Acetic Acid Bacteria Taxonomy from Early Descriptions to Molecular Techniques

The exploitation of acetic acid bacteria (AAB) has a long history in fermentation
processes and now represents an emerging field in biotechnological applications,
especially with regard to the biosynthesis of useful chemicals with a potentially
high economic value and, in food science, through the standardization of micro-
biological processes for the manufacture of both vinegar and other fermented
beverages.
Historically, AAB were recognized as ‘vinegar bacteria’ because the first stud-
ies were done on vinegar, and later on wine and beer spoilage. In fact, vinegar
AAB are a subset of a larger AAB group, which includes bacteria that interact with
flowers, fruits, the rhizosphere of plants, and even human beings (Table 3.1). It is
generally recognized that AAB are fastidious microorganisms, which means that
many of them are difficult to grow on laboratory media. Many efforts have been
made to isolate and culture colonies of AAB. Several media have been suggested
and tried, but none of them appears to satisfy the growth requirements of AAB.
This has hindered the application of cultivation-based techniques to the study of
AAB and, consequently, their taxonomic classification. However, the recent dis-
covery of new culture-independent methods has opened up new horizons for the
systematic study of AAB.