Study of Structural and Photocatalytic Activity of Cobalt Doped Nanocrystalline Gadolinium Aluminate via Facile Combustion Route

Up converting (UC) nanoparticles have been a milestone for the people of optical world in the past decade because of their extraordinary properties. In this article, a novel cobalt doped nanocrystalline Gadolinium Aluminate (GdAlO3:Co2+) have been successfully synthesized by the solution combustion method. The structure of the samples were characterized using X-ray diffractometer (XRD) shows that transition metal (TM) doped nanoparticles have smaller crystalline size the structural morphology was studied using Transmission electron microscopy (TEM) which shows irregular shaped, highly dispersed and the size was found to be in the range of 15–25 nm. The result demonstrated that the synthesized material could be useful for dye decolourisation as a photocatalyst.

Production of Ligninolytic Enzymes from Penicillium Sp. and Its Efficiency to Decolourise Textile Dyes

Background:The present study discussed the bio decolourization of synthetic textile dyes using extracellular crude laccase from an Ascomycetes fungusPenicilliumsp. Laccase based decolourization is found to be potentially advantageous to bioremediation technologies.Methods:In this study, the production of laccase was observed for 7 days of incubation under shaking conditions. Maximum laccase production was secreted by fungal strain on the 6thday of incubation under submerged fermentation. Incubation of fungal mycelium and culture filtrate as crude enzyme obtained fromPenicilliumsp. with textile dyes - Indigo, Reactive black-5, Acid blue -1 and Vat brown -5 on solid PDA medium and liquid PDA broth showed effective biological dye decolourisation.Result:Solid state dye decolourisation had shown 45%, 25%, 50% and 72% colour removal of dyes - Indigo, Reactive black-5, Acid blue -1 and Vat brown -5 whereas maximum decolourization of same dyes of 45%, 20%, 48%, and 75% was obtained in liquid state with crude enzyme within 3h.Conclusion:The results had shown the potential dye decolourisation capacity of thePenicilliumsp. extracellular crude laccase and pave a way to apply this strain on an industrial scale.

Decolourisation Capabilities of Ligninolytic Enzymes Produced byMarasmius cladophyllusUMAS MS8 on Remazol Brilliant Blue R and Other Azo Dyes

Marasmius cladophylluswas examined for its ability to degradatively decolourise the recalcitrant dye Remazol Brilliant Blue R (RBBR) and screened for the production of ligninolytic enzymes using specific substrates. Monitoring dye decolourisation by the decrease in absorbance ratio ofA592/A500shows that the decolourisation of RBBR dye was associated with the dye degradation.Marasmius cladophyllusproduces laccase and lignin peroxidase in glucose minimal liquid medium containing RBBR. Both enzyme activities were increased, with laccase activity recorded 70 times higher reaching up to 390 U L−1on day 12. Further in vitro RBBR dye decolourisation using the culture medium shows that laccase activity was correlated with the dye decolourisation. Fresh RBBR dye continuously supplemented into the decolourised culture medium was further decolourised much faster in the subsequent round of the RBBR dye decolourisation. In vitro dye decolourisation using the crude laccase not only decolourised 76% of RBBR dye in just 19 hours but also decolourised 54% of Orange G and 33% of Congo red at the same period of time without the use of any exogenous mediator. This rapid dye decolourisation ability of the enzymes produced byM. cladophyllusthus suggested its possible application in the bioremediation of dye containing wastewater.

Kinetic characterisation of a dye decolourising peroxidase from Streptomyces lividans: new insight into the mechanism of anthraquinone dye decolourisation

A dye decolourising haem peroxidase fromStreptomyces lividansdecolourises the anthraquinone dye RB19 through a disproportionation mechanism.

Bio-statistical evaluation of cultural conditions on industrial textile dye decolourisation using a native bacterium Micrococcus endophyticus (ES37)

An indigenous dye-decolourising bacterium Micrococcus endophyticus (ES37) was isolated from dye contaminated soil and identified by 16S rDNA sequencing. The bacterial strain ES37 exhibited 97.19% of dye removal capacity in Luria-Bertani broth composition within 48 h, while the culture containing yeast extract showed 53.4% decolourisation in 72 h. In the absence of carbon and nitrogen sources, the bacterial strain failed to decolourise the dye, even on extended incubation. The effect of environmental factors on decolourisation was investigated by Plackett–Burman design and the significant parameters were lactose, yeast extract and pH. Optimisation of these factors was done by response surface methodology with central composite design; the decolourisation ranged from 0.43 to 77.49%. The optimised levels of lactose, yeast extract and pH were found to be 0.85% (w/v), 0.71% (w/v) and 7.5%, respectively. Under the optimal conditions, decolourisation of remazol golden yellow by ES37 strain was 81.61%, which was in agreement with the predicted value of 79.99%. These findings revealed the interactions and importance of environmental factors on dye decolourisation using native bacteria and also their standard point for an effective dye removal process.