What might happen after the nitrile hydratase has done its job in a whole cell system?

...You've got to work with the amidase which converts the amide to the corresponding carboxylic acid.
Laura Cantarella, Alberto Gallifuoco, Agata Spera and Maria Cantarella look at the amidase in the NHase/amidase system of Microbacterium imperiale CBS 498-74 in the paper entitled "Nitrile, amide and temperature effects on amidase-kinetics during acrylonitrile bioconversion by nitrile-hydratase/amidase in-situ cascade system" in the journal Bioresource Technology with DOI:10.1016/j.biortech.2013.04.126.

Two recent articles on NHases

*Unique Biogenesis of High-Molecular Mass Multimeric Metalloenzyme Nitrile Hydratase: Intermediates and a Proposed Mechanism for Self-Subunit Swapping Maturation-

Zhou, Hashimoto, Cui, Washizawa, Mino, and Kobayashi in Biochemistry (2010)

DOI: 10.1021/bi100651v

An investigation of the subunit structure of the NHases in Rhodococcus rhodochrous J1.

.

*High-yield continuous production of nicotinic acid via nitrile hydratase-amidase cascade reactions using cascade CSMRs 

Cantarella, Gallifuoco, Malandra, Martinkova, Spera, and Cantarella in Enzyme and Microbrial Technology(article in press, 2010)

DOI: 10.1016/j.enzmictec.2010.12.010

This looks at using the NHase/amidase system from Microbacterium imperiale CBS 498-74 in a bioreactor to convert 3-cyanopyridine to nicotinic acid.