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Effect of neighbor tree competition on crown shape of Korean pine plantation in Northeast China was studied. A total of 48 trees aged 7–58 years were felled, and all living branches were measured. A novel neighbor competition index that considered the overlap length between subject tree and neighbor tree crowns was created and incorporated into crown shape model. The effects of neighboring competition on crown shape, largest crown radius, and inflection point were analyzed. A dummy variable approach was used to detect crown asymmetry. The crown length index (CLI) of the subject tree was selected as the best neighbor competition index, and the mean square error reduction compared with that of the basic model was 2.0% after incorporating CLI. Crown radius displayed differences in the four cardinal directions and followed the order north > west > south > east. The crown radius in four directions for different ages decreased with increasing CLI and the difference increased with increasing tree age. The competition index, which considers horizontal and vertical competition effects, can significantly improve the performance of crown shape model. Both of inflection point and largest crown radius increased with increasing of CLI; however, the Pearson correlation coefficient was not significant ( P > 0.05).

Organic matter (OM) has an excellent retention effect on stabilizing chromium (Cr), and functional groups on OM play a predominant role in this process. Based on this result, it is found that a considerable amount of Cr in tannery sludge is immobilized from ion exchangeable species into bound species, benefiting from complexing reaction with functional groups. Especially, the mentioned immobilizing process is enhanced in way of adding with montmorillonite (MMT) which performs adsorption reaction with Cr, as well as plays interaction with functional groups. The result is confirmed by employing density functional theory (DFT) analysis, suggesting the binding ability among Cr, functional groups, and MMT is stronger (- 77.36503 eV) than that of the system of Cr and MMT (- 61.29942 eV), indicating the synergetic roles of OM and MMT. This synergetic role could also be illustrated by a new peak (Cr-OH 20.1%) shown in XPS result. Meanwhile, DFT analysis emphasizes that functional groups on OM give the response for binding with Cr in the order of hydroxyl (-OH) carboxyl (-COOH) epoxy (-COC), and all the functional groups tend to donate electron to bind with Cr. In addition, the stabilizing process shows a better fitting effect with pseudo second-order kinetic model (R

Pollution by heavy metal cadmium (Cd) in soil is still serious and control measures are constantly updated. In this paper, one indoor culture method was applied to investigate the effect of phosphate and thermo-activated nano silicate combined application on soil cadmium (Cd) speciation transformation. A total of 7 treatments were designed, which were: simulated cadmium-contaminated soil without phosphate and silicate recorded as the reference (CK) treatment; mixtures of 0.5%, 1.0%, and 2.0% soil heavy dose of potassium dihydrogen phosphate and 700 °C thermo-activated nano serpentine (potassium dihydrogen phosphate: thermo-activated nano serpentine ratio = 1:2) added to simulated cadmium-contaminated soil, denoted as nPS700-0.5, nPS700-1.0, and nPS700-2.0, respectively; and 0.5%, 1.0%, and 2.0% soil heavy dose of potassium dihydrogen phosphate and 700 °C thermo-activated nano zeolite mixture (potassium dihydrogen phosphate: thermo-activated nano zeolite ratio = 1:2) added to simulated cadmium-contaminated soil, denoted as nPF700-0.5, nPF700-1.0, and nPF700-2.0, respectively. The results showed that the combined application of potassium dihydrogen phosphate with thermo-activated nano serpentine or potassium dihydrogen phosphate with thermo-activated nano zeolite reduced the soil exchangeable Cd content to varying degrees and increased levels of carbonate-bound, Fe-Mn oxide-bound, organic-bound, and residual Cd forms to different degrees. In combined application of phosphate and thermo-activated nano silicate, the higher the dosage level, the greater the reduction of exchangeable Cd content and the better the effect on Cd-contaminated soil remediation: nPS700-2.0 > nPS700-1.0 > nPS700-0.5, nPF700-2.0 > nPF700-1.0 > nPF700-0.5 (N, P, S, and F represent nano, KH2PO4, serpentine, and zeolite, respectively, and 700 represents the activation temperature). At the same dosage level, the combined application of potassium dihydrogen phosphate and thermo-activated nano serpentine was more effective than that of potassium dihydrogen phosphate and thermo-activated nano zeolite in repairing Cd-contaminated soil (nPS700-2.0 > nPF700-2.0, nPS700-1.0 > nPF700-1.0, nPS700-0.5 > nPF700-0.5), which indicated that the combination of phosphate and thermo-activated nano silicate can passivate heavy metal cadmium (Cd) to a certain extent and promote the transformation of bioavailable Cd into an unusable state. The reason why potassium dihydrogen phosphate, zeolite, and serpentine can absorb heavy metal cadmium after entering the soil is because the silicate mineral itself can directly absorb cadmium. Second, after nano treatment and thermal activation, the specific surface areas and pores of the minerals increase, which enhances the adsorption performance. Third, because the pH value of the mineral itself is high, the pH value of the soil environment will rise, thereby transforming H2PO4− into PO43−, which is conducive to the adsorption of Cd2+.

