 h autonomous self-healing through the synergistic effect of weak reversible imine bonds and stronger H-bonds. First, the SHP-HPNCs-initial and SHP-HPNCs-cut possess high long-term stability and dramatically suppressed lead leakage as low as 0.6 ppm along with a low leakage rate of 1.11 × 10-5 cm2 and 3.36 × 10-5 cm2 even over 6 months in water. Second, the Cs0.5 FA0.5 PbBr3 HPNCs and SHP-induced shattered-repaired perovskite glass substrate show the lowest lasing threshold values of 1.24 and 8.58 µJ cm-2 , respectively. This work provides an integrative and in-depth approach to exploiting SHP with intrinsic and entropic self-healing capabilities combined with HPNCs to develop robust and reliable soft-electronic backlight and laser applications.

Corrigendum: Phylogenetic and genomic analyses of two new species of Clavispora (Metschnikowiaceae, Saccharomycetales) from Central China.

[This corrects the article DOI: 10.3389/fmicb.2022.1019599.].

Phylogenetic and genomic analyses of two new species of Clavispora (Metschnikowiaceae, Saccharomycetales) from Central China.

Species in the genus Clavispora have previously been reported primarily in the northeast and northwest regions of China; the species diversity of Clavispora in central China is not currently clear. In this study, phylogenetic inferences of Clavispora based on sequences of a single-locus (LSU D1/D2) and a two-locus (LSU D1/D2 and ITS) were conducted. Two new species isolated from rotting wood in central China, namely Clavispora xylosa sp. nov. and Clavispora paralusitaniae sp. nov., were delimited and proposed based on morphological and molecular evidence. Cl. xylosa was closely related to C. thailandica CBS 10610T, but with 11.5% divergence in the LSU D1/D2 domains and 11.5% divergence in the ITS regions. Cl. paralusitaniae was a sister to Cl. lusitaniae CBS 6936T from which it differs with 4.7% divergence in the LSU D1/D2 domains and 5.4% divergence in the ITS regions. Description of Cl. xylosa sp. nov. and Cl. paralusitaniae sp. nov. was also supported by morphological comparisons and genomic analyses between the two new species and their closest relatives, C. thailandica CBS 10610T and Cl. lusitaniae CBS 6936T. These results indicate a potentially great diversity of Clavispora spp. inhabiting rotting wood in central China, ripe for future discovery.

Nanofiber-Based Odor-Free Medical Mask Fabrication Using Polyvinyl Butyral and Eucalyptus Anti Odor Agent.

Following the 2020 COVID-19 worldwide outbreak, many countries adopted sanitary and safety measures to safeguard public health such as wearing medical face mask. While face masks became a necessity for people, disadvantages impede their long period wearing such as uncomfortable breathability and odor. The intermediate layer of the medical face mask is composed of porous non-woven fabric to block external particles while maintaining breathability. To overcome aforementioned limitation, this study uses electrospinning to design and fabricate odorless face masks via the use of aromatic oil. Eucalyptus essential oil is encapsulated through mixing and layer-by-layer by hydrophobic polyvinyl butyral and further used to fabricate the medical mask intermediate layer. We found that adding 0.2 g of eucalyptus into polyvinyl butyral fabric through mixing results in the deodorization rate of 80% after 2 h, with fabric thickness of 440.9 µm, and melt-blown non-woven fabric thickness of 981.7 µm. The Particle Filtration Efficiency of 98.3%, Bacterial Filtration Efficiency above 99.9%, and the differential pressure of 4.7 mm H2O/cm2 meet the CNS 14774 standard on medical face masks. Therefore, this study successfully proved that this type of masks' middle layer not only effectively protects against coronavirus, but also provides better scents and makes it more comfortable for consumers.

Anthocyanin Accumulation and Molecular Analysis of Correlated Genes by Metabolomics and Transcriptomics in Sister Line Apple Cultivars.

