Which type of bacteria are commonly used to break down protein in the production of cocoa and chocolate?

Proteolytic bacteria are specifically known for their ability to break down proteins into smaller peptides and amino acids through the process of proteolysis. This characteristic is particularly useful in the production of cocoa and chocolate, where the fermentation process involves the breakdown of proteins found in cocoa beans. As cocoa beans ferment, proteolytic bacteria contribute to the development of the flavor and aroma by breaking down these larger protein molecules, allowing for the enhancement of the desired characteristics in the final chocolate product.

In contrast, other types of bacteria listed, such as lactic-acid and acetic-acid bacteria, play different roles in fermentation and may contribute to the acidity and overall fermentation process but do not specifically focus on protein breakdown. Carbon-dioxide bacteria is not a recognized group in this context, making proteolytic bacteria the most relevant and accurate choice for the question regarding their role in cocoa and chocolate production.