**6. Conclusions**

*Lactobacillus* is one of the most diverse group of microorganisms associated with the wine environment. Some *Lactobacillus* species have also displayed the ability to survive the harsh wine conditions, and, within this group, the species *Lactobacillus plantarum* has shown the most potential as a starter culture for the induction of malolactic fermentation. Global warming and the trend towards harvesting higher maturity grapes have resulted in the processing of higher pH musts. Microbial stability as a result of lactic acid bacteria activity will play a more important role in the warmer climates. Under these high pH conditions, *Lactobacillus plantarum* bacteria have shown especially interesting results, not only for their capacity to induce malolactic fermentation when inoculated either shortly after the yeas<sup>t</sup> (co-inoculation) into the must or in sequential inoculation after alcoholic fermentation, but also for their homo-fermentative properties for the metabolism of hexose sugars, which minimizes the risk of acetic acid production. *L. plantarum* was found to dispose over a more complex enzymatic system, which could play role in the modification of wine aroma. More research is certainly needed to study the expression of these enzyme activities in wine.

Applying a strong *Lactobacillus plantarum* inoculum with high malolactic activity assures the early onset of predictable and complete MLF in a short period of time (during AF) and allows an early stabilization of the wine. Even under limiting white wine conditions, a complete or partial malolactic fermentation can be induced. Since this species is very versatile, other application for bio-protection and acidification mat play a more important role in the use of this starter culture.

#### **Funding:** This research received no external funding.

**Acknowledgments:** The authors thank research partner James Osborne (Oregon State University USA) for the research collaboration on impact of malolactic fermentation on Pinot Noir color, and our colleague Magali Déléris-Bou from our research Laboratory at Lallemand SAS in Toulouse, for conducting the internal experiments.

**Conflicts of Interest:** The authors declare no conflict of interest.
