Abstract
For grouping organic carbon in sediment, organic carbon hydrolyzed in HCl solution was defined as the acid decomposable organic carbon, and organic carbon in fulvic acid, humic acid and kerogene which resist the hydrolysis, was defined as the hardly acid decomposable organic carbon. Protein, carbohydrate and lipid were hydrolyzed, and the released amino acids, sugars and fatty acids were analyzed respectively by the developed method using GC/MS. These proposed indexes applied to the sediment in Hakata bay.
The following results were obtained from a microbiological treatment of the sediment and analyses of 6 points of the sediments in Hakata bay.
(1) The acid decomposable organic carbon ratio (C%) in each the sediment of Hakata bay decreased from bay mouth to interior part, however, ratio of the hardly acid decomposable organic carbon increased. From this result, the organic substances in the sediment of interior part of Hakata bay were found to be more stable microbiologicaly than those of bay mouth.
(2) The both amounts of the acid decomposable carbon and hardly acid decomosable organic carbon in the sediment of interior part of Hakata bay did not decrease by the treatment using Neanthes japonica, the organic substances were found to be fairly stable and further microbial decomposition was difficult. The amounts of amino acids and sugars did not decrease by this treatment, while fatty acids were decreased ca. 40%.
