AUTHOR=Yeware Amar M. , Shurpali Ketaki D. , Athalye Meghana C. , Sarkar Dhiman 

TITLE=Superoxide Generation and Its Involvement in the Growth of Mycobacterium smegmatis

JOURNAL=Frontiers in Microbiology

VOLUME=8

YEAR=2017

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2017.00105

DOI=10.3389/fmicb.2017.00105

ISSN=1664-302X

ABSTRACT=<p>Superoxide generation is inevitable in aerobic organisms, most of which have developed mechanisms to detoxify superoxides. However, its significance has not been clearly understood in mycobacteria. This study demonstrates that NADH oxidase is the major source of superoxide in <italic>Mycobacterium smegmatis</italic> and elucidates the involvement of superoxide in <italic>M. smegmatis</italic> growth. The maximum inhibition of superoxide generation was observed in the presence of diphenyleneiodonium chloride (DPI), an NADH oxidase inhibitor, compared to other standard inhibitors. After incubation for 24 h, the number of colony forming units (CFUs) was reduced by 6.8 log<sub>10</sub> compared to the untreated culture. The inhibitory effect of DPI on <italic>M. smegmatis</italic> was reversed when the same culture was supplemented with menadione and pyrogallol, which are superoxide generators. Thus, this study reports the source of superoxide generation and its involvement in the growth of <italic>M. smegmatis</italic>.</p>