Molecular evidence of the existence of anaerobic ammonia oxidation bacteria in the gut of polychaete (Neanthes glandicincta)

Abstract

Neanthes are one of the most important groups of polychaete in coastal sediments, which play an important role on the nutrient cycling in coastal sediments. Here we report on the existence of anammox bacteria in the gut of polychaete Neanthes glandicincta based on the analysis of 16S rRNA gene and fluorescence in situ hybridization (FISH). Three distinct clusters of anammox bacteria are found in different gut sections of N. glandicincta, and one of them is considered as a novel, gut specific anammox bacteria after comparing with the anammox bacteria recovered from surrounding pre-digested sediment. The uniform axial distribution of anammox bacteria in different gut sections of N. glandicincta is also found in present study. These results extend our knowledge of microbial ecology of anammox bacteria in the natural environments.