教甄◆英文科題庫下載題庫

       For sustainability-minded fashionistas, materials made by fast-growing, eco-friendly bacteria offer an appealing alternative to leather or faux plastic replacements such as “pleather.” ____31____ A study published last week in Nature Biotechnology may offer a solution: genetically engineering bacteria to produce melanin pigment so the material can dye itself. 

       Bacteria-generated textiles are made of cellulose, an essential structural material in plants that is also produced by several species of bacteria. The durable textile, which scientists can quickly grow into custom shapes, has many of the same properties as traditional leather. Although bacterial cellulose textiles have fewer environmental impacts than leather or plastic, they are naturally beige. ____32____        Researchers from Imperial College London (ICL) wondered whether bacteria could be coaxed into producing cellulose that was naturally dark-colored. ____33____ Melanin is what gives color to tissue throughout the natural world, including human skin, eyes, and hair. Initial experiments faced challenges. Early experiments weren’t promising. The cellulose material appeared pale and faded, rather than dark black as the researchers had hoped. ____34____ To solve this problem, the team devised a two-step process to overcome this hurdle: culturing the cellulose first and then submerging it in a solution with the same pH as water to achieve a rich black color. Once they had the color they wanted, the scientists grew sheets of bacterial cellulose to the correct sizes and shapes needed to make a wallet and the upper part of a shoe. The melanin-dyed textiles appear to be just as durable as their undyed cellulose counterparts.  

       ____35____ Manufacturers have had trouble ramping up production for other kinds of biotextiles while still maintaining accessible prices for consumers. Nonetheless, the study represents a significant stride towards achieving environmentally friendly alternatives in the fashion world, driven by innovation at the intersection of biology and material science. 

(AB) If the trend catches on, it could provide a template for creating more sustainable materials for the fashion world. 

(AC) While advancements in bacterially produced textiles hold promise for sustainability-conscious consumers and manufacturers alike, challenges remain in affordability.

(AD) That means they are typically colored using traditional dyeing processes, which can use large amounts of water and release harsh chemicals into the environment.

(AE) To find out, they genetically engineered a cellulose-producing bacterium, Komagataeibacter rhaeticus by adding a gene from another bacterium that produces black melanin pigment.

(BC) For now, sustainability enthusiasts will have to wait for the other bacterially produced shoe to drop. (BD) It turned out that the culturing medium’s acidity hindered melanin production.

(BE) Yet coloring or adding patterns to these bacterial textiles can still mean working with environmentally harmful dyes.