Fig. 1.

E.coli ELMs for engineered on-demand bioproduction. a) Schematic of E. coli ELMs for expression and bioproduction in continuous culture. ELMs are fabricated by seeding Pluronic F127-BUM hydrogels with engineered E. coli cells. The mixture is transferred via syringe into a cylindrical silicone mold (diameter ​= ​4 ​mm and height ​= ​2 ​mm). The mold is placed in between glass slides and photocured with UV light (365 ​nm). Cast hydrogels are continuously cultured in EZ-RDM media. Fluorescent reporter gene expression from cells encapsulated in hydrogels is quantified using the direct-gel measurement method: cultured hydrogels are placed at the center of a microplate well pre-filled with fresh media for quantification using a microplate reader (see methods for additional details). b) sfGFP reporter expression from the pBT001-J2:RR2.CM.J23118 plasmid was measured at the time points indicated using the direct-gel measurement method. A gradual increase in ELM turbidity was observed with progressing culturing time (top inset). Bars represent the mean ​± ​standard deviation from n ​= ​5 technical replicates. c) High expression of sfGFP from encapsulated E. coli harboring pWS028.J3.J23106.sfGFP plasmid was measured using the direct-gel measurement method shown in a. Cast hydrogels and surrounding media were independently seeded with or without cells: acellular (light blue), no reporter (beige) or sfGFP-expressing (green) cells. Bars represent the mean ​± ​standard deviation from n ​= ​3 technical replicates. Statistical significance was assessed using a two-tailed unpaired Student's t-test (p ​> ​0.05). (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)