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Subject: Microbiology × Author: Debbarma, Prasenjit × Start date: 2007 × Type: Thesis × Thesis Type: Ph.D ×
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    ThesisItemOpen Access
    Biodegradation studies of electronic waste using indigenously developed microbial consortia
    (G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-08) Debbarma, Prasenjit; Goel, Reeta
    The management of electronic waste (e-waste) becomes a global issue in this digital era. Existing conventional practices are harmful for dealing with e-waste, therefore, indigenous soil bacteria were explored for e-waste treatment through enrichment culture approach followed by screening, identification and their bioformulation used for in situ investigation. Soil bacteria were enriched in the presence of e-waste after 30 days of incubation under standard laboratory conditions. This finding was established through optical density and _-max values that were higher in the case of soil enrichment than the control. Later, the identification and characterization of isolates was done by polyphasic approach. The optimum tolerance level (OTL) concentration of solubilized e-waste was found to be 3 mg mL-1 which was determined through UV-vis spectrophotometer. The selection and biocompatibility testing of potential isolates were performed for the formation of bacterial consortia. Two potential bacterial consortia were developed, viz. consortium C-1 comprises Achromobacter insolitus strain PE2 (MF943156), Acinetobacter nosocomialis strain PE5 (MF943157), Pseudomonas resinovorans strain PE8 (MF943158), Pseudomonas aeruginosa strain PE10 (MF943159) and Stenotrophomonas pavanii strain PE15 (MF943160) and consortium C-2 which is composed of all above four bacterial strains except strain PE10. The consortium C-3 consist of Microbacterium sp. strain MK3 (DQ318884), Bacterium Te68R strain PN12 (DQ423487) and Pseudomonas putida strain MK4 (DQ318885) was also used which is previously defined for its ability to degrade variety of polymers. Talc based bioformulation was prepared by mixing the talc in the sterilized dish with an active consortium. E-waste granules were incubated with freshly prepared bioformulation in soil pits for 9 months. The biodegradation of e-waste by the selected strains during enrichment and in situ experiment was confirmed by FT-IR, TGDTG-DTA, SEM, EDX and elemental analysis, respectively. The in situ trial of e-waste biodegradation using formulated consortia has shown the significant degradation by C-1 and C-3 followed by C-2. Bacterial community analysis revealed that the used strains were persisting in the experimental pits throughout the trial period. Thus, this study besides providing direct and standardized protocol for screening and selection of efficient e-waste utilizing bacteria is also demonstrating potential consortia which are ready to be used.