Some chemical and bacterial characteristics of bottom deposits from lakes and estuaries

Abstract

Chemical and bacteriological examination of muds from sources differing widely in the degree of pollution to which they were subject showed great differences in the contents of carbon, nitrogen and sulphide. These differences were not correlated with differences in the severity of faecal pollution. The amount of organic matter available for growth of micro-organisms in the mud of different depths was not reflected in the figures for organic carbon. A convenient index of this factor was obtained by measuring the volume of gas evolved during anaerobic digestion over a prolonged period of incubation. The rate of evolution was increased by the addition of an inoculum of digested sludge from a sewage works.Sulphate-reducing bacteria appeared to be of two different types. In samples of mud from fresh-water lakes much higher counts were usually obtained in a medium containing comparatively low concentrations of inorganic salts and of lactate than in a medium containing much higher concentrations of these constituents. In samples from locations where conditions were more saline the reverse was usually true.Counts of Bact. coli and of Strep, faecalis together probably constitute the best index of faecal pollution in the examination of samples of mud. These organisms are, however, largely confined to the surface layers.

The Faecal Coli‐aerogenes Flora of Soils From Various Geographical Areas

“…There was, however, a sharp increase in the numbers of these types from soils known to be polluted. This is in agreement with a study by Allen, Grindley & Brooks (1953) of bottom deposits from lakes and estuaries. Their elevated temperature test confirmed all positive MacConkey's broth presumptive tubes (37") in the same medium at 44".…”

OXYGEN CONSUMPTION BY THE SEABED. II. IN SITU MEASUREMENTS TO A DEPTH OF 180 m1

“…Anderson ( 1939), Kato ( 1956), and Edwards and Rolley (1965) likewise found no correlation between total oxygen consumed and total organic matter content of the sediment. Waksman and Hotchkiss (1937), Allen, Grindley, and Brooks (1953), and Volkmann and Oppenheimer (1962) observed different sediments to contain varying proportions of organic matter resistant to' bacterial decomposition, hence possibly a correlation could exist only between oxygen consumption and available organic matter. In fact, Waksman and Hotchkiss (1937) suggested that the rate of oxidation of organic matter in bottom material be used as a measure of the availability of its organic-matter content.…”

Indicator organisms for estuarine and marine waters

“…The presence of indicator bacteria in sediments has been reported by investigators [123][124][125][126]. Bottom sediments were found to contain larger numbers of E. coli [127] and Enterobacter aerogenes [128] than the overlying seawater, because of a higher concentration of organic matter in sediment.…”