Abstract:Carboxysome is an organelle-like structure that can concentrate CO2 from the environment. It exists in some autotrophic microorganisms and can promote cell growth. Among nitrogen-removal microorganisms, nitrifying bacteria, anaerobic ammonia oxidation (Anammox) bacteria and some denitrifying bacteria are autotrophic microorganisms. Understanding the composition, structure and function of carboxysome is helpful to reveal the growth of autotrophic microorganisms and to optimize the process of biological nitrogen-removal. Based on the literatures and our researches, the composition, structure, function and detection of carboxysome in autotrophic bacteria are summarized in this paper.