MORISAKI Hisao Ritsumeikan University, Faculty of Science and Engineering, Professor, 理工学部, 教授 (50125671)
IMAMURA Nobutaka Ritsumeikan University, Faculty of Science and Engineering, Associate Professor, 理工学部, 助教授 (10160061)
FUKAMI Hiroshi Ritsumeikan University, Faculty of Science and Engineering, Visiting Professor, 理工学部, 客員教授 (60026531)
|Budget Amount *help
¥12,100,000 (Direct Cost : ¥12,100,000)
Fiscal Year 1999 : ¥1,800,000 (Direct Cost : ¥1,800,000)
Fiscal Year 1998 : ¥3,500,000 (Direct Cost : ¥3,500,000)
Fiscal Year 1997 : ¥6,800,000 (Direct Cost : ¥6,800,000)
In this research project, we recognize water-plants, phytoplankton and microorganisms in Lake Biwa as "nonutillized biomass resources"(Lake Biwa Biomass, LBB) which grow by adsorbing (removing) the first pollutants as nutrients in the Lake. The purpose of the project is to improve and preserve water quality of the Lake by removing the first pollutants in the form of LBB, which are transformed to new resources with additional value. To achieve these goals, we must characterize the ecosystem for various processes concerning LBB.
I. Enchancing value of LBB with microbial activity : Waterweeds were utilized for solid state culture of industrial fungi and edible mushroom. (1) Several fungi such as Aspergillus oryzae grew well on the solid medium with SASABAMO, and produced useful hydrolyzing enzymes. (2) Hiratake also grew well on the solid medium with SASABAMO, and formed more fruiting bodies than those on a conventional medium with saw dust and rice bran. Use of several algae, mixing ratio
of submaterial, culture condition, cultivation of other edible mushrooms etc. were investigated. Occurrence of factor(s) in waterweeds was suggested, which promotes growth of mushroom mycelium. (3) Protoplast of HIRATAKE was formed by use of a cell-wall lytic enzyme found by the author. Analysis of the lytic enzyme was made in respect to enzyme species effective for degradation of cell-wall of mushroom mycelium.
II 2. The chemical ecology of the Lake Biwa biomass
1.Selective production of plan biomass : In order to obtain the fundamental knowledge about the selective production of plant biomass, were investigated the interaction between blue-green algae, Microcystis spp. and algae-lysing bacteria, and that between the algae and their predator cladoceran. As the results, many algae-lysing bacteria were obtained. A Strong algaecide produced by one of those bacteria was isolated, and its chemical structure was determined. It was also unveiled that the algae produced lethal toxins and feeding inhibitors against cladoceran.
2. Analysis of microbial flora in the sediment of Lake Biwa and its ecological relationship with plant-biomass : The microbial flora and pollutant-decomposing activity of sediments at specific sites in Lake Biwa was examined according to its depth. Microbial flora in the slime layer of a plant biomass, Microcystis sp., was studied from an ecological viewpoint. The attachment mechanism of Vibrio sp., casual agent of vibriosis for Ayu (Japanese river trout), was analyzed, and a novel finding, which demands reconsideration for an old attachment mechanism, was obtained. Less