Genetic Transformation System for Members of the Genera, Sphingomonas, Sphingobium, Novosphingobium and Sphingopyxis

Abstract

This paper describes a plasmid transformation system that permits genetic manipulation of the genus Sphingomonas. A cryptic indigenous plasmid, pAMI-1, of 10 kb from Sphingobium amiense was isolated and characterized. Nucleotide sequencing revealed that pAMI-1 contains five open reading frames, which are predicted to encode proteins associated with integration, recombination, conjugation and replication. Escherichia coli-S. amiense shuttle vectors were successfully introduced into Sphingomonas, Sphingobium, Novosphingobium and Sphingopyxis strains by electroporation. The copy number of the shuttle vector was estimated to be 1-2 per chromosome in the Sphingobium yanoikuyae cell.