Luca COCOLIN, Profesor de Microbiología de los Alimentos , Univ. Turín, Italia
Duncan HAMM, Senior Application Specialist. Chr Hansen
The use of selected cultures of the species Lactiplantibacillus plantarum in Oenology has grown in prominence in recent years.
While initial applications of this species centred very much around malolactic fermentation (MLF), there is strong evidence to show that certain strains can be harnessed for their bio-protective effects.
The efficacy of one particular strain of Lactiplantibacillus plantarum (Viniﬂora® NoVA™) was investigated in multiple studies.
In one of such studies the inhibition of the undesirable organisms Acetobacter aceti and Hansenia uvarum in the first steps of the fermentation process was measured. From a chemical point of view the wines inoculated with L. plantarum were also associated with a reduction of acetic acid and ethyl acetate content, both considered negative for wine quality. Inhibition of rogue Oenococcus oeni was investigated in another study, unwanted spontaneous MLF during alcoholic fermentation (AF) being a winemaking deviation that is very difficult to manage when it occurs.
Comparing the bio-protective culture with the more traditional approach of reducing must pH by the addition of tartaric acid, the adventitious Oenococcus oeni showed the most growth during AF in the control wine. Using qPCR to track microbial populations, the wines treated with Lactiplantibacillus plantarum exhibited a bacteriostatic effect against this species.
This has particular commercial relevance for controlling the flora in musts with high pH, or when the addition of tartaric acid is either not permitted or is prohibitive for other reasons. This overall set of results also highlights that the inoculation of L. plantarum represents an alternative to high levels of SO2 addition, leading to a fast decrease of the portion of microorganisms considered negative for wine quality.