Profiling gene expression to distinguish the likely active diazotrophs from a sea of genetic potential in marine sediments.

摘要: Nitrogen (N) cycling microbial communities in marine sediments are extremely diverse, and it is unknown whether this diversity reflects extensive functional redundancy. Sedimentary denitrifiers remove significant amounts of N from the coastal ocean diazotrophs typically regarded as inconsequential. Recently, fixation has been shown to be a potentially important source estuarine continental shelf sediments. Analysis expressed genes for nitrite reductase (nirS) nitrogenase subunit (nifH) was used identify likely active nitrogen fixers surface different seasons Narragansett Bay (Rhode Island, USA). The overall expressing nifH decreased along gradient head an offshore site. Two groups sequences related anaerobic sulphur/iron reducers sulphate dominated libraries genes. Quantitative polymerase chain reaction (qPCR) quantitative reverse transcription (qRT-PCR) data shows highest abundance both at mid bay site, expression estuary, regardless season. Several potential environmental factors, including water temperature, oxygen concentration metal contamination, may influence these two bacterial groups.