Genome assembly provides insights into the genome evolution of Baccaurea ramiflora Lour.

Baccaurea ramiflora Lour., an evergreen tree of the Baccaurea genus of the Phyllanthaceae family, is primarily distributed in South Asia, Southeast Asia, and southern China, including southern Yunnan Province. It is a wild or semi-cultivated tree species with ornamental, edible, and medicinal value, exhibiting significant development potential. In this study, we present the whole-genome sequencing of B. ramiflora, employing a combination of PacBio SMRT and Illumina HiSeq 2500 sequencing techniques. The assembled genome size was 975.8 Mb, with a contig N50 of 509.33 kb and the longest contig measuring 7.74 Mb. The genome comprises approximately 73.47% highly repetitive sequences, of which 52.1% are long terminal repeat-retrotransposon sequences. A total of 29,172 protein-coding genes were predicted, of which 25,980 (89.06%) have been annotated, Additionally, 3452 non-coding RNAs were identified. Comparative genomic analysis revealed a close relationship between B. ramiflora and the Euphorbiaceae family, with both being sister groups that diverged approximately 59.9 million years ago. During the evolutionary process, B. ramiflora exhibited positive selection in 278 candidate genes. Synonymous substitution rate and collinearity analysis demonstrated that B. ramiflora underwent a single ancient genome-wide triploidization event, without recent genome-wide duplication events. This high-quality B. ramiflora genome provides a valuable resource for basic research and tree improvement programs focusing on the Phyllanthaceae family.

The efficacy and safety of non-surgical treatment of diabetic foot wound infections and ulcers: A systemic review and meta-analysis.

This meta-analysis evaluates the efficacy and safety of non-surgical treatments for diabetic foot ulcers and infections. After a rigorous literature review, seven studies were selected for detailed analysis. The findings demonstrate that non-surgical treatments significantly reduce wound infection rates (standardized mean difference [SMD] = -15.15, 95% confidence interval [CI]: [-19.05, -11.25], p < 0.01) compared to surgical methods. Ulcer healing rates were found to be comparable between non-surgical and surgical approaches (SMD = 0.07, 95% CI: [-0.38, 0.51], p = 0.15). Importantly, the rate of amputations within 6 months post-treatment was significantly lower in the non-surgical group (risk ratio [RR] = 0.19, 95% CI: [0.09, 0.41], p < 0.01). Additionally, a lower mortality rate was observed in patients treated non-surgically (RR = 0.28, 95% CI: [0.13, 0.59], p < 0.01). These results affirm the effectiveness and safety of non-surgical interventions in managing diabetic foot ulcers, suggesting that they should be considered a viable option in diabetic foot care.

Fine mapping and analysis of candidate genes for qBT2 and qBT7.2 locus controlling bolting time in radish (Raphanus sativus L.).

KEY MESSAGE: Two major QTLs for bolting time in radish were mapped to chromosome 02 and 07 in a 0.37 Mb and 0. 52 Mb interval, RsFLC1 and RsFLC2 is the critical genes. Radish (Raphanus sativus L.) is an important vegetable crop of Cruciferae. The premature bolting and flowering reduces the yield and quality of the fleshy root of radish. However, the molecular mechanism underlying bolting and flowering in radish remains unknown. In YZH (early bolting) × XHT (late bolting) F2 population, a high-density genetic linkage map was constructed with genetic distance of 2497.74 cM and an average interval of 2.31 cM. A total of nine QTLs for bolting time and two QTLs for flowering time were detected. Three QTLs associated with bolting time in radish were identified by QTL-seq using radish GDE (early bolting) × GDL (late bolting) F2 population. Fine mapping narrowed down qBT2 and qBT7.2 to an 0.37 Mb and 0.52 Mb region on chromosome 02 and 07, respectively. RNA-seq and qRT-PCR analysis showed that RsFLC1 and RsFLC2 were the candidate gene for qBT7.2 and qBT2 locus, respectively. Subcellular localization exhibited that RsFLC1 and RsFLC2 were mainly expressed in the nucleus. A 1856-bp insertion in the first intron of RsFLC1 was responsible for bolting time. Overexpression of RsFLC2 in Arabidopsis was significantly delayed flowering. These findings will provide new insights into the exploring the molecular mechanism of late bolting and promote the marker-assisted selection for breeding late-bolting varieties in radish.