Maize straw deep burying into 20–40-cm layer before covering soil and plowing ridge is a useful practice to enhance soil carbon pool and make soil bacteria rich. Now, we hope to bury much more straw to reuse the huge number of them until catching the soil environmental carrying capacity in fertility, like soil organic carbon and enzyme activities. But the reasonable straw amount to return back has not been determined. Focusing on the actual output quantity of China maize straw, we designed a 7-year-term field experiment with 4 different straw deep-burying amounts of 0 t ha–1 (CK), 6 t ha–1 (SR1), 12 t ha–1 (SR2), and 18 t ha–1 (SR3). We clarified the reaction of straw amount to soil bacterial community and enzyme activities, by soil fertility, qPCR (quantitative real-time polymerase chain reaction), and Illumina high-throughput sequencing. According to the result, using 18 t ha–1 straw got the most enzyme activities of urease, cellulase, invertase, and dehydrogenase, more than others 4.71–332.38%. The 16S rRNA gene abundance of the sample with 18 t ha–1 straw has a significant rise compared to 0 t ha–1 (32.47%) and 6 t/ha (29.52%). Three domination bacteria of Proteobacteria, Actinobacteria, and Acidobacteria were sensitive to the straw using amount, and their relative abundance increased as straw amount enhancing. The microbial diversity changes finally increased the corn yield. Therefore, the more straw we used, the more abundance soil bacteria and the soil TOC we would get, in the condition of straw amount under 18 t ha–1 by deep-burying method. So we should put much more straw into soil rather than abandonment.

Evidence concerning the associations of ambient air pollution exposure with bone mineral density and osteoporosis has been mixed. We conducted cross-sectional and prospective analysis of the associations between air pollution exposure and osteoporosis using data from UK Biobank study. Estimated bone mineral density (eBMD) of each participant at baseline survey was calculated using quantitative ultrasound data, and incident osteoporosis cases were identified during the follow-up period according to health-related records. Air pollution concentrations were assessed using land use regression models. We fitted multivariable linear and logistic regression models to estimate the associations of air pollution with eBMD and osteoporosis prevalence at baseline. We applied cox proportional hazard regression models to assess the relationships between air pollution and osteoporosis incidence. Among the 341,311 participants at baseline, higher air pollution exposure was associated with lower eBMD levels and increased odds of osteoporosis prevalence. For example, an IQR increase in PM

In order to evaluate the potential responses of deep-burying and mulching on soil bacteria community abundance and soil fertility in the same cropping systems, we designed a field experiment as follows: (1) no straw residue (CK), (2) straw mulching (M); (3) straw residue placed in 20–40 cm (DS); and (4) straw residue placed in 20–40 cm with decomposing agent plus (DSP). The results showed that straw deep placement could increase soil organic matter and improve soil microbial community by Illumina HiSeq high-throughput sequencing approach and real-time quantitative PCR (qPCR). Straw deep-burying reduced soil pH (2%) and increased soil total organic carbon (TOC), microbial biomass carbon (MBC), microbial biomass nitrogen (MBN) by 27–339%, as well as soil enzyme activities (urease, dehydrogenase, and cellulase) by over 7%. Thereafter, we found that the deep buried straw residue increased the soil bacteria abundance by 175%, especially Proteobacteria, Bacteroidetes, and Acidobacteria. The family of Xanthomonadaceae and Chitinophagaceae had achieved remarkable growth. In canonical correspondence analysis (CAA), soil organic matter increasing and pH reducing were the main reasons to shift soil bacterial community. A positive correlation was found between straw deep-burying and soil bacteria community (P < 0.01). Therefore, our results highlight that deep-buried maize straw residue changes soil bacteria community abundance and improves soil fertility. Deep placement could potentially be an effective use of straw residues for the future sustainable cropping systems.

