Nitrate- and Nitrite-Reductase Activities in Mycobacterium Avium A5

dc.contributor.authorButala, Nitin Santoshen
dc.contributor.committeechairFalkinham, Joseph O. IIIen
dc.contributor.committeememberMukhopadhyay, Biswarupen
dc.contributor.committeememberGregory, Eugene M.en
dc.contributor.departmentBiological Sciencesen
dc.date.accessioned2014-03-14T20:41:26Zen
dc.date.adate2006-08-31en
dc.date.available2014-03-14T20:41:26Zen
dc.date.issued2006-06-09en
dc.date.rdate2012-05-08en
dc.date.sdate2006-07-14en
dc.description.abstractMycobacterium avium is human and animal opportunistic pathogen responsible for disseminated disease in immunocompromised patients. Mycobacteria have a capacity to adapt to the environmental conditions by inducing enzyme activities and altering their metabolism. M. avium A5 cells were grown in a defined minimal medium (Nitrogen Test Medium) with glutamine, nitrite, nitrate, or ammonia as sole nitrogen source at a concentration of 2 mM at 370C aerobically. The strain grew well on all the nitrogen sources except nitrite. It grew slowly on nitrite with a generation time of 6 days and cultures were not viable after 4 weeks of storage. These data confirm that M. avium can utilize a single nitrogen source in a defined minimal medium as documented by McCarthy (1987). M. avium genome has been sequenced and contains genes sharing sequence similarities to respiratory nitrate reductase and dissimilatory nitrite reductases. Because, M. avium can use nitrate or nitrite as sole nitrogen source for growth (McCarthy, 1987), it must have assimilatory nitrate- and nitrite-reductases. Nitrate- and nitrite-reductase activities of M. avium cells growing aerobically or undergoing anaerobic shift in the presence of ammonia, nitrate or ammonia and nitrate in combination were measured. M. avium produced nitrate- as well as nitrite-reductase activity. Nitrite- and nitrate-reductases used either NADH or NADPH as an electron donor. Nitrite reductase activity was greater than nitrate reductase activity. This observation supports the rapid reduction of nitrite and slow reduction of nitrate in M. avium as documented by McCarthy (1987) and explained why M. avium gives a negative result by the standard nitrate reductase test. In addition to assimilatory enzyme activity, M. avium A5 also produced dissimilatory nitrate- and nitrite-reductase activities.en
dc.description.degreeMaster of Scienceen
dc.identifier.otheretd-07142006-233503en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-07142006-233503/en
dc.identifier.urihttp://hdl.handle.net/10919/34004en
dc.publisherVirginia Techen
dc.relation.haspartNitin3.pdfen
dc.relation.haspartNitin2.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectnitrate reduction testen
dc.subjectnitrate- and nitrite-reductasesen
dc.subjectMycobacterium aviumen
dc.titleNitrate- and Nitrite-Reductase Activities in Mycobacterium Avium A5en
dc.typeThesisen
thesis.degree.disciplineBiological Sciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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