The majority of people believe that plastics do not biodegrade, this was the case until the 1980s when biodegradable plastics and polymers were first created.
There was a certain type of bacteria that was found in the early 1970s in Japan. Japanese scientists discovered this bacterium in pools of waste near a nylon factory. Two strains of the bacteria were developed to breakdown nylon these strains were found to possess enzymes known as 'nylonase' which are capable of breaking down nylon, neither of these bacteria were known to scientists before the invention of nylon.
Bioplastics are simply plastics that are made from either plants or other biological materials rather than using the commonly use petroleum.
There are two different types of bioplastics and they are made in different ways.
PLAs (Polylactic Acids) Plastics:
PLAs are made from the extraction of sugar from plants such as sugarcane and corn, this type of plastic can normally be found in food packing/containers or plastic films.
As this process can be a by-product of the creation of ethanol that large industrial factories make PLA plastics are the cheapest form of biodegradable plastic.
PHAs (polyhydroxyalkanoates) Plastics:
PHA plastics are created from genetically engineered microorganisms. The microbes are given low amounts of nutrients such as oxygen and nitrogen but high levels of carbon, this forces the microbes to produce PHA as a carbon reserve.
These plastics will normally be found in harder reusable plastics normally within the medical industry such as casts or bone plates, it's also found in several single use food packing.
Although biodegradable plastics were created to improve the issues we were having with petroleum plastics, there are many other issues related to biodegradable plastics. With e biodegradable plastics we can see that although somewhat solving the main issue at hand, they also have large drawbacks which cause issues in other concerning areas.
The issues with Biodegradable plastics come from when some of them decompose within landfills. During the decomposing process these plastics can produce methane gas. With methane gas being a very harmful greenhouse gas, the process worsens the issues we are currently having with global warming.
These biodegradable plastics also need exposure to ultraviolet light and high temperatures to actually decompose, without these conditions these plastics could take many years to break down and will likely still leave micro plastics which are toxic and harmful for the environment.
Food Supply / Land Space
As the majority of biodegradable plastics are PLA plastics it has led to a large amount of land which would have been used to supply the worlds food supply now being used to create plastic. Growing these crops for the sole purpose of making plastics also leads to other issues with global warming with the need to fuel the farm machinery.
Was of biodegrading plastics and creating different types of plastics have been around for a long time. However, Calia Bastioli has some of the most noteworthy work within the industry winning 'Inventor of the year' in 2007 for her starch-based bioplastics. Calia Bastioli is currently the CEO of Novamont who has also won awards from the plastics industry association for multiple plant based plastics.