I am Emma Briones Riquelme, an architect from Chile and a master’s student in Sustainable Habitat and Energy Efficiency at Universidad del Bío-Bío.
My work explores the relationship between architecture, circular materials, and biomanufacturing. I am currently developing Claris, a project that transforms post-consumer textile waste and biobased polymers into modular panels for non-structural interior applications.
Through How to Biomanufacture Almost Anything, I want to better understand living systems and explore how microbial fabrication can contribute to the development of new materials for energy efficiency, indoor comfort, and climate-resilient architecture.
See the navigation bar on the left to explore my work for How to Biomanufacture Almost Anything, Fall 2026.
Subsections of Emma Briones Riquelme — HTBAA Fall 2026
Week 1 HW: Final Project Ideas
HTBAA Homework 1
Bacterial Cellulose and Post Consumer Textile Waste Biofoam
Author: Emma Briones Riquelme Date: September 2026
1 What would you like to biomanufacture and why
I would like to biomanufacture a composite material from bacterial cellulose and post-consumer textile waste for modular, non-structural interior wall panels. The proposal seeks to harness cellulose-producing microorganisms to generate a fibrous matrix that grows on, around, or between recovered textile fibers, helping bind them together and transform them into a new material.
This material would be intended primarily for interior architecture applications, including wall coverings and panels with potential acoustic and thermal performance. Potential users include building-material manufacturers, architecture firms, construction companies, and organizations interested in incorporating circular materials into their projects. However, these functional properties must be verified experimentally and are not presented as demonstrated outcomes of the proposed system.
My interest arises from developing Claris, a project in which I work with biopolymers and textile waste to produce interior panels. This experience has allowed me to recognize both the potential of textile waste as a raw material and the difficulties associated with conventional or biobased binders, particularly fiber cohesion, porosity, moisture resistance, dimensional stability, and the durability required of construction materials.
The proposal addresses a global-scale problem. An estimated 92 million tonnes of textile waste are generated each year, and in 2023 only 8% of textile fibers produced came from recycled sources (United Nations Environment Programme [UNEP], 2025). In Chile, average clothing purchases increased from 13 garments per person in 2015 to 50 in 2020. Textiles may also account for nearly 7% of municipal solid waste, equivalent to approximately 572,119 tonnes per year (Ministerio del Medio Ambiente [MMA], n.d.).
Figure 1. Textile waste accumulated in the Atacama Desert. Note. Photograph by Tamara Merino. Reproduced from Atacama: de majestuoso desierto a enorme basural de moda fast fashion, by J. Bartlett, 2023, National Geographic.
Biomanufacturing offers the possibility of exploring a matrix that is not merely mixed with the waste but produced directly by a living system and developed in contact with the textile fibers. Bacterial cellulose is particularly promising because of its nanofibrillar structure, its ability to form continuous networks, and its potential to integrate with other fibrous materials (Lahiri et al., 2021).
Previous studies have examined textile waste as building insulation (Briga-Sá et al., 2013) and the production of low-thermal-conductivity bacterial cellulose aerogels (Fleury et al., 2020). However, the integration of compositionally variable post-consumer textile waste into a porous bacterial cellulose matrix for interior panels remains underexplored.
The objective is not to claim that bacterial cellulose can immediately replace the binder currently used in Claris, but to investigate whether it could serve as the primary matrix, a reinforcement, or a complementary component. The main questions are whether cellulose can grow uniformly between the fibers, how much waste can be incorporated without losing porosity, and how the combination affects cohesion, moisture response, fire behavior, durability, and thermal and acoustic performance.
As an architect, I am interested in developing new materials that contribute to energy efficiency and habitability. In an insulating material, porosity can immobilize low-thermal-conductivity air, while tortuosity hinders heat transfer. Performance also depends on density, pore connectivity, fiber orientation, and moisture content (Jelle, 2011). This work becomes increasingly relevant under future climate scenarios in which extreme heat events may compromise indoor comfort and safety (Intergovernmental Panel on Climate Change [IPCC], 2022).
In this way, the project would use biomanufacturing to explore new relationships among living organisms, waste, and architecture, advancing toward materials whose structure is partially grown rather than produced exclusively through conventional manufacturing processes.
2 What living system would you use
I would use a cellulose-producing bacterium from the genus Komagataeibacter, with K. xylinus as the reference organism. These aerobic bacteria convert sugars available in the culture medium into an extracellular cellulose network. Under static culture conditions, this network forms mainly at the air-liquid interface, where oxygen is more readily available. Final strain selection would depend on yield, availability, safety, compatibility with the textiles, and culture stability (Lahiri et al., 2021).
