エンジニアリングされた細菌性マイクロレンズの調整可能な光集束挙動と制御可能な形状

Recently, engineered bacterial cells have been shown to behave as optically-active photonic devices comparable to industrially fabricated microlenses¹. Bacterial cells can be encapsulated within a layer of polysilicate through surface display of the sea sponge enzyme silicatein, which mineralizes a polysilicate coating. The addition of this polysilicate layer significantly enhances the ability of these cells to guide, scatter, and focus light¹. However, this previous technique was limited to creating rod-shaped microlenses, which are not ideal for all applications. Here we expand upon this technology by engineering the shapes of silicatein-displaying bacterial cells. Through the overexpression of the genes bolA ^2-5 and sulA ^6,7 or through the use of the drug A22^8,9, we are able to alter Escherichia coli cells from their characteristic rod-like shape to either spherical or filamentous forms. Round cells encapsulated in polysilicate were shown to scatter light more intensely and symmetrically than rod-shaped cells, while encapsulated filamentous cells were shown to guide light similarly to an optical fiber. This control over the size and shape of optically-active cells is a major advancement towards developing bio-engineered photonic devices such as nanophotonic waveguides, spherical microlens arrays, and advanced biosensors.