Abstract
Distribution of vitamin B12, thiamine, and biotin in the sediment, both whole sediment and their interstitial water, of Harima-Nada Sea are described. And the possible role of these vitamins as a source of the ones contained in the sea water is discussed.
Most of vitamin B12 in the sediments were found to be absorbed on the sediment particles. Total vitamin B12 contents in the surface sediments ranged 4.14-88.3 ng/g wet weight. Vitamin B12 levels in the interstitial water of surface sediments were fairly low; the contents were 0.53-42.0 pg/g wet weight. The vitamin B12 contents in the whole sediment was generally highest in the surface and sharply decreased with the increasing sediment depth. But the levels of vitamin B12 in the interstitial water contained in the sediment of the unit wet weight were rather constant up to the depth of 15 cm of the core. Thiamine contents were 3.3-92.2 ng/g wet weight in the whole sediment and 0.45-9.18 ng/g wet weight in the interstitial water. The ranges of biotin content in the whole sediment and the interstitial water were 0.03-1.37 ng/g wet weight and 0.48-88.6 pg/g wet weight, respectively. The contents of these vitamins in the whole sediment were about 102-104 times as much as those in the water of this region. The vitamins accumulated in the sediment are suggested as an important source of the ones contained in the overlying water.