Trichloroethylene (TCE) is one of the most widely distributed pollutants in groundwater and poses serious risks to the environment and human health. In this study, sulfidated nanoscale zero-valent iron (S-nZVI) materials with different Fe/S molar ratios were synthesized by one-step methods. These materials degraded TCE in groundwater and followed a pathway that did not involve the production of toxic byproducts such as dichloroethenes (DCEs) and vinyl chloride (VC). The effects of sulfur content on TCE dechlorination by S-nZVI were thoroughly investigated in terms of TCE-removal efficiency, H2 evolution, and reaction rate. X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS) characterizations confirmed Fe(0) levels in S-nZVI were larger than for zero-valent iron (nZVI). An Fe/S molar ratio of 10 provided the highest TCE-removal efficiencies. Compared with nZVI, the 24-h TCE removal efficiencies of S-nZVI (Fe/S = 10) increased from 30.2% to 92.6%, and the Fe(0) consumed during a side-reaction of H2 evolution dropped from 77.0% to 12.8%. This indicated the incorporation of sulfur effectively inhibited H2 evolution and allowed more Fe(0) to react with TCE. Moreover, the pseudo-first-order kinetic rate constants of S-nZVI materials increased by up to 485% compared to nZVI. In addition, a TCE degradation was proposed based on the variation of detected degradation products. Noting that acetylene, ethylene, and ethane were detected rather than DCEs and VC confirmed that TCE degradation followed β-elimination with acetylene as the intermediate. These results demonstrated that sulfide modification significantly enhanced nZVI performance for TCE degradation, minimized toxic-byproduct formation, and mitigated health risks. This work provides some insight into the remediation of chlorinated-organic-compound-contaminated groundwater and protection from secondary pollution during remediation by adjusting the degradation pathway.

A novel cellulase-producing actinomycete strain Gxj-6T, isolated from soil in the cold region (Heihe city, Heilongjiang province, the northernmost part of China), subjected to a taxonomic study using a polyphasic approach. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain Gxj-6T fell within the clade comprising the type strains of species of the genus Microbispora. 16S rRNA gene sequence similarity studies exhibited that species Gxj-6T was most closely related to Microbispora bryophytorum NEAU-TX2-2T (99.45%), Microbispora fusca NEAU-HEGS1-5T (99.41%), Microbispora camponoti 2C-HV3T (99.31%) and Microbispora rosea subsp. rosea JCM 3006T (98.68%). Organism Gxj-6T contained MK-9(H2) as the predominant ubiquinone and C18:0 10-methyl as the major fatty acid. The major polar lipids of culture Gxj-6T were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside, three unidentified phospholipids, two unidentified glycolipids and two unidentified lipids. The DNA G+C content of strain Gxj-6T was 71.25 mol%. The morphological and chemotaxonomic properties of the strain are also consistent with those members of the genus Microbispora. Combinated with the lower DNA–DNA relatedness values, phenotypic properties, physiology and biochemistry distinctiveness with other recognized species strains, revealed that strain Gxj-6T is separated from other phylogenetically closely species of the genus Microbispora. Therefore, strain Gxj-6T is considered to represent a novel species of the genus Microbispora, for which the name Microbispora cellulosiformans sp. nov. is proposed. The type strain is Gxj-6T (= CGMCC 4.7605T = DSM 109712T).

Selective catalytic decomposition of hydrazine (N2H4) to provide a clean energy carrier hydrogen (H2) is a promising alternative to fossil fuels for the future energy economy. NiPt nanoparticles (NPs) dispersed on delamination of TiO2-decorated Ti3C2Tx (denoted as DT-Ti3C2Tx) nanosheets are prepared via a simple wet chemical reduction method and applied as an efficient catalyst for dehydrogenation of N2H4 in aqueous solution. The rich oxygen-containing functional groups on the surface of DT-Ti3C2Tx not only facilitate the formation and immobilization of monodisperse NiPt NPs but also enhance the synergistic effect between metal NPs and MXene support. Among all of the tested samples, the optimized Ni0.8Pt0.2/DT-Ti3C2Tx nanocatalyst exhibits the 100% H2 selectivity and best catalytic performance with a TOF value of 1220 h−1 for the selective decomposition of N2H4 at 323 K. In addition, this catalyst also shows excellent catalytic performance for hydrogen production from hydrazine borane (N2H4BH3) via the hydrolysis of borane group and selective decomposition of hydrazine moiety. The TiO2-decorated Ti3C2Tx MXene can be applied as an excellent support to obtain well-dispersed and ultrafine metal NPs for various applications.

