Study Finds More Microbes Can Degrade Plastics At Heavy Plastic Pollution Places

Gothenburg:  According to new research by the Chalmers University of Technology, the number of microbial enzymes with the ability to degrade plastic is growing, in correlation with local levels of plastic pollution. The study has been published in the ‘mBio Journal’.
The problems of global plastic pollution are all too widespread, as mass-production of plastic has exploded in the last 70 years or so — from around 2 million tonnes per year to around 380 million. This has given sufficient evolutionary time for various microbes present in the environment to respond to these compounds, and many different enzymes have been discovered in previous studies with the ability to degrade different plastics. The new study analysed samples of environmental DNA from hundreds of locations around the world. The researchers used computer modelling to search for microbial enzymes with plastic-degrading potential, which was then cross-referenced with the official numbers for plastic waste pollution across countries and oceans.

Using our models, we found multiple lines of evidence supporting the fact that the global microbiome’s plastic-degrading potential correlates strongly with measurements of environmental plastic pollution — a significant demonstration of how the environment is responding to the pressures we are placing on it, said Aleksej Zelezniak, Associate Professor in Systems Biology at the Chalmers University of Technology.

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In other words, the quantity and diversity of plastic-degrading enzymes is increasing, in direct response to local levels of plastic pollution. In total, over 30,000 enzyme ‘homologues’ were found with the potential to degrade 10 different types of commonly used plastic. Homologues are members of protein sequences sharing similar properties. Some of the locations that contained the highest amounts were notoriously highly polluted areas, for example samples from the Mediterranean Sea and South Pacific Ocean.

Currently, very little is known about these plastic-degrading enzymes, and we did not expect to find such a large number of them across so many different microbes and environmental habitats. This is a surprising discovery that really illustrates the scale of the issue,explained Jan Zrimec, first author of the study and former post-doc in Aleksej Zelezniak’s group, now a researcher at the National Institute of Biology in Slovenia.

Every year around 8 million tonnes of plastic escapes into the world’s oceans. The natural progresses for plastic degradation are very slow — the lifetime of a PET-bottle, for example, can be up to hundreds of years. The growth and accumulation of plastic waste in the oceans and on land is a truly global problem and there is an increasing need for solutions to manage this waste. The researchers believe that their results could potentially be used to discover and adapt enzymes for novel recycling processes.

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The next step would be to test the most promising enzyme candidates in the lab to closely investigate their properties and the rate of plastic degradation they can achieve. From there you could engineer microbial communities with targeted degrading functions for specific polymer types, explained Aleksej Zelezniak.

NDTV – Dettol have been working towards a clean and healthy India since 2014 via Banega Swachh India initiative, which is helmed by Campaign Ambassador Amitabh Bachchan. The campaign aims to highlight the inter-dependency of humans and the environment, and of humans on one another with the focus on One Health, One Planet, One Future – Leaving No One Behind. It stresses on the need to take care of, and consider, everyone’s health in India – especially vulnerable communities – the LGBTQ population, indigenous people, India’s different tribes, ethnic and linguistic minorities, people with disabilities, migrants, geographically remote populations, gender and sexual minorities. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign will continue to raise awareness on the same along with focussing on the importance of nutrition and healthcare for women and children, fight malnutrition, mental wellbeing, self care, science and health, adolescent health & gender awareness. Along with the health of people, the campaign has realised the need to also take care of the health of the eco-system. Our environment is fragile due to human activity,  that is not only over-exploiting available resources, but also generating immense pollution as a result of using and extracting those resources. The imbalance has also led to immense biodiversity loss that has caused one of the biggest threats to human survival – climate change. It has now been described as a “code red for humanity.” The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene. Banega Swasth India will also be taking forward the dream of Swasth Bharat, the campaign feels that only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and the country can become a Swasth or healthy India.