Bidirectional Modulation of Neuronal Cells Electrical and Mechanical Properties Through Pristine and Functionalized Graphene Substrates

In recent years, the quest for surface modifications to promote neuronal cell interfacing and modulation has risen. This course is justified by the requirements of emerging technological and medical approaches attempting to effectively interact with central nervous system cells, as in the case of brain-machine interfaces or neuroprosthetic. In that regard, the remarkable cytocompatibility and ease of chemical functionalization characterizing surface-immobilized graphene-based nanomaterials (GBNs) make them increasingly appealing for these purposes. Here, we compared the (morpho)mechanical and functional adaptation of rat primary hippocampal neurons when interfaced with surfaces covered with pristine single-layer graphene (pSLG) and phenylacetic acid-functionalized single-layer graphene (fSLG). Our results confirmed the intrinsic ability of glass-supported single-layer graphene to boost neuronal activity highlighting, conversely, the downturn inducible by the surface insertion of phenylacetic acid moieties. fSLG-interfaced neurons showed a significant reduction in spontaneous postsynaptic currents (PSCs), coupled to reduced cell stiffness and altered focal adhesion organization compared to control samples. Overall, we have here demonstrated that graphene substrates, both pristine and functionalized, could be alternatively used to intrinsically promote or depress neuronal activity in primary hippocampal cultures.

Selective Oxygenation of C-H and C=C Bonds with H2O2 by High-Spin Cobalt(II)-Carboxylate Complexes

Four cobalt(II)-carboxylate complexes [(6-Me3-TPA)CoII(benzoate)](BPh4) (1), (6-Me3-TPA)CoII(benzilate)](ClO4) (2), [(6-Me3-TPA)CoII(mandelate)](BPh4) (3), and [(6-Me3-TPA)CoII(MPA)](BPh4) (4) (HMPA = 2-methoxy-2-phenylacetic acid) of the 6-Me3-TPA (tris((6-methylpyridin-2-yl)methyl)amine) ligand were isolated to investigate their ability in H2O2-dependent selective...

Ottowia caeni sp. nov., a novel phenylacetic acid degrading bacterium isolated from sludge

A novel bacterium, designated BD-1T, was isolated from a sludge sample. Cells of the novel Gram-stain-negative strain were identified to be facultative anaerobic, non-motile and short rod-shaped. Growth occurred at 15–37 °C (optimum, 30 °C), pH 5.0–10.0 (pH 7.0) and in 0–4.0 % NaCl (2.0 %, w/v). The 16S rRNA gene sequence of strain BD-1T showed the highest sequence similarity to Ottowia thiooxydans DSM 14619T (97.0 %), followed by Ottowia pentelensis DSM 21699T (96.3 %) and less than 96 % to other related strains. The phylogenetic trees revealed that strain BD-1T clustered within the genus Ottowia . Summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c, 48.2 %), C16 : 0 (23.2 %) and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c, 8.6 %) were the major fatty acids (>5 %), and ubiquinone-8 was the respiratory quinone. Phosphatidylethanolamine, phosphatidylmethylethanolamine and phosphatidylglycerol were identified as the major polar lipids. Meanwhile, the G+C content of the DNA was 63.6 mol% based on the draft genome analysis. The average nucleotide identity and digital DNA–DNA hybridization values between strain BD-1T and DSM 14619T were 74.5 and 21.4 %, respectively. In addition, the novel strain completely degraded 500 mg l−1 phenylacetic acid within 72 h under the condition of 3 % NaCl. Given the results of genomic, phylogenetic, phenotypic and chemotaxonomic analyses, strain BD-1T was considered to represent a novel species of the genus Ottowia , for which the name Ottowia caeni sp. nov. is proposed. The strain is a potential resource for the bioremediation of phenylacetic acid contaminated water. The type strain is BD-1T (=CGMCC 1.18541T=KCTC 82183T).

Genotype-Dependent Effect of Silencing of TaCKX1 and TaCKX2 on Phytohormone Crosstalk and Yield-Related Traits in Wheat

The influence of silenced TaCKX1 and TaCKX2 on coexpression of other TaCKX gene family members (GFMs), phytohormone regulation and yield-related traits was tested in awned-spike cultivar. We documented a strong feedback mechanism of regulation of TaCKX GFM expression in which silencing of TaCKX1 upregulated expression of TaCKX2 genes and vice versa. Additionally, downregulation of TaCKX2 highly upregulated the expression of TaCKX5 and TaNAC2-5A. In contrast, expression of these genes in silenced TaCKX1 was downregulated. Silenced TaCKX1 T2 lines with expression decreased by 47% had significantly higher thousand grain weight (TGW) and seedling root mass. Silenced TaCKX2 T2 lines with expression of TaCKX2.2.1 and TaCKX2.2.2 decreased by 33% and 30%, respectively, had significantly higher chlorophyll content in flag leaves. TaCKX GFM expression, phytohormone metabolism and phenotype were additionally modified by Agrobacterium-mediated transformation. Two novel phytohormones, phenylacetic acid (PAA) and topolins, lack of gibberellic acid (GA) and changed phytohormone contents in the 7 days after pollination (DAP) spikes of the awned-spike cultivar compared to a previously tested, awnless one, were detected. We documented that major mechanisms of coregulation of the expression of TaCKX GFMs were similar in different spring wheat cultivars, but, depending on content and composition of phytohormones, regulation of yield-related traits was variously impacted.

