The effect of whole cell immobilisation on the biotransformation of benzonitrile and the use of direct electric current for enhanced product removal.

The nitrilase of Rhodococcus rhodochrous performs a one-step biotransformation of nitriles to their corresponding carboxylic acids. Application of a direct electric current moves the charged carboxylic acid towards an anode, across an anion exchange membrane, into a separate compartment. Cells encapsulated within alginate beads (2.

Enhanced biotransformations and product recovery in a membrane bioreactor through application of a direct electric current.

The simultaneous enhancement of biotransformation coupled to product recovery, purification and concentration is presented. The nitrilase of Rhodococcus rhodochrous LL100-21 catalyses the single-step hydrolytic biotransformation of benzonitrile to benzoic acid and ammonia. When a direct electric current is applied across a bioreactor containing the bacterium and benzonitrile, the charged product (benzoic acid) can be removed in situ across an anion exchange membrane and recovered in a separate compartment.

Bioaugmentation strategies for remediating mixed chemical effluents.

Operationally exhausted metal working fluids are chemically mixed, produced in large quantities (400 000 tonnes year in the U.K.), and potentially environmentally toxic.

Bacterial community structure and function in a metal-working fluid.

The diversity of bacterial populations colonizing spatially and temporally separated samples of the same metal-working fluid (MWF) formulation was investigated. Analyses were performed with a view to improve strategies for bioaugmentation of waste MWF in bioreactor systems and prevention of in-use MWF biodeterioration in engineering workshops. Significantly, complementary phenotypic, genotypic and in situ methods revealed that the bacterial communities in operationally exhausted MWFs had low diversity and were similar in species composition from different locations and uses.