Final answer:
Each Bacteroides species will have specialized enzymes for its specific function in the gut; B. theta likely has carbohydrases like cellulases, while B. caccae and B. vulgatus will also have their unique metabolic enzymes.
Step-by-step explanation:
The enzymes or proteins that each bacterial species is expected to have, allowing it to utilize its respective environment, are specific to the chemical processes it has adapted to engage in. For instance, Bacteroides thetaiotaomicron (b. theta) is known for digesting complex plant materials with enzymes that humans lack, indicating it would possess cellulases or other carbohydrases. Bacteroides caccae (b. caccae), which is closely related, may also have enzymes for carbohydrate metabolism, but may differ based on its specific substrate availability and function within the gut microbiome. Bacteroides vulgatus (b. vulgatus) is another gut bacterium likely to possess a suite of proteases and carbohydrases tailored to its niche in the gut ecosystem.