The process would begin by sorting the textile waste according to composition, followed by washing, drying, removal of non-textile components, and shredding. Fiber type and size would be recorded because these variables may affect distribution, oxygen availability, and material cohesion.
A culture medium containing water, a carbon source, and the nutrients required for bacterial growth would then be prepared. After adjusting the pH and sanitizing or sterilizing the system, the K. xylinus inoculum would be introduced.
Two integration routes would be compared. In the first, textile fibers would be distributed in trays and the cellulose would grow directly on and around them. This route would allow in situ biomanufacturing to be evaluated, although oxygen transfer and uneven growth could become limiting factors. In the second, cellulose would be cultured separately, disintegrated into a suspension, and subsequently mixed with the textile fibers. This alternative would provide greater control over composition and homogeneity but would require more conventional processing steps.
Temperature, pH, time, oxygen availability, and possible contamination would be monitored during cultivation. Once the cellulose network had integrated with the fibers, the material would be washed and purified to remove cells and culture-medium residues, producing a clean, inactivated biocomposite.
A porous structure could be created through physical foaming or controlled drying that prevents pore collapse. The material would then be molded, dried, and cut to obtain a dimensionally stable panel.
The product would be characterized through measurements of density, porosity, thermal conductivity, acoustic absorption, hygrothermal behavior, mechanical resistance, reaction to fire, and durability. The purpose of this sequence is not to assume that the material will work, but to compare both routes, identify their critical variables, and determine whether the biological integration hypothesis is viable.
3 How would you use automation
Automation would serve two purposes: accelerating experimentation and improving the repeatability of future production. I would not automate the entire process from the outset; I would first identify which variables account for most of the differences among samples.
During the experimental stage, I would use an automated liquid-handling system, such as Opentrons, to prepare variations of the culture medium, inoculate replicates, and conduct small-volume experiments. This would enable comparisons among carbon sources, pH levels, inoculum concentrations, textile proportions, and fiber sizes while reducing dosing errors.
The culture system would be complemented by temperature, pH, and oxygen sensors, together with continuous recording of environmental conditions. Periodic photography under controlled lighting would allow surface coverage, color changes, contamination, and material shrinkage to be observed. Each sample would have an identifier linked to its formulation, culture conditions, and final properties.
Automation would connect three groups of information: the formulation used, the actual process conditions, and the performance of the resulting material. Its value would lie not only in producing more samples but also in generating comparable data to identify which variables must be controlled during scale-up.
At the pilot stage, the liquid-handling robot would be replaced by modular trays, semi-automated dosing, and environmental control. Post-processing would require monitoring pressure, temperature, moisture, and mass to determine the end of drying and maintain consistent density and thickness.
Automation would be introduced progressively. It would first be used to understand what controls the material and then to reproduce those conditions at a larger scale. Automating the process before understanding its critical variables could increase production speed without resolving its biological variability.
4 How much would you need to make and how long would it take
a How much
Two scales are considered: a 1 m² demonstrator to validate the process and 20 m² to estimate its application in a pilot room. Preliminary parameters include a thickness of 0.020 m, a dry density of 50 kg/m³, and a composition of 60% textile waste and 40% bacterial cellulose. These are design assumptions and must be adjusted based on experimental results.
Dry mass is calculated as follows:
Dry mass = surface area × thickness × density
For 1 m²:
Dry mass = 1 m² × 0.020 m × 50 kg/m³ = 1.0 kg
The panel would require approximately 0.60 kg of textile fibers and 0.40 kg of dry bacterial cellulose. With a 20% production margin, 0.48 kg of cellulose would need to be produced. If a provisional yield of 5 g dry cellulose/L is assumed, the required volume would be:
Culture volume = 480 g ÷ 5 g/L = 96 L
For a 20 m² pilot room:
Dry mass = 20 m² × 0.020 m × 50 kg/m³ = 20 kg
This production would correspond to 12 kg of textile waste and 8 kg of bacterial cellulose. Including the 20% margin, 9.6 kg of dry bacterial cellulose would be required:
Culture volume = 9,600 g ÷ 5 g/L = 1,920 L
Rather than establishing definitive nominal values, this calculation identifies the variables that govern scale-up: thickness, density, cellulose proportion, biological yield, and process losses.
b How long
As a preliminary scenario, a parallel capacity of 480 L is considered, equivalent, for example, to 24 trays containing 20 L of medium each. This equivalence is used only to size the process. In static bacterial cellulose cultivation, productivity depends not only on volume but also on the available area at the air-liquid interface and on oxygen transfer.
