Biological hydrogen production by the algal biomass Chlorella vulgaris MSU 01 strain isolated from pond sediment

Chlorella vulgaris MSU 01 strain isolated from the sediment of the pond is able to produce molecular hydrogen in a clean way. To relate the dynamic coupling between the cultural conditions and biological responses, an original lab scale set up has been developed for hydrogen production. Different sources like mannitol, glucose, alanine, citric acid, aspartic acid, l-alanine, l-cysteine, sodium succinate and sodium pyruvate were used for algal media optimization. Corn stalk, from 1 to 5 g/L was tested for the effective algal growth and hydrogen production. The cell concentration of 1.6-19 g/L dry cell weight (DCW) was found at the 10th day. The kinetic parameters involved in the hydrogen production at 4 g/L corn stalk using the algal inoculum (50 mL) in the bioreactor volume (500 mL) was found to be with the hydrogen production potential (P_s) of 7.784 mL and production yield of (P_r) 5.534 mL respectively. The growth profile of the algal biomass at the above mentioned condition expressed the logistic model with R² 0.9988. The final pH of the broth was increased from 7.0 to 8.5-8.7. The anaerobic fermentation by C. vulgaris MSU 01 strain involved in the conversion process of complex carbon source has increased the H₂ evolution rate and higher butyrate concentration in the fermentate.     

Plant growth-promoting rhizobacterial mediated protection of tomato in the field against cucumber mosaic virus and its vector Aphis gossypii

Studies evaluated the effect of rhizobacterial interactions on a virus under natural conditions of high levels of vector–virus pressure on tomato plants. The rhizobacterium Bacillus subtilis was isolated from the rhizosphere soil of healthy tomato plant and the strain is referred to as BS3A25. The BS3A25 treatment of seeds significantly enhanced tomato seed germination rates to 99% compared to the control seeds at 78%. Combination of both seed and foliar spray treatments significantly protected the plants from cucumber mosaic virus (CMV) and also significantly enhanced plant growth. Strain BS3A25 possesses many positive traits such as phosphate solubilization ability, ACC utilization as the sole source of nitrogen and production of significantly higher concentrations of indoles, IAA and the cytokinin, IPA. The growth parameters of the aphid Aphis gossypii Glover such as development time, time from birth to adult (t_D) and prereproduction time (t_d) were longer, whereas the relative growth rate (RGR) and intrinsic rate of natural increase (r_m), were found to be lower in the BS3A25 supernatant treatment compared to commercial insecticide imidacloprid treatment. Noticeably, the present study recorded higher activity of phenylalanine ammonia lyase, Peroxidase, total phenols, and polyphenol oxidase in plants treated with BS3A25 generating the speculation of induced defence responses in plants. The results obtained in the field study showed that treatment by BS3A25 formulation as seed and foliar treatment proved highly effective in reducing the aphid population and CMV incidence compared to a commercially available insecticide. The highest cost:benefit ratio (1:2.5) was obtained in BS3A25 formulation treatment followed by imidacloprid (1:2.0) and control plants (1:1.4). These constitute an important step towards the production of BS3A25 as a commercially-available induced resistance agent.     

Cytotoxicity and superoxide anion generation by some naturally occurring quinones.

Four naturally occurring quinones, mansonone-D (MD), mansonone-H (MH), thespone (TP) and thespesone (TPE), extracted from the heartwood of Thespesia populnea have been tested for their cytotoxic action by aerobic incubation with human breast adenocarcinoma (MCF-7) cells. Toxicity of the quinones follows the order MD > TP > MH approximately TPE. EPR spectrometric and Clark electrode oximetric studies indicate that redox cycling of these quinones produce superoxide anion radical (O2*-) and H2O2 on aerobic incubation with NADH:cytochrome c reductase. Generation of superoxide radical during enzymatic reduction of quinones, was confirmed by EPR spin trapping experiment using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trap. Cyclic voltammetric studies show reversible redox couples for MD and TP whereas TPE and MH show irreversible redox couple. The electrochemical results indicate that MH and TPE are more difficult to reduce than TP and MD.     

Isolation and Characterization of ACC Deaminase Gene from Two Plant Growth-Promoting Rhizobacteria

Lowering of plant ethylene by deamination of its immediate precursor 1-aminocyclopropane-1-carboxylate (ACC) is a key trait found in many rhizobacteria. We isolated and screened bacteria from the rhizosphere of wheat for their ACC-degrading ability. The ACC deaminase gene (acdS) isolated from two bacterial isolates through PCR amplification was cloned and sequenced. Nucleotide sequence alignment of these genes with previously reported genes of Pseudomonas sp. strain ACP and Enterobacter cloacae strain UW4 showed variation in their sequences. In the phylogenetic analysis, distinctness of these two genes was observed as a separate cluster. 16S rDNA sequencing of two isolates identified them to be Achromobacter sp. and Pseudomonas stutzeri.     