Gut microbiota interacts with inflammatory responses in acute pancreatitis.

Acute pancreatitis (AP) is one of the most common acute abdominal conditions, and its incidence has been increasing for years. Approximately 15-20% of patients develop severe AP (SAP), which is complicated by critical inflammatory injury and intestinal dysfunction. AP-associated inflammation can lead to the gut barrier and function damage, causing dysbacteriosis and facilitating intestinal microbiota migration. Pancreatic exocrine deficiency and decreased levels of antimicrobial peptides in AP can also lead to abnormal growth of intestinal bacteria. Meanwhile, intestinal microbiota migration influences the pancreatic microenvironment and affects the severity of AP, which, in turn, exacerbates the systemic inflammatory response. Thus, the interaction between the gut microbiota (GM) and the inflammatory response may be a key pathogenic feature of SAP. Treating either of these factors or breaking their interaction may offer some benefits for SAP treatment. In this review, we discuss the mechanisms of interaction of the GM and inflammation in AP and factors that can deteriorate or even cure both, including some traditional Chinese medicine treatments, to provide new methods for studying AP pathogenesis and developing therapies.

A biological strategy for sulfide control in sewers: Removing sulfide by sulfur-oxidizing bacteria.

Sulfide produced from sewers is considered one of the dominant threats to public health and sewer lifespan due to its toxicity and corrosiveness. In this study, we developed an environmentally friendly strategy for gaseous sulfide control by enriching indigenous sulfur-oxidizing bacteria (SOB) from sewer sediment. Ceramics acted as bio-carriers for immobilizing SOB for practical use in a lab-scale sewer reactor. 16 S rRNA gene sequences revealed that the SOB consortium was successfully enriched, with Thiobacillus, Pseudomonas, and Alcaligenes occupying a dominant abundance of 64.7% in the microbial community. Metabolic pathway analysis in different acclimatization stages indicates that microorganisms could convert thiosulfate and sulfide into elemental sulfur after enrichment and immobilization. A continuous experiment in lab-scale sewer reactors confirmed an efficient result for sulfide removal with hydrogen sulfide reduction of 43.9% and 85.1% under high-sulfur load and low-sulfur load conditions, respectively. This study shed light on the promising application for sewer sulfide control by biological sulfur oxidation strategy.

Development of SNP and InDel markers by genome resequencing and transcriptome sequencing in radish (Raphanus sativus L.).

BACKGROUND: Single nucleotide polymorphisms (SNPs) and insertions/deletions (InDels) are the most abundant genetic variations and widely distribute across the genomes in plant. Development of SNP and InDel markers is a valuable tool for genetics and genomic research in radish (Raphanus sativus L.). RESULTS: In this study, a total of 366,679 single nucleotide polymorphisms (SNPs) and 97,973 insertion-deletion (InDel) markers were identified based on genome resequencing between 'YZH' and 'XHT'. In all, 53,343 SNPs and 4,257 InDels were detected in two cultivars by transcriptome sequencing. Among the InDel variations, 85 genomic and 15 transcriptomic InDels were newly developed and validated PCR. The 100 polymorphic InDels markers generated 207 alleles among 200 Chinese radish germplasm, with an average 2.07 of the number of alleles (Na) and with an average 0.33 of the polymorphism information content (PIC). Population structure and phylogenetic relationship revealed that the radish cultivars from northern China were clustered together and the southwest China cultivars were clustered together. RNA-Seq analysis revealed that 11,003 differentially expressed genes (DEGs) were identified between the two cultivars, of which 5,020 were upregulated and 5,983 were downregulated. In total, 145 flowering time-related DGEs were detected, most of which were involved in flowering time integrator, circadian clock/photoperiod autonomous, and vernalization pathways. In flowering time-related DGEs region, 150 transcriptomic SNPs and 9 InDels were obtained. CONCLUSIONS: The large amount of SNPs and InDels identified in this study will provide a valuable marker resource for radish genetic and genomic studies. The SNPs and InDels within flowering time-related DGEs provide fundamental insight into for dissecting molecular mechanism of bolting and flowering in radish.

