In 13 of 14 households, water samples collected from the source tap met microbial water quality standards (ie, no coliforms or P aeruginosa were detected and heterotroph
counts were less than 500 bacteria/ml).
The calculation of aerobic heterotrophs
was performed accordingly (Peressutti 2003).
A systematic shift from inverted biomass pyramids in oligotrophic areas to normal pyramids in more productive areas must then be the result of (1) a general decline in the specific production of phytoplankton and (2) a general increase in the turnover rate of heterotrophs
, along the same productivity gradient.
, these organisms are clearly different than the better-known colonial [N.sub.2]-fixing cyanobacteria, and might respond differently to Fe-addition if, for example, they were also limited by availability of organic substrate.
The next question is to figure out if particular heterotrophs
prefer to consume particular compounds.
The chemosynthetic production may be a significant source of nutrition to heterotrophs
found there in an otherwise nutrient-poor deep ocean, (Carney 1994, Pequegnat 1983).
This indicates whether an autotroph or a heterotroph
made the lipid.
However, those same sources were [sup.34]S-enriched (6[per thousand]-11[per thousand]), as indicated by resident heterotrophs
(Munidopsis sp., Methanoaricia dendrobranchiata Blake 2000, Alvinocaris stactophila Williams 1988, Phascolosoma turnerae Rice 1985), indicating that thiotrophy was a minor chemosynthetic method at the site.
The closest relatives (97% sequence similarity) to WH2K included a marine heterotroph
, Hoeflea marina LMG 128 (11), and several recently characterized epibionts associated with dinoflagellates (e.g., Ahrensia sp.
The organism Desulfobacter hydrogenophilus can operate as either an oxidative heterotroph
, requiring organic substrates, or a reductive autotroph (Moller et al., 1987).
We also found intense staining of the free-living alga Chlorella (strain NC64A--a green alga) and the related species Prototheca (strain 289--an achlorophylic, white alga that is an obligate heterotroph
and is also an opportunistic pathogen of livestock and humans), and the commensal algae of Paramecium bursaria and Chlorohydra viridissima.
(1979), when three bacteria, an obligate chemolithotroph, a facultative chemolithotroph (mixotroph), and a heterotroph
, competed for acetate and thiosulfate.