(402e) Peptidoglycan-Bioconjugates from Extremophillic Microorganisms for New Bioinspired Water-Responsive Materials

Due to their water-responsive actuation, the peptidoglycan polymers from 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 considered to be extremophiles such as halophiles (>3M NaCl) and hyperthermophiles (T > 80ºC).

In this research we have cultivated hyperthermophiles and halophiles and isolated their biomolecular material peptidoglycan. To further handle and control the positioning of the peptidoglycan we have formed novel bioconjugates based on biotin-multiarm PEG conjugation schemes. We studied its water-responsive strain, response speed, and energy densities by using the atomic force microscope (AFM) that we previously customized for this purpose. This data was compared the extracted material with those from commercially available sources and also with our previous work with B. subtilus and Halobacillus halophilus. 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 this novel, labeled biomaterial to appropriate levels for further use in water-responsive devices and materials. We hypothesize that cell wall adaptations in the peptidoglycan due to the challenging microenvironmental conditions of the hyperthermophile or halophile could result in biomolecular materials with more advantageous water-responsive actuation properties. We will use the bioconjugates formed to allow for precise positioning and control of the biomolecular material in the overall architecture.