Ultrafine NiFe nanoparticles (NPs) decorated by La(OH)3 have been successfully prepared via a facile one-step co-reduction method without the help of surfactant or support. It was found that after being decorated with La(OH)3, the NiFe–La(OH)3 NPs have a smaller particle size and lower crystallinity. The resultant NiFe–La(OH)3 nanocatalyst exhibits an excellent catalytic activity, 100% H2 selectivity, and satisfied recyclability for hydrogen evolution from hydrous hydrazine (N2H4·H2O) at 343 K under alkaline conditions, giving a high turnover frequency (TOF) value of 100.6 h−1, which is more than 35 times higher than pure NiFe NPs (2.8 h−1). The kinetics study shows that with respect to the concentration of catalyst and N2H4, the N2H4 dehydrogenation reaction follows fist-order kinetics and zero-order kinetics, respectively. Furthermore, NiFe–La(OH)3 also exhibits an outstanding performance and excellent recycle stability during high dehydrogenation of hydrazine borane (N2H4BH3). The excellent performances for the dehydrogenation of N2H4 and N2H4BH3 could be attributed to the strong interaction between La(OH)3 and NiFe NPs, as well as ultrafine and low crystalline NiFe NPs due to the addition of La(OH)3.

Coating and inhibitors are proposed as means to increase nitrogen (N) use, but their effects are variable. Coating and incorporation of inhibitors could be more effective. This study aimed at inves...

Background Sporobolomyces pararoseus is regarded as an oleaginous red yeast, which synthesizes numerous valuable compounds with wide industrial usages. This species hold biotechnological interests in biodiesel, food and cosmetics industries. Moreover, the ballistospores-shooting promotes the colonizing of S. pararoseus in most terrestrial and marine ecosystems. However, very little is known about the basic genomic features of S. pararoseus. To assess the biotechnological potential and ballistospores-shooting mechanism of S. pararoseus on genome-scale, the whole genome sequencing was performed by next-generation sequencing technology. Results Here, we used Illumina Hiseq platform to firstly assemble S. pararoseus genome into 20.9 Mb containing 54 scaffolds and 5963 predicted genes with a N50 length of 2,038,020 bp and GC content of 47.59%. Genome completeness (BUSCO alignment: 95.4%) and RNA-seq analysis (expressed genes: 98.68%) indicated the high-quality features of the current genome. Through the annotation information of the genome, we screened many key genes involved in carotenoids, lipids, carbohydrate metabolism and signal transduction pathways. A phylogenetic assessment suggested that the evolutionary trajectory of the order Sporidiobolales species was evolved from genus Sporobolomyces to Rhodotorula through the mediator Rhodosporidiobolus. Compared to the lacking ballistospores Rhodotorula toruloides and Saccharomyces cerevisiae, we found genes enriched for spore germination and sugar metabolism. These genes might be responsible for the ballistospores-shooting in S. pararoseus NGR. Conclusion These results greatly advance our understanding of S. pararoseus NGR in biotechnological potential and ballistospores-shooting, which help further research of genetic manipulation, metabolic engineering as well as its evolutionary direction.

An unexpected and direct synthesis of ethyl 2,4-bis(chloromethyl)-6-iodoquinoline-3-carboxylate (3) from the chlorotrimethylsilane (TMSCl)-promoted Friedlander reaction between 1-(2-amino-5-iodophenyl)ethanone (2) and ethyl 4-chloro-3-oxobutanoate has been disclosed. As a versatile and attractive building block, a synthetic application of the poly-functionalized quinoline 3 in the successive Williamson ether synthesis with various phenols and in situ ester hydrolysis reaction has been achieved and the corresponding 2,4-bis(aroxymethyl)quinoline-3-carboxylic acids (5a-k) were obtained in good yields of 71–86%.

