Researchers at RBG Kew made a significant discovery with plastic eating fungi in manmade plastisphere may help tackle global waste by decomposing plastic pollution. The international team of researchers discovered 184 fungal and 55 bacterial strains capable of decomposing polycaprolactone (PCL).
This study brings forth the existence of a terrestrial plastisphere in a man-made ecological niche. Bacteria from the Jonesia and Streptomyces genera showed high potential in degrading petroleum-based polymers. Under the campaign #BeatPlasticPollution this research came at the right time which is ahead of World Environment Day 2023.
Researchers at Royal Botanical Gardens Kew published a new study mentioning that they have identified a different microbiome of plastic-eating fungi and bacteria in the coastal salt marshes of Jiangsu in China.
This international scientists’ team counted 184 fungal and 55 bacteria strains that according to them were capable of breaking down polycaprolactone (PCL). This is biodegradable polyester that is commonly used in the production of different polyurethanes. Bacterial strains that have potential to further degrade other petroleum-based polymers were from genera Jonesia and Streptomyces.
This research about plastic eating fungi in plastisphere arrived ahead of 5-June-2023, which is World Environmental Day 2023. The theme of this event is to find possible solutions to solve plastic waste crisis under the #BeatPlasticPollution campaign.
Senior Research Leader in Fungal Diversity and Systematics at RBG Kew, Dr. Irina Druzhinina says, “Microbiologists across the board feel responsible for finding solutions to the ecologically friendly treatment of plastic waste because bacteria and fungi will be the first organisms to learn how to deal with this new material.
We have no doubt that microbes will figure out ways to effectively degrade plastic, but this may take thousands of years if we leave nature to run its course. That is why our task is to utilize the knowledge we already possess of microbial biology, to speed up and direct the evolution of microbes and their individual genes to do the job now.”
Among the samples, 14 genera of fungi were identified for the purpose, including the plant pathogens Fusarium and Neocosmospora. These fungi harm the plant from which they draw nutrients and this made researchers conclude that these fungi could be a better choice for degrading PCL plastics along with other synthetic polymers. It is also indicated that they may prove more useful to tackle global waste than saprotrophic fungi.
Alongside the samples derived from Dafeng, the research team recognized 2 other genera of bacteria Streptomyces and the recently discovered genus Jonesia. According to them, they are also among the promising candidates for plastic degradation research. This is due to the fact that the species Jonesia cf. Quinghaiensis dominated the 55 sampled bacterial strains.
The Royal Botanical Gardens Kew is the home to one of the world’s oldest and biggest fungaria with more than 1.25 million specimens. But still, the fungi kingdom is one of the biggest mysteries of the natural world that researchers are trying to solve. There are still several million species that are not discovered to date.
Scientists are positive about the fact that these undiscovered species could be a potential new source of medicine, food, and other beneficial compounds.
To this Dr. Druzhinina adds, “The ecological niche of the Dafeng salt marshes is precisely why we chose to investigate the microbial communities present in the plastic waste there, and so far, our findings have proven to be both exciting and promising.”
In this context, Dr. Feng Cai, Shenzhen University, China, says, “What strikes me the most is the sheer power of microbial diversity, especially if you consider how challenging it is to detect them; they are microscopic in size, secretive in nature, and simple in appearance. However, when we shift our perspective and view them through a biochemical lens, we gain access to an abundant complexity that awaits our exploration.
It is truly exhilarating to realize we have barely scratched the surface and have already discovered a wealth of potentially promising resources for future technologies. This realization fills me with an incredible sense of satisfaction, knowing that there are numerous discoveries still to be made and that our work can potentially lead to significant advancements in the field.”
In May 2021, these plastic eating fungi were sampled from Dafeng in Eastern China, which is a UNESCO protected site near Yellow Sea Coast. Since previous research has mainly concentrated on marine ecosystems, the term ‘terrestrial plastisphere’ is relatively new to terrestrial ecology. The sampling indicated the existence of a terrestrial plastisphere. Further research revealed that the microbiome of this “man-made ecological niche” of coastal plastic trash differed from the soil in the vicinity.
Scientists are researching microorganisms like bacteria and fungi to tackle the increasing plastic pollution. According to the United Nations Environment Program (UNEP), around 400 million tons of plastic waste is annually produced which has tremendously increased since 1970s. However, now researchers have high hopes to find the solution to this problem in the plastisphere.
Past researches have already brought up the potential of microorganisms to degrade plastic waste similar to plastic eating fungi in plastisphere. The 2017 study covering China and Pakistan also identified a strain of fungi Aspergillus tubingensis which was already breaking down plastics at a landfill in Islamabad, Pakistan.
Up till now, around 436 such fungi and bacteria species have been found and scientists from Kew believe their latest findings could further lead this research. They aim to develop efficient enzymes that are designed biologically to degrade plastic waste.
Source: RBG Kew