A Soil-Borne Mn(II)-Oxidizing Bacterium of Providencia sp. Exploits a Strategy of Superoxide Production Coupled To Hydrogen Peroxide Consumption To Generate Mn Oxides

Bacterial non-enzymatic Mn(II) oxidation involving reactive oxygen species (ROS) (i.e. indirect oxidation), initially discovered from a marine alpha-proteobacterium, is believed to be of importance in controlling biogeochemical cycles. For soil-borne bacteria, however, evidence of indirect Mn(II) oxidation remains unclear. In this study, the indirect Mn(II) oxidation was evidenced in a soil-borne bacterium, Providencia sp. LLDRA6. First, with and without 50 mM of Mn(II) exposure for LLDRA6, 300 differentially expressed genes were found to be linked to Mn(II) exposure via transcriptome sequencing. Among them, an operon, responsible for phenylacetic acid catabolism, was sharply upregulated in transcription, drawing us a special attention since its transcriptional upregulation has recently shown to be important for withstanding ROS. Next, a fluorometric probe, 2′,7′-Dichlorofluorescin diacetate (DCFDA), was used to qualitatively detect ROS from cells, showing a distinct increase in fluorescence intensities of ROS during Mn(II) exposure. Further, concentrations of superoxide and hydrogen peroxide from cells were detected respectively with and without Mn(II) exposure, exhibiting that when Mn(II) oxidation occurred, superoxide concentration significantly increased but hydrogen peroxide concentration significantly decreased. Particularly, superoxide produced by LLDRA6 was proven to be the oxidant for Mn(II) in the formation of Mn oxides. Finally, we predicted links between phenylacetic acid metabolism pathway and ROS during Mn(II) exposure, proposing that the excessive ROS, generated in response to Mn(II) exposure, transcriptionally activate phenylacetic acid catabolism presumably by increasing concentrations of highly reactive oxepins.

OPTIMASI VOLUME PREKURSOR Phenylacetic Acid (PAA) PADA PRODUKSI PENISILIN G DARI Penicillium chrysogenum

Salah satu metode untuk meningkatkan produktivitas penisilin G dari jamur Penicillium chrysogenum adalah dengan cara Optimasi PAA karena komposisi dari medium yang digunakan untuk kultivasi mikroorganisme dapat secara langsung berpengaruh pada fenotip fisiologis dan kinerja fermentasi mikroorganisme tersebut. Sampel jamur Penicillium chrysogenum terdiri atas koloni 2 dan 3 yang kemudian diberi perlakuan yang berbeda dengan menambahkan prekursor PAA dengan volume yang dibagi menjadi 3 variasi, yakni PAA 0,5 mL, 0,6 mL, dan 0,7 mL. Semua sampel kemudian dianalisis lebih lanjut dengan metode HP-LC dan analisis gula. Dari penelitian ini didapatkan hasil , pemberian PAA 0,7 menghasilkan rata-rata penisilin-G dalam jumlah yang paling besar (3787,2 dan 4021,4 ppm) dibandingkan dengan pemberian PAA 0,5 dan PAA 0,6. 2. Koloni 3 memiliki morfologi yang mendekati dengan morfologi koloni ideal yang dapat menghasilkan penisilin-G di atas 5000 ppm, yaitu berwarna hijau gelap dengan struktur yang menyerupai gunung dengan sebuah kawah di bagian tengah. Akan tetapi, belum bisa ditentukan volume PAA yang dapat digunakan untuk menghasilkan penisilin-G dengan jumlah maksimal.

The Effect of Phenyl Acetic Acid (PPA) On Micropropagation of Date Palm Followed By Genetic Stability Assessment

Date palm is propagated by the offshoots, the number of which is limited. Therefore, adult date palms produce shoot tips and axillary buds meristems through the use of tissue culture. The micropropagation of the date palm also still faces many obstacles. Here, we established an efficient plant-regeneration system for (Phoenix dactylifera L.) cv. Ashgar by tissue culture. Murashige and Skoog medium containing 6-benzyladenine (BA) (2.0 and 5.0 mg L− 1) and a-naphthaleneacetic acid (NAA) or phenylacetic acid (PAA) (0.05–2.00 mg L− 1) was used to initiate shoot formation from callus tissues. The maximum number of shoots per jar was produced on a medium containing 5.0 mgL− 1 BA and 0.5 mg L− 1 PAA. The medium supplemented with 2.0 mgL− 1 BA in combination with 0.05 m L− 1 PAA gave the highest callus induction (+++). A decrease in browning percentage was observed in the tissue cultured in the media supplied with BA in combination with NAA or PAA compared to the media provided with BA alone. In comparison with other treatments, the total amount of phenolic compounds was significantly reduced to 0.45 mg g− 1 in buds cultured in the media supplemented with 5.0 mg L− 1 BA and 0.5 mg L− 1 PAA. The RAPD DNA-based fingerprinting technique confirmed the genomic stability of this protocol. RAPD binding patterns showed no difference between the tissue culture-derived plants tested. The in vitro micropropagation protocol reported here can be presented to produce genetically stable date palm plants.