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Title: Biotransformation of 2,4‐dinitrotoluene in a phototrophic co‐culture of engineered Synechococcus elongatus and Pseudomonas putida

In contrast to the current paradigm of using microbial mono‐cultures in most biotechnological applications, increasing efforts are being directed towards engineering mixed‐species consortia to perform functions that are difficult to programme into individual strains. In this work, we developed a synthetic microbial consortium composed of two genetically engineered microbes, a cyanobacterium (Synechococcus elongatusPCC 7942) and a heterotrophic bacterium (Pseudomonas putidaEM173). These microbial species specialize in the co‐culture: cyanobacteria fix CO2through photosynthetic metabolism and secrete sufficient carbohydrates to support the growth and active metabolism ofP. putida, which has been engineered to consume sucrose and to degrade the environmental pollutant 2,4‐dinitrotoluene (2,4‐DNT). By encapsulatingS. elongatuswithin a barium–alginate hydrogel, cyanobacterial cells were protected from the toxic effects of 2,4‐DNT, enhancing the performance of the co‐culture. The synthetic consortium was able to convert 2,4‐DNT with light and CO2as key inputs, and its catalytic performance was stable over time. Furthermore, cycling this synthetic consortium through low nitrogen medium promoted the sucrose‐dependent accumulation of polyhydroxyalkanoate, an added‐value biopolymer, in the engineeredP. putidastrain. Altogether, the synthetic consortium displayed the capacity to remediate the industrial pollutant 2,4‐DNT while simultaneously synthesizing biopolymers using light and CO2as the primary inputs.

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Author(s) / Creator(s):
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Publisher / Repository:
Date Published:
Journal Name:
Microbial Biotechnology
Page Range / eLocation ID:
p. 997-1011
Medium: X
Sponsoring Org:
National Science Foundation
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