Which of the following is one of the services provided by beneficial microorganisms?

Beneficial microorganisms play a crucial role in various aspects of food production, making the option regarding their use in this field the correct choice. These microorganisms, such as bacteria and yeast, are integral in processes like fermentation. For instance, yeast is essential in producing bread, beer, and wine, while specific bacteria are crucial for making yogurt, cheese, and pickled vegetables. By participating in these processes, beneficial microorganisms enhance flavors, preserve food, and improve nutritional quality.

The other options highlight negative aspects associated with certain microorganisms but do not pertain to those that are beneficial. Microorganisms that spoil food or cause infections are typically harmful and do not represent the positive contributions made in food production and safety. Similarly, the mention of dangerous toxins refers to harmful microbial activity rather than the beneficial roles these organisms can play.