Osmotrophy

Osmotrophy is the uptake of dissolved organic compounds by osmosis for nutrition. Organisms that use osmotrophy are osmotrophs. Some mixotrophic microorganisms use osmotrophy to derive energy. The organisms that used osmotrophy are known to be an osmotrophs which are usually found in protists and fungi although exclusively osmotrophic feeding in contemporary ecosystems are restricted to microscopic bacteria thereby used the process of osmosis for the movement of food although some macroscopic animals like molluscs, sponges, corals, brachiopods and echinoderms used osmotrophic feeding as supplemental food source.

Osmotrophy is an efficient means of gathering nutrients in microscopic organisms that relies on the surface area to ensure that proper diffusion occurs throughout the cell. When organisms increased in size the surface area per volume ratio drops and osmotrophy becomes insufficient to meet the nutrient demands.

In stagnant waters photoautotrophs has a relative advantage over heterotrophic osmotrophs since the flux of photon as energy source is not hindered at low temperatures thus, it depend on diffusion for mass acquisition through Brownian diffusion.

The fluid motion of osmotrophs is an impenetrable importance because asymptotic reactions occurs in the absence of fluid motion, thus movement bring closer to the cell that correspond to the highest gradients though diffusional core is safe on average concentrations.

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