Biology Question:

For any chemical reaction, the reaction rate increases with temperature, so the higher the temperature, the faster the rate. For any enzymatic reaction, the reaction rate will increase with temperature until the temperature at which the enzyme begins to denature is reached, and this is the optimum temperature.

The denaturizing temperature depends on the composition of the protein (its amino acid sequence), which varies for catalyses from different organisms. Therefore, the answer to your question is that the optimum temperature is dependent on the source organism.