Hidrológiai Közlöny 1995 (75. évfolyam)
4. szám - Kurdi Péter–Borsodi Andrea: A Fertő-tó nádasok övezte belső tavai planktonikus baktériumközösségeinek numerikus analízise
244 HIDROLÓGIAI KÖZLÖNY 1995. 75. ÉVF. 2. SZ^JVI Numerical analysis on planktonic bacterial communities of reed beit surrounded "inner-lakes" of Laké Fertő Kurdi, P. - Borsodi, A. Abstract: The so-called "inner-lakes" (Herlakni, Kis-Herlakni, Hidegségi-tó) of the shallow, turbid and sodic steppe-lake, I>ake Fertő (Hungary) are isolated water bodies. They separated from the open laké water by wide reed belts and concomitantly have a very special water chemistry. The typically brown waters are characterised by high organic + 2 + 2content (humic acids too) and high salinity ( [Na J=450 mg/l, [Mg )»140 mg/l, [S0 4 ]=440 mg/l). Open water samples were taken from the three "inner-lakes", and the composition of bacterial communities was investigated by detailed biochemical-physiological characterisation of selected strains using numerical methods. The dominant microorganisms in the open water of all the three "inner-lakes" constitute of Micrococcus varians and of Flavobacterium species. The former seems to be highly adapted to these unique environments. Unfortunately the typically oligocarbophilic flavobacteria showed very little activity in the standard biochemical and physiological tests. Pleomorphic Gram positive rods were alsó isolated in lower numbers, which turnéd to be members of the genus Arthrobacter, a typical soil organism. Their presence is probably associated with the high organic substrate, especially hardly degradable biopolymer concentration of the inner laké water. Other very much pleomorphic but Gram íicgati ve rods could have been identified as members of the Cytophaga-Flavobacterium group belonging into genera Flectobacillus, Flexibacter and Cytophaga. These organisms are alsó active in the degradation of most diverse biopolymers. A local variety of Staphylococcus xylosus seems to play much less role in these special habitat as the above mentioned organisms, but the presence of Staphylococci in such habitats at least noticeable. Similarly the loss of importance of Pseudomonas species can possibly be elucidated by the special water chemistry of "inner-lakes", since these organisms are in dominant populatory position in the open water of Laké Fertő. Keywords: water bacteriology. species composition, numerical analysis. Laké Fertő, "inner lakes" Sk.W-10. ^
