Submitted Manuscript September 2021 1 Microbial Biotextiles for a Circular Materials Economy Authors: Theanne N. Schiros 1,2 †*, Romare Antrobus 3 †, Delfina Farias 1 , Yueh-Ting Chiu 3 , Christian Tay Joseph 2 , Shanece Esdaille 2 , Gwen Karen Sanchiricco 1 , Grace Miquelon 1 , Dong An 4 , Sebastian T. Russell 4 , Adrian M. Chitu 5 , Susanne Goetz 6 , Anne Marika Verploegh Chassé 7 , 5 Colin Nuckolls 8 , Sanat K. Kumar 4 , and Helen H. Lu 2 * Affiliations: 1 Department of Science and Mathematics, Fashion Institute of Technology; New York, NY 10001. 2 Materials Research Science and Engineering Center, Columbia University; New York, NY 10 10027. 3 Department of Biomedical Engineering, Columbia University; New York, NY 10027. 4 Department of Chemical Engineering, Columbia University; New York, NY 10027. 5 Materials Science and Engineering, Columbia University; New York, NY 10027. 6 Surface/Textile Design, Fashion Institute of Technology; New York, NY 10001. 15 7 Footwear and Accessories Design, Fashion Institute of Technology; New York, NY 10001. 8 Department of Chemistry, Columbia University, New York, NY 10027. †These authors contributed equally to this work. 20 *Co-corresponding authors. Email: ts2526@columbia.edu, hhlu@columbia.edu Abstract: Harnessing microbial biofabrication and inspired by indigenous practices, we engineer high-performance microbial nanocellulose (MC) biotextiles with a sustainable circular life cycle. Specifically, our plant-based lecithin phosphocholine treatment modulates cellulose cross- 25 linking through phosphate and methylene groups, to yield a biodegradable material with superior mechanical and flame-retardant properties. Coloration is achieved using natural dyes and waste- to-resource strategies. Life cycle impact assessment reveals MC biotextiles mitigate the carcinogenics of leather by a factor of 10 3 and the carbon footprint of synthetic leather and cotton by ~97%, for widespread application in fashion, interiors, and construction. The translational 30 potential of this approach is tremendous, as using microbes and green chemistry to engineer regenerative, high-performance products will disrupt linear production models and mitigate its environmental threats in a circular economy. One-Sentence Summary: We engineer high-performance, microbial biotextiles which mitigate 35 the climate and toxicity impacts of conventional textiles. (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. The copyright holder for this preprint this version posted September 24, 2021. ; https://doi.org/10.1101/2021.09.22.461422 doi: bioRxiv preprint