Publications

Vanillic acid (VA), as a plant-derived phenolic acid compound, has widespread applications and good market prospects. However, the traditional production process cannot meet market demand. In this study, Pseudomonas putida KT2440 was used for de novo biosynthesis of VA. Multiple metabolic engineering strategies were applied to construct these P. putida-based cell factories, including the introduction of a Hs-OMTopt, engineering the cofactor S-adenosylmethionine supply pathway through the overexpression of metX and metH, reforming solubility of Hs-OMTopt, increasing a second copy of Hs-OMTopt, and the optimization of the fermentation medium. The resulting strain, XCS17, de novo biosynthesized 5.4 g/L VA from glucose in a fed-batch fermentation system; this is the highest VA production titer reported up to recently. This study showed that P. putida KT2440 is a robust platform for achieving the effective production of phenolic acids.

No abstract is provided for this article.

Coexisting ammonium (NH4 +-N) and phosphate (PO4 3--P) in wastewater is one of the main causes of eutrophication, which poses severe risks to aquatic ecosystem and human health worldwide. Herein, magnesium-rich tricalcium aluminate (Mg/C3A), which was constructed by incorporating Mg into cement-based material C3A via solid-state reaction, was employed in the simultaneous removal of NH4 +-N and PO4 3--P. Considering the wastewater with unbalanced N/P ratio and fluctuant pH, the effect of multiple factors (Mg/C3A dosage, pH, initial contaminant concentration, and temperature) on the removal of both ions were systematically investigated by employing response surface methodology technique. The results demonstrated that the impact order of the factors on the NH4 + removal by Mg/C3A was: temperature > Mg/C3A dosage > initial NH4 + concentration > pH > initial PO4 3− concentration; the impact order on the PO4 3− removal was: initial PO4 3− concentration > Mg/C3A dosage > temperature > pH > initial NH4 + concentration. The maximum removal amount of NH4 + (54.13 mg g−1) and PO4 3− (56.47 mg g−1) were obtained at: Mg/C3A dosage = 3 g L−1, initial NH4 + concentration = 160 mg L−1, initial PO4 3− concentration = 160 mg L−1, temperature = 308 K, and pH = 7. In addition, the possible interactive influence mechanisms were elucidated in depth. Mg2+ played a major role in the PO4 3− removal by forming struvite (MgNH4PO4·6H2O) and newberyite (MgHPO4·3H2O). OH− released from Mg/C3A hydration mainly contributed to NH4 + removal. This work showed that Mg-rich C3A is a promising candidate for simultaneous removal of NH4 + and PO4 3−, shedding light on practical water remediation.

Quinoa is a dicotyledonous annual herb has cold and drought resistance. However, there is little research on quinoa under flooding stress. We analyzed the metabolomics and transcriptomics of Dianli-1299 (flooding-resistant strain), Dianli-60 and Yuncaili-2 (non-flooding-resistant strains) quinoa seedlings. Through metabolome, we detected a total of 1058 metabolites. 337, 300, and 386 differential metabolites were found in Dianli-1299, Dianli-60, and Yuncaili-2, respectively. Transcriptome analysis showed the expression of saccharides and alcohols related genes in Dianli-1299 was higher than that in Dianli-60 and Yuncaili-2. Gene-LOC110708270 and gene-LOC110681806, which were related to UTP-glucose-1-phosphate uridylyltransferase (UGP2), were significantly expressed in Dianli-1299 treatment group (TR1), and the regulated galactinol content was significantly accumulated in TR1. Gene-LOC110736796 in Dianli-60 treatment group (TR2) was significantly higher than that in TR1, and the D-Ribose-5P content, which is regulated by gene-LOC110736796 was lower in TR2 than that in TR1. In Dianli-1299, the raffinose content regulated by gene-LOC110707988 and gene-LOC110725594 was higher than that in Dianli-60 and Yuncaili-2. The correlation coefficients of 18 differential metabolites and differential genes were greater than 0.9, which suggested these genes and metabolites might key factors for quinoa to cope with flooding stress. Our results may provide a basis for breeding and identifying quinoa flood-resistant varieties.

Aspergillus flavus and Aflatoxins in grain crops give rise to a serious threat to food security and cause huge economic losses. In particular, aflatoxin B1 has been identified as a Class I carcinogen to humans by the International Agency for Research on Cancer (IARC). Compared with conventional methods, Surface-Enhanced Raman Scattering (SERS) has paved the way for the detection of Aspergillus flavus and Aflatoxins in grain crops as it is a rapid, nondestructive, and sensitive analytical method. In this work, the rapid detection of Aspergillus flavus and quantification of Aflatoxin B1 in grain crops were performed by using a portable Raman spectrometer combined with colloidal Au nanoparticles (AuNPs). With the increase of the concentration of Aspergillus flavus spore suspension in the range of 102-108 CFU/mL, the better the combination of Aspergillus flavus spores and AuNPs, the better the enhancement effect of AuNPs solution on the Aspergillus flavus. A series of different concentrations of aflatoxin B1 methanol solution combined with AuNPs were determined based on SERS and their spectra were similar to that of solid powder. Moreover, the characteristic peak increased gradually with the increase of concentration in the range of 0.0005-0.01 mg/L and the determination limit was 0.0005 mg/L, which was verified by HPLC in ppM concentration. This rapid detection method can greatly shorten the detection time from several hours or even tens of hours to a few minutes, which can help to take effective measures to avoid causing large economic losses.