Overexpression of POLA2 in hepatocellular carcinoma is involved in immune infiltration and predicts a poor prognosis.

BACKGROUND: Hepatocellular carcinoma (HCC) is the second malignancy worldwide. POLA2 initiates DNA replication, regulates cell cycle and gene repair that promote tumorigenesis and disease progression. However, the prognostic and biological function roles of POLA2 in HCC had not been conclusively determined. METHODS: The expression levels and prognosis role of POLA1 and POLA2 in HCC were analyzed based on TCGA-LIHC database and recruited 24 HCC patients. Gene mutations were analyzed using "maftools" package. POLA2 and immune cells correlations were analyzed by TIMER. POLA2 co-expressed genes functional enrichment were evaluated using Metascape. The mRNA and protein level of POLA2 was detected in HCC cells and tissues. Cell migration, invasion, proliferation, cell cycle and HCC cell lines derived xenograft model were performed to investigate POLA2 biological function. RESULTS: POLA2 was significantly high expressed in HCC than in normal liver tissue in both TCGA-LIHC and our collected HCC samples. In validation cohort, POLA2 significantly related to tumor differentiation, tumor size and Ki-67 (p < 0.05). In TCGA-LIHC cohort, overexpression of POLA2 predicted a low OS and associated with different clinical stages. Multivariate Cox regression showed overexpression of POLA2 effectively distinguished the prognosis at different T, N, M, stages and grades of HCC. POLA2 expression correlated with mutation burden, immune cells infiltration and immune-associated genes expression of HCC. Functional enrichment revealed that POLA2 co-expressed genes were linked to cellular activity, plasma membrane protein complex and leukocyte activity, immune response-regulated cell surface receptor signaling pathway, and immune response-regulated signaling pathway. Moreover, POLA2 was also positively co-expressed with some immune checkpoints (CD274, CTL-4, HAVCR2, PDCD1, PDCD1LG2, TIGIT, and LAG3) (p < 0.001). Gene knockdown revealed that POLA2 promoted proliferation, migration, invasion, and cell cycle of SMMC-7721 and HepG2. The HCC xenograft tumor model also demonstrated remarkably tumor size inhibition, tumor proliferation inhibtion and tumor necrosis promotion when POLA2 knockdown. CONCLUSIONS: POLA2 influenced immune microenvironment and tumor progression of HCC indicated that it might be a potential molecular marker for prognostic evaluation or a therapeutic target for HCC.

Stimulating anaerobic digestion to degrade recalcitrant organic pollutants: Potential role of conductive materials-led direct interspecies electron transfer.

This review aims to provide a comprehensive understanding of the potential of CMs-dominated DIET in the degradation of recalcitrant organic pollutants in AD. The review covers the mechanisms and efficiencies of recalcitrant organic pollutant degradation by CMs-dominated DIET, the comparison of degradation pathways between DIET and chemical treatment, recent insights on DIET-enhanced degradation, and the evaluation of the potential and future development of CMs-dominated DIET. The review emphasizes the importance of coupled syntrophic microorganisms, electron flux, and physicochemical properties of CMs in enhancing the degradation performance of AD. Additionally, it highlights the advantages of DIET-led syntrophic metabolism over traditional oxidation technologies in terms of environmental friendliness and efficiency. Finally, the review acknowledges the potential risks associated with introducing CMs into AD systems and provides guidance for waste treatment and energy recovery.

The long noncoding RNA LINC15957 regulates anthocyanin accumulation in radish.

