Publications by authors named "Zheng-xiang Wang"

Pullulanase, a starch debranching enzyme, is required for the preparation of high glucose/maltose syrup from starch. In order to expand its narrow reaction conditions and improve its application value, Bacillus naganoensis pullulanase (PulA) was mutated by site-directed mutagenesis and the biochemical characteristics of the mutants were studied. The mutant PulA-N3 with mutations at asparagine 467, 492 and 709 residues was obtained.

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Article Synopsis
  • The study aimed to explore how the expression levels of KAI1 (CD82) and miR-633 relate to the prognosis and survival of patients with melanoma and colorectal cancer (CRC).
  • Data from 195 patients were analyzed, revealing that lower KAI1 and higher miR-633 levels were linked to poorer survival outcomes.
  • The findings indicate that KAI1 expression is an important factor in predicting the prognosis for patients suffering from both melanoma and CRC.
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Objective: Malignant melanoma with gastric cancer is one of the most malignant tumors. However, there have been no reports on the effects of KAI1 and miRNA-633 on the survival and prognosis of patients with malignant melanoma with gastric cancer.

Methods: Fifty patients with malignant melanoma and gastric cancer were collected from October 2017 to December 2019.

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A new aminopeptidase (An-APa) was identified and biochemically characterized from CICIM F0215. It had maximal activity at 40 °C and pH 7.0 and exhibited a broad substrate specificity both on hydrophilic and hydrophobic amino acid residues at N-terminals.

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Two new aspartic proteases, PepAb and PepAc (encoded by and ), were heterologously expressed and biochemically characterized from F0215. They possessed a typical structure of pepsin-type aspartic protease with the conserved active residues D (84, 115), Y (131, 168) and D (281, 326), while their identity in amino acid sequences was only 19.0%.

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To find a lipase for synthesis of flavor esters in food processing, a total of 35 putative lipases from F0215 were heterologously expressed and their esterification properties in crude preparations were examined. One of them, named An-lipase with the highest esterification rate (23.1%) was selected for further study.

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Premise Of The Study: Understanding resource allocation to reproduction, a key factor in life history tradeoffs, has long intrigued plant ecologists. Despite the recognized importance of understanding the movement of resources among flowers following variable pollination, the patterns of resource reallocation to plant reproductive organs have not been thoroughly addressed. In this study, we aimed to empirically explore how resources redistribute within inflorescences in response to differential pollination intensities.

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It has been reported that zerumbone (ZER) has marked effects on the regulation of cell proliferation and migration in multiple types of cancer, and has anti-cancer effects on various types of malignant cell. However, the effects and underlying molecular mechanisms of treatment with ZER on melanoma cells remain unclear. In the present study, the effect of treatment with ZER on the proliferation, migration and mitochondrial function of the human melanoma cell line CHL-1 was investigated.

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By using GdO, propanedioic acid (Hpda) and oxalic acid (Hox), a new Gd-based metal-organic framework (MOF) [Gd(pda)(ox)(HO)] (1) has been successfully constructed and structurally characterized. Interestingly, temperature- and vapor-induced reversible single-crystal-to-single-crystal transformations occurred and two new MOFs, namely [Gd(pda)(ox)(HO)] (1a) and [Gd(pda)(ox)] (1b), have been obtained. Complex 1 displays a two-dimensional (2D) layer structure composed of zigzag [Gd(pda)] chains and it could also be made up of numerous Gd macrocycles.

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This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy).

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During a fermentation process, the formation of the desired product during the cell growth phase competes with the biomass for substrates or inhibits cell growth directly, which results in a decrease in production efficiency. A genetic switch is required to precisely separate growth from production and to simplify the fermentation process. The ldhA promoter, which encodes the fermentative D-lactate dehydrogenase (LDH) in the lactate producer Escherichia coli CICIM B0013-070 (ack-pta pps pflB dld poxB adhE frdA), was replaced with the λ p(R) and p(L) promoters (as a genetic switch) using genomic recombination and the thermo-controllable strain B0013-070B (B0013-070, ldhAp::kan-cI(ts)857-p(R)-p(L)), which could produce two-fold higher LDH activity at 42°C than the B0013-070 strain, was created.

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Fine tuning of the key enzymes to moderate rather than high expression levels could overproduce the desired metabolic products without inhibiting cell growth. The aims of this investigation were to regulate rates of lactate production and cell growth in recombinant Escherichia coli through promoter engineering and to evaluate the transcriptional function of the upstream region of ldhA (encoding fermentative lactate dehydrogenase in E. coli).

