Iridescent nanostructures reflect light to create intense, angle-dependent hues and are of importance for the development of novel optical surfaces (via biomimetics) and using bacteria as a reporter in diagnostic assays. Nature has a rich variety in iridescence but little is known about the underlying genetics and the relevant genes have not been identified in any kingdom of life. However, for the first time in any organism we have recently found responsible gene clusters in the bacterium Flavobacterium IR1 using high-throughput transposon mutagenesis screening. Homologous genes will be identified in metagenomics datasets and other iridescent isolates to understand their ecological significance. Moreover we aim to identify novel bacteria with different iridescent properties and the evolutionary relationship from a dataset of > 100,000 genomes using information from IR1 as a starting point.

These work supports the use of iridescent bacteria as design studios to create new optical materials (for paints, clothing, security applications) and the use of iridescent cellular assays in diagnostics (suitable for resource limited setting). The project is also of academic significance given the widespread incidence of iridescence in the natural world but the near complete lack of information on genetics and evolution.

The project is a collaboration between NIOZ (primary applicant) providing culture experience and contributing strains and genome sequences of relevant Flavobacteria; Utrecht (Hotel) with the expertise to perform the genomics/metagenomics/evolutionary bioinformatics and Hoekmine BV (commercial partner) contributing a Flavobacterium (genome sequence, gene clusters, unsequenced mutants) that will allow the genetics of structural colour to be approached and applied commercially.

• dr. A.L. (Aldert) Zomer

• Colin Ingham (Hoekmine BV)
• Henk Bolhuis (NIOZ)