TitleMicrobial Activity in the Cariaco Trench
AuthorsMorris I., Glover H. E., Kaplan W. A., Kelly D. P., Weightman A. L.
PublicationMicrobios.. 1985 Jan; 42(169):133-144.
AbstractA station in the eastern Basin of the Cariaco Trench was occupied for 7 day at the end of March, 1979. The distribution of oxygen, sulphide and dissolved inorganic nitrogen compounds (NO super(-)d3, NO super(-)d2, N sub(2)O and NH super(+)d4) was related to the metabolic activity of bacteria in the water column. Emphasis was placed on the search for autotrophic CO sub(2) fixation, either by nitrifying bacteria oxidizing reduced nitrogen compounds or by those oxidizing reduced sulphur compounds. Changes in the concentrations of dissolved N sub(2)O paralleled those of NO super(-)d3. However, few nitrifiers could be isolated. Although the decrease in NO super(-)d3 at the lower depths has been attributed to denitrification, neither the measurements of N sub(2)O in acetylene-blocked samples, not the isolation of denitrifiers suggested high denitrification rates. Neither measurements of dark CO sub(2) fixation nor those of RUBPCase suggested high densities of autotrophic bacteria at the oxic-anoxic interface.