For over a century, simple lactic acid bacteria has been one of the most reliable additives to keep food and drinks safe for over a century. Although widespread today, Denmark was one of the first countries to enlist lactic acid bacteria’s help at an industrial scale, particularly for its dairy products. The labels indicated that they contained lactic acid bacteria cultures that date back to the late 1800s. The fact that we were able to extract genetic information from bacteria used in Danish butter production 130 years ago was far more than we had dared to hope for,” microbiologist and study co-author Jørgen Leisner recounted in a statement. Leisner and colleagues identified DNA from Lactococcus cremoris, a bacterium that is still used to acidify milk today.