To investigate the chemical constituents of Clematis aethusifolia,a traditional Mongolian medicine for resolving hard lump.Bioactive guided isolation and purification of Clematis aethusifolia was performed by normal and reverse phase column chromatography, Sephadex LH-20 and preparation HPLC. The structures were identified by 1D,2D-NMR and MS spectral analysis and comparison with literature data. Cytotoxicity of compounds were determined by CCK-8 cell staining method for detecting growth inhibition to five kinds of human solid tumor cell lines.Eight compounds were isolated and identified as vanillicacid( 1),protocatechuic acid( 2),( +)-pinoresinol diglucoside( 3),( +)-pinoresinol-4’-O-β-D-glucopyranoside( 4),( +)-syringaresinol-4’-O-β-Dglucopyranoside( 5),7,9,9’-trihydroxy-3,3’-dimethoxy-8-O-4’-neolignan-4-O-β-D-glucopyranoside( 6),butyl-β-D-fructopyranoside( 7),butyl-β-D-fructofuranoside( 8). Compounds 2,8 showed strong cytotoxic activity.All the compounds are isolated from this plant for the first time, Results: Eight compounds were isolated and identified as vanillicacid( 1), protocatechuic acid( 2),( +)-pinoresinol diglucoside( 3),( +)-pinoresinol-4’-O-β-D-glucopyranoside( 4),( +)-syringaresinol-4’-O-β-Dglucopyranoside( 5),7,9,9’-trihydroxy-3,3’-dimethoxy-8-O-4’-neolignan-4-O-β-D-glucopyranoside( 6),butyl-β-D-fructopyranoside( 7),butyl-β-D-fructofuranoside( 8). Compounds 2,8 showed strong cytotoxic activity. compounds 3,6 ~ 8 are isolated from Clematis genus for the first time, compounds 6 and 8 are isolated from Ranunculaceae family for the first time. Compounds 2,8 may be the effective components in Clematis aethusifolia.

High-definition (HD) maps are essential in testing autonomous driving systems (ADSs). HD maps essentially determine the potential diversity of the testing scenarios. However, the current HD maps suffer from two main limitations: lack of junction diversity in the publicly available HD maps and cost-consuming to build a new HD map. Hence, in this paper, we propose, FEAT2MAP, to automatically generate concise HD maps with scenario diversity guarantees. FEAT2MAP focuses on junctions as they significantly influence scenario diversity, especially in urban road networks. FEAT2MAP first defines a set of features to characterize junctions. Then, FEAT2MAP extracts and samples concrete junction features from a list of input HD maps or user-defined requirements. Each junction feature generates a junction. Finally, FEAT2MAP builds a map by connecting the junctions in a grid layout. To demonstrate the effectiveness of FEAT2MAP, we conduct experiments with the public HD maps from SVL and the open-source ADS Apollo. The results show that FEAT2MAP can (1) generate new maps of reduced size while maintaining scenario diversity in terms of the code coverage and motion states of the ADS under test, and (2) generate new maps of increased scenario diversity by merging intersection features from multiple maps or taking user inputs.

The change of external quality,physiological index and environmental gas of sweet cherry at different storage con-ditions was compared.Preservation effect and mechanism of controlled freezing-point and modified atmosphere box preserva-tion on sweet cherry were preliminary studied.Results showed that controlled freezing-point and modified atmosphere box preservation could slow down fruit decay,stalk withering and flesh browning.It also inhibited the increase of MDA content and decrease of soluble solids content,titratable acidity and reducing sugar content.The sweet cherry was preserved better in the modified atmosphere boxes with one old and one new vent opening compared with other treatments.

Selecting suitable plants as green manures is essential for improving marginal soil fertility and sustainable agroecosystems. Sophora alopecuroides is a highly salt- and alkali-tolerant leguminous plant that is often used as green manure. However, the molecular mechanism underlying saline-alkali tolerance in S. alopecuroides remains largely unclear. In this study, we investigated the molecular mechanisms underlying saline-alkali stress tolerance through physiological and transcriptomic analyses in S. alopecuroides seedlings. Comparative transcriptome analysis revealed that saline-alkali stress induced the expression of genes involved in cell wall modification, thereby increasing the contents of pectin and hemicellulose in roots and improving saline-alkali stress tolerance. The expression of genes related to the glycolysis pathway was induced, whereas genes involved in the TCA cycle and primary nitrogen metabolism were downregulated under salt and alkali stresses, indicating that S. alopecuroides plants modulate carbon flow to provide energy and ultimately regulate saline-alkali stress adaptation. Saline-alkali stress also modulated phytohormone signaling pathways in S. alopecuroides. Moreover, the leaves of seedlings under salt and alkali stresses contained elevated potassium, zinc and manganese contents, and the roots of seedlings under salt stress contained higher iron content. Taken together, these adaptive mechanisms to saline-alkali stress provide a physiological basis for the coordinated nutrient cycling of S. alopecuroides green manure. These results provide a molecular basis for the phytoremediation and utilization of saline-alkali soil, enabling the design of an integrated nutrient cycling system and optimization of the cultivation and field management of S. alopecuroides green manure.

Proteasome activator 28γ (PA28γ) binds to and activates the proteasome in an ATP-independent manner to promote mainly ubiquitin-independent protein degradation in cells. Previously, four transcript variants of PA28γ have been identified, which have been closely correlated with the progression of cancers. In the present study, we predicted the alternative splicing of PA28γ via the bioinformatics tool ASPicDB and 49 splices were predicted. Then, we cloned some new segment according to predication in oral cancer cells using reverse transcription PCR and a novel variant of PA28γ was found. The novel transcript encodes a truncated form compared with other isoforms of PA28γ. However, it contains most of the conserved residues and the 'activation loop' of the PA28γ family. In order to explore its function, we overexpressed the variant in HEK293 cells and demonstrated that this variant is likely to further regulate cell cycle and apoptosis via regulating p53 and the mouse double minute2 homolog (Mdm2).

No abstract is provided for this article.