Credit: Gerd Altmann, Pixabay
A scientific paper titled “Enhancing Microbial Cooperation for Plastic Transformation” has recently been published in the journal Nature Communications.
In order to address the concerning increase in plastic pollution on a global scale, the study has engineered a synthetic microorganism community that collaboratively transforms plastics into desired chemicals. Instead of attempting to create a single organism capable of executing all stages of the transformation, the researchers employed two strains of bacteria to efficiently break down one of the most prevalent plastics, polyethylene terephthalate (PET), into non-hazardous, eco-friendly, and biodegradable polymers.
The utilization of microorganisms for bioconversion is rapidly emerging as a promising substitute for traditional polymer transformation techniques due to its potential to streamline production processes, amalgamating waste decomposition with product generation. For instance, diverse microbial isolates have been identified and harnessed to decompose and absorb PET. Engineered bacterial and fungal strains have also been developed to expedite PET hydrolysis, converting plastic waste into valuable chemicals and products. Despite these encouraging advancements, the intricacies of polymer transformation present numerous obstacles for contemporary biotransformation strategies that concentrate on monocultures.
In this study, the authors adapted two variations of the soil-dwelling bacterium Pseudomonas putida to break down PET. Each variation was responsible for handling one of the two compounds generated as byproducts during the chemical breakdown of plastics: terephthalic acid or ethylene glycol. These variations enhanced productivity when employed in conjunction, as opposed to employing a single variation for both products. Subsequently, these bacteria transformed the plastic into the biodegradable polymer medium-chain length polyhydroxyalkanoates (mcl-PHA) and the precursor to polyurethane and adipic acid known as cis-cis muconate (MA). Polyurethane is used in insulating materials, foams, coatings, and adhesives, while nylon is derived from adipic acid.
This engineered transformation consortium can be utilized to produce various other chemicals beyond mcl-PHA and muconate. This can be accomplished by introducing new biosynthetic pathways and integrating them with the primary metabolic hubs in terephthalic acid (TPA) and ethylene glycol (EG) degradation, leveraging their modular structure. Furthermore, even though the study was limited to PET transformation, the fundamental concept and strategies hold promise for addressing other types of plastics, offering valuable insights into the development of a sustainable bio-based economy.
