Disclosed herein are bacteria engineered to treat diseases associated with hyperammonemia and methods of use thereof. Specifically, the bacteria are engineered to comprise a racemase to enable the detection of non-naturally occurring metabolites as an indication that the engineered bacteria are effectively converting ammonia.

The present invention relates to a recombinant microbial cell for producing at least one compound having structural Formula III from at least one simple carbon source:

##STR00001## wherein the simple carbon source is selected from the group consisting of glucose, sucrose, xylose, arabinose, mannose and glycerol; and wherein the cell comprises a further genetic modification to increase production of L-lysine in the cell from at least one of the simple carbon sources.