A new locus affects cell motility, cellulose binding, and degradation by Cytophaga hutchinsonii

Appl Microbiol Biotechnol. 2012 Oct;96(1):161-70. doi: 10.1007/s00253-012-4051-y. Epub 2012 Apr 29.

Abstract

Cytophaga hutchinsonii is a Gram-negative gliding bacterium, which can rapidly degrade crystalline cellulose via a novel strategy without any recognizable processive cellulases. Its mechanism of cellulose binding and degradation is still a mystery. In this study, the mutagenesis of C. hutchinsonii with the mariner-based transposon HimarEm3 and gene complementation with the oriC-based plasmid carrying the antibiotic resistance gene cfxA or tetQ were reported for the first time to provide valuable tools for mutagenesis and genetic manipulation of the bacterium. Mutant A-4 with a transposon mutation in gene CHU_0134, which encodes a putative thiol-disulfide isomerase exhibits defects in cell motility and cellulose degradation. The cellulose binding ability of A-4 was only half of that of the wild-type strain, while the endo-cellulase activity of the cell-free supernatants and on the intact cell surface of A-4 decreased by 40%. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of proteins binding to cellulose in the outer membrane showed that most of them were significantly decreased or disappeared in A-4 including some Gld proteins and hypothetical proteins, indicating that these proteins might play an important role in cell motility and cellulose binding and degradation by the bacterium.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / analysis
  • Cellulose / metabolism*
  • Cytophaga / genetics*
  • Cytophaga / metabolism
  • Cytophaga / physiology*
  • DNA Transposable Elements
  • Electrophoresis, Polyacrylamide Gel
  • Gene Knockout Techniques
  • Genes, Bacterial*
  • Genetic Complementation Test
  • Genetics, Microbial / methods
  • Locomotion*
  • Molecular Biology / methods
  • Mutagenesis, Insertional
  • Protein Disulfide-Isomerases / genetics
  • Proteome / analysis

Substances

  • Bacterial Proteins
  • DNA Transposable Elements
  • Proteome
  • Cellulose
  • Protein Disulfide-Isomerases