Year: 1999
Type: article
Abstract: Cyanobacteria are a dominant structural component of NZ-fixing microbial mats in diverse marine ecosystems.As a result, much of the measured N2 fixation activity has been attributed to the cyanobacterial component.Until recently, the contribution of heterotrophic N2 fixers has received much less attention.In this study, the presence, diversity, and ubiquity of heterotrophic N2 fixers were investigated in 3 cyanobacteria (Microco1eus)-dominated, intertidal microbial mats obtained from Tomales Bay, California, Sippewissett Salt Marsh, Massachusetts, and Bird Shoal, North Carolina.Using PCR techniques, a diverse array of heretofore uncharacterized heterotrophic nifH (gene encoding the Fe-protein subunit of nitrogenase) sequences were found in these geographically disparate microbial mats, suggesting that heterotrophic diazotrophs may play a larger role in NZ fixation dynamics than previously thought.Phylogenetically similar heterotrophic diazotrophic sequences were obtained from the 3 sites, potent.iallyindicating that similar heterotrophic NZ-fixing communities are responsible for thls process at diverse locations.
Source: Aquatic Microbial Ecology
DOI: 10.3354/ame019029
Authors: JB Olson, RW Litaker, HW Paerl
Institution: Florida Atlantic University
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: bronze
Funder: National Science Foundation
OpenAlex ID: W2043565904