Mahatma, LalitTopivala, M.A.2017-11-222017-11-222016-07http://krishikosh.egranth.ac.in/handle/1/5810036290Present investigation was carried out on “Molecular and biochemical characterization of oil degrading bacteria”. Total six isolates from the different area were isolated. All these six isolates showed lipid solubilization index in the range of 5.4 to 2.33. NAULM-1 showed maximum lipid solubilization index (5.4). NAULM-4 showed lowest 2.33 lipid solubilization index. NAULM-2, NAULM-3, NAULM-5 and NAULM-6 gave 3.3, 2.85, 3.2 and 2.43 solubilization index respectively. All the isolates were Gram negative rod-shaped, motile and non spore forming bacteria. On solid media all these bacterial isolates showed raised elevated colonies with undulated margins. Best pH for the lipase production was neutral and the production of the same decreases with the further increase or decrease of the pH. Temperature 35ºC, was found optimum for lipase production by three isolates (NAULM-1, NAULM-2 and NAULM-4 with 8.01 U/ml, 5.72 U/ml and 4.91 U/ml lipase production at 35ºC whereas 30ºC temperature was optimum for NAULM-3 (4.91 U/ml lipase). One per cent concentration of the substrate was most suitable for the lipase production. ABSTRACT Abstract… To supply the organic nitrogen source, casein was best for the isolate NAULM-1, NAULM-2 and NAULM-3. Whereas tryptone was most preferred by NAULM-4. Among the different inorganic nitrogen sources NaNO3 was preferred by isolates NAULM-1, NAULM-2 and NAULM-4 whereas maximum 5.35 U/ml lipase expressions was observed in NAULM-3 in KNO3 as inorganic nitrogen source. Overall NAULM-1 and olive oil was the best combination of isolate and substrate source for the efficient lipase production in vitro. Heavy metal Cu, Pb, Cd. drastically reduced expression of lipase in vitro. The crude enzyme worked best with high stability at pH 7.0 and temperature 35ºC. Activities of the enzyme was not much affected at lower temperature up to 25ºC tested by all the isolates. All the isolates were identified using Biolog Microlog GN2 microplates and by partial sequencing of the 16S rDNA sequencing. Universal primer pairs, 27F and 1525R amplified ~1.5 kb fragment of partial 16S rDNA in all the isolates. On sequencing obtained 1153 bp sequence of NAULM-1, 999 bp sequences of sequence of NAULM-2, 1166 bp sequence of NAULM-3 and 960 bp sequence of NAULM-4. The results of the Biolog and Sequencing matched. On the basis of their identification the isolate NAULM-1 was tentatively named as Pseudomonas pseudoalcaligenes (LCB-14) NAULM-1, isolate NAULM-2 was tentatively named as Pseudomonas aeruginosa (ABG5) NAULM-2, isolate NAULM-3 was tentatively named as Pseudomonas aeruginosa (M2) NAULM-3 and isolate NAULM-4 was tentatively named as Pseudomonas aeruginosa (PS_4) NAULM-4. All these isolates belong to pseudomonas cluster of Gamma-Proteobacteriaceae. Pseudomonas is one of Abstract… the widely recognized species for the production of lipase. P. pseudoalcaligenes had been used in the past for bioremediation and commercial lipase production by many of the organizations. All the isolates can be used for the commercial lipase production; however, Pseudomonas pseudoalcaligenes (LCB-14) NAULM-1 found most preferred and can be exploited for the purpose.ennullThesis