An important cause of tooth decay by the bacterium Streptococcus mutans is because of their ability to attach to teeth surface by producing slime layer from

Streptococcus mutans is the primary bacterium responsible for dental caries (tooth decay). Its ability to adhere to the tooth surface is directly linked to the metabolism of dietary sugars, especially sucrose.

• Biofilm Formation: The bacterium utilizes an enzyme called glucansucrase to convert sucrose into long-chain, sticky polysaccharides known as glucans.
• Slime Layer: These glucans form a gelatinous "slime layer" or biofilm (commonly known as dental plaque), which allows the bacteria to stick firmly to the enamel and resist being washed away by saliva.
• Acid Production: Once attached, the bacteria ferment sugars to produce lactic acid. This acid lowers the pH on the tooth surface, causing demineralization of the enamel, which eventually leads to cavities.

Thus, sugar acts as the substrate for creating the adhesive slime layer that enables bacterial colonization and subsequent decay.