Fig. 4: Upcycling of hydrolyzed PET into mcl-PHA.

a Design of a synthetic consortium that produces mcl-PHA from TPA and EG co-degradation. The consortium was created by introducing an mcl-PHA biosynthetic pathway into Pp-T and Pp-E along with additional knockouts. b Design of an engineered strain that synthesizes mcl-PHA and co-utilizes TPA and EG. The strain was developed by adding an mcl-PHA synthesis pathway into Pp-TE along with additional knockouts. c–e Comparison of mcl-PHA production from pure TPA and EG by different Pp-T (c), Pp-E (d), and Pp-TE (e) derivatives. Pp-T has three derivates: Pp-TS, Pp-TP, and PpΔ-TP. Pp-E has three derivates: Pp-ES, Pp-EP, and PpΔ-EP. Pp-TE has three derivates: Pp-TES, Pp-TEP, and PpΔ-TEP. f, g Temporal profiles of direct PET hydrolysate fermentations under nitrogen-limiting conditions by the TP-EP consortium (f) and its single-strain counterpart Pp-TEP (g). An initial 1:3 inoculation ratio was used for Pp-TP and Pp-EP. h, i Temporal profiles of fed-batch fermentations under nitrogen-limiting conditions by the TP-EP consortium (h) and Pp-TEP (i). An initial 1:3 inoculation ratio was used for Pp-TP and Pp-EP. j The mcl-PHA titer and monomer composition of mcl-PHA produced by the TP-EP consortium and single-strain counterparts Pp-TEP in nitrogen-limiting batch and fed-batch cultures. k, The mcl-PHA yield from PET hydrolysate by the TP-EP consortium and Pp-TEP in different batch and fed-batch cultures. For panels a and b, blue text indicates overexpressed genes whereas red cross (‘×’) indicates the deletion of genes in dark gray. In panels c–e, j, and k, mcl-productions were calculated at the time point when TPA and/or EG were fully degraded. In panels c–e, results were compared using one-way ANOVA (one-sided) with Dunnett’s multiple comparison test. Experimental data are presented as mean values with standard deviations from three independent experiments. Source data are provided as a Source Data file.