Removal of ethene to very low concentrations by immobilised <i>mycobacterium</i> E3

Abstract

Abstract Removal of ethene to concentrations below 1 vpm from the air in storage facilities is necessary to prevent the deterioration of stored fruits, vegetables and flowers. Ethene‐utilising Mycobacterium E3 organisms are able to oxidise ethene to these low concentrations. Ethene was oxidised at the same rate by organisms immobilised on lava or perlite as it was by the suspension of cells. The residence times in a gas/solid bioreactor necessary to convert 66% of the ethene with an initial concentration of 3.2 vpm, and with cell loads on lava of 0.72 or 0.36 mg protein g −1 support, were 15 s and 33 s respectively. Mycobacterium E3 organisms immobilised on lava lost half of their activity in 250 h while organisms immobilised on perlite lost half of their activity in 60 h. Although the operational stability of the biocatalyst should be improved and the biocatalyst is only suitable at temperatures above 10°C, the application of ethene‐utilising bacteria in a gas/solid bioreactor appears attractive.