Zymomonas mobilis CP4: a clarification of strains via plasmid profiles

There has been confusion regarding the nomenclature of cultures of Zymomonas mobilis CP4 (Gonçalves de Lima et al., 1970). Thus five cultures from different laboratories but originally received from a single source (Recife, Brazil) were compared by analysis of their plasmid profiles and the restriction digest patterns of the plasmids. Four cultures of Z. mobilis CP4 showed identical plasmid profiles and restriction digest patterns. One culture of CP4 (ZM4, ATCC 31821), cultured in P.L. Rogers' laboratory in Australia, and cultures derived from it and deposited in connection with recent patents, strain ZM401 (ATCC 31822) and strain ZM481 (ATCC 31823), differed from the first four cultures with respect to both plasmid profiles and restriction digest pattern. The reason for the plasmid differences between the two groups of cultures is unclear, but may have arisen in the original distribution, by natural selection while in continued culture or perhaps by selection of a minor strain in the original culture. In order to clarify the status of the two variant groups, the cultures that possess the same plasmid profile as the CP4 culture currently being distributed from the Recife culture collection are now designated CP4 (and derivatives). The cultures that possess the plasmid profile of the Rogers' CP4 (ZM4) are now designated by the Rogers' laboratory notation as ZM4 (and derivatives) and prior citation to CP4 removed from their nomenclature.