ChromSoc nitrilase flow chemistry project 5

We have looked at the conversion of 4-cyanopyridine to isonicotinic acid using our mesoscale flow chemistry apparatus containing a nitrilase enzyme immobilized in alginate. Here is an example of our results.

Rob flowed the reaction medium through the device, and took a measurement of the amount of ammonia (using our colorimetric nitrilase assay) available after each cycle. Each cycle took about 20 minutes. It has not reached completion but seems to be a fairly robust system as far as it goes.

ChromSoc nitrilase flow chemistry project 4

Once you have the track filled with immobilized enzyme and the two halves stuck together, you just need to condition it and check there are no leaks.

Then it is just a case of getting the reaction going using a water bath to get the appropriate temperature. We tend to set it up so that we have a separate starting and receiving flask so that we can track aliquots through the enzyme bed, but you can just the two pipe operating out of /into the same flask obviously.

ChromSoc nitrilase flow chemistry project 3

Rob has shown made a supply of  the plates that go together to make a flow cell for flow biocatalysis. The 3D printed master copy (the one with the wall around the shape) has provided another silicone mould which has then be used to make polyurethane casts.

They can then be stuck together with the track filled with immobilized enzymes. Alongside these reactions we are also running comparable batch reactions in glassware to see how they compare.

ChromSoc nitrilase flow chemistry project 2

We have a range of nitrilases which we use as starting points for all our projects. Most of them are listed in this ChemComm. We've used them both as cell free extract and with many different types of immobilization. A good place to start we have found is in simple alginate beads which are easy to make, and give a consistent performance under our standard reaction conditions. Their synthesis using a powered syringe dropping into a stirred beaker has a somewhat hypnotic quality.

ChromSoc nitrilase flow chemistry project 1

I have an undergraduate student, Rob, working with us this summer on nitrilase reactions. He is kindly sponsored by the Chromatographic Society to work on a project using HPLC and GC to compare batch processes run on immobilized enzyme in a flask with those run on the same enzyme preparation using our in-house mesoscale flow reactor system. The flow reactor system is something we have been working on for a while and its genesis was part of a project based around using 3D printing to make bespoke laboratory equipment which is described in the Tumblr blog here, with a video of the system in operation doing a nitro reduction here. My intention is to relate here a real time log of progress with this project.

Two copies of the track fit together, and the solution

is flowed through. The track contains enzyme immobilized

on beads.