抄録
The microbiological studies were carried out in the Sohara Lake Group of Volcano Bandai, Fukushima Prefecture. The depths of water of these lakes ranged from 1.5 to 4.0 meters and their bottoms were covered with aquatic plants. The water temperatures were 1519°C and the pH values of surface water were neutral. The amount of mineral salts was very little except Lake Kurodoro-numa.
The bacteria were counted 105314 × 103/ cc. in water and 12335 × 104/ g in bottom mud, the largest amount in both the water and mud being observed in Lake Sohara-ko. The multiplication of bacteria was successful in the lake waters of the harmonic Sohara Group.
The zoospores of aquatic Phycomycetes were very scarce there were obtained only 4 species, among which Phytium sp. and Aphanomyces sp. predominated. The frequency of occurrence of fungi in the bottom mud ranged 5080%, and no saprolegniaceous fungi could be found in the reduced black mud of Lake Kurodoro-numa.
The fungi of 330-5660/l of water were counted and of 1005500/g in bottom mud. The fungi particularly abounded in the bottom mud of Lake Sohara-ko, but not observed in Lake Kurodoro-numa. The fungi were rich in the number of species in lake water, while any one species predominated in the bottom mud as was usually seen in the other lakes. According to the microbial productivity, the lakes of the Sohara Group may be ranged as follows :
Sohara-ko>Naka-ike>Osawa-numa>Ashio-numa>Kurodoro-numa.
