Colonization and degradation of rubber pieces by Nocardia sp.

The growth of a Nocardia sp. occurs essentially on the insoluble rubber substrate and the cells are tightly bound to the rubber in the initial stage of the growth in spite of vigorous stirring of the cultures. The colonization of rubber pieces was followed by staining with Schiff reagent, and it was revealed that not only the thickness of rubber pieces, but also their length and width greatly influenced microbial colonization and degradation of natural rubber products. Among rubber pieces of various shapes, long strips were most rapidly covered by many microbial colonies and experienced the highest rate of rubber degradation. The rate of degradation (expressed by % weight loss) of the long strips of rubber was a linear function of surface area per unit weight of rubber. Thin and wide films of rubber were also rapidly colonized and degraded, while the colonization and degradation of short and narrow pieces were substantially slower and less extensive.