Biodiversity, dynamics and ecology of bacterial community during grape marc storage for the production of grappa

• Published in: International journal of food microbiology 2013-03, Vol.162 (2), p.143-151
• Main Authors: Maragkoudakis, Petros A., Nardi, Tiziana, Bovo, Barbara, D'Andrea, Maura, Howell, Kate S., Giacomini, Alessio, Corich, Viviana
• Format: Article
• Language: English
• Subjects: Acetobacter; Alcoholic Beverages - microbiology; Antimicrobial activity; Bacteria; Bacteria - classification; Bacteria - genetics; Bacteria - isolation & purification; Bacterial Typing Techniques; Biodiversity; Biofilm; Biological and medical sciences; Ecology; Fermentation; Food Handling; Food industries; Food Microbiology; Fundamental and applied biological sciences. Psychology; Genotyping; Grape marc; Lactobacillus plantarum; Oenococcus oeni; RNA, Ribosomal, 16S - genetics; Time Factors; Vitaceae; Vitis - microbiology
• ISSN: 0168-1605; 1879-3460
• DOI: 10.1016/j.ijfoodmicro.2013.01.005

The Italian spirit obtained from grape marc, grappa, is produced by an extended storage of the marc which allows alcoholic fermentation. Bacterial populations can develop and are associated with off-flavour production. Grape marc acidification before storage is a common practice in distilleries to control bacterial proliferation. Few studies have been published on the microbial biodiversity in grape marc and no information exists about microbiology of acidified marcs and physiological properties needed for colonizing such an environment. The aim of this study was to investigate the composition and dynamics of grape marc bacterial populations during the long-period storage by microbiological analyses of acidified and untreated marcs. Eight bacterial species were identified by ARDRA — 16s rRNA sequencing at the beginning of the fermentation. Among them the bacterial species of Tatumella terrea, Acetobacter ghanensis and Tatumella ptyseos were identified for the first time in a wine environment. In later stages Oenococcus oeni and members of the Lactobacillus plantarum group became dominant in acidified and non-acidified grape marc, respectively. Further molecular typing of L. plantarum isolates yielded 39 strains. To explain the prevalence of L. plantarum in untreated samples, all strains were tested for potential antimicrobial activity and for biofilm formation ability. Although no antimicrobial activity was found, many strains exhibited the ability to form a biofilm, which may confer an ecological advantage to these strains and their dominance during marc storage. ► Marc acidification significantly affected bacterial growth. ► Eight bacterial species were identified by rDNA sequencing at the start of the fermentation. ► L. plantarum was the dominant species in non-acidified marc after 30days while O. oeni dominated in the acidified pomace. ► Most of L. plantarum strains tested exhibited biofilm formation capability. ► Bacteria–yeast interaction influenced biofilm formation efficiency.