Lactic acid bacteria vs Biogenic amines
The presence and accumulation of biogenic amines depends on many factors such as the presence of specific bacteria having the necessary decarboxilase enzymes, availability of free amino acids (which may imply the presence of a microflora having proteolytic activity allowing peptides hydrolyse into free amino acids) and the existence of proper environmental physical conditions.
The Project: To imobilize regional lactic acid bacteria starters for wine industry
Ana Paula Marques - PhD-student
Partners:
The project aims to select non producing BA Lactic acid bacteria, isolated from Portuguese wine regions, to produce immobilized LAB to be used as 'Regional' starters to induce MLF in wine, as an alternative to the existing 'Universal' lyophilised ones.
- LAB isolation and identification (phenotipic and molecular characterization
Along the work, were isolate 295 LAB from Douro wines (42 Lactobacillus, 24 Pediococcus, 2 Leuconostoc and 227 Oenococcus), that were identified using molecular biology at the species level and characterised by the respective profiles of cellular total proteins (SDS-PAGE) and ‘M13-PCR fingerprinting’ (partners UTAD/ICAT-FCUL). Moreover, 121 Oenococcus oeni were also isolated and identified 43 from Dão wines, 36 from Ribatejo and 42 from Alentejo ones.
- Selection process
LAB enzymes and genetic profile
Growth and survival under different conditions
Amino acid decarboxylase and beta-glucosidase activities
Amino acid decarboxylase and beta-glucosidase genes
- LAB Transcriptome under differnt medium conditions
After a long selection process, the expression of the codifying genes for amino acid decarboxilases (de enzymes responsible by amino acid decarboxilation with subsequent amines formation) under the harsh wine environmental conditions was studied.
- Production of immobilized LAB
- The bacteria immobilizing process was developed by the Company PROENOL and tests under cellar conditions are planed.
