A bacterial isolate is subcultured to two blood agar plates, one of which is incubated in an anaerobic jar, and the other is incubated on a shelf in the incubator. After incubation, growth is observed on the plate from the anaerobic jar, but there is no growth on the plate incubated on the incubator shelf. Based on these results, how would this organism be categorized

obligate anaerobe

Explanation: This experiment established that a bacterial isolate is subcultured into same medium in two different plates, but one is placed in an aerobic condition (i.e., presence of oxygen) while the other in an anaerobic condition (i.e., absence of oxygen), and the result shows that there was no growth on the plate incubated on the incubator shelf, whereas there was growth on the plate conditioned anaerobically.

This simply translates that the bacterium does not need oxygen to grow i.e., It’s an anaerobe. Moreso, assuming it grows on the two plates we would say it's a facultative anaerobe.

Thus, since it growth was only established on the plate with anaerobic condition, it's an obligate anaerobic bacterium.