Prokaryotes and protists are important players in the carbon biogeochemistry of marine ecosystems, and temperature is one of the physical factors most influential in the metabolism and composition of plankton communities. Small changes in temperature can change the flow of carbon and the community structure of planktonic ecosystems, and climatological models predict a rise in temperature of 2 t...

Oscillating diurnal rhythms of gene transcription, metabolic activity, and behavior are found in all three domains of life. However, diel cycles in naturally occurring heterotrophic bacteria and archaea have rarely been observed. Here, we report time-resolved whole-genome transcriptome profiles of multiple, naturally occurring oceanic bacterial populations sampled in situ over 3 days. As antici...

The effects of various parameters on bromate reduction were tested using lab-scale batch reactors with sulfur based autotrophic and methanol based heterotrophic denitrification processes. The initial bromate (BrO3-) concentration of 100 and 500 μg/L was completely reduced and bromide (Br-) was produced stoichiometrically from bromate in all batch reactors. In all experiments, nitrate was comple...

An experimental study was conducted uslng large enclosures to examine the effects of nutrients, presence of planktivorous fish, and depth of the water colun~n on the components of the microbial food web. Enclosures (8 m in diameter) were installed, open to the sediments, at both 3.5 and 11 nl depths in Lac Croche, a small oligotrophic lake on the Canadian Shield The abundance of protozoans, inc...

[1] Effects of sediment resuspension-induced benthic detrital flux on the heterotrophic part of the microbial food web in Lake Michigan were examined using a threedimensional (3-D) coupled biological and physical model. The model was driven by the realistic meteorological forcing observed in March 1999. Wind-induced surface wave dynamics were incorporated into the physical model to generate the...

The Euglenida consists mostly of free-living flagellates with very diverse modes of nutrition. A number of heterotrophic euglenids (e.g., Petalomonas and Ploeotia) are limited to bacteriotrophy (Fig. 1a–c) while others (e.g., Dinema and Peranema) are capable of ingesting eukaryotic prey (Fig. 1f). We use the label “eukaryotroph” to distinguish the latter taxa from the bacteriotrophs (Triemer an...

Ecophysiological interactions between the community members (i.e., nitrifiers and heterotrophic bacteria) in a carbon-limited autotrophic nitrifying biofilm fed only NH(4)(+) as an energy source were investigated by using a full-cycle 16S rRNA approach followed by microautoradiography (MAR)-fluorescence in situ hybridization (FISH). Phylogenetic differentiation (identification) of heterotrophic...

Although cyanobacteria are photoautotrophs, they have the capability for heterotrophic metabolism that enables them to survive in their natural habitat. However, cyanobacterial species that grow heterotrophically in the dark are rare. It remains largely unknown how cyanobacteria regulate heterotrophic activity. The cyanobacterium Leptolyngbya boryana grows heterotrophically with glucose in the ...

Non-photosynthetic, or heterotrophic, tissues in C3 plants tend to be enriched in C compared with the leaves that supply them with photosynthate. This isotopic pattern has been observed for woody stems, roots, seeds and fruits, emerging leaves, and parasitic plants incapable of net CO2 fixation. Unlike in C3 plants, roots of herbaceous C4 plants are generally not C-enriched compared with leaves...

Chlorella pyrenoidosa was cultivated under photoautotrophic, mixotrophic and cyclic light-autotrophic/dark-heterotrophic conditions. The influence of light on the carbon and energy metabolism of microalgae was investigated by the use of metabolic flux analysis. The respiratory activity of microalgae in the light was assessed from the autotrophic flux distribution. Results showed that the glycol...