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Yunhao Liu

B.Sc., M.Sc.


physical: Building 16.11 // The Station Crescent // Oteha Rohe
tel: +64 9 4140800 ext 43813 // email: yunhao.liu.1(at)


I completed my master study in Prof. Paul Rainey’s group at Massey University. The histidine utilization locus (hut) confers Pseudomonas fluorescens SBW25 with an ability to grow on histidine as a sole carbon and/or nitrogen source. Regulation of hut is complex and not fully understood. Previous work (Zhang & Rainey, 2007) showed that HutD (a protein to which no previous function had been assigned) functions as a governor of hut expression that sets an upper limit to the level of hut activity. The MSc project focused on the determination of HutD structure in order to find out the function of HutD.


My research focuses on the mechanism of carbon catabolite repression in Pseudomonas fluorescens SBW25.

Bacteria living in nutrient-rich environment selectively use energetically favourable carbon sources firstly. The presence of preferred carbon sources prevents the expression and the activity of catabolic systems that enable the use of secondary substrates. I am a Ph.D student and currently working on the characterization of the xylose utilization (xyl) operon in P. fluorescens SBW25. Regulation mechanism of the xyl operon is currently unknown in Pseudomonas. The expression of xyl genes is repressed when preferred carbon sources are available. The xyl operon can be used as a model system to study carbon catabolite repression in P. fluorescens SBW25.


Zhang, X.-X., Liu, Y.-H. & Rainey P. B. (2010). CbrAB-dependent regulation of pcnB, a poly(A) polymerase gene involved in polyadenylation of RNA in Pseudomonas fluorescens. Environmental Microbiology 12, 1674.

Yunhao Liu