Scientists in the Faculty of Chemistry, at the Institute of Food Science and Biotechnology – Doc. Ing. Jiřina Omelková, CSc. and Ing. Miroslava Zichová - have developed a technology for preparing and using the crushed flakes colourless PET bottles on which bioactive materials can be immobilized. Immobilization in biotechnology means: “techniques used for the physical or chemical fixation of cells, organelles, enzymes or other proteins (e.g. monoclonal antibodies) on a solid surface of held by a membrane“(2).
The process of preparing the carrier for immobilizing PET bottles consists in crushing and shredding the plastic containers into small fragments. These fragments (flakes) are then separated into partial fractions, where particles less than 0.8 mm are used for immobilization. Activating the carrier of enzyme immobilization is realized by shaking these flakes in combination with acetone for 5 to 10 hours. The obtained carrier for enzyme immobilization is dried. The enzyme is then applied to the reaction mixture.
In practice, the invention means the stability of enzymes is increased and an opportunity is provided for their repeated or continuous use. Another advantage of immobilized enzymatic systems is their technological property, which enables products to be more easily separated and the biocatalyst recovered. One of the possible uses is in the degradation of complex polysaccharides into fermentable carbohydrates, which makes the whole biotechnological procedure quicker and easier.
Even though the best waste is that which is never produced in the first place, this recycling method enables waste to be used as a carrier for enzyme immobilization in biotechnological processes, in particular in the food and pharmaceutical industries or in processing waste materials of herbal origin into fermentable carbohydrates. As PET containers are normally used in the food industry, food is not exposed to contact with substances (carriers) which are not permitted in this sector. The technology can then be used in fermentation processes for the production of bioethanol.
The technology offers us an effective use of a waste material which significantly reduces the cost of the carrier, whose price and process of acquisition is normally far more costly and demanding. The solution is unique since PET bottles have not yet been used for producing a carrier which would be used to immobilize bioactive substances. PET flakes to date have been used for producing everyday polymeric products. Currently, there are functional samples of the technological solution at BUT and the technology has been granted a patent and utility model.
References:
(1) EKO-KOM. Budoucnost odpadového hospodářství ČR. Odpady a obce: Hospodaření s komunálními odpady [online]. 2013 [cit. 2014-03-10]. 14. ročník, 129 s. Available at: http://www.ekokom.cz/uploads/attachments/Obecne/sborniky/sbornik_Odpady_a_obce_2013.pdf
(2) PURKRTOVÁ, Z. Imobilizace: pokus o přehled v oblasti enzymů a buněk. Vscht.cz [online]. Vysoká škola chemicko-technologická v Praze: 2012 [cit. 2014-03-10]. Available at: http://biomikro.vscht.cz/vyuka/ib/9_prednaska2012.pdf