The co-existence of heavy metals and polycyclic aromatic hydrocarbons (PAHs) challenges the remediation of polluted soil. This study aimed to investigate whether a combined amendment of biochar-immobilized bacterium (BM) could enhance the phytoremediation of heavy metals and PAHs in co-contaminated soil. The Bacillus sp. KSB7 with the capabilities of plant-growth promotion, metal tolerance, and PAH degradation was immobilized on the peanut shell biochar prepared at 400 °C and 600 °C (PBM4 and PBM6, respectively). After 90 days, PBM4 treatment increased the removal of PAHs by 94.17% and decreased the amounts of diethylenetriamine pentaacetic acid-extractable Zn, Pb, Cr, and Cu by 58.46%, 53.42%, 84.94%, and 83.15%, respectively, compared with Kochia scoparia-alone treatment. Meanwhile, PBM4 was more effective in promoting K. scoparia growth and reducing the uptake of co-contaminants. The abundance of Gram-negative PAH-degrader and 1-aminocyclopropane-1-carboxylic deaminase-producing bacteria within rhizosphere soil was significantly improved after PBM4 treatment. Moreover, the relative abundance of the Bacillus genus increased by 0.66 and 2.05 times under PBM4 treatment compared with biochar alone and KSB7, indicating that KSB7 could colonize in the rhizosphere soil of K. scoparia. However, the removal of PAHs and heavy metals after PBM6 and 600 °C biochar-alone treatments caused no obvious difference. This study suggested that low-temperature BM-amended plant cultivation would be an effective approach to remove PAHs and heavy metals in co-contaminated soil.

Owing to containing high fraction of organic matter, the tannery sludge seemed to be fit for composting. Actually, it was intensively harmful to the environment, due to containing chromium (Cr). So it might undergo a long time of storage until finding a proper way to dispose it. In the storage period, it would expose the surrounding environment a risk via releasing Cr. In this study, an approach was proposed to minimize the amount of released Cr, and reveal the mechanism on immobilizing Cr. Collagen protein waste (CPW) was adopted to immobilize Cr, and it was evaluated via leaching experiment. The lowest leaching concentration of Cr was 12 mg/L, meeting the limits of related standard in China (GB 5085.3-2007, Tcr 15 mg/L). Moreover, the compositions and functional groups of the optimum sample (12 mg/L) were also characterized, confirming that the dominant functional groups cross-linking with Cr were hydroxyl (-OH), carboxyl (-COOH), and epoxy (-COC). Importantly, density functional theory (DFT) calculation was also employed, suggesting that Cr was restrained by accepting electrons from O atoms donating by functional groups.

In this study, the effect of strip clear-cutting on the natural regeneration performance of mature

Background and aims Returning straw into soil could increase soil organic carbon (SOC) and promote crop growth. However, little has been reported on the source of C for increased SOC (straw C or crop photosynthetic C). Methods To investigate the assimilation of photosynthetic C and its distribution in soil in the maize growth season, we set up a one-year 13C pulse-labelling experiment in a consecutive maize straw returning long-term trial. Four treatments were included: no straw return (control), straw mulching on the soil surface (cover), return in 0–20 cm layer (shallow) and 20–40 cm layer (deep). Results We found that the deep straw incorporation significantly (P 13C assimilation in shoots by 17.4% and the partitioning of photosynthetic 13C to soil by 7.9% at early jointing, and by 11.5% at maturity. The contribution of photosynthetic C to microbial biomass C (MBC) and dissolved organic C (DOC) was highest at jointing, and at harvest amounted to 39.1 % of MBC and 28.8% of DOC. Conclusion The results highlighted the importance of regulating the soil carbon dynamics via the deep straw return strategy. In conclusion, deep straw incorporation significantly increased photosynthetic efficiency and facilitated partitioning of photosynthetic C to roots and soil, thus promoting maize growth.

Recently, N2O, CO2, and CH4 have been gaining attention as major greenhouse gases (GHGs) that contribute to global warming. Agricultural water-saving irrigation technology has become more and more important and is widely applied to the arid areas. These influences have important and strategic significances for reducing greenhouse effects. However, there is limit information regarding the influence of irrigation methods on soil gases emissions. We investigated the effect of mulched drip irrigation (MDI), drip filtration irrigation (DFI), and conventional irrigation (CK) on N2O, CO2, CH4 emissions, affecting factors and their correlations in a greenhouse soil. Observations were performed from April to August in 2015 on the entire tomato growth season. We monitored the flux of GHG emissions by the static chamber-gas chromatograph method under three irrigation conditions: mulched drip irrigation (MDI), drip filtration irrigation (DFI), and conventional irrigation (CK). To investigate the effects of affecting factors on soil GHG emissions, we also measured soil temperature (5 cm), soil moisture, and air temperature. Compared with the cumulative emission of GHGs (N2O and CH4 calculation in the form of CO2), we created the concept of the ratio of yield and gas (crop yield and soil accumulated GHG emissions). Tomato yield of MDI and DFI is significantly higher than CK. Soil moisture is the main factor affecting N2O emissions and CH4 exchange during the tomato-growing season. N2O emission fluxes have an extremely significant correlation with water-filled pore space (WFPS) at suitable temperatures. CO2 emissions demonstrated a significant correlation with environment temperature (soil and air). CO2 emissions gradually increased and had seasonal variations with rising temperatures and plant growth in each irrigation method. CH4 exchange fluxes showed a significant correlation with WFPS. MDI obtains high yields, is cost-efficient, conserves water, and produces the least amount of integrated GHGs. It helps to mitigate global warming and it would be the best irrigation method.

