Heterologous phi X174 gene E-expression in Ralstonia eutropha: E-mediated lysis is not restricted to gamma-subclass...

E-lysis of Ralstonia eutropha H16, which belongs to the beta-subclass, was undertaken to verify whether transmembrane tunnel formation is possible in bacteria which do not belong to the enterobacteriaceae. For this purpose, a new gene E expression plasmid, pKG12, with two origins of replication, oriV and oriT, from plasmid pRP4, chloramphenicol and kanamycin resistance genes and a casette composed of lambda cI857 and lambda pR gene E was constructed. Temperature upshift of R. eutropha H16 (pKG12) from 28 to 45 degrees C during exponential growth resulted in lysis of the strain with features characteristic of E-mediated lysis of Escherichia coli. The cytoplasmic contents released can easily be separated from the still intact envelope fraction by centrifugation or filtration. As R. eutropha H16 represents an important industrial organism, E-mediated lysis could facilitate procedures for the recovery of intracellular mediators or products like polyhydroxyalkanoates.