<span style="font-size:11.0pt;mso-bidi-font-size: 10.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:AR-SA" lang="EN-GB"><span style="mso-bidi-font-size:14.0pt;color:windowtext;font-style:normal;mso-bidi-font-style: italic;text-decoration:none;text-underline:none">Banana<span style="mso-bidi-font-size:14.0pt"> peel as substrate for <span style="mso-bidi-font-size:9.0pt;color:windowtext;text-decoration:none; text-underline:none">α-<span style="mso-bidi-font-size:14.0pt; color:windowtext;font-style:normal;mso-bidi-font-style:italic;text-decoration: none;text-underline:none">amylase production<span style="mso-bidi-font-size: 14.0pt"> using <i style="mso-bidi-font-style:normal">Aspergillus niger </i>NCIM 616 and process optimization</span></span></span></span></span></span>

314-319Amylases are well known for applications ranging from starch and food processes industry to medical applications. In the present study, the potential of banana peel was evaluated for α-amylase production using the fungal culture of Aspergillus niger NCIM 616 in solid submerged (SmF) and solid state (SSF) fermentation. The effect of different parameters, such as, substrate concentration, water content, layer thickness and external salt addition was studied in terms of the amylase activity. In SmF, 25% peel concentration was found optimum for the maximal amylase activity; while in SSF, 30% water content in the 3 cm thick substrate bed was optimum. The activity was also influenced by the addition of external salts and the combination of 1% NH4NO3 with 0.5% CaCl2 was found to have maximal effect. A comparative evaluation of two different fermentation systems showed 80% higher specific activity of α-amylase in SSF as compared to that in SmF, which clearly demonstrated the superiority of the SSF system. The study suggests that banana peel could be used as a potential raw material for α-amylase production

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Not AvailablePrimary photochemical reactions and the activities of the antioxidant enzymes chloroplastic superoxide dismutase (SOD), glutathione reductase (GR) and glutathione-Stransferase (GST) were determined in water-stressed pearl millet (Pennisetum glaucum L. cv. HHB-67) plants sprayed with the thiol compounds dithiothreitol (DTT), thioglycollic acid (TGA) and thiourea (TU) and the thiol modifiers 5,5’-dithio-bis-2-nitrobenzoic acid (DTNB) and N-ethylmaleimide (NEM) at the earhead emergence stage (47 days after sowing, DAS), together with a control. Sampling was done at 54 and 67 days after sowing. Photosystem I and II (PS I and II) activities (ferricyanide site) were found to increase in plants sprayed with TU, TGA and DTT at both stages (54 and 67 DAS), but a reduction in PS II activity (DCQ Site) compared with the control was caused by NEM (66.66%) and DTNB (27.77%) at 54 DAS. A similar decrease in the activity of PS II (ferricyanide site) was found at 67 DAS for DTNB (55.55%). The chloroplastic SOD activity increased in chloroplasts isolated from leaves sprayed with thiol compounds at both sampling stages, except for NEM at 54 and 67 DAS. The activities of GR and GST in the leaves were higher in thiol-treated plants than in the control at 54 and 67 DAS, while the lowest GR activity was seen for the sulphydryl modifiers (DTNB and NEM) in leaves at 54 DAS. The experimental data suggest an enhancement in the primary photochemistry and antioxidant enzyme activities of water-stressed pearl millet in response to foliar spraying with thiol compounds.Not Availabl

Synthesis, characterization and photocatalytic activity studies of tellurium containing defect pyrochlores, MSn_0.5Te_1.5O₆ (M = K, Ag, Cu_0.5 and Sn_0.5)

1174-1181Four new metal tin tellurites, MSn0.5Te1.5O6 (M = K, Ag, Cu0.5 and Sn0.5), have been synthesized by standard solid-state and facile ion exchange reactions and characterized by powder X-ray diffraction, FTIR, SEM-EDS and UV-vis diffuse reflectance spectroscopic techniques. All the compositions crystallize in cubic lattice with Fdmspace group, and are isomorphous with KTi0.5Te1.5O6. The photocatalytic activity of the as prepared materials for methylene blue and methyl violet degradation has been investigated under visible light irradiation. The AgSn0.5Te1.5O6 photocatalyst exhibits higher photocatalytic activity than MSn0.5Te1.5O6 (M = K, Cu0.5 and Sn0.5) for photodegradation of methylene blue and methyl violet. The higher photocatalytic performance of AgSn0.5Te1.5O6 is ascribed to its low band gap energy, which endows it with a very strong photooxidation ability to produce OH● and O2●- radicals as active species. The catalyst stability and mechanism of photocatalysis is also discussed