We have a plastic problem
Plastic shows up everywhere in our lives, and for good reason. It is an amazing and durable material , making it an ideal candidate for use in everything from food packaging to clothing. However, the same thing that makes plastic such an amazing material - its durability - is also the reason why plastic pollution is so persistent when it is inadvertently released into the environment. Approximately 60% of the all plastic made since the 1950s still exists, leading to vast amounts of waste accumulation. Many people claim that plastic lasts forever. However, most organic materials will eventually succumb to the combined forces of nature, generally as a result of sunlight and the extensive diversity of microbes that evolve new ways to utilize carbon-rich compounds. The problem with plastics is time, and in the case of many plastic polymers, the fact that most microbes only come in contact with the surfaces of what can be a very thick solid material. Recent reports have identified microbes that can break down plastics like polyethylene terephthalate (PET or PETE), which is a type of polyester commonly found in food and beverage containers. Our laboratory is studying microbes that break down polyethylene, a polymer that is much more common, and much more difficult to degrade. However, in spite of these difficulties, there are microbes that slowly biodegrade polyethylene. Our laboratory is researching the nature of this biodegradation, and trying to determine methods to elucidate the enzymes and pathways that are essential to this process. The image below is an electron micrograph of a piece of polyethylene that is pitted by the action of one of the microbes we have isolated and are studying in the laboratory.
Our approach
Using techniques that include general microbiology approaches and efforts to collect environmental samples from specific site across Minnesota, we have enriched communities of microbes that are able to utilize polyethylene surrogates. From this work, we have isolated and identified more than 100 different microbial strains, and confirmed that more than 30 different microbial strains have the potential to decompose these plastics on their own. We have sequenced and published the genomes of a large number of these bacteria, and are currently working to develop specific genetic techniques that will enable us to formulate the general pathways at allow these microbes to utilize these recalcitrant polymers.
Collaboration
Our laboratory is open to collaboration with other laboratories. We are funded through the Environment and Natural Resources Trust Fund (ENTRF) through the Legislative-Citizen Commission on Minnesota Resources. This continuing funding allows our laboratory to continue this work. Shown below is an image of microbes grown with polyethylene as the sole carbon source following several weeks of culture.
