16S rRNA and hydrazine gene-based profiling of the Candidatus Scalindua community from the Arabian Sea hypoxic sediments

Abstract

Anammox bacterial diversity and abundance were studied from the organic-rich hypoxic sediments of the Arabian Sea utilizing the partial 16S rRNA, and hydrazine synthase, hzsA and hydrazine oxidoreductase, hzo genes. Among all the clades obtained, phylotypic diversity was high within the Candidatus genus Scalindua with an abundance of </= 7 � 10(4) copies/g dry wt. As such, Scalindua is known to play a significant role in fixed nitrogen removal through anaerobic ammonium oxidation (anammox) pathway. From these analyses, it is inferred that searching for hzo gene yields robust evidence for detecting anammox community than the widely used 16S rRNA gene marker.