THE USE OF MICROBIAL MEMBRANES TO ACHIEVE ANAEROBIOSIS

Several years ago, it was observed that sterile microbial membrane preparations stimulated recovery of certain radiation-injured bacteria. Later it was noted that these same preparations reduce dissolved oxygen to water in a variety of environments, including bacteriological media. This reduction of oxygen is an enzymatic process and is influenced by parameters such as temperature, pH, and the availability of specific oxidizable substrates. Oxygenreducing membrane preparations can be made from several different bacterial species. When added to liquid or solid bacteriological media, membrane preparations rapidly produce and maintain anaerobic conditions favorable for the growth of a wide variety of oxygen-sensitive microorganisms. When used with a specifically designed disposable dish, membrane preparations allow the development of colonies of many anaerobic microorganisms on the surface of agar without the use of anaerobic hoods or other devices. In addition to providing conditions suitable for the growth of anaerobes, membrane preparations stimulate recovery of heat and cold injured bacteria of several different genera including facultative organisms. These results are reminiscent of the early observations regarding the recovery of radiation-injured bacteria. In addition to their usefulness in microbiology, oxygen-reducing membrane preparations have the potential for protecting a wide variety of oxygen-sensitive organic compounds.