Radish (Raphanus sativus L.) is an important root vegetable crop belonging to the Brassicaceae family. Anthocyanin rich radish varieties are popular among consumers because of their bright color and high nutritional value. However, the underlying molecular mechanism responsible for skin and flesh induce anthocyanin biosynthesis in transient overexpression, gene silencing and transcriptome sequencing were used to verify its function in radish anthocyanin accumulation, radish remains unclear. Here, we identified a long noncoding RNA LINC15957, overexpression of LINC15957 was significantly increased anthocyanin accumulation in radish leaves, and the expression levels of structural genes related to anthocyanin biosynthesis were also significantly increased. Anthocyanin accumulation and expression levels of anthocyanin biosynthesis genes were significantly reduced in silenced LINC15957 flesh when compared with control. By the transcriptome sequencing of the overexpressed LINC15957 plants and the control, 5,772 differentially expressed genes were identified. A total of 3,849 differentially expressed transcription factors were identified, of which MYB, bHLH, WD40, bZIP, ERF, WRKY and MATE were detected and differentially expressed in the overexpressed LINC15957 plants. KEGG enrichment analysis revealed the genes were significant enriched in tyrosine, L-Phenylalanine, tryptophan, phenylpropanol, and flavonoid biosynthesis. RT-qPCR analysis showed that 8 differentially expressed genes (DEGs) were differentially expressed in LINC15957-overexpressed plants. These results suggested that LINC15957 involved in regulate anthocyanin accumulation and provide abundant data to investigate the genes regulate anthocyanin biosynthesis in radish.

Conductive materials as fantastic toolkits to stimulate direct interspecies electron transfer in anaerobic digestion: new insights into methanogenesis contribution, characterization technology, and downstream treatment.

Direct interspecies electron transfer (DIET) stimulated by conductive materials (CMs) enables intercellular metabolic coupling that can address the unfavorable thermodynamical dilemma inherent in anaerobic digestion (AD). Although the DIET mechanism and stimulation have been extensively summarized, the methanogenesis contribution, characterization techniques, and downstream processes of CMs-led DIET in AD are surprisingly under-reviewed. Therefore, this review aimed to address these gaps. First, the contribution of CMs-led DIET to methanogenesis was re-evaluated by comparing the effect of various factors, including volatile fatty acids, free ammonia, and functional enzymes. It was revealed that AD systems are usually intricate and cannot allow the methanogenesis stimulation to be singularly attributed to the establishment of DIET. Additionally, considerable attention has been attached to the characterization of DIET occurrence, involving species identification, gene expression, electrical properties, cellular features, and syntrophic metabolism, suggesting the significance of accurate characterization methods for identifying the syntrophic metabolism interactions. Moreover, the type of CMs has a significant impact on AD downstream processes involving biogas purity, sludge dewaterability, and biosolids management. Finally, the central bottleneck consists in building a mathematical model of DIET to explain the mechanism of DIET in a deeper level from kinetics and thermodynamics.

Morusin Protected Ruminal Epithelial Cells against Lipopolysaccharide-Induced Inflammation through Inhibiting EGFR-AKT/NF-κB Signaling and Improving Barrier Functions.

Using phytogenic extracts for preventing or treating rumen epithelial inflammatory injury is a potential alternative to antibiotic use due to their residue-free characteristics. In this study, the efficacy of Morus root bark extract Morusin on ruminal epithelial cells (RECs) against pathogenic stimulus was investigated for the first time. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and quantitative real-time polymerase chain reaction (qPCR) results showed that the Morusin did not affect the cell viability of RECs and exerted anti-inflammatory effects in a concentration-dependent manner. Transcriptome analysis further revealed that the Morusin significantly downregulated the inflammatory-response-related cell signaling, while it upregulated the cell-proliferation-inhibition- and barrier-function-related processes in RECs upon lipopolysaccharide (LPS) stimulation. The epidermal growth factor receptor (EGFR) blocking and immunoblotting analysis further confirmed that the Morusin suppressed LPS-induced inflammation in RECs by downregulating the phosphorylation of protein kinase B (AKT) and nuclear factor-kappaB (NF-κB) p65 protein via inhibiting the EGFR signaling. These findings demonstrate the protective roles of Morusin in LPS-induced inflammation in RECs.

Combined impact of organic matter, phosphorus, nitrate, and ammonia nitrogen on the process of blackwater.