Temperate mixed forests, along with other high latitudinal ecosystems, are more vulnerable to global warming in comparison with warm sites, because of the slower carbon (C) turnover and higher soil organic carbon (SOC) accumulation. Lignin and cellulose are two major components of plant litter, and usually make contributions to the recalcitrant and labile SOC pool, respectively. Because the chemical composition of SOC plays key role in regulating the bioavailability of soil C pool, understanding the relationship between soil lignin or cellulose content and temperature are of great significance in evaluating the feedbacks between SOC pool and the future scenarios of global warming. The biological degradation of soil lignin or cellulose is mainly dependent on soil enzymatic activities, and thus, the response of ligninolytic and cellulolytic enzymes to increased temperature would determine C release under future warming scenarios. However, the responses of the soil lignin/cellulose content and the activity of cellulolytic and ligninolytic enzymes to increased mean annual temperature (MAT) have rarely been studied, and the factors driving these changes are not fully understood. Latitudinal gradients are often used for monitoring global-warming-related problems, because of its natural gradients of temperature. In this study, we demonstrate the latitudinal pattern of lignin/cellulose content and the activities of cellulose- and lignin- degrading enzymes in a temperate Broad-leaved Korean pine mixed forests distributed along a latitudinal gradient (with MAT ranging from −1.9 to 5.1 °C) in northeastern China. The linear mixed model revealed that soil lignin content was negatively correlated with MAT (Slope = −7.604, t = −2.608, P = 0.011), whereas soil cellulose content showed no response to increased MAT. The activity of soil polyphenol oxidase (PPO), one of the enzymes catalyze lignin decomposition, was higher in high-latitude sites, in contrast, the activity of the cellulase (CEL) complex was higher in low-latitude plots. Structural equation model (SEM) analysis indicates that MAT can directly influence soil lignin or cellulose content, and indirectly through changing NRCB, plant litter C/N, microbial biomass, and degrading enzymatic activities. The value of soil lignin/(lignin + cellulose) ratio and soil lignocellulose index (LCI, lignin/(lignin + holocellulose) ratio), varied between 0.8–0.9, and 0.6–0.8, respectively, indicating that the SOC pool in this temperate ecosystem is dominated by recalcitrant components. The negative correlations between MAT and LCI, soil lignin/(lignin + cellulose), and log (PPO + PER)/log(CEL) (Slope = −0.008, t = −2.363, P = 0.021; Slope = −0.004, t = −3.134, P = 0.003, and Slope = −0.057, t = −4.477, P

Soil organic nitrogen fractions and soil-soluble nitrogen pools are important indicators of soil fertility and plant nutrition requirements. However, little is known about soil organic nitrogen fractions and their correlations with soil mineral nitrogen (SMN) and soluble organic nitrogen (SON). A five-year field experiment was conducted to determine the effects of lower irrigation limits (25, 35, and 45 kPa) and nitrogen fertilization (75, 300, and 525 kg ha−1) rates on greenhouse soil organic nitrogen fractions and soil-soluble nitrogen pools. The results indicated that the soil organic nitrogen fractions and soil-soluble nitrogen pools were significantly affected by the irrigation and nitrogen fertilization rates and their interactions at various greenhouse soil depths (P

