The chief importance of nitrogenous compounds depends upon their assimilation by living plants, which, in their development, absorb these compounds from the soil, wherein they are formed mainly by the action of nitrifying bacteria.
It is probable that important consequences of these actions result from the presence of nitrifying bacteria in rotten stone, FIG.
The idea that this film of bacteria oxidizes the alcohol beneath by merely condensing atmospheric oxygen in its interstices, after the manner of spongy platinum, has long been given up; but the explanation of the action as an incomplete combustion, depending on the peculiar respiration of these organisms - much as in the case of nitrifying and sulphur bacteria - is not clear, though the discovery that the acetic bacteria will not only oxidize alcohol to acetic acid, but further oxidize the latter to CO 2 and 01-1 2 supports the view that the alcohol is absorbed by the organism and employed as its respirable substance.
By nitrifying bacteria - it is probably comparatively small.
The change takes place in two stages and is effected by two special groups of nitrifying bacteria, which are present in all soils.
The discoveries that some species of nitrifying bacteria and perhaps pigmented forms are capable of carbon-assimilation, that others can fix free nitrogen and that a number of decompositions hitherto unsuspected are accom fished by Schizomycetes have ut thequestions of P Y Y, P d nutrition and fermentation in quite new lights.
It is invariably present in soils, where compounds are formed by nitrifying bacteria.
Fresh manure abounds in de-nitrifying bacteria, and these organisms not only reduce the nitrates to nitrites, even setting free nitrogen and ammonia, but their effect extends to the undoing of the work of what nitrifying bacteria may be present also, with great loss.