Department of Chemistry, Faculty of Science, Okayama University of Science, Ridaicho, Kita-ku, Okayama, 700-0005, Japan.
Research Faculty of Agriculture, Hokkaido University, Sapporo, 060-8589, Japan.
Sci Rep. 2022 May 6;12(1):7423. doi: 10.1038/s41598-022-11482-4.
The microplastic that pollutes the ocean is a serious problem around the world. The bioplastic consisting of biopolymers which is degraded in nature, is one of the strategies to solve this problem. Although the bioplastics consisting of protein, polysaccharide, polylactic acid, etc., have been reported, which consist of DNA, one of the most important materials in the genetic process, have not been reported to the best of our knowledge. In addition, a large amount of DNA-containing materials, such as salmon milts, is discarded as industrial waste around the world. Therefore, we demonstrated the preparation of a bioplastic consisting of salmon milt DNA. The DNA plastic was prepared by the immersion of a DNA pellet in a formaldehyde (HCHO) solution and heating. As a result, the water-stable DNA plastics were obtained at the HCHO concentration of 20% or more. Particularly, the DNA plastic with a 25% HCHO treatment showed water-insoluble, thermally stable, and highly mechanical properties. These are due to the formation of a three-dimensional network via the crosslinking reaction between the DNA chains. In addition, since DNA in plastic possesses the double-stranded structure, these plastics effectively accumulated the DNA intercalator, such as ethidium bromide. Furthermore, the DNA plastics indicated a biodegradable property in a nuclease-containing aqueous solution and the biodegradable stability was able to be controlled by the HCHO concentration. Therefore, salmon milt DNA has shown the potential to be a biodegradable plastic.
海洋中的微塑料污染是一个全球性的严重问题。由在自然界中可降解的生物聚合物组成的生物塑料是解决这个问题的策略之一。尽管已经报道了由蛋白质、多糖、聚乳酸等组成的生物塑料，但据我们所知，还没有报道由 DNA 组成的生物塑料，DNA 是遗传过程中最重要的物质之一。此外，大量含有 DNA 的材料，如三文鱼精液，在世界各地都被当作工业废料丢弃。因此，我们展示了一种由三文鱼精液 DNA 组成的生物塑料的制备方法。通过将 DNA 颗粒浸泡在甲醛（HCHO）溶液中并加热来制备 DNA 塑料。结果，在 HCHO 浓度为 20%或更高的情况下，获得了耐水的 DNA 塑料。特别是，经过 25%HCHO 处理的 DNA 塑料表现出不溶于水、热稳定和高机械性能。这是由于 DNA 链之间的交联反应形成了三维网络。此外，由于塑料中的 DNA 具有双链结构，这些塑料可以有效地积累 DNA 插入剂，如溴化乙锭。此外，这些 DNA 塑料在含有核酸酶的水溶液中表现出可生物降解的特性，并且可生物降解的稳定性可以通过 HCHO 浓度来控制。因此，三文鱼精液 DNA 显示出成为可生物降解塑料的潜力。
