Exploratory Metataxonomic Characterization of Bacterial Communities in Street-Vended Raw Milk from Ankara, Türkiye,...

Street-vended raw milk may harbor diverse bacterial communities influenced by environmental exposure, handling practices, and storage conditions. This exploratory pilot study aimed to characterize the bacterial community composition of raw milk obtained from three independent street vendors in Ankara, Türkiye, using 16S rRNA gene amplicon sequencing-based metataxonomic analysis. Following DNA extraction, the V3-V4 region of the bacterial 16S rRNA gene was sequenced, and sequence data were processed using the QIIME2 pipeline with taxonomic assignment against the SILVA 138 reference database. Sequencing generated 158,959, 160,946, and 313,696 high-quality reads for samples SS1, SS2, and SS3, respectively. The bacterial communities were predominantly composed of members of the phyla Pseudomonadota and Bacillota. At the genus level, Pseudomonas (49.75%), Acinetobacter (20.64%), Lactococcus (35.31%), Aerococcus (8.81%), and Enterococcus (7.10%) were among the predominant taxa identified across the samples. Principal coordinates analysis indicated variation in bacterial community composition among the three samples, with SS2 and SS3 exhibiting greater similarity than SS1. Overall, this exploratory pilot study provides baseline metataxonomic information on the bacterial communities associated with street-vended raw milk obtained from informal vendors in Ankara. Given the limited sample size, the findings should be regarded as preliminary descriptive observations that may support future investigations involving larger sample sizes, broader geographical coverage, and complementary functional analyses.