Isolation of transposon mutants and characterization of genes involved in biofilm formation by Pseudomonas fluorescens TC222.
Biofilm formation mutants are often found to have defective or altered motility. The motility phenotype was exploited to identify Pseudomonas fluorescens biofilm formation mutants. Fourteen motility mutants were obtained from P. fluorescens isolate TC222 and eight stable mutants were studied further. The eight transposon insertion mutants showed altered ability to form biofilm compared with the parent. Five Tn5-inserted genes from these mutants were cloned and sequenced. Genetic analysis showed that two insertions were located in genes affecting multiple cell surface characteristics, including lipopolysaccharide (rfbD) and polar flagella (fliR). Three genes encoding for a putative Mig-14 family protein (epsB), a probable bacteriophage signal peptide protein (bspA) and a soluble pyridine nucleotide transhydrogenase (pyrA) were reported for the first time to be involved in biofilm formation. Complementation experiments of rfbD and epsB genes proved that biofilm formation of the corresponding mutants could be restored. Further semi-quantitative reverse transcription-PCR analysis showed that both rfbD and epsB can express their transcripts much higher in the complemented strains than that in wild-type strains. The transcripts of both genes in their mutants could not be detected.
Nian
Hongjuan
H
State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100094, People's Republic of China.
Zhang
Jie
J
Song
Fuping
F
Fan
Liqiang
L
Huang
Dafang
D
D018441:Biofilms / Q000254:growth & development*; D004251:DNA Transposable Elements / Q000235:genetics*; D005798:Genes, Bacterial; D020409:Molecular Motor Proteins / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*; D011551:Pseudomonas fluorescens / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology*
D004251:DNA Transposable Elements; D020409:Molecular Motor Proteins