Ethanol production by novel thermophilic anaerobe isolate/S via consolidated bioprocessing

The research work summarizes a very significant, industrially and globally important topic. Particularly the isolation of microorganisms efficient in fermentation at higher than normal temperature and utilizing renewable biomass, is of economic importance. The work presented in this thesis with future perspective has a potential for larger scale consolidated bioprocessing for ethanol production.<br

Aminotroponiminates as Ligands for Potential Metal-Based Nitric Oxide Sensors

A family of new fluorescently labeled ligands, HRDATI, was prepared to develop transition-metal-based NO sensing strategies. The ligands are composed of aminotroponiminates (ATIs) with a dansyl fluorophore on one of the imine nitrogen atoms and an alkyl substituent, either i-Pr (8), t-Bu (9), or Bz (10), on the other. Bis(chelate) Co2+ ([Co(i-PrDATI)2] (12), [Co(t-BuDATI)2] (14), [Co(BzDATI)2] (15)) and Zn2+ ([Zn(i-PrDATI)2] (13)) complexes were prepared and characterized by X-ray crystallography. The bis(ATI) complex [Co(i-Pr2ATI)2] (11) was also prepared and its X-ray crystal structure determined. Cyclic voltammetry reveals reversible redox waves at −2.57 and −0.045 V (vs Cp2Fe/Cp2Fe+) in THF for the Co2+/Co+ and Co3+/Co2+ couples, respectively, of 11. Only a Co2+/Co+ wave at −2.09 V is observed for 12. When excited at 350 nm, the HRDATI ligands and the diamagnetic Zn2+ complex 13 fluoresce around 500 nm, whereas the paramagnetic Co2+ complexes quench the fluorescence. These air-stable cobalt compounds react with nitric oxide to dissociate a DATI ligand and form neutral dinitrosyl complexes, [Co(NO)2(RDATI)]. The release of the fluorophore-containing ligand is accompanied by an increase in fluorescence intensity, thus providing a strategy for fluorescent NO sensing. Linking two DATI moieties via a tetramethylene chain affords the ligand H2DATI-4 (18). The Co2+ complex [Co(DATI-4)] (19) reacts more readily with NO than the bis(DATI) compounds and also displays an increase in fluorescence intensity upon NO binding

Aminotroponiminates as Ligands for Potential Metal-Based Nitric Oxide Sensors

A family of new fluorescently labeled ligands, HRDATI, was prepared to develop transition-metal-based NO sensing strategies. The ligands are composed of aminotroponiminates (ATIs) with a dansyl fluorophore on one of the imine nitrogen atoms and an alkyl substituent, either i-Pr (8), t-Bu (9), or Bz (10), on the other. Bis(chelate) Co2+ ([Co(i-PrDATI)2] (12), [Co(t-BuDATI)2] (14), [Co(BzDATI)2] (15)) and Zn2+ ([Zn(i-PrDATI)2] (13)) complexes were prepared and characterized by X-ray crystallography. The bis(ATI) complex [Co(i-Pr2ATI)2] (11) was also prepared and its X-ray crystal structure determined. Cyclic voltammetry reveals reversible redox waves at −2.57 and −0.045 V (vs Cp2Fe/Cp2Fe+) in THF for the Co2+/Co+ and Co3+/Co2+ couples, respectively, of 11. Only a Co2+/Co+ wave at −2.09 V is observed for 12. When excited at 350 nm, the HRDATI ligands and the diamagnetic Zn2+ complex 13 fluoresce around 500 nm, whereas the paramagnetic Co2+ complexes quench the fluorescence. These air-stable cobalt compounds react with nitric oxide to dissociate a DATI ligand and form neutral dinitrosyl complexes, [Co(NO)2(RDATI)]. The release of the fluorophore-containing ligand is accompanied by an increase in fluorescence intensity, thus providing a strategy for fluorescent NO sensing. Linking two DATI moieties via a tetramethylene chain affords the ligand H2DATI-4 (18). The Co2+ complex [Co(DATI-4)] (19) reacts more readily with NO than the bis(DATI) compounds and also displays an increase in fluorescence intensity upon NO binding

Microplastics and nanoplastics in the soil-plant nexus: Sources, uptake, and toxicity

The agricultural sector is increasingly dependent upon the use of plastic products to enhance productivity. In addition to many incidental inputs, plastic fragments are progressively accumulating in soil following the degradation of plastic products. Microplastics (MPs, <5 mm) and nanoplastics (NPs, <1 µm) in agricultural soils have caused substantial concerns recently. The insidious interactions between plants, soil, and MPs/NPs in the agricultural environment could affect soil health, crop productivity, and threaten food safety and human health. Importantly, finer NPs can be taken up by plants, induce oxidative stress and negatively affect plant growth. Even though interactions of MPs/NPs with plants in the plant-soil nexus have been reported, a comprehensive review of the state of knowledge is lacking, which hinders continued progress in this emerging field. This review aims to fill the gap by extensively summarizing MPs/NPs sources in agriculture, techniques to investigate, impact on soil properties and accumulation in the plants. The synergistic effect of organic and inorganic co-contaminants and MPs/NPs are highlighted due to the widespread presence of these chemicals in agricultural soils. This review also presented possible mechanisms of MPs/NPs phytotoxicity. Although new information is emerging there is a paucity of data on the fate and impact of MPs/NPs in the plant-soil nexus. More efforts are needed to elucidate the fate and impact of MPs/NPs in agricultural soils to gain a deeper understanding of their health and safety implications.</p

Endonuclease IV is stimulated by the addition of Magnesium and Calcium ions.

