The probiotics not only accelerate the decomposition process of biodegradable plastic waste, but also accelerate the composting process from some organic waste. The quality of the output makes the garbage look like it is disinfected and can be used for land reclamation in a sustainable way.
Scientists at the Vietnam Academy of Science and Technology have just announced three preparations to accelerate the biodegradation process of some types of plastic waste.
According to Assoc.Prof.Dr. Dang Thi Cam Ha, Institute of Biotechnology - the project's director, these products are initially aimed at biodegradable plastic bags and waste. That means, the products can only be used to treat waste that has been classified as biodegradable or compostable.
In early June 2019, the three products were granted a patent by the Intellectual Property Office of Vietnam. One of them was made from a combination of four “basidiomycota” (strains of mushrooms) that were newly isolated and identified, the other two were made from heat-resistant “actinomycetes” strains isolated from garbage (composting domestic waste), in which “actinomycetes” have a stronger effect on decomposition than “basidiomycota”. According to the research team, the products utilize the genetic resources of Vietnamese nature and are created in the Vietnamese laboratory, so the material will not be exhausted.
These products have been tested on the following groups of polymer and plastic bags: EU biodegradable bags collected in the Netherlands, Germany, and the Czech Republic; two types of biodegradable bags which are research products of the Institute of Chemistry - Vietnam Academy of Science and Technology; and 4 types of bags labeled as "eco-friendly" or "biodegradable" manufactured in Vietnam by imported technology. In particular, "environmentally friendly" is understood as garbage must be decomposed 60% within 2 years and "biodegradable" is understood as "waste completely decomposed into water and CO2.
According to the results, the extracellular enzymes produced by the “basidiomycota” fungus decompose different types of polymer and plastic bags with different chemical structure with decomposition efficiency after 30 days of testing, respectively: bags with EU certification, bags of the Institute of Chemistry - Vietnam Academy of Science and Technology, bags made with imported technology. In which EU-certified bags lose about 34% of their weight (decomposition efficiency is reflected in the declining mass, changes in surface structure morphology, the emergence of new functional groups and new bonds ... ).
As above, after 30 days of treatment, the enzymes produced by thermophilic actinomycetes at high temperature (55oC) were capable of degrading polymer and plastic bags with the same decomposition efficiency as for example. with mushrooms, in which EU certified bags lost 34-37% of their weight. In particular, treated with actinomycetes Streptomyces sp.XKBD21, the average molecular weight of the bag researched by the Vietnam Academy of Science and Technology decreased by 91%.
According to the research team, the compositions not only accelerate the decomposition of biodegradable plastic waste, but also the composting process from some organic wastes with output quality "like being disinfected". ” - can be used for sustainable soil improvement or as a safe fertilizer.
After this research, scientists are continuing to study more microbial and fungal combinations that have the ability to further accelerate the decomposition of biodegradable plastic waste and progress to non-biodegradable plastic waste.
Prof. Nguyen Van Hieu, Chairman of the Science Council of Materials Science of the Vietnam Academy of Science and Technology, assessed that the topic achieved was "very important". However, to bring this research result to life "is still very arduous, it needs the cooperation and implementation of environmental enterprises".
Information on the granted patents related to biological products for the treatment of plastic waste of the author's group: Patent No. VN 1-0021300, VN 1-0021301, VN 1-0021302, All were published by the IP Viet Nam on July 25, 2019.
.png)
Photo: Assoc. Prof. Dr. Dang Thi Cam Ha is discussing with colleagues about the biodegradability of new microbial and fungal combinations for some types of plastic bags and cups.