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Titolo:
ON THE STRATEGY OF EATING YOUR COMPETITOR - A MATHEMATICAL-ANALYSIS OF ALGAL MIXOTROPHY
Autore:
THINGSTAD TF; HAVSKUM H; GARDE K; RIEMANN B;
Indirizzi:
UNIV BERGEN,DEPT MICROBIOL,JAHNEBAKKEN 5 N-5020 BERGEN NORWAY WATER QUAL RES INST DK-2970 HORSHOLM DENMARK
Titolo Testata:
Ecology
fascicolo: 7, volume: 77, anno: 1996,
pagine: 2108 - 2118
SICI:
0012-9658(1996)77:7<2108:OTSOEY>2.0.ZU;2-A
Fonte:
ISI
Lingua:
ENG
Soggetto:
POTERIOOCHROMONAS-MALHAMENSIS; BACTERIVORY; FLAGELLATE; LAKE; PHYTOFLAGELLATE; CHRYSOPHYCEAE; PHAGOTROPHY; ENCLOSURES; PHOSPHORUS; INGESTION;
Keywords:
COMPETITION-PREDATION THEORY; MICROBIAL FOOD WEBS; MIXOTROPHY; PHAGOTROPHY; PHOTOAUTOTROPHY;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
33
Recensione:
Indirizzi per estratti:
Citazione:
T.F. Thingstad et al., "ON THE STRATEGY OF EATING YOUR COMPETITOR - A MATHEMATICAL-ANALYSIS OF ALGAL MIXOTROPHY", Ecology, 77(7), 1996, pp. 2108-2118

Abstract

Recent experimental evidence indicates the importance in some pelagicsystems of mixotrophic protists that combine photosynthetic ability with the ability to ingest bacteria. If both bacteria and phytoplanktonare mineral nutrient limited, this should provide the mixotrophs withthe double benefit of combining removal of their competitor with ingestion of the limiting nutrient in pelleted form. It is the objective of this study to expand the classical theories of competition and predation to explore the effect on the microbial food web of one trophic group possessing both strategies. In a chemostat scenario, we analyzed the two-species situation of a mixotroph preying on mineral-nutrient-limited bacteria, and also the situations when the mixotroph in additionhas to compete with specialized photoautotrophic and phagotrophic protists, each superior to the mixotroph in their specialized nutritionalmodes. In the mixotroph-bacteria relationship, somewhat paradoxically, high predatory abilities will reduce the quantitative importance of predation in the mixotroph's nutrition. The reason is a strong reduction in prey abundance, allowing the mixotroph to survive as a photoautotroph despite its low competitive ability. In the three-species case with mixotrophs, bacteria, and specialized phagotrophs, it is shown that the mixotroph can compensate for a ''price'' paid in reduced affinity for bacterial prey by a sufficiently high affinity for mineral nutrients. In the other three-species case where the mixotroph has to compete with a specialized photoautotroph, the situation is more complex; there is an optimum value fur the mixotroph's predatory ability at which mixotroph biomass is maximized. In the general situation with all four species (bacteria, mixotrophs, and specialized auto- and phagotrophs) potentially present, different mixotrophic strategies will alter the equilibrium composition of the consortium, with the mixotroph being most successful with a high affinity for nutrients and an intermediateaffinity for bacteria, In the simple form used here, the model predicts no equilibrium with all four species simultaneously present. The theory is in principle directly applicable to laboratory experimentation.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 15/01/21 alle ore 23:16:09