<p>The 5′ end-labeled substrate subDS-AP (800 fmol) was incubated with 2 fmol of End with various metal ions at a concentration of 2 mM (lanes 1–8), with EDTA (lanes 10–13) and with DTT (lanes 14–18). Concentrations (mM) of EDTA and DTT are indicated on the figures. Substrate incubated with the enzyme without the addition of metal ion, EDTA or DTT was used as control (lane 9). Graphical representation of lanes 1–9, 10–13 and 14–18 of figure A is shown in B, C and D, respectively. The data in the graphs represent mean (±standard errors) of two independent experiments carried out in duplicates. The reaction was carried out for 15 min at 37°C and the products were analyzed on 20% polyacrylamide gels containing 8 M Urea and the DNA bands were visualized by autoradiography.</p

Endonuclease IV Is the Major Apurinic/Apyrimidinic Endonuclease in <i>Mycobacterium tuberculosis</i> and Is Important for Protection against Oxidative Damage

<div><p>During the establishment of an infection, bacterial pathogens encounter oxidative stress resulting in the production of DNA lesions. Majority of these lesions are repaired by base excision repair (BER) pathway. Amongst these, abasic sites are the most frequent lesions in DNA. Class II apurinic/apyrimidinic (AP) endonucleases play a major role in BER of damaged DNA comprising of abasic sites. <i>Mycobacterium tuberculosis</i>, a deadly pathogen, resides in the human macrophages and is continually subjected to oxidative assaults. We have characterized for the first time two AP endonucleases namely Endonuclease IV (End) and Exonuclease III (XthA) that perform distinct functions in <i>M.tuberculosis</i>. We demonstrate that <i>M.tuberculosis</i> End is a typical AP endonuclease while XthA is predominantly a 3′→5′ exonuclease. The AP endonuclease activity of End and XthA was stimulated by Mg²⁺ and Ca²⁺ and displayed a preferential recognition for abasic site paired opposite to a cytosine residue in DNA. Moreover, End exhibited metal ion independent 3′→5′ exonuclease activity while in the case of XthA this activity was metal ion dependent. We demonstrate that End is not only a more efficient AP endonuclease than XthA but it also represents the major AP endonuclease activity in <i>M.tuberculosis</i> and plays a crucial role in defense against oxidative stress.</p></div

Exonuclease III is stimulated by the addition of Magnesium and Calcium ions.

<p>The 5′ end-labeled substrate subDS-AP (800 fmol) was incubated with 2 fmol of XthA with various metal ions at a concentration of 2 mM (lanes 2–9), with EDTA (lanes 10–13) and with DTT (lanes 14–19). Concentrations (mM) of EDTA and DTT are indicated on the figures. Substrate incubated with the enzyme without the addition of metal ion, EDTA or DTT was used as control (lane 1). Graphical representation of lanes 1–9, 10–13 and 14–19 of figure A is shown in B, C and D, respectively. The data in the graphs represent mean (±standard errors) of two independent experiments carried out in duplicates. The reaction was carried out for 15 min at 37°C and the products were analyzed on 20% polyacrylamide gels containing 8 M Urea and the DNA bands were visualized by autoradiography.</p

A silver stained gel showing various secretory proteins.

<p>Lane <b>M</b>: molecular weight markers, <b>A</b>: Leishmanial secretory proteins (40 µg/well) on 12% SDS-PAGE ranging from 10–170 kDa, <b>B</b>: Secretory proteins on native gel, <b>C</b>: Identified peroxidase (25 kDa) on native gel showing peroxidase activity, <b>D</b>: Purified 25 kDa protein (20 µg) corresponding to peroxidase on 12% SDS-PAGE (CBB stained gel).</p

Levels of TNF-α, IFN-γ and IL-12 in cultured supernatant of peritoneal macrophages in various experimental conditions.

<p>After 24 h, cell supernatants were collected and cytokines were estimated by cytokine ELISA and values were expressed in pg/ml. The cytokines level was decreased in the peroxidase treated group (LPS+PrxB) as compared to LPS induced cells (LPS+B). The lower picture depicts their relative mRNA expression levels after subsequent amplification with mRNA specific primers (ANOVA was done to obtain significance level between LPS+B and LPS+PrxB).</p

List of mouse specific primers.

<p>List of mouse specific primers.</p