A new type of biodegradable plastic hits the world in the United States

Can stench faeces become necessary for everyday life? This is not a science fiction novel, but it was really realized by a group of young American entrepreneurs who just graduated from college. This idea sounded unbelievable, but after careful study, one has to admire the greatness of its creativity. These young entrepreneurs use microbes to digest the carbon in organic fertilizers and turn them into plastic raw materials. After the plastic products made of this raw material are discarded, they can be degraded after about one year. In this way, it not only solves the problem of manure disposal, but also reduces the pollution of plastics to the environment, and it also reduces the dependence of plastic products on petroleum.

The idea of ​​“changing into excrement” was proposed by a newly-built small company located in Sacramento, the capital of California. The company is called Micromidas and its six major members are graduates of the University of California, Davis. Four of them graduated from the Department of Chemistry, one from the Department of Microbiology, and one from the Department of Architecture and the Environment. During the school's inauguration, John Bissell, CEO of Micromads, completed the school's green technology entrepreneur training and several other senior entrepreneur training programs. After setting up the company to obtain seeds, he also led the company to participate in various competitions to publicize the company's philosophy and win a variety of green technology awards from local to national. In Micro-Maders, "green technology" is not just a slogan, but the cornerstone and development goal of the company.

Let various micro-organisms cooperate

It is known that many microorganisms feed on feces, which is a naturally occurring process. The key to turning manure into plastic raw materials is how to select suitable microorganisms and make rational use of this natural process. According to John Bissell, CEO of Micro-Meades, "We are not using the popular genetic modification technology to create a 'Jordan' type of super-strong team; instead, we form a team to use tactical cooperation to solve it. "The problem is that, letting different types of micro-organisms cooperate in the division of labor, what we eat is the dirtiest and most odorous domestic sewage, but the pollution-free plastic material is produced. A single genetically modified bacterium needs to survive in a strictly controlled and stable environment. This requires the preparation of expensive ingredients. The bacterial community cultivated by Micro-Meaders can survive in all kinds of harsh environments and can resist the invasion of many kinds of microorganisms. As long as they use a steady stream of domestic waste, they can feed them completely.

According to the micromads official website, this microbial community can digest the carbon in organic fertilizers and convert them into polyhydroxyalkanoates (PHAs), which are stored as "fat" in the "body." Polyhydroxyalkanoates are an intracellular polyester that many microorganisms can synthesize - a natural polymeric biomaterial, and a polymer that is composed of various subunits (the smallest covalent units of the quaternary structure of the constituent proteins). Polyester formed. There are more than 150 known subunits that can be polymerized into PHA. By changing the position of the bond and the type of subunit in the PHA molecule, plastics made from PHA can have different hardness and elasticity. All PHAs also have common characteristics, namely high temperature resistance, UV resistance, water resistance, and gas barrier. These properties make this material have application value in many fields.

Today's common PHA is usually a combination of polyhydroxybutyrate (PHB) and polyhydroxyvalerate (PHV). When the ratio of the two substances is appropriate, the properties are very close to polypropylene (PP). Polypropylene is widely used in various containers including household utensils, auto parts, and the like. In addition, equipment made of polypropylene as a raw material can be directly produced using polyhydroxyalkanoates as raw materials without modification. In other words, this plastic, which is transformed from feces, can easily be used for production.

Can be degraded after implantation in the human body

This kind of plastic product can not only be degraded in the garbage field after being discarded, but also be degraded after being implanted into the human body, and it has no toxic or side effects, and it will not cause the rejection phenomenon such as inflammation, which makes this plastic very useful in biological medicine. Large application prospects, for example, can be made into absorbable medical sutures, as well as temporary stents or catheters that are free to be removed.

The PHA-made plastics have an average degradation time of one and a half years. If it is on the shelf or cupboard, it can be stored for longer. However, if they are thrown into landfills, compost heaps or even seas, they will degrade quickly without leaving any harmful substances. According to statistics, 100 million tons of non-degradable plastic floats in the North Pacific waters, endangering marine life and destroying the food chain. Applying this new technology, it is expected to greatly reduce the damage to the environment caused by plastics.

The perfect unity of environmental protection and efficiency

The traditional method of manure treatment is mainly incineration or chemical treatment. These methods are costly and convert organic carbon into large amounts of carbon dioxide and release it into the atmosphere, which aggravates the greenhouse effect. Traditional plastics are extracted from petroleum, transforming limited petroleum into non-degradable white waste and endangering the environment. And this innovative technology has a double-edged sword, clever use of the transformation of microorganisms in the natural world, "changing into a treasure," while reducing pollution while producing economic benefits.

Although the company is still in the initial stage of trials, it can only handle a few tons of fecal sludge every day, and only produces dozens of kilograms of plastic raw materials. However, the company has already been encouraged to innovate in the field of water resources, “God Hunting Project”, 2010. The year "Water Resources Innovation Leadership" and other awards, and received a certain amount of investment. People have reason to hope that this technology can be widely adopted and used. It is also hoped that such environment-friendly business ideas will emerge in an endless stream, proving that environmental protection and benefits do not necessarily go against each other. Through smart innovation, environmental protection and benefits can also be perfectly unified.