A greenhouse field experiment involving tomato (Solanum lycopersicum) was performed using different nitrogen (N) management regimes: sole application of differing rates of chemical N fertilizer (SC) (SC treatments: N0, N1, N2, and N3) and combined application of manure and chemical N fertilizer (MC) (MC treatments: MN0, MN1, MN2, and MN3). These were used to understand the relationship between comprehensive fruit composition, yield, and N fractions (soil mineral N; soil soluble organic N; soil microbial biomass N, and soil fixed ammonium) under greenhouse conditions. The results showed that the MC treatments significantly increased vitamin C and soluble sugar content compared with SC treatments. In addition, the MN2 treatment produced a high yield and had a positive effect on fruit composition. The N3 (563 kg N/ha) and MN3 (796 kg N/ha) treatments resulted in a high loss of N below the root zone (0–30 cm), consequently reducing N use efficiency. Soil mineral N, soil soluble organic N, and soil fixed ammonium tended to be higher during the first fruiting period, whereas soil microbial biomass N tended to be higher during the second fruiting period. MC treatments significantly increased the N fraction in the 0- to 30-cm soil layer; N fractions tended to be higher with the MN2 treatment. According to an optimum regression equation, soil fixed ammonium during the first fruiting period and soil microbial biomass N during the second fruiting period had a more significant influence on tomato yield and fruit composition. Overall, application MC at an appropriate rate (MN2: 608 kg N/ha) is a promising approach to achieving high yields and optimum taste, and it offers a more sustainable fertilizer management strategy compared with chemical N fertilization.

Carotenoids are ubiquitous constituents of living organisms. These structurally diverse pigments have received considerable attention due to their biotechnological applications and potential beneficial effects on human health. In this study, we characterized an over-producing β-carotene mutant of Sporidiobolus pararoseus, obtained by ultraviolet mutagenesis, named MuY9. We compared the transcriptome between the wild-type and MuY9. A total of 348 differential expressed genes (DEGs) were found, and only one DEG crtYB is involved in carotenoid biosynthesis. The overproduction of β-carotene in MuY9 should be attributed to the up-regulation of crtYB. Functional identification of crtYB was performed using heterologous complementation in Escherichia coli. Our findings indicate that the enzymatic conversions of geranylgeranyl pyrophosphate to phytoene, as well as lycopene to β-carotene, are catalyzed by this CrtYB. Furthermore, our insights into the crtYB gene should facilitate a more detailed understanding of the carotenogenic pathway in S. pararoseus, and advance the development of the genetic engineering for the bio-production of carotenoids.

Hydrous hydrazine (N2H4·H2O) is considered a highly promising liquid chemical hydrogen storage material because of its high hydrogen content (8.0 wt%), simple byproduct (i.e., N2) and safe handling. In this work, noble-metal-free NiFe nanoparticles (NPs) supported on nano CeZrO2 solid solutions have been facilely synthesized and successfully applied as a highly efficient catalyst for the rapid and complete decomposition of N2H4 in aqueous solution. The turnover frequency (TOF) value of the NiFe/CeZrO2 catalyst for hydrogen generation from N2H4 reached 119.2 h−1 under alkaline conditions at 343 K, which is 28-fold higher than that of the benchmark catalyst, pure NiFe NPs (4.2 h−1). Moreover, the H2 selectivity and activity show almost no decrease after five runs, indicating that the prepared NiFe/CeZrO2 catalyst possesses high durability and stability under the current conditions. The high catalytic performance can be attributed to the synergistic electronic effect between NiFe NPs and nano CeZrO2 solid solutions, as well as small nanoparticles with highly dispersed active sites.

Carotenoids represent a diverse class of aliphatic C40 molecules with a variety of applications in the food and pharmaceutical industries. Sporidiobolus pararoseus NGR produces various carotenoids, including torulene, torularhodin and β-carotene. Salt stress significantly increases the torulene accumulation of S. pararoseus NGR. However, little is known, about the molecular mechanisms underlying the increased torulene biosynthesis. In this work, we investigated the effects of NaCl treatment on the contents of carotenoids (both qualitatively and quantitatively) and transcriptome. A total of 12.3 Gb of clean bases were generated in six cDNA libraries. These bases were de novo assembled into 9,533 unigenes with an average length of 1,654 nt and N50 of 2,371 nt. Transcriptome analysis revealed that of 3,849 differential expressed genes (DEGs) in response to salt stress, 2,019 were up-regulated, and 1,830 were down-regulated. Among these DEGs, we identified three carotenogenic genes crtE, crtYB, and crtI. In addition, fourteen candidate genes were predicted to participate in the conversion from torulene to torularhodin. Our findings should provide insights into the mechanisms of carotenoid biosynthesis and salt-tolerance of S. pararoseus NGR.