Characterization of lactic and acetic acid bacteria and their phages from a California winery

Abstract Spoilage of wine from volatile acidity or off flavors caused by uncontrolled growth of lactic acid bacteria (LAB) and acetic acid bacteria (AAB) results in significant economic losses. We aim to survey the persistence of LAB and AAB throughout the wine processing stages, and to evaluate the potential of phages as targeted microbial control. Cabernet Sauvignon samples were collected from a winery in Livermore, California during 2025 harvest season, covering grape rinse, juice/must, the end of primary fermentation and malolactic fermentation steps. Bacterial 16S amplicon sequencing of these samples identified key species that persist through the wine processing steps, including Lactiplantibacillus plantarum and Levilactobacillus lactis among LAB, and Acetobacter oryzoeni and Acetobacter pasteurianus among AAB. Phages targeting L. brevis , A. pasteurianus and A. fabarum were isolated. L. brevis phages Indaco_L1 and Indaco_L2 (genome size of 135,623 bp and 141,184 bp, respectively) are related to phages in the Tybeckvirus genus of the Herelleviridae family, but distinct enough to form two novel species. The two novel Acetobacter phages, a first reported Acetobacter jumbo phage Vinphasol_A1 (genome size 397,952 bp) and Vinphasol_A2 (genome size 56,636 bp), share little DNA sequence similarity to phages in the current NCBI database. These isolated phages were able to inhibit the growth of L. brevis, A. pasteurianus and A. fabarum for up to 7 days in conditions simulating wine fermentation, suggests their potential application in controlling microbial spoilage during wine making processes.