Lactic acid bacteria (LAB) are responsible for many fermented foods such as sauerkraut, pickles and yogurt. They have also been isolated from wines at various states of vinification. In wines they are responsible for malolactic fermentation (MLF) which can be beneficial in some cases and undesirable in others. Besides conducting MLF, these bacteria under certain conditions can also cause undesirable changes in wine flavor which renders the wine undrinkable. Many species of LAB do not conduct MLF and their growth in wine can cause some serious wine spoilage.