At this capacity, producing the equivalent culture volume of 1,920 L would require:
Number of cycles = 1,920 L ÷ 480 L/cycle = 4 cycles
If each cultivation cycle lasts approximately 10 days:
Cultivation time = 4 cycles × 10 days/cycle = 40 days
Including fiber and medium preparation, inoculation, purification, forming, drying, and quality control, the total time is preliminarily estimated at 55 to 65 days.
During prototyping, automation would be used to prepare formulations, control variables, and compare small samples. Pilot production would require replacing this system with modular trays, environmental sensors, and semi-automated dosing, washing, and drying operations.
The primary purpose of this estimate is not to predict industrial capacity but to identify the process bottleneck. The first experiments should therefore measure productivity as grams of dry cellulose per liter, per unit of culture surface area, and per day. These data would replace the initial assumptions and indicate whether scaling the material is technically and energetically viable.
5 What do you not know yet
The first uncertainty is whether bacterial cellulose can grow continuously and adhere around textile waste of variable composition, particularly natural, synthetic, and blended fibers. This would be evaluated by comparing direct growth on the fibers with the incorporation of cellulose produced separately and by observing material coverage, penetration, and distribution.
The second uncertainty concerns the relationship among composition, porosity, and cohesion. A higher fiber content could improve reinforcement, but it could also disrupt the cellulose matrix or create weak areas. The proportions of both components must therefore be varied and their density, porosity, strength, and thermal and acoustic performance measured.
The third uncertainty is the material’s stability under moisture exposure and aging. Bacterial cellulose is hydrophilic, so the panel could absorb water, deform, or support biological growth. This condition would be studied through absorption, water-vapor, hygrothermal-cycle, dimensional-stability, and reaction-to-fire tests.
In summary, the priority questions are: Can bacterial cellulose bind textile waste of variable composition? Which combination can preserve both cohesion and porosity? Can the material maintain its properties over a service life compatible with an interior application?
Use of AI
I used ChatGPT, developed by OpenAI, as a support tool to organize the document, improve the clarity of the writing, and verify the reference format. The idea, design decisions, assumptions, and interpretation of the project are my own. Artificial intelligence was not used to generate experimental results or replace review of the original sources.
The main prompts used were:
“Review the bibliography of the assignment document and provide a summary of each source.”
“Develop the quantity and time calculation, prioritizing the reasoning criteria over nominal values.”
“Review the text as if you were an MIT evaluator selecting proposals for integration into research nodes.”
“Reduce the content to the information strictly necessary to understand and evaluate the proposal.”
“Review the references and correct their APA 7 formatting.”
The generated responses were reviewed, revised, and verified before being incorporated into the document.
References
Briga-Sá, A., Nascimento, D., Teixeira, N., Pinto, J., Caldeira, F., Varum, H., & Paiva, A. (2013). Textile waste as an alternative thermal insulation building material solution. Construction and Building Materials, 38, 155–160. https://doi.org/10.1016/j.conbuildmat.2012.08.037
Fleury, B., Abraham, E., De La Cruz, J. A., Chandrasekar, V. S., Senyuk, B., Liu, Q., Cherpak, V., Park, S., ten Hove, J. B., & Smalyukh, I. I. (2020). Aerogel from sustainably grown bacterial cellulose pellicles as a thermally insulative film for building envelopes. ACS Applied Materials & Interfaces, 12(30), 34115–34121. https://doi.org/10.1021/acsami.0c08879
Intergovernmental Panel on Climate Change. (2022). Climate change 2022: Impacts, adaptation and vulnerability (H.-O. Pörtner et al., Eds.). Cambridge University Press. https://doi.org/10.1017/9781009325844
Jelle, B. P. (2011). Traditional, state-of-the-art and future thermal building insulation materials and solutions—Properties, requirements and possibilities. Energy and Buildings, 43(10), 2549–2563. https://doi.org/10.1016/j.enbuild.2011.05.015
Lahiri, D., Nag, M., Dutta, B., Dey, A., Sarkar, T., Pati, S., Basu, D., Abdul Kari, Z., Wei, L. S., & Ray, R. R. (2021). Bacterial cellulose: Production, characterization, and application as antimicrobial agent. International Journal of Molecular Sciences, 22(23), Article 12984. https://doi.org/10.3390/ijms222312984
Petzold, C. J., & Mukhopadhyay, A. (2025). From bench to biofactory: High-throughput technologies and automated workflows to accelerate biomanufacturing. Current Opinion in Biotechnology, 94, Article 103320. https://doi.org/10.1016/j.copbio.2025.103320
My project aims to develop a bacterial cellulose biofoam incorporating textile waste and explore its use in interior panels for thermal and acoustic insulation. For this assignment, I have narrowed the genetic design to an earlier question: can the organization and porosity of cellulose be modified while the bacterium produces it? Incorporating textile fibers is part of the biofabrication process. I do not assume that it requires a genetic modification or that more porous cellulose will automatically become an insulating foam.
