Solazyme's Sugar Eating Algae

The above video shows Solazyme's mehod for creating oil from algae. It is one of the nicest productions so far regarding algae. Solazyme's algae does not use photosynthesis, which would seem to defeat the whole point of using algae for fuel. The offered reason for not using photosynthesis is that the algae produces oil more efficiently when using sugars. It seems that statement would depend on your definition of efficient. The sugars that these algae eat has to come from somewhere, so somewhere in the chain it uses land and sunlight. However, Solazyme claims that their process uses cellulosic sugars from non-food stocks. I wonder if the process can use cellulosic food stocks now or if that is something they are working towards? Anyway, it is a good video but I have become convinced that a photosynthetic algae will be the best solution. In particular, I am waiting anxiously for Craig Venter's group at Synthetic Genomics to produce their fourth generation biofuel.