Red coloration in apples, an important quality trait, is primarily attributed to the accumulation of anthocyanins. Centuries of breeding have produced a wide variety of apples with different levels of anthocyanins in response to genetic and environmental stimuli. The Huashuo apple shows a much darker red color than its sister line, Huarui. Thirteen different anthocyanins were detected in Huashuo and Huarui apples, of which ten were significantly more abundant in Huashuo apples, confirming that the color difference is indeed attributed to high anthocyanins accumulation rather than the types of anthocyanins. In particular, the contents of cyanidin 3-O-galactoside levels were highest among anthocyanins in both cultivars, reaching >5000 µg·g−1 at the last color transition stage in Huashuo apples, while only >3000 µg·g−1 in Huarui apples. Moreover, the expression of most structural genes, especially DFR, CHI, and 4CL associated with anthocyanin synthesis, were higher in Huashuo apples than in Huarui apples. Combined transcriptomics, metabolomics, and qRT-PCR analysis revealed that six transcription factors from the MYB and bZIP transcription factor families likely play key roles in the dark coloring of Huashuo apples. These results provide deeper insights into apple coloring and suggest a series of candidate genes for breeding anthocyanin-rich cultivars.

Transposon insertions regulate genome-wide allele-specific expression and underpin flower colour variations in apple (Malus spp.).

Allele-specific expression (ASE) can lead to phenotypic diversity and evolution. However, the mechanisms regulating ASE are not well understood, particularly in woody perennial plants. In this study, we investigated ASE genes in the apple cultivar 'Royal Gala' (RG). A high quality chromosome-level genome was assembled using a homozygous tetra-haploid RG plant, derived from anther cultures. Using RNA-sequencing (RNA-seq) data from RG flower and fruit tissues, we identified 2091 ASE genes. Compared with the haploid genome of 'Golden Delicious' (GD), a parent of RG, we distinguished the genomic sequences between the two alleles of 817 ASE genes, and further identified allele-specific presence of a transposable element (TE) in the upstream region of 354 ASE genes. These included MYB110a that encodes a transcription factor regulating anthocyanin biosynthesis. Interestingly, another ASE gene, MYB10 also showed an allele-specific TE insertion and was identified using genome data of other apple cultivars. The presence of the TE insertion in both MYB genes was positively associated with ASE and anthocyanin accumulation in apple petals through analysis of 231 apple accessions, and thus underpins apple flower colour evolution. Our study demonstrated the importance of TEs in regulating ASE on a genome-wide scale and presents a novel method for rapid identification of ASE genes and their regulatory elements in plants.

microRNA172 targets APETALA2 to regulate flavonoid biosynthesis in apple (Malus domestica).

MicroRNA172 (miR172) plays a role in regulating a diverse range of plant developmental processes, including flowering, fruit development and nodulation. However, its role in regulating flavonoid biosynthesis is unclear. In this study, we show that transgenic apple plants over-expressing miR172 show a reduction in red coloration and anthocyanin accumulation in various tissue types. This reduction was consistent with decreased expression of APETALA2 homolog MdAP2_1a (a miR172 target gene), MdMYB10, and targets of MdMYB10, as demonstrated by both RNA-seq and qRT-PCR analyses. The positive role of MdAP2_1a in regulating anthocyanin biosynthesis was supported by the enhanced petal anthocyanin accumulation in transgenic tobacco plants overexpressing MdAP2_1a, and by the reduction in anthocyanin accumulation in apple and cherry fruits transfected with an MdAP2_1a virus-induced-gene-silencing construct. We demonstrated that MdAP2_1a could bind directly to the promoter and protein sequences of MdMYB10 in yeast and tobacco, and enhance MdMYB10 promotor activity. In Arabidopsis, over-expression of miR172 reduced flavonoid (including anthocyanins and flavonols) concentration and RNA transcript abundance of flavonoid genes in plantlets cultured on medium containing 7% sucrose. The anthocyanin content and RNA abundance of anthocyanin genes could be partially restored by using a synonymous mutant of MdAP2_1a, which had lost the miR172 target sequences at mRNA level, but not restored by using a WT MdAP2_1a. These results indicate that miR172 inhibits flavonoid biosynthesis through suppressing the expression of an AP2 transcription factor that positively regulates MdMYB10.

One-pot conversion of wheat straw into biobased chemicals in methanol/water medium using cheap mixed acid catalyst.