What molecules am I expressing?
Cellulose is the final material, but it is not a protein that I can encode directly in a genetic construct. The bacterium produces it using its own synthesis machinery. Within that machinery, BcsA (catalytic protein that forms cellulose chains) participates in synthesis, while BcsD (protein associated with the organization of those chains) contributes to the structure of the material (Römling & Galperin, 2015).
In this assignment, I do not propose expressing an additional copy of BcsD. Instead, I propose expressing dCas9 (deactivated Cas9 protein that can bind to DNA without cutting it) and an sgRNA (single guide RNA that directs the protein to a specific DNA region). Together, they form a CRISPRi system (genetic interference system that reduces gene expression). My aim is to decrease the expression of a gene already present in the bacterium and observe whether this changes the structure of the cellulose it produces (Qi et al., 2013).
This choice is based on Huang et al. (2022), who reduced the expression of bcsD (gene associated with cellulose organization) in Gluconacetobacter xylinus CGMCC 2955 and observed changes in porosity estimated from microscopy images. Their result supports my research question, although it does not yet show that the same effect will occur in the strain selected for my project.
What is the sequence, and where does it come from?
The gene I want to regulate, rather than introduce, is present in the reference chromosome of Komagataeibacter rhaeticus iGEM, accession LT575493.1. In that record, it is annotated as acsD (gene for subunit D of the cellulose synthesis system), at positions 670250–670720, with the identifier KRIGEM_00627 and the product description “Cellulose synthase operon protein D” (European Nucleotide Archive, 2016). I use acsD when referring to the iGEM genome annotation and bcsD when referring to the gene studied by Huang et al. (2022).
As an initial candidate for the RNA unit, I selected the 337+ guide region described by Huang et al. (2022): 5′-CCGCTGGATCACGTCGCAGC-3′. Comparison with LT575493.1 shows that all 20 bases match positions 670588–670607 of acsD. This supports considering the region for a design in the iGEM strain; it does not establish how strongly it would reduce gene expression. The complete sgRNA sequence (single guide RNA, including its structural scaffold) and the specific dCas9 CDS (DNA coding sequence for the dCas9 protein) still need to be selected from verifiable sources before these parts can be recorded as final in Kernel.
What is the host or chassis?
The host, or chassis, will be Komagataeibacter rhaeticus iGEM, a cellulose-producing bacterium with a published genome and documented tools for modifying gene expression (Florea et al., 2016; Teh et al., 2019). Using this strain as my reference allows me to connect the proposal to a specific chromosomal sequence. It also means that the promoters, the sequences needed to produce dCas9, and the vector must be chosen with their function in this bacterium in mind. A guide region matching its genome does not, by itself, demonstrate that the complete system will work in this strain.
Where do the products need to go?
dCas9 (regulatory protein) and the sgRNA (single guide RNA) need to act inside the bacterium, where they can recognize the DNA containing acsD. For that reason, I do not propose adding a signal peptide to secrete them. BcsD (protein involved in cellulose organization) is part of the bacterium’s natural system; my design aims to change its expression level, not its cellular destination.
Bacterial cellulose, the material of interest, is produced outside the cell. At a later stage, I will study how this network grows in the presence of textile fibers and whether the resulting composite has the properties needed for an interior panel. The intracellular location of the regulatory system and the extracellular formation of the material therefore serve different functions within the same proposal.
Part 2. Design Your Genetic Parts
I propose organizing the system into two expression units. The first would produce dCas9 (regulatory protein without DNA-cutting activity) and would require a bacterial promoter, an RBS (ribosome binding site, a sequence that helps initiate protein production), a dCas9 CDS (DNA coding sequence for the protein), and a transcription terminator. The second would produce the sgRNA (single guide RNA): it would require a promoter, the guide sequence joined to its structural scaffold, and a terminator. This second unit does not need an RBS because its functional product is an RNA, not a protein. Together, dCas9 and the guide could obstruct transcription of the selected gene, which is the principle of CRISPRi (genetic interference system) (Qi et al., 2013).
