Induction of phospholipase- and flagellar synthesis in Serratia liquefaciens is controlled by expression of the flagellar master operon flhD

Mol Microbiol. 1995 Feb;15(3):445-54. doi: 10.1111/j.1365-2958.1995.tb02258.x.


When a liquid culture of Serratia spp. reaches the last part of the logarithmic phase of growth it induces the synthesis of several extracellular hydrolytic enzymes. In this communication we show that synthesis and secretion of the extracellular phospholipase is coupled to expression of flagella. Expression of flagella is demonstrated to follow a growth-phase-dependent pattern. Cloning, complementation studies and DNA-sequencing analysis has identified a genetic region in Serratia liquefaciens which exhibits extensive homology to the Escherichia coli flhD flagellar master operon. Interruption of the chromosomal flhD operon in S. liquefaciens results in non-flagellated and phospholipase-negative cells, but the synthesis of other exoenzymes is not affected. By placing the flhD operon under the control of a foreign inducible promoter we have shown that increased transcription through the flhD operon leads to induction of flagellar synthesis and phospholipase expression.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Bacterial Proteins / biosynthesis*
  • Bacterial Proteins / genetics
  • Base Sequence
  • Cloning, Molecular
  • DNA, Bacterial / genetics
  • DNA, Bacterial / metabolism
  • DNA-Binding Proteins / biosynthesis
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Enzyme Induction
  • Escherichia coli / genetics
  • Escherichia coli Proteins
  • Flagella / metabolism*
  • Flagellin / biosynthesis*
  • Flagellin / genetics
  • Gene Expression Regulation, Bacterial*
  • Genes, Bacterial
  • Molecular Sequence Data
  • Operon / genetics*
  • Phospholipases / biosynthesis*
  • Phospholipases / genetics
  • Promoter Regions, Genetic
  • Recombinant Fusion Proteins / biosynthesis
  • Sequence Alignment
  • Sequence Homology
  • Serratia / genetics*
  • Serratia / growth & development
  • Serratia / metabolism
  • Trans-Activators / biosynthesis
  • Trans-Activators / genetics
  • Trans-Activators / physiology*


  • Bacterial Proteins
  • DNA, Bacterial
  • DNA-Binding Proteins
  • Escherichia coli Proteins
  • Recombinant Fusion Proteins
  • Trans-Activators
  • flhC protein, E coli
  • flhD protein, E coli
  • Flagellin
  • Phospholipases