PHYSICAL MAP OF THE GENOME OF OENOCOCCUS-OENI PSU-1 AND LOCALIZATION OF GENETIC-MARKERS

A physical map of the chromosome of Oenocccus oeni PSU-1 was construct ed. This represents the first map for a strain of this species. A tota l of 37 restriction sites for the rare-cutting endonucleases Asci. Fse l, Notl and Sfil were mapped on the chromosome, which was found to be circular with an estimated size of 1857 kb. Fragment order was determi ned using several approaches: analysis of partial and double digestion s, two-dimensional pulsed-field gel electrophoresis, isolation of link ing clones, and Southern hybridization with labelled restriction fragm ents both from PSU-1 and from O. oeni strain CM. Oenococcal genes alsS lalsD, mleA and mir, two phage attachment sites and recurrent sequence s such as IS1165-like elements and rm loci were located on the physica l map. Specific fragments hybridizing with gene probes from Lactococcu s lactis. Leuconostoc mesenteroides and Bacillus subtilis were also id entified. The two ribosomal operons have been precisely located and th eir transcription direction determined.