%0 Journal Article %A LÉVY-FRÉBAULT*, VÉRONIQUE %A RAFIDINARIVO, ÉLIE %A PROMÉ, JEAN-CLAUDE %A GRANDRY, JEANNINE %A BOISVERT, HENRI %A DAVID, HUGO L. %T Mycobacterium fallax sp. nov. %D 1983 %J International Journal of Systematic and Evolutionary Microbiology, %V 33 %N 2 %P 336-343 %@ 1466-5034 %R https://doi.org/10.1099/00207713-33-2-336 %I Microbiology Society, %X A new species, Mycobacterium fallax, is described. A study of 22 strains showed that they form a homogeneous group with an internal phenotypic similarity value of 94.6 ± 4.1%. The colony morphology resembled that of Mycobacterium tuberculosis, with cord formation on solid medium. The characteristic features of these strains were that they were nonchromogenic and grew rapidly at 30°C but slowly at 37°C. Most formed a thermolabile catalase and produced nitrate reductase. A lipid analysis showed that tuberculostearic acid was present and that only α-mycolic acids were formed. These α-mycolic acids were di- and tri-unsaturated acids, a feature that has not been described previously in the mycobacteria. The type strain has been deposited in the Collection Nationale de Cultures de Microorganismes, Paris, France, as strain CIP 8139. %U https://www.microbiologyresearch.org/content/journal/ijsem/10.1099/00207713-33-2-336