title: Postfragmentation density function for bacterial aggregates in laminar flow.
abstract: The postfragmentation probability density of daughter flocs is one of the least well-understood aspects of modeling flocculation. We use three-dimensional positional data of Klebsiella pneumoniae bacterial flocs in suspension and the knowledge of hydrodynamic properties of a laminar flow field to construct a probability density function of floc volumes after a fragmentation event. We provide computational results which predict that the primary fragmentation mechanism for large flocs is erosion. The postfragmentation probability density function has a strong dependence on the size of the original floc and indicates that most fragmentation events result in clumps of one to three bacteria eroding from the original floc. We also provide numerical evidence that exhaustive fragmentation yields a limiting density inconsistent with the log-normal density predicted in the literature, most likely due to the heterogeneous nature of K. pneumoniae flocs. To support our conclusions, artificial flocs were generated and display similar postfragmentation density and exhaustive fragmentation.
authors: Department of Applied Mathematics, University of Colorado at Boulder, Boulder, CO 80309, USA.
authors: Erin
authors: E
authors: Byrne
authors: Steve
authors: S
authors: Dzul
authors: Michael
authors: M
authors: Solomon
authors: John
authors: J
authors: Younger
authors: David M
authors: DM
authors: Bortz
references: Langmuir. 2006 May 23;22(11):4959-67
references: 16700581
references: Appl Microbiol. 1974 Oct;28(4):672-8
references: 4607526
references: Bull Math Biol. 2008 Apr;70(3):745-68
references: 18071828
references: Langmuir. 2005 Jun 7;21(12):5298-306
references: 15924453
references: J Colloid Interface Sci. 2000 May 15;225(2):273-284
references: 11254264
references: J Colloid Interface Sci. 2010 Feb 15;342(2):261-8
references: 19948345
references: J Colloid Interface Sci. 1996 Dec 25;184(2):579-85
references: 8978562
references: Langmuir. 2004 Mar 30;20(7):2614-27
references: 15838950
references: J Colloid Interface Sci. 1998 Aug 15;204(2):320-7
references: 9698410
references: Langmuir. 2004 Jul 20;20(15):6450-7
references: 15248736
references: Clin Microbiol Rev. 1998 Oct;11(4):589-603
references: 9767057
references: Water Res. 2005 Sep;39(14):3273-8
references: 16009394
references: Water Sci Technol. 2004;50(12):55-62
references: 15686003
references: Appl Environ Microbiol. 2011 Mar;77(5):1777-82
references: 21239544