Stoichiometry and Population Growth in Osmotrophs and Non-Osmotrophs. Cherif, M. In eLS. John Wiley & Sons, Ltd, 2001.
Stoichiometry and Population Growth in Osmotrophs and Non-Osmotrophs [link]Paper  doi  abstract   bibtex   
Growth is a process fundamental to life. It implies an increase in not only energy and information but also matter content. Recent advances in ecology have demonstrated that the elemental composition of organisms – their stoichiometry – is inextricably linked to their growth rate. Unbalances between the demands of elements for growth and their relative availabilities often result in elemental limitation. Also, different cellular components have different elemental compositions, and thus changes in allocation between uptake and assembly machineries affect both growth rate and elemental composition at the organismal level. Osmotrophs (including autotrophs) acquire essential elements through a vast set of separate molecules, resulting in more flexible stoichiometries compared to non-osmotrophs that ingest their preys in one package. Relationships between elemental composition and growth rate should be considered differently for individuals and for populations, as processes and mechanisms differ between the two scales, and more generally among the various biological scales. Key Concepts Key Concepts * Growth for organisms is by nature a stoichiometric process that involves multiple currencies: energy, information and matter, itself made of multiple essential elements. * Most organisms are stoichiometrically homeostatic, that is, they need to keep the ratios of elements in their protoplasm within narrow limits. However, some organisms use storage structures, such as vacuoles, to further modulate their stoichiometry. * According to Liebig's law of the minimum, growth is mostly limited by the element that is in least supply compared to the demand of the growing organism. * Organisms can resort to a set of behavioural and physiological strategies when facing elemental limitation. * Osmotrophs (including autotrophs), which can regulate the stoichiometry of their diet at the uptake level, differ from non-osmotrophs (including some large protists and all metazoans), which ingest all the essential elements at once. * Another strategy is to adapt the relative investment into cellular machineries that differ in their elemental composition, but this comes with important repercussions on cellular functions. * Excretion of the elements in excess is another strategy, but there are associated costs, too, leading to only a narrow range of diet elemental composition that optimises growth. * A priori, elemental limitation at the level of populations should differ from limitation of individual growth because of demographic processes. * Even if differences between the two biological levels are ignored, including stoichiometry into classical population models yields interesting novel predictions, confirming the importance of stoichiometry to understand the growth process.
@incollection{cherif_stoichiometry_2001,
	title = {Stoichiometry and {Population} {Growth} in {Osmotrophs} and {Non}-{Osmotrophs}},
	copyright = {Copyright © 2001 John Wiley \& Sons, Ltd. All rights reserved.},
	isbn = {978-0-470-01590-2},
	url = {http://onlinelibrary.wiley.com.proxy.ub.umu.se/doi/10.1002/9780470015902.a0026353/abstract},
	abstract = {Growth is a process fundamental to life. It implies an increase in not only energy and information but also matter content. Recent advances in ecology have demonstrated that the elemental composition of organisms – their stoichiometry – is inextricably linked to their growth rate. Unbalances between the demands of elements for growth and their relative availabilities often result in elemental limitation. Also, different cellular components have different elemental compositions, and thus changes in allocation between uptake and assembly machineries affect both growth rate and elemental composition at the organismal level. Osmotrophs (including autotrophs) acquire essential elements through a vast set of separate molecules, resulting in more flexible stoichiometries compared to non-osmotrophs that ingest their preys in one package. Relationships between elemental composition and growth rate should be considered differently for individuals and for populations, as processes and mechanisms differ between the two scales, and more generally among the various biological scales.

Key Concepts
Key Concepts



* Growth for organisms is by nature a stoichiometric process that involves multiple currencies: energy, information and matter, itself made of multiple essential elements.

* Most organisms are stoichiometrically homeostatic, that is, they need to keep the ratios of elements in their protoplasm within narrow limits. However, some organisms use storage structures, such as vacuoles, to further modulate their stoichiometry.

* According to Liebig's law of the minimum, growth is mostly limited by the element that is in least supply compared to the demand of the growing organism.

* Organisms can resort to a set of behavioural and physiological strategies when facing elemental limitation.

* Osmotrophs (including autotrophs), which can regulate the stoichiometry of their diet at the uptake level, differ from non-osmotrophs (including some large protists and all metazoans), which ingest all the essential elements at once.

* Another strategy is to adapt the relative investment into cellular machineries that differ in their elemental composition, but this comes with important repercussions on cellular functions.

* Excretion of the elements in excess is another strategy, but there are associated costs, too, leading to only a narrow range of diet elemental composition that optimises growth.

* A priori, elemental limitation at the level of populations should differ from limitation of individual growth because of demographic processes.

* Even if differences between the two biological levels are ignored, including stoichiometry into classical population models yields interesting novel predictions, confirming the importance of stoichiometry to understand the growth process.},
	language = {en},
	urldate = {2017-05-27},
	booktitle = {{eLS}},
	publisher = {John Wiley \& Sons, Ltd},
	author = {Cherif, Mehdi},
	year = {2001},
	doi = {10.1002/9780470015902.a0026353},
	keywords = {\#nosource, autotrophs, compensatory feeding, droop model, elemental limitation, excretion, homeostasis, metazoans, osmotrophs, phosphorus, ribosomes, uptake},
}

Downloads: 0