BACKGROUND: Environmental concerns and the diminishing availability of unrenewable resources have spurred research into the use of agricultural waste as a feedstock for industrial applications. Efficient conversion of wheat straw into biobased chemicals is an important way to realize the potential value of renewable agricultural biomass. This study investigated one-pot conversion of wheat straw into two notable platform chemicals, levulinic acid (LA) and methyl levulinate (ML). RESULTS: A mixed acid catalyst system, including 1% H2 SO4 and 0.015 mol L-1 Al2 (SO4 )3 , was an efficient catalyst for the conversion of wheat straw due to the combination of Brønsted acid and Lewis acid. A ratio of wheat straw to methanol of 5 g/50 mL was identified as the preferred solid/liquid ratio, and a methanol/H2 O medium with 25% water content aided the simultaneous production of LA and ML from wheat straw. Under optimum conditions, the maximum total yield of LA and ML reached 23.01% at 220 °C and 3 h. The kinetics of biobased chemical formation and the reaction pathways in methanol/water were investigated. CONCLUSION: The presence of water in the methanol/H2 O medium affected the distribution of products and promoted hydrolysis reactions. The methanol/H2 O medium not only inhibited the side reactions but also promoted the degradation of wheat straw and increased the total yield of LA and ML. This study provides a feasible method for the conversion of wheat straw to prepare biobased chemicals. © 2021 Society of Chemical Industry.

Four new species of Trichomonascaceae (Saccharomycetales, Saccharomycetes) from Central China.

Trichomonascaceae is the largest family of ascomycetous yeast in the order Saccharomycetales. In spite of the extensive body of research on Trichomonascaceae in China, there remain new species to be discovered. Here, we describe four new species isolated from several rotting wood samples from Henan Province, Central China. Phylogenetic analysis of a combined ITS and nrLSU dataset with morphological studies revealed four new species in the Trichomonascaceae: Diddensiellaluoyangensis, Sugiyamaellacylindrica, Su.robnettiae, and Zygoascusdetingensis. Clustering in the Diddensiella clade, D.luoyangensis' closest neighbour was D.transvaalensis. Meanwhile, Su.cylindrica clustered in the Sugiyamaella clade closest to Su.marilandica and Su.qingdaonensis. Also clustering in the Sugiyamaella clade, Su.robnettiae was most closely related to Su.chuxiongensis. Finally, Z.detingensis occupied a distinct and separated basal branch from the other species of the genus Zygoascus. These results indicate a high species diversity of Trichomonascaceae.

Kodamaeahongheensis f.a., sp. nov., Kodamaeaovata f.a., sp. nov. and Kodamaeayamadae f.a., sp. nov., three new yeast species of Kodamaea (Saccharomycetales, Debaryomycetacae) from China.

Kodamaea includes a growing number of interesting yeasts of the family Debaryomycetacae that are widely distributed in temperate, subtropical and tropical regions of different continents. During recent yeast collections in Henan and Yunnan Province in China, several isolates of Kodamaea were obtained from rotting wood, all of which represent undescribed taxa. Based on morphological and phylogenetic analyses (ITS and LSU rDNA), three new species are proposed: K.hongheensis f.a., sp. nov., K.ovata f.a., sp. nov. and K.yamadae f.a., sp. nov. In addition, sixteen Candida species, which are members of the Kodamaea clade based on phylogenetic analysis, are transferred to Kodamaea as new combinations. Our results indicate high species diversity of Kodamaea waiting to be discovered in rotting wood from tropical and subtropical China.

New species of Yamadazyma from rotting wood in China.

Yamadazyma is one of the largest genera in the family Debaryomycetaceae (Saccharomycetales, Saccharomycetes) with species mainly found in rotting wood, insects and their resulting frass, but also recovered from flowers, leaves, fruits, tree bark, mushrooms, sea water, minerals, and the atmosphere. In the present study, several strains obtained from rotting wood in Henan and Yunnan Provinces of China were isolated. Based on morphology and a molecular phylogeny of the rDNA internal transcribed spacer region (ITS) and the D1/D2 domain of the large subunit (LSU) rDNA, these strains were identified as three new species: Yamadazymaluoyangensis, Y.ovata and Y.paraaseri; and three previously described species, Y.insectorum, Y.akitaensis, and Y.olivae. The three new species are illustrated and their morphology and phylogenetic relationships with other Yamadazyma species are discussed. Our results indicate a high undiscovered diversity of Yamadazyma spp. inhabiting rotting wood in China.

MdPR4, a pathogenesis-related protein in apple, is involved in chitin recognition and resistance response to apple replant disease pathogens.

