The cell organization underlying structural colour is involved in Flavobacterium IR1 predation

Abstract

Flavobacterium IR1 is a gliding bacterium with a high degree of colonial organization as a 2D photonic crystal, resulting in vivid structural coloration when illuminated. Enterobacter cloacae B12, an unrelated bacterium, was isolated from the brown macroalga Fucus vesiculosus from the same location as IR1. IR1 was found to be a predator of B12. A process of surrounding, infiltration, undercutting and killing of B12 supported improved growth of IR1. A combination of motility and capillarity facilitated the engulfment of B12 colonies by IR1. Predation was independent of illumination. Mutants of IR1 that formed photonic crystals less effectively than the wild type were reduced in predation. Conversely, formation of a photonic crystal was not advantageous in resisting predation by Rhodococcus spp. PIR4. These observations suggest that the organization required to create structural colour has a biological function (facilitating predation) but one that is not directly related to the photonic properties of the colony. This work is the first experimental evidence supporting a role for this widespread type of cell organization in the Flavobacteriia.

SIBR-Cas enables host-independent and universal CRISPR genome engineering in bacteria

“…4E, S9 and S10). In accordance, the phenotype of the SprF mutants displayed similar characteristics when compared to previous studies 18,19 (Fig. 4F).…”

“…Lastly, we focused on the non-model organism Flavobacterium IR1, which is a recent isolate best known for its iridescent, structural colour 18,19 . The lack of genomic tools, low transformation efficiency and the low HR efficiency of IR1 are currently the main bottlenecks holding back the fundamental characterization and commercial exploitation of this phenomenon (i.e.…”

Gliding motility of a uranium tolerant Bacteroidetes bacterium Chryseobacterium sp. strain PMSZPI: Insights into the architecture of spreading colonies

“…The coloration could have resulted from interaction of natural light with periodic cellular organization as visualized in PMSZPI colony (Fig. 3C) which has been commonly reported within Flavobacteria (Kientz et al, 2012b;Kientz et al, 2016;Johansen et al, 2018;Hamidjaja et al, 2020). The corresponding PMSZPI colonies on soft agar (0.35%) with medium concentrations ranging from 1/2 LB to 1/50 LB (Fig.…”

“…Bacterial iridescence is unknown in natural ecosystems. The structural coloration is proposed to attribute towards photoprotection or thermoregulation in marine Bacteroidetes members (Kientz et al, 2012a) or optimum cellular organization to degrade biological polymers (Johansen et al, 2018) or predation (Hamidjaja et al, 2020) in the soil bacterium, F. johnsoniae. Our work here provides the first evidence for iridescence in the Bacteroidetes gliding bacterium, Chryseobacterium PMSZPI isolated from uranium/metal enriched environment.…”

Does Structural Color Exist in True Fungi?

“…Within the prokaryotes, we also find examples of structural color, albeit not as individual cells, but in bacteria colonies. Gliding bacteria such as Flavobacterium IR1 ( Figure 3) and Cellulophaga lytica are known to produce vivid and iridescent coloration due to the periodic organization of their cells [18][19][20][21]. Therefore, considering that such structural colors are so widespread in a great variety of living organisms, it is puzzling that structural colors have never been reported in the Eumycetes.…”