Title: How bacteria take care for their kids: Evidence for controlled and fair distribution of PHB granules to daughter cells

Presenter: Prof. Dieter Jendrossek

University: University Stuttgart, Germany

Time: 10:30-11:30, October 18, 2011

Venue: A203, Institute of Microbiology, Chinese Academy of Sciences

Abstract: Ralstonia eutropha H16 has become the model organism for studying metabolism of poly(3-hydroxybutyrate) (PHB), an important biodegradable biopolymer that is sustainable produced worldwide in the scale of 10^5 t/a from renewable resources such as sugars. R. eutropha cells usually accumulate about a dozen PHB granules during growth at high C/N-ratios. While biochemistry and molecular biology of PHB accumulation and PHB biodegradation have been investigated in great detail during the last two decades only little is known whether and how subcellular localization of PHB granules is controlled by the bacteria. We addressed this question by performing a two-hybrid approach to screen for proteins with the ability to interact with proteins of the PHB granule surface. Two novel Pha proteins were identified which control subcellullar localization of PHB granules and ensure almost equal distribution of PHB granules to daughter cells after cell division as revealed by fluorescence microscopy and transmission electron microscopy. A revised model for PHB granule formation will be proposed.