CDF23, a new species of Caulobacter

		Lane 1: E.coli PN200 Lane 2. MCDF100 Lane 3. MCDF23
Electron Microscope image of sewage isolate CDF23. 16S rDNA sequence analysis identifies this as a new species of Caulobacter	Eckhardt Gel Analysis of Recombinant Caulobacter containing pPN1

MCDF23, a rifampicin resistant derivative of CDF23, was able to receive Rhizobium symbiotic plasmid (pSym) genes by conjugation. The resulting transonjugant Caulobacter, MCDF100, was able to induce a tumour- like growth on white clover seedlings after receiving the pPN1 co-integrate plasmid from E.coli strain PN200. Eckhardt gel analysis confirmed that the transconjugant Caulobacter carried the R68.45:pSym co-integrate plasmid. Bacteroids were absent but Caulobacter cells were found in the outer two or three layers of the growth and the plant cells in this region had degenerated.

(Reproduced with permission. EM Photo taken at HortResearch, Palmerston North. Conjugation and clover experiments carried out by Michael Fenton, Dept of Microbiology and Genetics, Massey University, Palmerston North, NEW ZEALAND)