Firstly, research is still going on on the existence of microorganisms in space. There are no conclusive published results as yet. Still, I would say if bacteria reside in the outer space, they definitely would be anaerobic because of complete absence of oxygen. They would also probably have enzymes like peroxidase and catalase to scavenge the lethal free radicals generated by UV radiations in the bacterial cells.
Below is a link that mentions a list of microbes that were able to survive in space simulated conditions in an experiment.
List of microorganisms tested in outer space
Some of those microbes could actually be phototrophic anaerobes that could utilize sunlight to photosynthesize their own food.
These are just presumptions however.
https://www.quora.com/Can-anaerobic-bacteria-survive-in-space/answer/Rituparna-Saha-1