tailieunhanh - Báo cáo khoa học: Super life – how and why ‘cell selection’ leads to the fastest-growing eukaryote

What is the highest possible replication rate for living organisms? The cellular growth rate is controlled by a variety of processes. Therefore, it is unclear which metabolic process or group of processes should be activated to increase growth rate. An organism that is already growing fast may already have optimized through evolution all processes that could be opti-mized readily, but may be confronted with a more generic limitation. | Super life - how and why cell selection leads to the fastest-growing eukaryote Philip Groeneveld1 Adriaan H. Stouthamer1 and Hans V. Westerhoff1 2 3 1 Department of Molecular CellPhysiology MathematicalBiochemistry Netherlands Institute for Systems Biology Vrije Universiteit Amsterdam The Netherlands 2 The Manchester Centre for Integrative Systems Biology Manchester Interdisciplinary Biocentre Schoolof ChemicalEngineering and AnalyticalScience The University of Manchester UK 3 Swammerdam Institute for Life Sciences Netherlands Institute for Systems Biology University of Amsterdam The Netherlands Keywords highest eukaryotic growth rate modular control analysis pH-auxostat selection surface-to-volume ratio optimization systems biology Correspondence H. V. Westerhoff The Manchester Centre for Integrative Systems Biology SCEAS The University of Manchester Manchester Interdisciplinary Biocentre MIB 131 Princess Street Manchester M1 7ND UK Fax 44 161 306 8918 Tel 44 161 306 4407 E-mail Received 20 December 2007 revised 26 October 2008 accepted 3 November 2008 doi What is the highest possible replication rate for living organisms The cellular growth rate is controlled by a variety of processes. Therefore it is unclear which metabolic process or group of processes should be activated to increase growth rate. An organism that is already growing fast may already have optimized through evolution all processes that could be optimized readily but may be confronted with a more generic limitation. Here we introduce a method called cell selection to select for highest growth rate and show how such a cellular site of growth control was identified. By applying pH-auxostat cultivation to the already fast-growing yeast Kluyveromyces marxianus for a sufficiently long time we selected a strain with a 30 increased growth rate its cell-cycle time decreased to 52 min much below that reported to date for any eukaryote. The .