The Bacterial Oxidation of Rubber

Abstract

Abstract In studying the biological oxygen demand of sea water, it has been observed that rubber stoppers increase the amount of oxygen consumed. In fact, the small amount of rubber gasket exposed to the water in citrate of magnesia bottles perceptibly increases the amount of oxygen consumed after 5 to 10 days' incubation. Heat-sterilized as well as formaldehyde-preserved controls proved that the increased oxygen consumption is attributable to biological activity. One-gram samples of various kinds of rubber, cut in small pieces to give a surface area of approximately 10 sq. cm., were placed in 160-cc. glass-stoppered bottles. After sterilizing in an autoclave at 120° C for 20 minutes, the bottles were filled with sterile water saturated with oxygen. Half the bottles were inoculated; the others were left sterile. Duplicate bottles were analyzed for oxygen immediately by the Winkler technique, and the others were incubated in the water bath for one to five days at 22° C, after which the amount of oxygen con...