| one publication added to basket [108974] | The utilization of dissolved organic compounds in aquatic environments
Sepers, A.B.J. (1977). The utilization of dissolved organic compounds in aquatic environments. Hydrobiologia 52(1): 39-54
In: Hydrobiologia. Springer: The Hague. ISSN 0018-8158; e-ISSN 1573-5117, more
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| Keywords |
Environments > Aquatic environment
Food absorption
Microorganisms > Bacteria
Population functions > Growth
Suspended organic matter
Marine/Coastal; Brackish water; Fresh water |
| Abstract |
Many marine invertebrates possess the ability to take up dissolved organic compounds (DOM) from the ambient sea water. Uptake is a surface related phenomenon and is mediated by an active transport process. In fresh water invertebrates the uptake of DOM proceeds at a considerably lower rate or is completely absent. There are indications that the uptake of DOM is incompatible with chloride-and osmoregulatory processes. DOM may have some nutritional value as an additional nutrient source especially at shortage of particulate food. The hypothesis that marine invertebrates can rely totally on the pool of dissolved organic matter to meet their nutrient requirements is only justified as far as the pogonophores are concerned. Some phytoplankters can grow heterotrophically in the dark utilizing dissolved organic substrates as a C and energy source. The range of compounds permitting heterotrophic growth is generally very limited. Many algae are able to take up organic compounds in the light. These substrates can serve as an additional C or N source. Uptake of DOM by algae is mediated by an active transport system. As evidenced by the vales of the kinetic parameter K Sub(t), heterotrophic bacteria possess uptake systems for dissolved organic matter which are especially adapted to very low substrate concns. Comparison of the characteristics of the uptake of DOM by bacteria with the corresponding data of invertebrates and phytoplankton shows that, in view of the low substrate levels, the uptake of dissolved organic compounds in natural waters is primarily a bacterial process. |
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