Isolation of dihydroxyacetone-producing acetic acid bacteria in Vietnam

Abstract

Sixty-six acetic acid bacteria (AAB) were isolated from fourty-five flowers and fruits collected in Hochiminh City, Vietnam. Of the sixty-six, thirty-one isolates were selected as dihydroxyacetone (DHA)-producing AAB based on the reaction with Fehling’s solution and grouped into three groups by routine identification with phenotypic features. Group I composed of fourteen isolates and was assigned to the genus Acetobacter, Group II composed of thirteen isolates and was assigned to the genus Gluconobacter and Group III was the remaining four isolates and was assigned to the genus Gluconacetobacter. Ten isolates among the thirteen isolates of Group II gave a larger amount of DHA (22.2–26.0 mg/mL) than Gluconobacter oxydans NBRC 14819T (19.8 mg/mL), promising for the potential use in producing DHA. In phylogenetic analysis based on 16S rRNA gene sequences, six isolates of the ten potential DHA producers were suggested to be candidates for new taxa in the genus Gluconobacter.