Year: 2013
Type: article
Abstract: The microbial loop is the conventional model by which nutrients and minerals are recycled in aquatic eco-systems. Biochemical pathways in different organisms become metabolically inter-connected such that nutrients are utilized, processed, released and re-utilized by others. The result is that unrelated individuals end up impacting each others' fitness directly through their metabolic activities. This study focused on the impact of programmed cell death (PCD) on a population's growth as well as its role in the exchange of carbon between two naturally co-occurring halophilic organisms. Flow cytometric, biochemical, ¹⁴C radioisotope tracing assays, and global transcriptomic analyses show that organic algal photosynthate released by Dunalliela salina cells undergoing PCD complements the nutritional needs of other non-PCD D. salina cells. This occurs in vitro in a carbon limited environment and enhances the growth of the population. In addition, a co-occurring heterotroph Halobacterium salinarum re-mineralizes the carbon providing elemental nutrients for the mixoheterotrophic chlorophyte. The significance of this is uncertain and the archaeon can also subsist entirely on the lysate of apoptotic algae. PCD is now well established in unicellular organisms; however its ecological relevance has been difficult to decipher. In this study we found that PCD in D. salina causes the release of organic nutrients such as glycerol, which can be used by others in the population as well as a co-occurring halophilic archaeon. H. salinarum also re-mineralizes the dissolved material promoting algal growth. PCD in D. salina was the mechanism for the flow of dissolved photosynthate between unrelated organisms. Ironically, programmed death plays a central role in an organism's own population growth and in the exchange of nutrients in the microbial loop.
Source: PLoS ONE
Language: English
Subfield: Oceanography
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $2,382
Awards: Interrogation of systems level mechanisms controlling DNA repair processes, G222768804, ITR: Development of an Integrated Computational and Experimental Approach to Predict Biological Networks in Halobacterium sp, Collaborative Research: Marine microgels: A microlayer source of summer CCN in high Arctic open leads, G2969889089, Design and Implementation of Effective Solutions for Archiving and Processing Systems Biology Data: Research Integrated with an Ongoing High School Education Program., MOLECULAR ASSEMBLIES, GENES AND GENOMICS INTEGRATED EFFICIENTLY (MAGGIE): COMPONENT 3: SYSTEMS APPROACH IN A MULTI-ORGANISM STRATEGY TO UNDERSTAND BI, QSB: Modeling Predictive Biological Networks in Halobacterium sp., BE/Gen-En: The Oxygen-stress Response in the Extremophile Halobacterium sp. NRC-1: Systems Analysis and Development of Supplemental High School Instruction Modules, Pacific Northwest Center for Oceans and Human Health, G5578326127, Carbon Sequestration: Tracing the Source and Fate of Marine Biopolymers using Proteomics and Antibody Display Technology, Multiscale kinetic analysis of Cu/Zn efflux in Halobacterium sp. NRC-1, G7452799666, G7598438513, Quantitative Systems Biology
OpenAlex ID: W1965540688