Engineering living building materials for enhanced bacterial viability and mechanical properties

• Published in: iScience Vol. 24; no. 2; p. 102083
• Main Authors: Qiu, Jishen, Artier, Juliana, Cook, Sherri, Srubar, Wil V., Cameron, Jeffrey C., Hubler, Mija H.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 19.02.2021; Elsevier
• Subjects: Biomaterials; Civil Engineering; Composite Materials; Materials Synthesis; Materials Synthesis; Composite Materials; Civil Engineering; Biomaterials
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2021.102083

Living building materials (LBMs) utilize microorganisms to produce construction materials that exhibit mechanical and biological properties. A hydrogel-based LBM containing bacteria capable of microbially induced calcium carbonate precipitation (MICP) was recently developed. Here, LBM design factors, i.e., gel/sand ratio, inclusion of trehalose, and MICP pathways, are evaluated. The results show that non-saturated LBM (gel/sand = 0.13) and gel-saturated LBM (gel/sand = 0.30) underwent distinct failure modes. The inclusion of trehalose maintains bacterial viability under ambient conditions with low relative humidity, without affecting mechanical properties of the LBM. Comparison of biotic and abiotic LBM shows that MICP efficiency in this material is subject to the pathway selected: the LBM with heterotrophic ureolytic Escherichia coli demonstrated the most mechanical enhancement from the abiotic controls, compared with either ureolytic or CO2-concentrating mechanisms from Synechococcus. The study shows that tailoring of LBM properties can be accomplished in a manner that considers both LBM microstructure and MICP pathways. [Display omitted] •Tailoring LBM mechanical properties via gel/sand ratio and MICP pathway is feasible•LBM failure mode varies with the honeycombed gel structure and its biomineralization•Exogenous addition of desiccation protectant trehalose in LBM increases cell viability Civil Engineering; Materials Synthesis; Biomaterials; Composite Materials