Numerical Analysis
INTERNATIONAL JOURNAL SYSTEMATIC OF BACTERIOLOGY, 1976, p. 146-157 Apr. Copyright 0 1976 International Association of Microbiological Societies
Vol. 26, No. 2 Printed in U . S A .
Phenotypic Description, Numerical Analysis, and Proposal for an Improved Taxonomy and Nomenclature of the Genus Zymomonas Kluyver and van Niel 1936
J. DE LEY
Laboratory
of
AND
J. SWINGS
Microbiology and Microbial Genetics, Faculty of Sciences, State University, K . L . Ledeganckstraat 35, B-9000 Gent, Belgium
One hundred thirty-eight phenotypic features were determined in 38 Zymomonas strains from diverse origin (Zairese fermenting palm saps, Mexican pulque, British spoiled beer, and sick cider). The similarity between all the strains was very high: 27 features were present, and 74 features were absent in all of them; 37 features were variable. By numerical analysis all strains formed one cluster above the simple matching coefficient of 0.88. There were no significant differences between motile and nonmotile strains or between sucrosefermenting and non-sucrose-fermenting strains. A strain from sick cider in Bristol, United Kingdom, was a border case in its phenotypic features, deoxyribonucleic acid relatedness, and protein electropherograms. We propose: (i) to discontinue the use of the species name of Zymomonas anaerobia and its subspecies Z. anaerobia subsp. anaerobia and 2. anaerobia subsp. irnmobilis, and to include all of the strains in this species in Zymomonas mobilis; (ii) to consider Zymomonas congolensis as a nomen nudum and as a synonym of 2. mobilis. We concluded the following from our data: that 2. mobilis is the only species in the genus Zymomonas so far; that all the strains of our Zymomonas collection except one belong in 2. mobilis subsp. mobilis, the type strain of which is ATCC 10988; and that the cider sickness organisms belong in 2. mobilis subsp. pomaceae (Millis) comb. nov., with type strain T. H. Delft ( = strain I [Barker] = ATCC 29192). The
Vol. 26, No. 2 Printed in U . S A .
Phenotypic Description, Numerical Analysis, and Proposal for an Improved Taxonomy and Nomenclature of the Genus Zymomonas Kluyver and van Niel 1936
J. DE LEY
Laboratory
of
AND
J. SWINGS
Microbiology and Microbial Genetics, Faculty of Sciences, State University, K . L . Ledeganckstraat 35, B-9000 Gent, Belgium
One hundred thirty-eight phenotypic features were determined in 38 Zymomonas strains from diverse origin (Zairese fermenting palm saps, Mexican pulque, British spoiled beer, and sick cider). The similarity between all the strains was very high: 27 features were present, and 74 features were absent in all of them; 37 features were variable. By numerical analysis all strains formed one cluster above the simple matching coefficient of 0.88. There were no significant differences between motile and nonmotile strains or between sucrosefermenting and non-sucrose-fermenting strains. A strain from sick cider in Bristol, United Kingdom, was a border case in its phenotypic features, deoxyribonucleic acid relatedness, and protein electropherograms. We propose: (i) to discontinue the use of the species name of Zymomonas anaerobia and its subspecies Z. anaerobia subsp. anaerobia and 2. anaerobia subsp. irnmobilis, and to include all of the strains in this species in Zymomonas mobilis; (ii) to consider Zymomonas congolensis as a nomen nudum and as a synonym of 2. mobilis. We concluded the following from our data: that 2. mobilis is the only species in the genus Zymomonas so far; that all the strains of our Zymomonas collection except one belong in 2. mobilis subsp. mobilis, the type strain of which is ATCC 10988; and that the cider sickness organisms belong in 2. mobilis subsp. pomaceae (Millis) comb. nov., with type strain T. H. Delft ( = strain I [Barker] = ATCC 29192). The