Modeling the bacterial contribution to planktonic community respiration in the regulation of solar energy and nutrient availability

• Published in: Ecological complexity Vol. 23; pp. 25 - 33
• Main Authors: Alijani, Maryam Khajeh, Wang, Hao, Elser, James J.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.09.2015
• Subjects: Algae; Bacteria; Carbon; Light; Phosphorus; Respiration; Stoichiometry; Stoichiometry; Light; Algae; Phosphorus; Bacteria; Respiration; Carbon
• ISSN: 1476-945X
• DOI: 10.1016/j.ecocom.2015.05.002

•A stoichiometric model for a planktonic ecosystem in the consideration of light and nutrient.•The model is complex since bacteria and algae have both mutualism and competition relationships.•Predictions about how the relative balance of algae and bacteria should change in response to varied nutrient and light.•The theoretical framework successfully reproduces published empirical data.•Under moderate nutrient supply, the bacterial respiration percentage is maximal at intermediate light intensity. In planktonic ecosystems, algae and bacteria exhibit complex interrelationships, as algae provide an important organic matter source for microbial growth while microbial metabolism recycles limiting nutrients for algae in a loose commensalism. However, algae and bacteria can also compete for available nutrients if supplies of organic matter are sufficient to satisfy bacterial demand. We developed a stoichiometrically explicit model of bacteria–algae interactions that incorporated realistic assumptions about algal light and nutrient utilization, algal exudation of organic matter, and bacterial processing of organic matter and nutrients. The model makes specific predictions about how the relative balance of algae and bacteria should change in response to varied nutrient and light availability seen in lakes and oceans. The model successfully reproduces published empirical data and indicates that, under moderate nutrient supply, the bacterial percentage of total respiration should be maximal at intermediate light intensity.