Purpose: The main topic of this research was to address the similarity/dissimilarity between soil and juice strains and pinpoint a “quasi-species”, i.e., an intermediate between different evolutionary states.
Methods: 23 strains from soil and two strains from spoiled pear juice (CB-1 and CB-2) were characterized at biochemical (growth range for pH, temperature, resistance to salt, effect of anaerobiosis, amino acid and sugar utilization, enzymatic patterns) and molecular levels (16S rDNA sequencing and RAPD).
Results: Data of soil-borne strains pinpointed that they could be divided into three blocks, represented by soil strains and by strains moving from soil to other niches. In this context, phenotyping and genotyping did not group the strains in the same way and many strains phylogenetically different showed the same phenotypic trend, thus suggesting that A. acidoterrestris could exist as a genomovar. In addition, the strain CB-1 was distant from other alicyclobacilli, although it possessed the same traits as the other isolates from juice (CB-2); therefore, it is probably a fast-clock organism or the in beginning of an alternative pathway in alicyclobacilli evolution.
Significance: The characterization of A. acidoterrestris represents the first step to design an efficient approach to inhibit and/or control spores in juices. The results from this research showed that the classical ideas of genus and species, as well the international cut-off point for 16S rDNA (95 and 98%), could not satisfactorily describe A. acidoterrestris.