Engineered Living Materials: Taxonomies and Emerging Trends

The fusion of synthetic biology with classical materials science has yielded breakthrough materials innovations and spawned a new biotechnology field: engineered living materials (ELMs). Taxonomic classifications of ELM research highlight states of the art, opportunities, challenges, and emerging trends. Opportunities abound to engineer bacteria, fungi, plants, mammalian cells, and diverse consortia of those organisms to produce – and persist within – complex, biologically active materials for applications in therapeutics, electronics, construction, and beyond. Principal challenges for the maturing ELM field concern scaling beyond the biofilm, increasing production rates and volumes, engineering consortia of microorganisms, and developing policies related to biocontainment, standardized metrology, and workforce development to address global scientific and engineering challenges. At the intersection of synthetic biology and materials science, the field of engineered living materials (ELMs) has evolved into a new, standalone discipline. The fusion of bioengineering’s design–build–test–learn approaches with classical materials science has yielded breakthrough innovations in the synthesis of complex, biologically active materials for functional applications in therapeutics, electronics, construction, and beyond. However, the transdisciplinary nature of the ELM field – and its rapid growth – has made holistic comprehension of achievements related to the tools, techniques, and applications of ELMs difficult across disciplines. To this end, this review proposes an emergent taxonomy of ELM research and uses the categorization to discuss current trends and state-of-the-art advancements, significant opportunities, and imminent challenges for scientists and engineers in the field. At the intersection of synthetic biology and materials science, the field of engineered living materials (ELMs) has evolved into a new, standalone discipline. The fusion of bioengineering’s design–build–test–learn approaches with classical materials science has yielded breakthrough innovations in the synthesis of complex, biologically active materials for functional applications in therapeutics, electronics, construction, and beyond. However, the transdisciplinary nature of the ELM field – and its rapid growth – has made holistic comprehension of achievements related to the tools, techniques, and applications of ELMs difficult across disciplines. To this end, this review proposes an emergent taxonomy of ELM research and uses the categorization to discuss current trends and state-of-the-art advancements, significant opportunities, and imminent challenges for scientists and engineers in the field. aggregates of fiber-like proteins. the formation or accumulation of minerals by organisms especially into biological tissues or structures (e.g., bones, teeth, and shells). the multistep, enzyme-catalyzed process where substrates are converted into more complex products in living organisms. the concurrent cultivation or growth of multiple organisms. A microbial consortium is a group of two or more different species that work together and function at a higher level than they could alone. as artifacts, engineered materials are composed of living cells that form or assemble the material itself or modulate the functional performance of the material in some manner. As a field, the integration of synthetic biology, namely, the rational design–build–test–learn methodology to design and re-design organisms for the express purpose of material production, with classical materials science. a qualitative measure of how straightforward it is to create a mutant organism that either completely lacks a gene or to create a mutant organism in which a gene product is expressed for the first time and/or in excess. the field concerning the discovery and design of new materials. Materials scientists study how processing a material influences its structure and how its structure affects its properties and performance. the cultivation or growth of a single organism. a supporting material framework (e.g., hydrogels, hydrogel–sand composites) in or on which cells can grow or proteins, polymers, or minerals can be affixed. a field of science and bioengineering that involves application of engineering principles (i.e., design–build–test–learn) to design (and re-design) organisms for useful purposes or to engineer them to have new abilities. a field of synthetic biology that aims to engineer and program a single cell to differentiate and produce complex tissues, structures, and biological systems. an orderly classification. In the context of this review, ELM taxons include scale, approach, organism, function, and end-use application. a mathematical method that optimizes material layout within a given design space for a given set of forces, boundary conditions, and constraints with the goal of maximizing the performance or structural efficiency of the entire system. a strain, gene, or other organism characteristic that prevails in natural conditions, as distinct from an atypical mutant (or engineered) type.