Immobilized Antimicrobials for the Enhanced Control of Microbial Contamination

The active control of problematic microbial populations aboard spacecraft, and within future lunar and planetary habitats is a fundamental Advanced Life Support (ALS) requirement to ensure the long-term protection of crewmembers from infectious disease, and to shield materials and equipment from biofouling and biodegradation. The development of effective antimicrobial coatings and materials is an important first step towards achieving this goal and was the focus of our research. A variety of materials were coated with antibacterial and antifungal agents using covalent linkages. Substrates included both granular media and materials of construction. Granular media may be employed to reduce the number of viable microorganisms within flowing aqueous streams, to inhibit the colonization and formation of biofilms within piping, tubing and instrumentation, and to amplify the biocidal activity of low aqueous iodine concentrations. Antimicrobial coatings were also applied to the surfaces of materials used in areas dedicated to food storage and handling, crew hygiene, solid waste treatment and storage, and biological experimentation. Such coatings inhibit microbial colonization and decomposition of materials, and control airborne human and plant pathogens. As a result of this program, coatings were developed with high antimicrobial activity against gram-negative and gram-positive bacteria, and fungi.