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20212
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Subject: Environmental Science × End date: 2021 × Start date: 2021 × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Biodegradation of Zenzo (α) Pyrene by native bacteria employing nanoparticles
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-02) Punetha, Arjita; Rai, J.P.N.
    In present study, potential of microorganisms to degrade a high molecular weight polyaromatic hydrocarbon viz. Benzo(α)Pyrene (BaP) has been investigated. Three bacteria isolated from coal tar contaminated and fire affected soils were tested for their BaP degrading ability in minimal medium and soil slurry. Based on their morphological, biochemical and molecular characterization, the bacterial isolates were identified as Cellulomaons sp. 4D, Commamonas sp.1B and Streptomyces sp. 2C. All the isolates performed best at pH 7, temperature 30° C and shaking speed 100 rpm. Supplementing the minimal medium with additional carbon and nitrogen sources enhanced the rate of BaP degradation by the bacterial isolates. Comparative studies showed that BaP degradation potential of consortium is better than individual bacteria. Viability of bacterial cells has also been tested by storing them in bioformulation made of charcoal and talc and in alginate beads for 60 days. BaP degradation was also investigated using bacterial isolates immobilized in sodium alginate beads and using nanoparticles in both minimal medium and soil. Results showed that the degradation potential of bacterial isolates increased when used in immobilized form. Nanoparticles enhanced the ability of bacterial isolates to degrade BaP in soil though much difference was not observed in minimal medium. HPLC and FTIR analysis confirmed the degradation of BaP by the selected bacterial isolates. The current study clearly demonstrated that Cellulomaons sp. 4D, Commamonas sp. 1B and Streptomyces sp.2C were able to degrade BaP effectively in media and soil and therefore can be used profitably for field scale bioremediation technology
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    ThesisItemOpen Access
    Decolourization and degradation of textile dyes (Orange G and Methylene blue) by immobilized and free state bacteria
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-02) Anamika Kumari; Rai, J.P.N.
    In the present research, ability of microorganisms to decolorize and degrade textile dyes has been investigated. Bacterial strains were isolated from wastewater released from dye industries and were tested for their dye degrading ability in minimal medium and nutrient both. Based on the cultural, morphological and molecular characterization, the bacteria were identified as Lysinibacillus Ek.IIPR, Bacillus thuringiensis N3, Bacillus muralis 1Y118. These bacteria and their mixed consortium were used for the treatment of different concentrations of azo dye Orange G and basic dye Methylene Blue. Comparative studies show that consortium was most efficient in dye degradation and was able to degrade upto 94.10 and 92.56% of Orange G and Methylene Blue respectively. Dye decolourization was also checked by these bacteria immobilized in alginate beads. The use of bacteria in immobilized static state showed better decolourization potential as compared to the freely suspended bacterial cells. Anaerobic condition is obtained under static condition which favors the breakdown of azo dyes. The favorable pH recorded was 7 and optimum temperature for dye degradation was 30 °C above which, the degrading rate slowed down. Comparative study investigating the Phytotoxicity of pure dye samples and bacterial treated samples was also conducted. The germination % observed after the treatment was 76.66 and 81.26 % respectively. In FTIR study, peak at 1622 and 1624 cm-1 in Orange G and Methylene Blue indicates presence of azo bond as chromogen in control sample. Whereas, FTIR spectra of bacterial consortium treated dye samples reveal shifting of band and formation of new peaks in bacterial treated Orange G and Methylene Blue dye solution, which indicates degradation of dye. Comparative study of HPLC chromatogram of Orange G and Methylene Blue was also done.