noun. An organism, such as a bacterium, that can live in the absence of free oxygen.

noun. An anaerobic organism; one that does not require oxygen to sustain its metabolic processes.

noun. an organism (especially a bacterium) that does not require air or free oxygen to live

"The host (facultative aerobe implies facultative anaerobe, doesn't it?) could handle aerobic conditions already, presumably because it had peroxisomes as oxygen sink. t's funny that you mention peroxisomes, as people once thought they were endosymbionts but now evidence seems to point to en origin from the ER."

being  organism  

obligate anaerobe  

adenovirus  aerobe  aerobic bacteria  amoeba  anaerobic bacteria