Improper disposal of plastic is a rising concern for life on our planet.
Plastics are non-biodegradable which means that they cannot be degraded by
microbes and other decomposers leading to the accumulation of plastic products.
When these plastic products are burned, harmful chemicals and gases are produced
as a result of their combustion leading to air pollution and as a result living
organisms including humans are exposed to these harmful chemicals. Moreover,
some animals might ingest these plastic products and since they lack the proper
enzymes to degrade plastic, they mostly die or suffer from disorders. This is
especially true in the case of marine life; due to the enormous amount of
plastic products being dumped into the sea, many fish can often find themselves
trapped in shopping bags or even more terrifyingly, they may ingest these
products and when these fish are eaten by larger organisms, they may pass on
this disorder to the entire food chain.
While scientists have been looking to find a solution for this problem for
several years now, they haven’t been able to find an impactful solution to this
apparent “plastic crises”. However, with time, scientists have started coming up
with new solutions in hopes of battling this crises. In 2016, researchers at the
Kyoto Institute of Technology discovered a new novel class of bacteria that can
degrade PET plastic. PET is the most abundant form of plastic and is found in
many products such as water bottles. The researchers discovered that this new
strain of bacteria was able to degrade PET plastic into digestible biochemical
compounds as it possessed an enzyme called PETase. The sample in which this
bacteria was found came from a PET contaminated sediment found near a bottle
recycling facility. Prior to its discovery only a certain fungi and bacteria
were known to have a small if any effect on PET plastics.
This new bacteria is named Ideonella sakaiensis and is a rod-shaped
Gram-negative bacteria that optimally grows at about a temperature of about 30
to 37 degrees Celsius and at a pH of about 7 to 7.5. When grown on PET, these
bacteria produces enzymes capable of hydrolyzing PET and converting it into
harmless compounds: terephthalic acid and ethylene glycol. These compounds are
then used by the bacteria to produce other biochemical compounds that can be
used in metabolic processes such as the Krebs cycle to produce energy.
So the question arises, why aren’t our plastic problems being solved by these
microbes efficiently? Why isn’t plastic pollution being reduced? The answer to
these questions is that although this bacteria can degrade plastic, it has to be
of low crystallinity and it has to be thin but as you all might have guessed,
all plastics are not like that and so further research is going into how we can
increase the efficiency of the enzymes that this bacteria produces. In more
recent example researchers from the University of Portsmouth accidently in 2018
enhanced the efficiency of this bacteria and where previously it would take a
couple of weeks to degrade PET, now this bacteria can degrade PET in a matter of
However, the amount of plastic that is being accumulated every day is very huge.
Approximately 8 million pieces of plastic pollution find their way into our
oceans every day so you can understand the gravity of this situation. While
scientists are doing their best in finding an efficient solution to this
environmental crises and while the discovery of Ideonella sakaiensis is one of
the best scientific discoveries of the past decade, we must not forget our
individual roles because we are also responsible for our environment and we must
strive to save it from devastation.