(602g) Biomaterial Composites with Filamentous Microorganisms for New Bioinspired Water-Responsive Materials

Due to their water-responsive actuation, the peptidoglycan containing spores of bacteria have been used as building blocks for stimuli-responsive materials and nanogenerators. It has been hypothesized that the microbial cell wall polymer peptidoglycan inside spores can dominate the spores’ powerful water-responsive behavior. Consequently, peptidoglycan has been recognized as a promising biomolecular source material for use as a component in bioinspired water-responsive energy transducing devices. The structure variations of peptidoglycan vary widely, however, thus far, only a limited number of these subtypes of this highly complex polymer have been investigated as biomolecular materials, and none to our knowledge from microbes that are filamentous in nature.

In this research we have cultivated filamentous cyanobacteria in a controlled fashion and isolated the biomolecular material peptidoglycan from these organisms using a range of decellularization treatments. We studied the peptidoglycan's water-responsive strain, response speed, and energy densities by using the atomic force microscope (AFM) that we previously customized for this purpose. From these structures we constructed a range of composites with various sustainable polymers ranging from poly(ethylene glycol) (PEG)-based to protein based with particulate and luminescent additives. To aid in controlling and positioning the composite biomaterial we conducted peptidoglycan bioconjugation. We looked at the water-responsiveness of these materials and this data was compared with those from commercially available sources and also with our previous work with B. subtilus. In further studies we have used the biosynthetic uptake of fluorescent D-amino acids to label and characterize the 3D structure of fluorescent peptidoglycan using AIRYSCAN superresolution microscopy. We conclude that we can scale up the production of these novel, labeled composite biomaterials to appropriate levels for further use in sustainable water-reponsive devices and materials. We hypothesize that cell wall adaptations in the peptidoglycan due to the characteristics of various filamentous species could result in biomolecular materials with more advantageous water-responsive actuation properties.