Blackwater events are frequently reported over the world and become a serious environmental problem. However, the mechanisms of blackwater occurrence are not fully understood yet. This study simulated the process of blackwater with the combined pollution in an orthogonal experiment, which had 4 factors (TOC, TP, NH4+-N, and NO3--N) and 4 levels (None, Low, Middle, and High). Results showed that the process of water condition changes was divided into two parts, which were "exogenous" and "algae-derived" blackwater, and the influence of four different pollutants on the occurrence of the blackwater was ranked as follows: TOC > TP > NO3--N > NH4+-N. With the increase of organic matter addition, the anaerobic condition in water was prolonged and the concentration of Fe2+ had a significant increase. In addition, under the None phosphorus condition, the descent rates of DO and COD in the water were reduced, and the algae bloom was obviously deferred. Moreover, the addition of organic matter or phosphorus changed the microbial community structure and led to different water processes. Particularly, only on the condition of the high content of TOC and phosphorus, the diversity of sulfate-reducing bacteria (e.g., Pseudomonas, Paludibacter, and Bacteroides) increased significantly, which accounted for 51.4%, causing the significant production of S2- in the water. Water's lack of phosphorus showed a low rate of decomposition of organic matter, which might be the result of a considerable increase in the abundance of aerobic Trichococcus and Malikia. This study shows that organic matter and phosphorus have synergistic effect on blackwater occurrence. In the treatment of blackwater, the exogenous pollutant control should reduce the discharge of organic pollutants, and endogenous control should focus on phosphorus abatement and reduce nitrogen control.

The role of vesicular overexpressed in cancer pro-survival protein 1 in hepatocellular carcinoma proliferation.

BACKGROUND: Recently, hepatocellular carcinoma (HCC) has been ranked as the second leading cause of cancer-associated death. However, the underlying molecular mechanisms of HCC progression remain unclear. Vesicular overexpressed in cancer pro-survival protein 1 (VOPP1) could be upregulated in a quantity of human cancers, including squamous cell carcinoma (SCC), gastric cancer, and glioblastoma. However, the precise functional mechanism of VOPP1 in HCC remains poorly understood. The present study aimed to investigate the role of VOPP1 in HCC proliferation. METHODS: Immunohistochemistry (IHC), Western blot and Reverse-transcription polymerase chain reaction (RT-PCR) were used to analyze the protein and mRNA expressions of VOPP1, mitogen-activated protein kinase (MAPK) 14, ribosomal protein S6 kinase ß1 (RPS6KB1), cylindromatosis (CYLD) and Twist family bHLH transcription factor 1 (TWIST1). The cell proliferation and apoptosis were tested using Celigo cell imaging analyzer and annexin V-APC apoptosis detection kit respectively. Colony formation and tumor xenograft assays were performed to understand their roles in tumorigenicity. RESULTS: The expression of VOPP1 in HCC samples was higher than that in adjacent noncancerous tissues by immunohistochemistry. In addition, the down-regulation of VOPP1 using shRNA inhibited cell proliferation and tumour growth, and induced cell apoptosis in vitro and in vivo. Furthermore, VOPP1 silencing increased the expression of MAPK14 and RPS6KB1, indicating that the MAPK and mTOR signalling pathways might be involved in VOPP1-mediated cancer cell proliferation. CONCLUSION: The present data indicate that VOPP1 may play an important role in the progression of HCC by targeting the MAPK and mTOR signalling pathways, and that VOPP1 may potentially be a candidate as a novel molecular target for HCC therapy.

Skin-stretching device promotes the treatment effect of vacuum sealing drainage technique on phases III and IV stress-induced injuries in aged patients with chronic critical illness: A retrospective study of 70 patients.

Stress-induced injury is a common complication associated with patients with chronic critical illness (CCI). Skin-stretching device (SSD) and vacuum sealing drainage (VSD) technique are 2 approaches that can facilitate wound healing.In the present study, the effect of the concatenated application of the 2 techniques on the phases III and IV stress-induced injuries in aged patients with CCI was assessed. About 70 patients with CCI with stress-induced injuries were selected from February 2015 to October 2017. The treatment outcomes of the combined method and VSD method were assessed by comparing their clinicopathologic parameters.The results showed that the combined treatment shortened the average healing duration of wounds. Moreover, the total area of pressure sores, incidence of bleeding, bacteria amount, 28-day cure rate, peripheral C-reactive protein (CRP) level, and the hospitalization duration were all significantly improved in patients treated with SSD and VSD. The overall effective rate (97.14%) of patients treated with VSD and SSD was significantly higher than that (77.14%) in patients treated with VSD.The present study showed that the combined application of VSD and SSD improved the treatment outcomes of phases III and IV stress-induced injuries in aged patients with CCI.