To maximize breeding and exploitation of disease resistance traits for managing apple replant disease (ARD), it is of great importance to understand the mechanisms of apple root resistance. Currently, little is known about the functions of the specific genes that confer resistance traits in apple root. In this study, molecular, biochemical, and genetic approaches allowed an in-depth understanding of the role of the MdPR4 gene in the defense response of apple root. The MdPR4 encoding gene showed upregulation following ARD pathogen inoculation in our previous transcriptome data. Subcellular localization analyses revealed that MdPR4 is localized on the plasma membrane, endoplasmic reticulum, and apoplast, which is mainly determined by its signal peptide. Molecular docking analysis between MdPR4 protein with chitin molecule and in vitro MdPR4 chitin affinity assay proved its chitin-binding ability, which provided evidence for its role in chitin-mediated immune responses. Purified MdPR4 protein and MdPR4 overexpressed apple callus inhibited spore germination and mycelial growth of ARD-related Fusarium spp. pathogens. These data support the conclusion that MdPR4 is a chitin-binding protein in apple vegetative tissues that may play an important role in defense activation in response to ARD pathogen infection.

Diversity of the genus Sugiyamaella and description of two new species from rotting wood in China.

Species of the genus Sugiyamaella (Trichomonascaceae, Saccharomycetales), found in rotting wood in China, were investigated using morphology and the molecular phylogeny of a combined ITS and nrLSU dataset. Nine taxa were collected in China: two were new species (viz. Sugiyamaella chuxiong sp. nov. and S. yunanensis sp. nov.) and seven were known species, S. americana, S. ayubii, S. novakii, S. paludigena, S. valenteae, S. valdiviana and S. xiaguanensis. The two new species are illustrated and their morphology and phylogenetic relationships with other Sugiyamaella species are discussed. Our results indicate a potentially great diversity of Sugiyamaella spp. inhabiting rotting wood in China just waiting to be discovered.

Identification of gene co-expression networks and key genes regulating flavonoid accumulation in apple (Malus × domestica) fruit skin.

Anthocyanin provides a red color for apple and health benefit for human. To better understand the molecular mechanisms of regulating apple color formation, we analyzed 27 transcriptomes of fruit skin from three cultivars 'Huashuo' (red-skinned), 'Hongcuibao' (red-skinned), and 'Golden Delicious' (yellow-skinned) at 0, 2, and 6 days after bag removal. Using pairwise comparisons and weighted gene co-expression network analyses (WGCNA), we constructed 17 co-expression modules. Among them, a specific module was negatively correlated to anthocyanin accumulation. The genes in the module are enriched in flavonoid biosynthesis pathways. These pathway genes were used to construct gene co-expression network of anthocyanin accumulation. Finally, a R2R3-MYB repressor designated MdMYB28 was identified as a key hub gene in the anthocyanin metabolism network. During the anthocyanin accumulation of apple fruit skin reaching a peak, MdMYB28 expression level was negatively correlated with the anthocyanin content. MdMYB28 was shown to directly bind to the promoter of MdMYB10 in yeast one-hybrid analyses. Over-expression of MdMYB28 decreased the anthocyanin biosynthesis in tobacco flower petals, suggesting that MdMYB28 acts as a negatively regulator of anthocyanin biosynthesis.

Field detection of multiple RNA viruses/viroids in apple using a CRISPR/Cas12a-based visual assay.

Co-infection of apple trees with several viruses/viroids is common and decreases fruit yield and quality. Accurate and rapid detection of these viral pathogens helps to reduce losses and prevent virus spread. Current molecular detection assays used for apple viruses require specialized and expensive equipment. Here, we optimized a CRISPR/Cas12a-based nucleic acid detection platform for the diagnosis of the most prevalent RNA viruses/viroid in apple, namely Apple necrotic mosaic virus (ApNMV), Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV), Apple chlorotic leaf spot virus (ACLSV) and Apple scar skin viroid (ASSVd). We detected each RNA virus/viroid directly from crude leaf extracts after simultaneous multiplex reverse transcription-recombinase polymerase amplification (RT-RPA) with high specificity. Positive results can be distinguished by the naked eye via oligonucleotide-conjugated gold nanoparticles. The CRISPR/Cas12a-RT-RPA platform exhibited comparable sensitivity to RT-qPCR, with limits of detection reaching 250 viral copies per reaction for ASPV and ASGV and 2500 copies for the others. However, this protocol was faster and simpler, requiring an hour or less from leaf harvest. Field tests showed 100% agreement with RT-PCR detection for 52 samples. This novel Cas12a-based method is ideal for rapid and reliable detection of apple viruses in the orchard without the need to send samples to a specialized laboratory.

