The microbiome of draught no- and low-alcohol beer

The microbiological ecosystem of commercially available draught dispensed no- and low-alcohol beers was evaluated, with a focus on identifying predominant microorganisms with spoilage potential and characterizing variation in community structure. More than 50 samples, representing 20 no- and low- alcohol beers (7 different beer styles: lager, India pale ale, pale ale, wheat, radler, pilsner and amber ale; and 17 brands) were collected for analysis across 12 different public houses (accounts) in Nottingham, UK. Bacterial and fungal identification was achieved via third generation sequencing technologies, using amplicon-based nanopore sequencing (Oxford Nanopore Technologies). Analysis of samples indicated that species of Acetobacter, Brettanomyces and Saccharomyces were core microbiome members. The account from which a beer was sampled was shown to harbor distinct microbial communities and was the dominant factor in determining microbial community structure, explaining 72.6% of variation. This is the first study to apply third-generation sequencing technology for the analysis of draught no- and low-alcohol beers. The findings underscore the vulnerability of draught products to microbial spoilage, and highlight the importance of implementing strict hygiene control focused on draught lines, taps, keg couplers and nozzles, especially when dispensing microbiologically sensitive no- and low-alcohol beverages.