Assessment of the genetic polymorphism and biogenic amine production of indigenous Oenococcus oeni strains isolated from Greek red wines

In the warm climate country of Greece malolactic fermentation (MLF) has received limited attention. Molecular techniques and High Performance Liquid Chromatography (HPLC) were used to study the genetic polymorphism of autochthonous lactic acid bacteria developing towards the end of spontaneous MLF of Greek red wines and for the assessment of their potential to produce harmful biogenic amines. This research revealed that native Oenococcus oeni isolates are very much adapted to specific winery conditions since the majority of spontaneous MLF were driven mostly or exclusively by a single strain of O. oeni. Native O. oeni strains showed only limited dispersion since cluster analysis uncovered only few common genotypes among indigenous isolates from different wineries. The genotype of a frequently used malolactic starter was more than often detected among autochthonous isolates without nevertheless compromising the biodiversity of natural microflora residing in wineries but rather becoming a part of it. For the majority of the wine samples studied, MLF implementation and storage in bottles resulted in negligible changes on the levels of the BA histamine, tyramine, phenylethylamine, cadaverine as well as of ethylamine, methylamine, isobutylamine. We provide evidence that autochthonous O. oeni isolates can only contribute to putrescine accumulation in Greek wines but still the specific trait behaves as strain-specific with a limited dispersion.

► We studied the polymorphism of native Oenococcus oeni from Greek wines and their potential to produce biogenic amines. ► Each winery is characterized by a specific bacteria flora. ► Bacterial starters become part of the natural bacterial flora residing in wineries. ► Only putrescine was increased during spontaneous MLF of wines. ► A limited number of native O. oeni isolates was able to produce putrescine.