Chemosynthesis enhances net primary production and nutrient cycling in a hypersaline microbial mat

Abstract

Photosynthetic microbial mats are macroscopic microbial ecosystems consisting of a wide array of functional groups and microenvironments arranged along variable redox gradients. Light energy ultimately drives primary production and a cascade of daisy-chained metabolisms. Heterotrophic members of these communities remineralise organic material, decreasing net primary production, and returning nutrients to the aqueous phase. However, reduced inorganic and one-carbon substrates such as trace gases and those released as metabolic byproducts in deeper anoxic regions of the mat, could theoretically also fuel carbon fixation, mitigating carbon loss from heterotrophy and enhancing net primary produc..