No signs of oxidative stress? any anti-oxidant mechanisms? Christos Chinopoulos, Semmelweis University 23 June 2010 I assume that because these organisms are subject to extremely low oxygen, they do not exhibit signs of oxidative stress. I wonder if they still possess anti-oxidant mechanisms (such glutathione, catalase, superoxide dismutases), or they are equipped with different kind of mechanisms to meet their needs in a high sulfide environment. Competing interests No conflict of interest.