The International Journal of Mycobacteriology

ORIGINAL ARTICLE
Year
: 2018  |  Volume : 7  |  Issue : 4  |  Page : 328--331

Nitrate and nitrite reductase activities of Mycobacterium avium


Nitin S Butala, Joseph Oliver Falkinham 
 Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA

Correspondence Address:
Joseph Oliver Falkinham
Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia 24061
USA

Background: In spite of the fact that the standard test for nitrate reductase activity is negative for Mycobacterium avium, it can grow in a defined minimal medium with either nitrate (NO3) or nitrite (NO2) as sole nitrogen sources. Methods: NO3-and NO2-reductase activities were measured in soluble and membrane fractions of aerobically grown cells of M. avium and those grown aerobically and shifted to anaerobiosis. Results: NO3- and NO2-reductase activities were only detected in the membrane fractions and the two enzyme activities were significantly reduced if cells were grown aerobically in the presence of ammonia (NH4). The NO2-reductase activity of membrane fractions was 2-fold higher than that of NO3-reductase consistent with the fact that NO3-reductase activity of M. avium cannot be detected if measured by nitrite formation. Membrane fractions of M. avium cells grown 1 week aerobically and then 2 weeks under anaerobic conditions had NO3-and NO2-reductase activities. Conclusion: The results are consistent with the presence of assimilatory NO3-and NO2-reductase activities in cells of M. avium grown under aerobic conditions. Further, the data suggest that a shift to anaerobic conditions results in the appearance of ammonium-insensitive NO3-and NO2-reductase activities; quite possibly that function in a dissimilatory role (redox balancing).


How to cite this article:
Butala NS, Falkinham JO. Nitrate and nitrite reductase activities of Mycobacterium avium.Int J Mycobacteriol 2018;7:328-331


How to cite this URL:
Butala NS, Falkinham JO. Nitrate and nitrite reductase activities of Mycobacterium avium. Int J Mycobacteriol [serial online] 2018 [cited 2019 Mar 26 ];7:328-331
Available from: http://www.ijmyco.org/article.asp?issn=2212-5531;year=2018;volume=7;issue=4;spage=328;epage=331;aulast=Butala;type=0