Gene cloning of phenolic acid decarboxylase from Bacillus subtilis and expression in top-fermenting yeast strain

Phenolic acid decarboxylase (PADC) gene, encoding phenolic acid decarboxylase, was cloned from Bacillus subtilis and ligated with a shuttle vector YEp352 to generate a novel plasmid YPADC. By analysis of sequencing and the restriction endonuclease digestion, the validity of construction was proved. Subsequently, the new vector was successfully transformed into wild-type top-fermenting yeast strain W303-1A; the mutant yeast strain W303+padc was obtained, which was tested on the laboratoryscale mashing and fermentation experiments. At the end of fermentation, the results showed an obvious increase of 4-vinylguaiacol content in top-fermented beers brewed with mutant yeasts. The final 4-vinylguaiacol concentration obtained with wild-type and mutant yeasts was 1.20 and 1.70mg/l, respectively. Additionally, the level of esters produced by the mutant strain was higher than that of the wild-type; there were therefore a marked clove-like and ester aroma in top-fermented beers brewed with the former. However, no evident differences were found in brewing characteristic between wild-type and mutant strains, especially the ability of utilizing fermentable sugar and reducing diacetyl. Taken together, these approaches indicated the possibility of cloning PADC gene and enhancing the concentration of 4-vinylguaiacol in top-fermented beers.size.Keywords: Clone, phenolic acid decarboxylase, top-fermenting yeast, 4-vinylguaiacolAfrican Journal of Biotechnology Vol. 9(33), pp. 5284-5291, 16 August, 201

Two-stage acceleration of interstellar ions driven by high-energy lepton plasma flows

We present the particle-in-cell (PIC) simulation results of the interaction of a high-energy lepton plasma flow with background electron-proton plasma and focus on the acceleration processes of the protons. It is found that the acceleration follows a two-stage process. In the first stage, protons are significantly accelerated transversely (perpendicular to the lepton flow) by the turbulent magnetic field "islands" generated via the strong Weibel-type instabilities. The accelerated protons shows a perfect inverse-power energy spectrum. As the interaction continues, a shockwave structure forms and the protons in front of the shockwave are reflected at twice of the shock speed, resulting in a quasi-monoenergetic peak located near 200 MeV under the simulation parameters. The presented scenario of ion acceleration may be relevant to cosmic-ray generation in some astrophysical environments

Determination of 4-vinylgaiacol and 4-vinylphenol in top-fermented wheat beers by isocratic high performance liquid chromatography with ultraviolet detector

This work aimed at determining 4-vinylguaiacol and 4-vinylphenol in the top-fermented wheat beers using different wavelength and the mobile phase for HPLC. Best results for isocratic elution were obtained at 260 nm and the mobile phase comprising methanol/ultrapure water/phosphoric acid (400/590/10, V/V). Under these conditions, the retention time of 4-vinylguaiacol and 4-vinylphenol was 25 and 27min, respectively

[In Press] Institutional isomorphism pressure and multinational corporations' environmental and social performance

The influence of institutional isomorphism pressure (IIP) on multinational corporations’ (MNCs) environmental and social responsibility has attracted considerable attention from academics. Therefore, this study uses data from MNCs on the 2019 Forbes Global 2000 list to investigate the relationship between IIP (coercive, normative, and mimetic) and MNCs’ environmental and social performance. Our results show that (1) IIP effectively enhances MNCs’ environmental and social performance; (2) compared with other institutional factors, the current coercive-related institutional factors (e.g. regulations) fail to promote environmental performance, and (3) normative related institutional factors (e.g. social norms) do not improve MNCs’ environmental performance in China and Japan. Our study reveals the relationship between IIP and MNCs’ environmental and social performance and provides a more comprehensive description approach of IIP measurement. Moreover, suggestions on enhancing MNCs’ environmental responsibility by strengthening IIP also provide policymakers and MNCs

Resveratrol Suppresses Epithelial-Mesenchymal Transition in GBM by Regulating Smad-Dependent Signaling

Glioblastoma (GBM) is the most common and malignant intracranial tumor in adults. Despite continuous improvements in diagnosis and therapeutic method, the prognosis is still far away from expectations. The invasive phenotype of GBM is the main reason for the poor prognosis. Epithelial-mesenchymal transition (EMT) is recognized as a participator in this invasive phenotype. Resveratrol, a natural plant-derived compound, is reported to be able to regulate EMT. In the present study, we used TGF-β1 to induce EMT and aimed to evaluate the effect of resveratrol on EMT and to explore the underline mechanism in GBM. Western blotting was used to detect the expression of EMT-related markers, stemness markers, and Smad-dependent signaling. Wound healing assay and transwell invasion assay were performed to evaluate the migratory and invasive ability of GBM cells. Gliosphere formation assay was used to investigate the effect of resveratrol on the ability of self-renewal. Xenograft experiment was conducted to examine the effect of resveratrol on EMT and Smad-dependent signaling in vivo. Our data validated that resveratrol suppressed EMT and EMT-associated migratory and invasive ability via Smad-dependent signaling in GBM cells. We also confirmed that resveratrol obviously inhibited EMT-induced self-renewal ability of glioma stem cells (GSCs) and inhibited EMT-induced cancer stem cell markers Bmi1 and Sox2, suggesting that resveratrol is able to suppress EMT-generated stem cell-like properties in GBM cells. Furthermore, we also showed the inhibitory effect of resveratrol on EMT in xenograft experiments in vivo. Overall, our study reveals that resveratrol suppresses EMT and EMT-generated stem cell-like properties in GBM by regulating Smad-dependent signaling and provides experimental evidence of resveratrol for GBM treatment