A Metagenomic-Based Approach for the Characterization of Bacterial Diversity Associated with Spontaneous Malolactic Fermentations in Wine

• Published in: International journal of molecular sciences 2019-08, Vol.20 (16), p.3980
• Main Authors: Berbegal, Carmen, Borruso, Luigimaria, Fragasso, Mariagiovanna, Tufariello, Maria, Russo, Pasquale, Brusetti, Lorenzo, Spano, Giuseppe, Capozzi, Vittorio
• Format: Article
• Language: English
• Subjects: 16S rRNA metataxonomy; Acids; Bacteria; Biomass; Communication; Fermentation; Fermentation - genetics; Fermentation - physiology; Inoculation; Investigations; lactic acid bacteria; Lactobacillales - genetics; Lactobacillales - metabolism; Lactobacillus plantarum; Lactobacillus plantarum - genetics; Lactobacillus plantarum - metabolism; Malic acid; malolactic consortium; malolactic fermentation; Metabolites; Metagenome - genetics; Metagenomics; Metschnikowia pulcherrima; Microbiota; Oenococcus oeni; Quality; RNA, Ribosomal, 16S; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Saccharomyces cerevisiae - metabolism; Starter cultures; Torulaspora - genetics; Torulaspora - metabolism; Torulaspora delbrueckii; Wine; Wine - microbiology; Wines; Yeast
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms20163980

This study reports the first application of a next generation sequencing (NGS) analysis. The analysis was designed to monitor the effect of the management of microbial resources associated with alcoholic fermentation on spontaneous malolactic consortium. Together with the analysis of 16S rRNA genes from the metagenome, we monitored the principal parameters linked to MLF (e.g., malic and lactic acid concentration, pH). We encompass seven dissimilar concrete practices to manage microorganisms associated with alcoholic fermentation: Un-inoculated must (UM), (PdC), (SC), and co-inoculated and sequentially inoculated, as well as and co-inoculated and sequentially inoculated. Surprisingly, each experimental modes led to different taxonomic composition of the bacterial communities of the malolactic consortia, in terms of prokaryotic phyla and genera. Our findings indicated that, uncontrolled AF (UM, PdC) led to heterogeneous consortia associated with MLF (with a relevant presence of the genera and ), when compared with controlled AF (SC) (showing a clear dominance of the genus ). Effectively, the SC trial malic acid was completely degraded in about two weeks after the end of AF, while, on the contrary, malic acid decarboxylation remained uncomplete after 7 weeks in the case of UM and PdC. In addition, for the first time, we demonstrated that both (i) the inoculation of different non- ( and ) and, (ii) the inoculation time of the non- with respect to resources (co-inoculated and sequentially inoculated) influence the composition of the connected MLF consortia, modulating MLF performance. Finally, we demonstrated the first findings of delayed and inhibited MLF when and were inoculated, respectively. In addition, as a further control test, we also assessed the effect of the inoculation with and at the end of alcoholic fermentation, as MLF starter cultures. Our study suggests the potential interest in the application of NGS analysis, to monitor the effect of alcoholic fermentation on the spontaneous malolactic consortium, in relation to wine.