Transcriptome analysis of transgenic apple fruit overexpressing microRNA172 reveals candidate transcription factors regulating apple fruit development at early stages.

BACKGROUND: MicroRNA172 (miR172) has been proven to be critical for fruit growth, since elevated miR172 activity blocks the growth of apple (Malus x domestica Borkh.) fruit. However, it is not clear how overexpression of miR172 affects apple fruit developmental processes. METHODS: To answer this question, the present study, analyzed global transcriptional changes in miR172-overexpressing (miR172OX) and nongenetically modified wild-type (WT) apple fruit at two developmental stages and in different fruit tissues via RNA-seq. In addition, two cultivars, 'Hanfu' and 'M9', which have naturally fruit size variation, were included to identify miR172-dependent DEGs. qRT-PCRwas used to verify the reliability of our RNA-seq data. RESULTS: Overexpression of miR172 altered the expression levels of many cell proliferation- and cell expansion-related genes. Twenty-four libraries were generated, and 10,338 differentially expressed genes (DEGs) were detected between miR172OX and WT fruit tissues. 'Hanfu' and 'M9' are two common cultivars that bear fruit of different sizes (250 g and 75 g, respectively). Six libraries were generated, and 3,627 DEGs were detected between 'Hanfu' and 'M9'. After merging the two datasets, 6,888 candidate miR172-specific DEGs were identified. The potential networks associated with fruit size triggered traits were defined among genes belonging to the families of hormone synthesis, signaling pathways, and transcription factors. Our comparative transcriptome analysis provides insights into transcriptome responses to miR172 overexpression in apple fruit and a valuable database for future studies to validate functional genes and elucidate the fruit developmental mechanisms in apple.

Five new additions to the genus Spathaspora (Saccharomycetales, Debaryomycetaceae) from southwest China.

Spathaspora is an important genus of d-xylose-fermenting yeasts that are poorly studied in China. During recent yeast collections in Yunnan Province in China, 13 isolates of Spathaspora were obtained from rotting wood and all represent undescribed taxa. Based on morphological and phylogenetic analyses (ITS and nuc 28S), five new species are proposed: Spathaspora elongata, Sp. mengyangensis, Sp. jiuxiensis, Sp. parajiuxiensis and Sp. rosae. Our results indicate a high species diversity of Spathaspora waiting to be discovered in rotting wood from tropical and subtropical southwest China. In addition, the two Candida species, C. jeffriesii and C. materiae, which are members of the Spathaspora clade based on phylogeny, are transferred to Spathaspora as new combinations.

Kazachstania jinghongensis sp. nov. and Kazachstania menglunensis f.a., sp. nov., two yeast species isolated from rotting wood.

Five yeast strains were isolated from rotting wood samples collected in the Xishuangbanna Tropical Rainforest, Yunnan Province, PR China. Phylogenetic analysis of the D1/D2 domains of the large subunit rRNA gene indicated that these strains represent two novel species of the genus Kazachstania. Kazachstania jinghongensis sp. nov. produces one to two spherical ascospores per ascus, and is most closely related to Kazachstania lodderae and Kazachstania spencerorum. Kazachstania jinghongensis sp. nov. differed from the type strains of the two latter species by 13-24 substitutions in the D1/D2 domains and by 39-56 substitutions in the ITS regions. Kazachstania menglunensis f.a., sp. nov. is a member of the Kazachstania jiainica subclade, but the formation of ascospores was not observed on various sporulation media. Kazachstania menglunensis sp. nov. differed from other members of the subclade by 23-26 substitutions in the D1/D2 domains and by more than 67 substitutions in the ITS regions. The holotype of Kazachstania jinghongensis sp. nov. is NYNU 17944 (CBS 15232) and the holotype of Kazachstania menglunensis sp. nov. is NYNU 18913 (CBS 16054).