The research groups of Assistant Professor Shosuke Yoshida (currently affiliated with the Graduate School of Engineering, Kyoto University), Associate Professor Kenji Miyamoto, Professor Emeritus Kohei Oda, and Professor Emeritus Yoshiharu Kimura of Kyoto Institute of Technology are Teijin Co., Ltd. and ADEKA Co., Ltd. In collaboration with, we discovered a bacterium that decomposes and proliferates polyethylene terephthalate (PET), and succeeded in elucidating the decomposition mechanism.The results of this research are published in the American scientific journal "Science" published in March 2016.
PET is manufactured from petroleum and is widely used as a material for PET bottles and clothes.However, only 4.1% of total production is recycled and most is discarded.In addition, as a PET recycling method, the mainstream chemical recycling has problems such as consuming enormous energy.
While exploring various environmental samples, the research group discovered that a wide variety of microorganisms gathered and decomposed on PET film.We have succeeded in isolating PET-degrading bacteria from this microbial community. The strain, named "Ideonella sakaiensis 201-F6 strain," was found to not only degrade PET, but also serve as a nutrient source.Furthermore, when the genome analysis of the 201-F6 strain was performed, two enzymes, "PETase", which preferentially decomposes PET and has high decomposition activity even at room temperature, and "MHETase", which hydrolyzes PET, are used. I found.It was found that the 2-F2 strain efficiently decomposes PET into the raw materials terephthalic acid and ethylene glycol by the action of these two enzymes.
Until now, PET has been thought not to be decomposed in nature, but this research has revealed that there is a biological route that can be incorporated into biorecycling.In the future, in order for humankind to create a sustainable society, it will be necessary to break away from dependence on limited resources and promote recycling.If the activity and stability of the enzyme found this time can be enhanced, it is thought that the realization of ideal PET recycling with low energy consumption and environmental friendliness will be approached.
