They're too long to include in a blog post so I've posted them here.
Bottom line: the reviews are largely favourable so our manuscript is provisionally accepted!
The main concern of the referees is the growth issues I've written about here: the cells would not grow in the medium specified by the original authors (I had to add glutamate) and the medium I used was supplemented with 3 µM phosphate and it's basal phosphate contamination had not been measured.
Most of the issues can either be just clarified in the text or declared to be beyond the scope of this work, but we're going to try to directly measure the basal phosphate contamination in the medium. (We're worried that previous analyses of phosphate-buffered materials may have decreased the sensitivity of the LC-MS system we used.)
Of course we'll also address the comments on the manuscript posted by readers of this blog. And we'll post the complete Response to Reviewers here.