Synthesis and characterization of biomass lignin-based PVA super-absorbent hydrogel.

The traditional polyvinyl alcohol composite hydrogel exhibited poor swelling and mechanical properties, which limited its application. To solve these issues, we use biomass lignin as raw material, PVA as matrix template and epichlorohydrin as cross-linker to prepare the Lignin-PVA super-absorbent hydrogels with the swelling ratio of up to 456 g/g under mild condition. When the lignin concentration was increased from vacancy to 5%, the swelling ratio of the Lignin-PVA hydrogels was increased from 92 g/g to 456 g/g. The lignin-based hydrogel synthesized by the higher molecular weight PVA showed better swelling performance. Softwood lignin, hardwood lignin and corncob lignin could also be used to fabricate the Lignin-PVA super-absorbent hydrogels with the swelling ratio of higher than 500 g/g. However, the optimum amount varied from different lignin types, which was related to the molecular weight and phenolic hydroxyl content of lignin. The structural mechanism of the Lignin-PVA hydrogel was proposed to clearly certify the enhancing role of lignin. The adsorption capacity of the Lignin-PVA hydrogel with respect to rhodamine 6G, crystal violet and methylene blue dyes was up to 196, 169 and 179 mg/g, respectively. The Lignin-PVA hydrogel presents great potential applications in the fields of soil water retention and seed cultivation in agriculture, and dye pollutant removal.

Facile preparation of biomass lignin-based hydroxyethyl cellulose super-absorbent hydrogel for dye pollutant removal.

The severe preparation process, poor swelling properties and mechanical properties of traditional cellulose and polyvinyl alcohol (PVA) composite hydrogels heavily limited their practical applications. To solve these issues, we use long-chain hydroxyethyl celluloses (HECs) as framework backbones, short-chain PVAs as branched chains, lignin molecules as extended crosslinkers and epichlorohydrin molecules as crosslinkers to prepare the lignin-based hydroxyethyl cellulose-PVA (LCP) super-absorbent hydrogels in the alkaline aqueous solution under mild reaction conditions, demonstrating high swelling ratio of up to 1220 g/g. The LCP hydrogels could take up large amounts of positively charged dyes rhodamine 6G, crystal violet and methylene blue with uptakes of 153, 184 and 196 mg/g, respectively. The LCP super-absorbent hydrogels also present excellent water retention, biodegradability and excellent swelling properties, which are very promising for applications in the fields of commercial diapers, soil water retention and seed cultivation in agriculture, and dye pollutant removal.

Improved enzymatic hydrolysis of hardwood and cellulase stability by biomass kraft lignin-based polyoxyethylene ether.

Water-soluble kraft lignin-based polyoxyethylene ether (KL-PEG), synthesized from the black liquor of kraft pulping and PEG, was used to improve the enzymatic hydrolysis efficiency of dilute acid pretreated (DA-pretreated) Eucalyptus hardwood and cellulase stability. The physicochemical properties of KL-PEG polymer such as solubility, surface tension, charge and aggregation behavior in the solution were first studied. KL-PEG could enhance the enzymatic hydrolysis of Avicel and DA-pretreated Eucalyptus from 63.6% and 58.3% to 78.5% and 93.8%, respectively. The enzymatic activity of cellulase after the enzymatic hydrolysis of Avicel and DA-pretreated Eucalyptus for 72 h remained approximately 84% and 44% in the presence of KL-PEG polymer. KL-PEG could improve the stability and longevity of the cellulase, facilitate the recovery and save the amount of cellulase. The efficient utilization of the pulping black liquor lignin was of great significance to alleviate the pressure brought by the shortage of petrochemical resources, and build an energy-saving and low-carbon society.

Effect of lignin-based amphiphilic polymers on the cellulase adsorption and enzymatic hydrolysis kinetics of cellulose.

