Abstract: In order to explore the function of two-component signal transduction systems (TCSs) in the growth and environmental adaptation of Pseudomonas fluorescens, the dominant?spoilage?organism in aquatic products, the sequence analysis and function prediction of the TCSs in P. fluorescens PF08 were carried out by bioinformatic methods. The results showed that there were 63 histidine kinases (HKs), 84 response regulators (RRs), 39 pairs of TCSs and 25 fusion HKs in P. fluorescens PF08. All HKs in the bacterium possessed the HATPase_c and HisKA domains, and all RRs possessed the REC domain. The phylogenetic analysis suggested that the TCSs with the same domains were clustered in the same cluster, indicating similar functions of these TCSs. The biological functions of 25 pairs of TCSs in P. fluorescens PF08 were successfully predicted, mainly participating in the regulation of nutrient metabolism, material transport, cell differentiation, adaptation to adverse environments, cell resistance and virulence. This study may provide some references for further elucidating the functions of TCSs in the environmental adaptation of P. fluorescens PF08 from aquatic products.

Key words: aquatic products; Pseudomonas fluorescens; two-component signal transduction system; sequence analysis; functional prediction