Abstract
The decomposition of chitin in the marine sediments was investigated chiefly at Aburatsubo Inlet. The greater parts of precipitated chitin in the sediments was estimated to be decomposed in the topmost microzone aerobically, because the rate of decomposition in the oxydized layer is very rapid and is as much as twofold greater than that in the sea. Although anaerobic chitinoclastic bacteria are detected in the topmost layer of the eutrophic region of the sea, almost all the chitinoclastic bacteria are aerobic.
In the radiolarian ooze of the abyssal region, chitinoclastic bacteria analogous to Beneckea hyperoptica was collected, which indicates the presence of chitinoclastic activity in the depth of the ocean.