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Coupling lactate fermentation with cell growth was investigated in shake-flask and bioreactor cultivation systems by increasing aeration to improve lactate productivity in Escherichia coli CICIM B0013-070 (ackA pta pps pflB dld poxB adhE frdA). In shake-flasks, cells reached 1 g dry wt/l then, cultivated at 100 rpm and 42°C, achieved a twofold higher productivity of lactic acid compared to aerobic and O(2)-limited two-phase fermentation. The cells in the bioreactor yielded an overall volumetric productivity of 5.

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In order to further improve the utilization rate of raw materials and increase ethanol productivity, the gene Asp, encoding aspartic protease in Neurospora crassa was cloned and expressed in industrial ethanol-producing yeast. To promote secretion of the acid protease, the gene was fused to signal sequence of the yeast α-factor gene and constitutively expressed under transcriptional control of the Saccharomyces cerevisiae PGK1 promoter. The resultant recombinant enzyme was characterized with respect to pH and temperature optimum.

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Filamentous fungi are used in a variety of industrial processes including the production of primary metabolites (e.g., organic acid, vitamins, and extracellular enzymes) and secondary metabolites (e.

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In order to rationally manipulate the cellular metabolism of Escherichia coli for D: -lactate production, single-gene and multiple-gene deletions with mutations in acetate kinase (ackA), phosphotransacetylase (pta), phosphoenolpyruvate synthase (pps), pyruvate formate lyase (pflB), FAD-binding D-lactate dehydrogenase (dld), pyruvate oxidase (poxB), alcohol dehydrogenase (adhE), and fumarate reductase (frdA) were tested for their effects in two-phase fermentations (aerobic growth and oxygen-limited production). Lactate yield and productivity could be improved by single-gene deletions of ackA, pta, pflB, dld, poxB, and frdA in the wild type E. coli strain but were unfavorably affected by deletions of pps and adhE.

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The GPD2 gene, encoding NAD(+)-dependent glycerol-3-phosphate dehydrogenase in an industrial ethanol-producing strain of Saccharomyces cerevisiae, was deleted. And then, either the non-phosphorylating NADP(+)-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPN) from Bacillus cereus, or the NADP(+)-dependent glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from Kluyveromyces lactis, was expressed in the obtained mutant AG2 deletion of GPD2, respectively. The resultant recombinant strain AG2A (gpd2Δ P (PGK)-gapN) exhibited a 48.

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Article Synopsis
  • * Two recombinant strains, APA (with secreted protease) and APB (with cell-surface protease), were created and showed improved biomass yields compared to wild-type yeast.
  • * Both recombinant strains reached nearly maximum ethanol yield while exhibiting higher growth rates and lower byproduct formation, indicating that expressing the protease enhances ethanol productivity significantly.
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A newly isolated active producer of raw starch digesting amyloltic enzymes, Rhizopus microsporus var. chinensis CICIM-CU F0088 was screened and identified by morphological characteristics and molecular phylogenetic analysis. This fungus was isolated from the soil of Chinese glue pudding mill, and produced high levels of amylolytic activity under solid state fermentation with supplementation of starch and wheat bran.

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Background: Some strains of Bacillus licheniformis have been improved by target-directed screening as well as by classical genetic manipulation and used in commercial thermostable alpha-amylase and alkaline protease production for over 40 years. Further improvements in production of these enzymes are desirable.

Results: A new strain of B.

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Role of the calcium-binding residues Asp231, Asp233, and Asp438 of Bacillus amyloliquefaciens alpha-amylase (BAA) on the enzyme properties was investigated by site-directed mutagenesis. The calcium-binding residues Asp231, Asp233, and Asp438 were replaced with Asn, Asn, and Gly to produce the mutants D231N, D233N, and D438G, respectively. The mutant amylases were purified to homogeneity and the purified enzymes was estimated to be approximately 58 kDa.

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Objective: To identify the function of the gene encoding Neurospora crassa EAA33149.1 protein which has 46.85% similarity with Aspergillus niger phA gene.

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The two homologous genes GPD1 and GPD2, encoding two isoenzymes of NAD(+)-dependent glycerol-3-phosphate dehydrogenase in industrial yeast Saccharomyces cerevisiae CICIMY0086, had been deleted. The obtained two kinds of mutants gpd1Delta and gpd2Delta were studied under alcoholic fermentation conditions. gpd1Delta mutants exhibited a 4.

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Candida glycerinogenes WL2002-5, an excellent glycerol producer, has been used for industrial scale fermentation of glycerol by an aerobic process. However, our knowledge about glycerol biosynthesis at the molecular level and genetic background of this yeast species lags far behind those of model yeasts such as Saccharomyces cerevisiae et al. In this report, inverse primers, in conjunction with degenerated primers, were used to amplify the NAD+-dependent glycerol 3-phosphate dehydrogenase (GPD) encoding gene from C.

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