Metabolic characterization of Kloeckera apiculata strains from star fruit fermentation

A total of 37 strains of Kloeckera apiculata was isolated during the spontaneous fermentation of star fruit must. Each strain was differentiated from the others on the basis of its capacity to produce acetaldehyde, ethyl acetate, higher alcohols, acetoin and acetic acid. All the strains were characterized by the low production of higher alcohols and the high production of ethyl acetate, whereas consistent differences in the production of acetaldehyde, acetoin and acetic acid served to differentiate star fruit apiculate strains into six different phenotypes, present at different stages of the fermentation process. The metabolic strain diversity found can be interpreted as a natural consequence of environmental conditions, which influenced the frequency and selection of specific apiculate strains. From the biotechnological point of view the different metabolic biotypes represent an important source of strains for potential use as starter cultures for star fruit fermentation.