Activation of Hsp90-eNOS and increased NO generation attenuate respiration of hypoxia-treated endothelial cells

Hypoxia induces various adoptive signaling in cells that can cause several physiological changes. In the present work, we have observed that exposure of bovine aortic endothelial cells (BAECs) to extreme hypoxia (1-5% O(2)) attenuates cellular respiration by a mechanism involving heat shock protein 90 (Hsp90) and endothelial nitric oxide (NO) synthase (eNOS), so that the cells are conditioned to consume less oxygen and survive in prolonged hypoxic conditions. BAECs, exposed to 1% O(2), showed a reduced respiration compared with 21% O(2)-maintained cells. Western blot analysis showed an increase in the association of Hsp90-eNOS and enhanced NO generation on hypoxia exposure, whereas there was no significant accumulation of hypoxia-inducible factor-1alpha (HIF-1alpha). The addition of inhibitors of Hsp90, phosphatidylinositol 3-kinase, and NOS significantly alleviated this hypoxia-induced attenuation of respiration. Thus we conclude that hypoxia-induced excess NO and its derivatives such as ONOO(-) cause inhibition of the electron transport chain and attenuate O(2) demand, leading to cell survival at extreme hypoxia. More importantly, such an attenuation is found to be independent of HIF-1alpha, which is otherwise thought to be the key regulator of respiration in hypoxia-exposed cells, through a nonphosphorylative glycolytic pathway. The present mechanistic insight will be helpful to understand the difference in the magnitude of endothelial dysfunction.     

Synthesis and biological evaluation of pentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecane derivatives as potential therapeutic agents in Parkinson's disease

In previous studies, the polycyclic cage amine 8-benzylamino-8,11-oxapentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecane (NGP1-01) and a number of its derivatives showed positive effects in neuroprotection studies with MPTP, in vivo. In view of these findings, we examined these compounds for their effects on [(3)H]dopamine ([(3)H]DA) release and uptake inhibition in murine striatal synaptosomes, as well as for inhibition of baboon liver monoamine oxidase (MAO) B. In order to assess specificity, initial experiments focused on compounds that blocked dopamine uptake without causing appreciable release (<40% at 100 microM) of the transmitter. NGP1-01 blocked the uptake of [(3)H]DA with an IC(50) of 57 microM, while another compound, 8-phenylethyl-8,11-oxapentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecane, blocked uptake at an IC(50) value of 23 microM. These values were comparable to that of another polycyclic cage amine, amantadine (IC(50); 82 micro), that is used in parkinsonian therapy. Structure-activity relationships of this series of compounds support the importance of geometric and steric, rather than electronic effects, in determining biological activity. MAO-B inhibition for this group was weak, with less than 50% inhibition at 300 microM for any of the compounds in the series. The present study suggests that blockage of the dopamine transporter may underlie, at least in part, their neuroprotective effects against MPTP-induced parkinsonism. These compounds may be considered as potential lead compounds for Parkinson's Disease therapy.     

Formation of multilamellar vesicles ('onions') in peptide based surfactant

Concentration dependent morphological characteristics of a novel dipeptide derivative Lys-Asp-Lauryl.HBr (1) has been presented. Evidence for "onion" like vesicle formation at higher concentration (>8.2 x 10(-3) M) of peptide (1) in aqueous medium was obtained from conductance and 90 degrees light scattering measurements, and cryo-transmission electron microscopic studies.     

Anomalous temperature dependence of peptide films at air-water interface

The tetrapeptide derivative Tyr-Gly-Phe-Ala-OBz (1) forms monolayers as confirmed by compressibility studies carried out at various temperatures. Peptide 1 monolayer exhibits an anomalous structural transition at 40 degrees C as evidenced by pi-A isotherms recorded at different temperatures. The structural transition is also observed in aqueous solution of trifluoroacetate of peptide 1 as evidenced by fluorescence and Raman scattering intensity measurements.     

Enhanced Stability of Li Metal Anodes by Synergetic Control of Nucleation and the Solid Electrolyte Interphase

Use of a protective coating on a lithium metal anode (LMA) is an effective approach to enhance its coulombic efficiency and cycling stability. Here, a facile approach to produce uniform silver nanoparticle‐decorated LMA for high‐performance Li metal batteries (LMBs) is reported. This effective treatment can lead to well‐controlled nucleation and the formation of a stable solid electrolyte interphase (SEI). Ag nanoparticles embedded in the surface of Li anodes induce uniform Li plating/stripping morphologies with reduced overpotential. More importantly, cross‐linked lithium fluoride‐rich interphase formed during Ag⁺ reduction enables a highly stable SEI layer. Based on the Ag‐LiF decorated anodes, LMBs with LiNi_1/3Mn_1/3Co_1/3O₂ cathode (≈1.8 mAh cm^?2) can retain >80% capacity over 500 cycles. The similar approach can also be used to treat sodium metal anodes. Excellent stability (80% capacity retention in 10 000 cycles) is obtained for a Na||Na₃V₂(PO₄)₃ full cell using a Na‐Ag‐NaF/Na anode cycled in carbonate electrolyte. These results clearly indicate that synergetic control of the nucleation and SEI is an efficient approach to stabilize rechargeable metal batteries.