In recent years, scientists have been concerned with the problem of global pollution of water and soil with plastic. Therefore, the discovery that some bacteria can break down plastic became particularly important. However, for a long time it was not clear how they achieved this. A researcher from Leiden University (Netherlands) analyzed how different types of bacteria interact with plastic waste.
The scientist analyzed 96 strains of actinobacteria – streptomycetes. He used the bacterial collection held at Leiden University. Researchers have generally used it to develop drugs, but a scientific group led by Jo-Anne Verschoor decided to see if they could recycle plastic.
PET is one of the most common types of plastic used in the pharmaceutical and food industries, mechanical engineering, electrical engineering and everyday life.
As a result, it turned out that almost 18% of them were able to separate polyethylene terephthalate (PET) and its oligomer bis(2-hydroxyethyl)terephthalate (BGET). Moreover, Vershur discovered that bacteria, if stimulated, helped decompose much more plastic. According to the authors of the article, microorganisms begin to take action only when they are “hungry”.
“At one point we literally ‘fed’ the bacteria with the smallest particles of plastic and observed how the lack of food affected the rate at which PET and BHT were processed,” said Jo-Ann Verschoor.
Additionally, biologists discovered that bacteria are helped in this regard by three types of LIPA esterase enzymes: ScLIPA, S2LIPA and S92LIPA. During experiments, scientists removed bacteria Streptomyces coelicolor The gene responsible for the ScLIPA enzyme. This resulted in a reduction in the degradation of BHET.
At the same time, overexpression (activation) of genes encoding all variants of LIPA significantly increased the degradation of BHT. The scientists also found that the bacteria “worked” most effectively at a temperature of about 25 degrees Celsius and a pH of 7.
Thanks to this research, the diversity of microorganisms that can process plastic has increased significantly. Some global companies have already adopted this method and are using microorganisms and their enzymes to decompose various types of plastic. The study was published in the journal Biology of Communication.
Source: Port Altele
