Week 1 HW: Final Project Ideas

(1) What you would like to biomanufacture and why?

I would like to biomanufacture fabric from bacterial cellulose. The textile industry is incredibly consumer driven and wasteful and contributes to the accumulation of pollution as well as the emission of greenhouse gases. Finding a sustainable source for fabric production and making that fabric biodegradable offers a solution to both issues. Making an impact in the textile industry means making an impact on climate change on a global scale.

(2) What living system would you use?

I would use bacteria such as Acetobacter Xylinum that produce cellulose as an extracellular matrix. The production of cellulose by bacteria is not efficient enough to be cost or time efficient. Therefore, I would be working to modify metabolic pathways in these bacteria to overproduce cellulose or find a way to harvest it as it is made.

This might involve transducing a genetic circuit into the bacteria to overexpress the things responsible for cellulose production. Or it could mean directing evolution towards more cellulose production.

Then the chemical approach would be to find a gentle extraction of just cellulose from the matrix to try to alleviate the steric hindrance between nutrients and cell membranes.

(3) How would you use automation?

Automating the process of directed evolution would not only reduce errors in managing multiple generations of bacteria but would also lead to more efficient data collection. Specifically, automation of transferring cultures to new growth media would speed up the process of breeding multiple generations and allow it to be done independent of human time constraints.I would automate most of the directed evolution process if possible to allievate it from error and expidite results.

(4) How much would you need to make, and how long would it take?

If the end goal is selling this fabric in bulk to manufacturers, it needs to be on the order of 100,000 meters per sold unit which is the average amount bought by manufactures. Assuming we would have about 10 units of fabric in stock at any given time, this would amount to a million meters of fabric. From a fabric calculator, I found 200g of cellulose makes 1 meter of medium weight fabric so a total of 200,000 kilograms of cellulose would be needed to make the entire stock.

With ideal conditions, which I hope to create, Acetobacter Xylinum could produce 1g of cellulose per L of bacterial culture in 2 days. Assuming we have the capacity and the funding, we could potentially be producing 1000kg of cellulose every 2 days (in a small commercial storage room of 1,000 cubic meters.) The transition from cellulose to fabric would also take time. From purification to drying and finishing, the whole process would take about a week. Making 1000kg of cellulose every 2 days + 7 days of post production = 9 days per 1000kg. At this rate, it would take about 5 years to produce a million meters of fabric. This also comes out to about 170,000 meters of fabric per month.

(5) What don’t you know yet?

Foremost, I would need to learn how to create an environment that would select for overproduction of cellulose by A. Xylinum to efficiently use directed evolution. Once this is understood, I would then need a method of extracting cellulose from these bacteria without destroying them. This would probably require further knowledge of cellulose chemistry. Finally, the next largest gap in knowledge would be the post cellulose harvesting production, ie. how to turn pure cellulose into a fabric.

Chao Y, Ishida T, Sugano Y, Shoda M. Bacterial cellulose production by Acetobacter xylinum in a 50-L internal-loop airlift reactor. Biotechnol Bioeng. 2000 May 5;68(3):345-52. doi: 10.1002/(sici)1097-0290(20000505)68:3<345::aid-bit13>3.0.co;2-m. PMID: 10745203. Gomes, Rodrigo José et al. “Bacterial cellulose production by Komagataeibacter hansenii can be improved by successive batch culture.” Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology] vol. 54,2 (2023): 703-713. doi:10.1007/s42770-023-00910-w

AI Chat GPT prompts : What bacteria could I engineer to mass produce a fabric with?

Final Project