Exploring the microbial ecology in rum production: quantita-tion, diversity, and significance

Анотація

This study aims to characterize the microbial diversity associated with rum production with a focus on understanding the microbial factors contributing to variability in fermentation processes. Samples were systematically collected from critical process points including the molasses storage vessels, yeast propagation tanks, fermenters, water, and dunder across four months at Bundaberg Distilling Company (BDC). Using culture-dependent methodologies, the study quantified total bacterial load, lactic acid bacteria, and yeast populations to characterize microbial succession across the rum production cycle. The microbial populations exhibited variations across different stages and sampling points, highlighting the dynamic nature of microbial communities during rum production. Distinct microbial profiles were observed at different stages, underscoring the dynamic nature of microbial community structure in an industrial fermentation context. Molasses samples exhibited high bacterial diversity, prominently featuring Lactobacillus spp., while water and dunder maintained consistently low microbial loads, reflecting their importance in preserving process integrity. Quantitative analyses revealed significant Lactobacillus proliferation during early fermentation, followed by a progressive dominance of Saccharomyces cerevisiae, which reached peak populations of 7.8 × 10⁷ CFU/mL. Multivariate statistical analyses, including principal coordinate analysis (PCoA), Shannon diversity indices, and Bray-Curtis dissimilarity metrics, revealed both temporal and spatial separation of microbial communities. A marked decline in alpha diversity (from 1.49 to 0.68) was observed as fermentation progressed, alongside increasing inter-sample dissimilarity, indicating ecological succession toward a less diverse but functionally specialized yeast-dominated community. The findings of this study advance the understanding of microbial population dynamics in rum fermentation and provide a framework for optimizing production processes. Identifying the key microbial players and the succession patterns enables targeted manipulation of the microorganisms to improve batch consistency, fermentation efficiency, and ultimately, product quality.