Luminescence activity as a biosensor of isobutyraldehyde production in cyanobacteria

Abstract

With the world’s increasing energy demands, there exists a tremendous need for the development and industrialization of energy-dense biofuels. Metabolically engineered cyanobacteria provide a promising means, as the utility of photosynthesis bypasses the need for harvesting, transporting and deconstructing biomass. The idea proposed is to manipulate circadian pathways in an effort to optimize cyanobacterial isobutyraldehyde (IBA) production. Bioluminescence has proven successful as a real-time reporter of circadian gene activity, so the objective was to determine whether it is a feasible means of measuring IBA levels.

The automated high-throughput system developed expands upon the “Kondotron” system, utilizing a twelve-channel turntable with stepper motor and a CCD-cooled camera. The new system makes use of commercially available parts and is controlled entirely with custom LabView software. It features several software improvements, most notably to colony selection and processing.

Luminescence activity was found to increase with increasing IBA vapor concentrations, thereby allowing for efficient screening and monitoring of IBA-producing mutants. It is expected that system performance will only improve when long-chain aldehydes, alcohols, or alkanes are the desired end-product. A similar high-throughput system could be developed for monitoring bacterial fluorescence.