India discovers first-of-its-kind plastic-eating bacteria and fungi

Indian scientists have surprised the world with the discovery of first-of-its-kind plastic-eating bacteria and fungi at a mountainous solid waste dump site in Pirana, Gujarat. When commercialized, this discovery is expected to solve the plastic waste menace that India and the world currently face, with several tonnes entering the sea and creating ecological problems for future generations.

Capable of being engineered, these bacteria and fungi are expected to clear the plastic garbage currently being dumped in the open air. While plastic is not the natural source of sustenance for these organisms, scientists discovered that mutation could have led to a change in their behaviour. According to reports, two researchers from the Gujarat Biotechnology Research Centre (GBRC), namely the director of the institute Prof Chaitanya Joshi, and joint director Dr Madhvi Joshi, along with Prof Manish Kumar from IIT Gandhinagar (IIT-Gn), authored an article titled ‘Landfill microbiome harbours plastic-degrading gene: A metagenomics study of solid waste management.’

The research paper was recently published in the leading science periodical Elsevier journal about the findings. These Indian scientists discovered 17 classes of bacteria and 9 fungi that eat plastics while analyzing samples from several solid waste management (SWM) sites in Gujarat. These findings are expected to revolutionize the world plastic industry and its post-consumption treatment.

Polystyrene demand-supply (‘000 tonnes)
Particulars	2020-21	2021-22	2022-23	2023-24(f)	2024-25(f)
Capacity	490	490	518	518	518
Production	212	240	260	315	330
Imports	42	34	65	60	60
Exports	27	30	25	60	60
Apparent demand	227	240	300	315	330
Demand growth (%)	(-)9.9	5.7	25.0	5.0	4.8

Sources: Chemicals and Petrochemicals Manufacturers Association (CPMA), and Polymerupdate Research

Sample testing
The article further states that samples were collected from 10 different locations and depths at the Pirana dump site, with the materials coming in from a depth of 45 meters. These samples were studied to conclude. The results confirmed the presence of bacterial isolates that have been globally identified as capable of degrading plastic waste like polyethylene (PE) bags, polyethylene terephthalate (PET), and polystyrene (PS), the revealed in the article.

Experts mentioned that several enzymes present in the genome sequence of the microorganisms showed that the plastic materials were being used as a carbon and energy source. The paper reveals that the bacterial attach themselves to the surface of plastic polymers after oxidization in the presence of water, following which they start disintegrating the PE, PET, or PS.

Earlier focus on PS alone
Researchers at the Shiv Nadar University (SNU) in Greater Noida, Utter Pradesh, claimed in 2019 that they have discovered ‘plastic-eating’ bacteria from the wetlands of Greater Noida, which may lead to eco-friendly alternative clean-up methods for plastic waste worldwide. Named Exiguobacterium sibiricum strain DR11 and Exiguobacterium undae strain DR14, these bacterial strains discovered at SNU were announced to have the potential to decompose PS, a key component in single-use plastic (SUP) items such as disposable cups, cutlery, toys, packaging materials, among others. These bacterial strains were isolated from the wetlands adjoining the university.

PS is resistant to degradation due to its high molecular weight and long-chain polymer structure. This is the reason for its persistence in the environment. The study said that the exponential production and consumption of PS in various sectors has presented a great environmental risk and raised the problem of waste management. SNU’s Associated Professor Richa Priyadarshini believes, “Strains of extremophile bacterium Exiguobacterium are capable of degrading polystyrene and can be further used to mitigate the environmental pollution caused by plastics.”

Richa further states, “Wetlands are one of the richest habitats of microbial diversity but are relatively unexplored. Hence, these ecosystems are ideal grounds for isolating bacteria and novel biotechnology applications. It is worth mentioning here that Richa, along with her team, discovered the bacteria strains at the Department of Life Sciences, School of Natural Sciences. According to industry estimates, India consumes around 16.5 million tonnes of plastic annually. For this plastic production, India produces 14 million tonnes of polystyrene, which is non-biodegradable.

Massive plastic production affects both terrestrial and marine life, e.g. single-use plastic (SUP) like a plastic fork can take up to 450 years or even more to decompose. In the universe of plastic items used today, SUP constitutes around a fifth in volume. The research team identified that upon coming into contact with the PS, the two isolated bacterial strains use it as a carbon source, and create biofilms. The process alters the physical properties of PS and initiates a process of natural degradation with the release of hydrolyzing enzymes to break the polymer chains.

Waste generation
Despite several initiatives, India continues to confront the enormous challenge of the plastic waste industry. According to the Central Pollution Control Board (CPCB), India generates nearly 26,000 tonnes of plastic waste each day, accumulating to 3.46 million tonnes per year, more than any economy except the USA and European Union. Of this, three polymers such as polypropylene (PP), polyethylene (PE), and polyvinyl chloride (PVC), account for nearly 75 percent while the rest stems from the other members of the polymer family. Packaging dominates consumption, with a share of 59 percent, followed by building and construction (13 percent), and agriculture (9 percent.).

India aimed to recycle around half of its plastic, but this research radically reduces that estimate. A significant share of household waste is plastic, with 50 percent to 80 percent of that material being collected, and only 40 percent of that segregated for resource recovery. The rest is either incinerated or dumped and can find its way into water bodies and become part of the food chain for humans, and marine and terrestrial life.

Present scenario
Currently, India recycles only a minute quantity of plastics the country generates due to improper collection systems and inadequate recycling facilities. Consequently, India is estimated to lose a substantial volume of business in the plastic circular economy, which remains irreversible and unrecoverable.

A study carried out by the Federation of Indian Chambers of Commerce and Industry (FICCI) and Accenture, India is estimated to lose over US$133 billion of plastic material value over the coming next 10 years until 2030 owing to unsustainable packaging out of which almost 75 percent of the value, or US$100 billion, can be retrieved. Therefore, articles made of plastic focus on levers and strategies that could be put in place to transition India toward a circular economy.


DILIP KUMAR JHA
Editor
dilip.jha@polymerupdate.com