Authigenic aragonite preserves a carbon isotopic record of heterotrophic microbial influences on dissolved inorganic carbon (DIC) in microenvironments within shallow subtidal stromatolites from Highborne Cay, Bahamas. A greater amount of aragonite precipitates when and where respiration, rather than photosynthesis, influences local DIC, which is consistent with sulfate reduction promoting carbo...

Pico and nano-sized plankton play an important role in regulating the trophic dynamics and key biogeochemical cycles in most pelagic environments, such changes in their abundance and population dynamics can alter ecosystem-level changes [1,2]. Both heterotrophic (Hpico) and phototrophic (Ppico) picoplankton are particularly important in oligotrophic lakes, with deep water column depths and long...

The relative contribution of various inorganic and organic forms of nitrogen to the nitrogen requirements of picoplankton was examined with 15N tracers. Size fractionation was used to measure uptake by < l-pm size microorganisms, and inhibitors of protein synthesis were used to separate procaryotic from eucaryotic nitrogen uptake, Picoplankton utilized mainly ammonium and amino acids and only n...

Here, we report the draft genome sequence of Acidocella sp. strain MX-AZ02, an acidophilic and heterotrophic alphaproteobacterium isolated from a geothermal lake in western Mexico.