A model is outlined for the major biochemical respiratory mechanisms of a conceptualised heterotrophic facultative organism (representing the heterotrophic facultative mass of activated sludge) subjected to four different sets of conditions: steady-state aerobic, steady-state anoxic, steady-state aerobic changed to anoxic, and steady-state anoxic/anaerobic changed to aerobic. Proposals and impl...

BACKGROUND Samples of drinking water were collected directly from the personal water bottles of students at an elementary school in Calgary, Alberta. METHODS Total and fecal coliforms and heterotrophic bacteria were enumerated using membrane filtration and agar plate count methods respectively. RESULTS The Canadian Drinking Water Quality Guidelines (CWQG) criterion was exceeded for total co...

In chlorophyll-containing spores of Onoclea sensibilis, depletion of lipid reserves during germination is correlated with increases in the activity of the glyoxylate cycle enzymes isocitrate lyase and malate synthase. In Onoclea, the heterotrophic activity associated with lipid catabolism occurs at the same time that autotrophic activity is taking place. Increases in chlorophyll content and in ...

Nowadays, pollution caused by energy production systems is a major environmental concern. Therefore, the development of sustainable energy sources is required. Amongst others, the microbial fuel cell (MFC) seems to be a possible solution because it can produce clean energy at the same time that waste is stabilized. Unfortunately, mainly due to industrial discharges, the wastes could contain nit...

Microbial heterotrophic activity was investigated in oxic sub-seafloor sediments at North Pond, a sediment pond situated at 23°N on the western flank of the Mid-Atlantic Ridge. The North Pond sediments underlie the oligotrophic North Atlantic Gyre at 4580-m water depth and cover a 7-8 million-year-old basaltic crust aquifer through which seawater flows. Discrete samples for experimentation were...

[1] It is generally assumed that sinking particulate organic carbon (POC) constitutes the main source of organic carbon supply to the deep ocean’s food webs. However, a major discrepancy between the rates of sinking POC supply (collected with sediment traps) and the prokaryotic organic carbon demand (the total amount of carbon required to sustain the heterotrophic metabolism of the prokaryotes;...

Drilling operations of petroleum generate oily wastes. The disposal of a significant amount of oil-based drill muds has caused soil contamination and critical environmental impacts in the last decades.The current study aimed to investigate the potential of microbial remediation for an aged oil-based drilling waste and to monitor the fluctuation in microbial population throughout a ...

The conversion of fixed nitrogen to N2 in suboxic waters is estimated to contribute roughly a third to total oceanic losses of fixed nitrogen and is hence understood to be of major importance to global oceanic production and, therefore, to the role of the ocean as a sink of atmospheric CO2. At present heterotrophic denitrification and autotrophic anammox are considered the dominant sinks of fix...

The seasonal succession of all major planktonic groups, i.e., phytoplankton, bacteria, heterotrophic flagellates, ciliates, rotifers, and crustaceans, was investigated during five years (1987-1991) of weekly sampling with elaborate sampling methods and microscopic countings. This allows to study the seasonal changes of the biomass and production allocation patterns within the epilimnetic food w...