Biotransformation of 2,4-dinitrotoluene in a phototrophic co-culture of engineeredSynechococcus elongatusandPseudomonas putida

Abstract

16In contrast to the current paradigm of using microbial monocultures in most 17 biotechnological applications, increasing efforts are being directed towards engineering 18 mixed-species consortia to perform functions that are difficult to program into individual 19 strains. Additionally, the division of labor between specialist species found in natural 20 consortia can lead to increased catalytic efficiency and stability relative to a monoculture or 21 a community composed of generalists. In this work, we have designed a synthetic co-22 sucrose as a carbon source and to perform the biotransformation of 2,4-DNT. The division 41 of labor in this synthetic co-culture is reminiscent of that commonly observed in microbial 42 communities and represents a proof-of-principle example of how artificial consortia can be 43 employed for bioremediation purposes. Furthermore, this co-culture system enabled the 44 utilization of freshwater sources that could not be utilized in classical agriculture settings, 45 reducing the potential competition of this alternative method of bioproduction with 46 current agricultural practices, as well as remediation of contaminated water streams. 47 48 49 consortia; bioproduction 50 polyhydroxyalkanoate (PHA) (Figure 1). This was accomplished through the pairing of an 131 engineered strain of P. putida, containing the genes needed to both metabolize sucrose and 132 to degrade 2,4-DNT with the sucrose-exporting S. elongatus CscB encapsulated in alginate 133 hydrogel beads. Approaching the bioremediation of this compound via the synthetic 134 consortium method allows for the bioprocess to be photosynthetically powered while 135 avoiding the complexities of introducing a new enzymatic pathway into photosynthetic 136 cyanobacteria. We demonstrated that these co-cultures can successfully execute the 137 biotransformation of 2,4-DNT via the engineered pathway and are also able to accumulate 138Eng 11:1-36. 595

Biotransformation of 5‐Hydroxymethylfurfural to 2,5‐Furandicarboxylic Acid by a Syntrophic Consortium of Engineered Synechococcus elongatus and Pseudomonas putida

“…Similar phenomena were also observed in some other researches. [ 18,29 ] It has been reported that the chromosomally‐located sucrose catabolose ( csc ) regulon of E. coli W required a relatively high concentration of sucrose (>1%) to activate. [ 30–32 ] Therefore, the accumulation of the basal amount of sucrose might be due to the insensitivity of the CscA system to low sucrose concentration.…”

Integrating greenhouse gas capture and C1 biotechnology: a key challenge for circular economy

“…Strategies involving co‐cultivation of methanotrophic and oxygenic photosynthetic bacteria in biogas have been already explored (Van der Ha et al ., 2012; Hill et al ., 2017). An engineered Synechococcus elongatus able to convert CO 2 into secreted sucrose can be used in co‐culture with other bacteria to generate biotechnological applications (Löwe et al ., 2017; Weiss et al ., 2017; Fedeson et al ., 2020; Zhang et al ., 2020b).…”

Photobiological production of high-value pigments via compartmentalized co-cultures using Ca-alginate hydrogels

“…Alginate encapsulation of S. elongatus 7942 was found to enhance its sucrose production and co-culture stability with polyhydroxybutyrate producing Halomona boliviensis over 5 months, and the encapsulated cyanobacteria resisted invasive microbial species during that time 19 . Moreover, the same alginate-encapsulated sucrose-secreting cyanobacteria (within a barium-alginate hydrogel) and Pseudomonas putida formed a co-culture that both enhanced the degradation of an environmental pollutant, 2,4-dinitrotoluene, and synthesized the biopolymer polyhydroxyalkanoate 6 . As this example demonstrates, hydrogel encapsulation connects individual species that possess different metabolic features, and it supports biological functions over long time periods.…”