Bacteria of the genus Asaia contaminating non-alcoholic beverages produce biogenic amines, posing a health risk

Bacteria of the genus Asaia,which frequently contaminate non-alcoholic beverages, are considered undesirable from both health and technological perspective. Contamination with Asaia spp. results in reduced beverage quality, manifested by off-odours, turbidity, sediment formation, and biofilm development. Certain species, such as Asaia bogorensis and A. lannensis, are opportunistic pathogens capable of causing severe infections in immunocompromised individuals. Although the production of biogenic amines (BAs) by Asaia spp. is of toxicological relevance, it remains largely unexplored. This study aimed to identify 11 strains of Asaia spp. isolated from industrially contaminated non-alcoholic non-carbonated beverages and to assess their potential to produce BAs, based on previous reports concerning acetic acid bacteria. All isolates were identified as A. lannensis with ≥99.64% identity by 16S rRNA gene sequencing, further confirmed by MALDI-TOF MS using a custom in-house database. All identified 16S rRNA sequences and MALDI-TOF MS protein spectra, including those of three reference Asaia spp. strains, have been deposited in the newly created BioProject PRJNA1282453. HPLC analysis revealed that all 11 A. lannensis isolates and two reference Asaia spp. strains produced BAs, with total concentrations ranging from 2.20 to 824.20 mg L–1. The highest level (824.20 mg L–1) was detected in isolate A. lannensis 12, dominated by putrescine (785.30 mg L–1) and cadaverine (22.50 mg L–1). This study provides the first evidence that Asaia spp. can produce biogenic amines (BAs), highlighting their potential health risk in non-alcoholic beverages and the need to monitor and control A. lannensis to ensure beverage safety.