Scientists from the University of Cambridgediscovered that some naturally-occurring lake bacteria grow faster and more efficiently on the remains of plastic bags than on natural matter like leaves and twigs. Their study included 29 European lakes.The carbon compounds in plastic are broken down by bacteria and used as food for their growth.

Figure 1: Natural cleaner - plastic are broken down by bacteria.

Figure 1 shows thatLake bacteria were found to prefer plastic-derived carbon compounds over natural ones. The scientists believe this is because the carbon compounds from plastics are easier for the bacteria to break down and use as food. [1]

“It’s almost like the plastic pollution is getting the bacteria’s appetite going. The bacteria use the plastic as food first, because it’s easy to break down, and then they’re more able to break down some of the more difficult food – the natural organic matter in the lake,” said Dr Andrew Tanentzap.

The effect varied depending on the diversity of bacterial species present in the lake water – lakes with more different species were better at breaking down plastic pollution.When plastics break down, they release simple carbon compounds. The researchers found that these are chemically distinct to the carbon compounds released as organic matter like leaves and twigs break down.

The carbon compounds from plastics were shown to be derived from additives unique to plastic products, including adhesives and softeners.The new study also found that bacteria removed more plastic pollution in lakes that had fewer unique natural carbon compounds. This is because the bacteria in the lake water had fewer other food sources. [2]

The study involved sampling 29 lakes across Scandinavia between August and September 2019. The scientists cut up plastic bags from four major U.K. shopping chains, and shook these in water until their carbon compounds were released.

At each lake, glass bottles were filled with lake water. A small amount of the 'plastic water' was added to half of these, to represent the amount of carbon leached from plastics into the environment, and the same amount of distilled water was added to the others. After 72 hours in the dark, bacterial activity was measured in each of the bottles.

The study measured bacterial growth - by increase in mass, and the efficiency of bacterial growth - by the amount of carbon-dioxide released in the process of growing.In the water with plastic-derived carbon compounds, the bacteria had doubled in mass very efficiently. Around 50 percent of this carbon was incorporated into the bacteria in 72 hours. [3]

References:

1. https://scitechdaily.com/bacteria-can-remove-plastic-pollution-from-lakes-stimulating-the-whole-food-web/
2. https://theprint.in/science/bacteria-can-remove-plastic-pollution-from-lakes-study/1056647/
3. https://www.msn.com/en-us/news/technology/plastic-pollution-can-be-removed-from-lakes-by-naturally-occurring-bacteria-researchers/ar-AA101Sf6

Cite this article:

Sri Vasagi K (2022), Bacteria Can Remove Plastics from Lakes, AnaTechMaz, pp.59