The origin, amount, hydrophilicity, charge, molecular weight and its distribution of lignin have significant influences on the enzymatic hydrolysis of lignocellulose. The enzymatic hydrolysis of lignocellulose was essentially enhanced by lignin-based polyoxyethylene ether (EHL-PEG), whereafter followed by PEG4600 and lignosulfonate (LS). The effect of LS, EHL-PEG and PEG4600 on the adsorption and enzymatic hydrolysis kinetics of cellulase on the gold surface and cellulose film was investigated by Quartz Crystal Microbalance with dissipation monitoring (QCM-D). Results showed that the interaction of LS or EHL-PEG with cellulase was electrostatic attractive and hydrophobic effect, respectively, and formed hydrophilic cellulase aggregates. LS-Cellulase peeled off the cellulose film layer by layer, while the hydrophobic phenylpropane structure of EHL-PEG-Cellulase acted as a cellulose binding domain to hydrolysis cellulose through "Hollow" effect and made cellulose become more loose and swollen. At last, a strategy to enhance the enzymatic hydrolysis of lignocellulose by lignin-based amphiphilic polymers was proposed as well.

[Expression, purification and characterization of 3-Deoxy-D-manno-octulosonate 8-phosphate synthase from Phyllostachys edulis].

3-Deoxy-D-manno-octulosonate 8-phosphate synthase (KDO8PS) is the key enzyme to synthesize eight-carbon sugar in plant and gram-negative bacterial cell wall. To analyze the polymerization and characterization in plant KDO8PS, the candidate gene was cloned from fresh Phyllostachys edulis seedling by RT-PCR. The open reading frame of PeKDO8PS is 876 bp deduced into 291 amino acid residues. The target protein was overexpressed in Escherichia coli induced by IPTG and then lager amount of fusion protein was purified through two-step methods with affinity chromatography and size-exclusion chromatography (SEC). SEC analysis shows that PeKDO8PS protein existed mainly in the form of dime in solution. Glutaraldehyde cross-linking experiments confirmed that the enzyme could form dimers. Further we identified that KDO8PS at high concentration two dimers could form tetramer in aqueous solution by analytical ultracentrifuge (AUC) analysis. The pH of the catalytic reaction was between 4.0 and 9.0, the optimum pH value was 8, the thermal stability range was between 25 and 65 ℃, and the optimum temperature was about 55 ℃. The enzyme activity was inhibited by some metal ions at lower concentrations, especially in the presence of Fe3+metal ion and activated by metal protease inhibitor EDTA at low concentration.

[Expression, purification and characterization of arabinose-5-phosphate isomerase from Arabidopsis thaliana].

Arabinose-5-phosphate isomerase (KdsD) is the first key limiting enzyme in the biosynthesis of 3-deoxy-D-manno-octulosonate (KDO). KdsD gene was cloned into prokaryotic expression vector pET-HTT by seamless DNA cloning method and the amount of soluble recombinant protein was expressed in a soluble form in E. coli BL21 (DE3) after induction of Isopropyl ß-D-1-thiogalactopyranoside (IPTG). The target protein was separated and purified by Ni-NTA affinity chromatography and size exclusion chromatography, and its purity was more than 85%. Size exclusion chromatography showed that KdsD protein existed in three forms: polymers, dimmers, and monomers in water solution, different from microbial KdsD enzyme with the four polymers in water solution. Further, the purified protein was identified through Western blotting and MALDI-TOF MASS technology. The results of activity assay showed that the optimum pH and temperature of AtKdsD isomerase activities were 8.0 and 37 ℃, respectively. The enzyme was activated by metal protease inhibitor EDTA (5 mmol/L) and inhibited by some metal ions at lower concentration, especially with Co²âº and Cd²âº metal ion. Furthermore, when D-arabinose-5-phosphate (A5P) was used as substrate, Km and Vmax of AtKdsD values were 0.16 mmol/L, 0.18 mmol/L·min. The affinity of AtKdsD was higher than KdsD in E. coli combined with substrate. Above results have laid a foundation for the KdsD protein structure and function for its potential industrial application.