I selected the region called 337+ by Huang et al. (2022) as my initial candidate. Its 20-base recognition sequence, 5′-CCGCTGGATCACGTCGCAGC-3′, appears without differences in the chromosome of K. rhaeticus iGEM, at positions 670588–670607 of the gene annotated as acsD. Comparison with the LT575493.1 FASTA file (text format containing a DNA sequence) showed a 20/20-base match and an adjacent NGG-type PAM (short DNA motif required for recognition by the corresponding version of Cas9). I also checked the other four regions published by Huang, and all matched exactly in this reference genome. I chose 337+ as an initial candidate because, in the published experiment, it was associated with relative bcsD expression of 29.39% compared with the control, one of the strongest reductions in that study. That figure describes the result in G. xylinus CGMCC 2955; it is not a quantitative prediction for the iGEM strain (Huang et al., 2022; European Nucleotide Archive, 2016).
To complete the construct in Kernel, I still need to select a specific dCas9 sequence, promoters, an RBS, terminators, and a vector that can be maintained and selected in K. rhaeticus iGEM. Teh et al. (2019) provide evidence of genetic parts for cellulose-producing bacteria and genetic interference in a related species, but this does not automatically validate a particular combination in my strain. In Kernel, I will record each part’s type, name, sequence, and verifiable source, and distinguish imported parts from my own design decisions. Until those sequences have been selected and checked, the diagram represents a proposed architecture, not a complete plasmid ready for synthesis.
My hypothesis is that reducing acsD expression will allow me to explore changes in the microstructure and porosity of cellulose produced by the iGEM strain. The sequence match makes it reasonable to study Huang’s guides in this strain, but the strength of regulation, bacterial growth, and material properties must be evaluated experimentally. Later, I can study whether that cellulose integrates with textile fibers and whether the resulting material has useful properties for an interior panel.
Part 3. Assemble Your Construct
To be developed.
Part 4. Optimize and Quality Check
To be developed.
Part 5. From Design to Build
To be developed.
Part 6. What Don’t You Know Yet?
To be developed.
Note on AI Use
I used ChatGPT (OpenAI, 2026) to review the literature, compare the sequences reported by Huang et al. with LT575493.1, and support the writing of Parts 1 and 2. I checked the claims against the cited article and records.
Florea, M., Hagemann, H., Santosa, G., Abbott, J., Micklem, C. N., Spencer-Milnes, X., de Arroyo Garcia, L., Paschou, D., Lazenbatt, C., Kong, D., Chughtai, H., Jensen, K., Freemont, P. S., Kitney, R., Reeve, B., & Ellis, T. (2016). Engineering control of bacterial cellulose production using a genetic toolkit and a new cellulose-producing strain. Proceedings of the National Academy of Sciences, 113(24), E3431–E3440. https://doi.org/10.1073/pnas.1522985113
Huang, L.-H., Li, X.-J., Sun, X.-W., Wang, X., Wang, Y.-T., Jia, S.-R., & Zhong, C. (2022). Regulating the structure of bacterial cellulose by altering the expression of bcsD using CRISPR/dCas9. Chinese Journal of Biotechnology, 38(2), 772–779. https://doi.org/10.13345/j.cjb.210318
Qi, L. S., Larson, M. H., Gilbert, L. A., Doudna, J. A., Weissman, J. S., Arkin, A. P., & Lim, W. A. (2013). Repurposing CRISPR as an RNA-guided platform for sequence-specific control of gene expression. Cell, 152(5), 1173–1183. https://doi.org/10.1016/j.cell.2013.02.022
Römling, U., & Galperin, M. Y. (2015). Bacterial cellulose biosynthesis: Diversity of operons, subunits, products, and functions. Trends in Microbiology, 23(9), 545–557. https://doi.org/10.1016/j.tim.2015.05.005
Teh, M. Y., Ooi, K. H., Teo, S. X. D., Bin Mansoor, M. E., Lim, W. Z. S., & Tan, M. H. (2019). An expanded synthetic biology toolkit for gene expression control in Acetobacteraceae. ACS Synthetic Biology, 8(4), 708–723. https://doi.org/10.1021/acssynbio.8b00168
