Bacteria with a Sense for Fashion

The gift of…or wait, the genes for cellulose production were not only given to green plants, a couple of algae and odd fungus-like organisms (oomycetes) but also to some genera of bacteria like Aerobacter, Agrobacterium, Pseudomonas, Rhizobium and Sarcina. For synthesis of microbial cellulose (MC) on a bigger scale, Acetobacter xylinus from the genus Acetobacter (common vinegar bacteria) is mostly exploited. This obligatory aerobic fellow can polymerise up to 200,000 glucose molecules per second into β-1,4-glucan chains, which are then secreted to the medium as ribbon-like bundles of microfibrils. No one yet knows for sure, why A. xylinum or other bacteria species produce cellulose but the main point is that they do. And that’s because you can use it to suit your own cause. Nata de Coco for example, a Philippine dessert, is produced by the fermentation of coconut water. Microbial cellulose gives it its typical jelly-like texture. Medicine has also discovered the beauty of MC; here, it is used as scaffolds for tissue engineering and for artificial blood vessels.

And now, Acetobacter xylinum has finally found its way into the world of fashion as well. Currently on display in London’s Science Museum is a collection of bacteria-produced garments. The collection was designed by Suzanne Lee, a UK-based designer and senior research fellow at the School of Fashion & Textiles in London. In an attempt to bring science and fashion design closer together, Lee teamed up with David Hepworth, a scientist specialising in biological materials. Together they came up with a formula to grow cellulose in their vats. Even though, the two are keeping the exact ingredients a secret, Lee reveals in an interview with the New Scientist that it consists of “a sugary green tea solution to which is added a bacterial cellulose culture, which also contains yeast and other organisms”. She says that it takes about three weeks for the pellicle that forms at the surface to reach the required thickness of 15 mm. Then it takes another week for the layer to dry, which is done over a wooden surface. Depending on the recipe, the end result is said to feel either like leather or paper. After the production process is finished, the “fabric” is ready to be dyed (preferably with blueberry or beetroot juice) and made into a unique piece of clothing. Take that, Mr. Lagerfeld!  

Apart from the obvious advantages like biodegradability, the material also comes with some challenges that still have to be tackled. Lee admits, “The biggest issue is absorbency. […] if it gets wet, it quickly soaks up moisture and returns to a more gelatinous state.” It’s easy to imagine that this would slightly impair the wearing comfort of your MC clothes, so at the moment the two are “looking into engineering some hydrophobicity”.

However, it might still take some time before you can buy BioCouture in your fashion boutique around the corner but, for the time being, you could try growing clothes yourself. Here is the recipe for the culture medium of Acetobacter xylinum (according to Schramm & Hestrin): 2% (w/v) glucose, 0.5% (w/v) peptone, 0.5% (w/v) yeast extract, 0.27% anhydrous disodium phosphate and 0.15% (w/v) citric acid monohydrate.

By the way, some studies from Thailand have shown that Acetobacter xylinum TISTR 975 produces the thickest cellulose layer on a Gingko biloba L extract and strain TISTR 998 showed the highest productivity when using coconut juice.

And now excuse me; I’m off to grow some new pants!