Aims: To identify strains of Zymomonas mobilis at the subspecies level by a fast and reliable technique.
Methods and results: Amplified ribosomal DNA restriction analysis (ARDRA) was used to identify strains of Z. mobilis at the subspecies level using the restriction enzyme StuI. This technique allowed for easy and quick differentiation between Z. mobilis subsp. mobilis and Z. mobilis subsp. pomaceae. By using other enzymes, the presence of two ARDRA profiles within the subspecies Z. mobilis subsp. pomaceae was observed, one profile corresponded to collection strains (British origin) while the other corresponded to wild type strains isolated from 'framboise' ciders in France.
Conclusions: A rapid method for identification of strains of Z. mobilis at the subspecies level was developed and shown to be more reliable and faster than the conventional method based on physiological tests. Furthermore, consistent differences in the 16S rDNA sequences between collection and wild type strains of Z. mobilis subsp. pomaceae were observed suggesting that the French isolates correspond to a new genomovar within this subspecies.
Significance and impact of the study: This is the first description of a molecular method for the identification of Z. mobilis strains at the subspecies level. It will certainly prove to be useful in identifying this beer and cider spoiling micro-organism.