Hidrológiai Közlöny 2001 (81. évfolyam)

5-6. szám - XLII. Hidrobiológus Napok: „A magyar hidrobiológia időszerű kérdései az ezredfordulón” Tihany, 2000. október 4–6.

331 Köszönetnyilvánítás Vizsgálatainkat az EU INCO-COPERN1CUS nemzetközi kutatási programhoz kapcsolódóan és az FVM K+F támogatásával végeztük. Irodalom Conte, E. D„ Shen, C.-Y., Miller, D. W„ Perschbacher, P. W. 19%. Microwave distillation - solid phase adsorbent trapping device for the determination of off-flavors, gcosmin and methylisoborneol, in catfish tissue below their rejection levels Anal Chem. 68: 27132716. Cross, T. 1981. Aquatic actinomycetes: a critical survey of the occurrence, growth and role of actinomycetes in aquatic habitats. Journal of Applied Bacteriology 50: 397-423. From, J., Horlyck, V. 1984 Sites of uptake of geosmin, a cause of earthy flavor, in rainbow trout (Salmo gairdneri). Canadian Journal of Fisheries and Aquatic Sciences 41: 1224-1226. Gerber, N. N. 1968. Geosmin from microorganisms is trans-1,10dimethyl-trans-9-decalol. Tetrahedron Letters, 25: 2971-2974. Gerber, N. N. 1969. A volatile metabolite of actinomycetes, 2methylisobomeol. Journal of Antibiotics, 22: 508-509. Gerber, N. N. 1983. Volatile substances from Actinomycetes: their Role in the Odor Pollution of Water. Wat. Sei. Tech. 15, 115-125. Johnsen, P. B.. Kuan J. W. 1987. Simplified method to quantify geosmin and 2-methylisobomeol concentrations in water and microbiological cultures. Journal of Chromatography, 409: 337-342. Küster, E-, Williams S. T. 1964. Selection of media for isolation Streptommycetes. Nature 202, 928-929. Lipták, M„ Pékár, F., Szabó, P. és Csengeri, I. 1995. Előkísérletek a halhús minőségét rontó természetes eredetű szag- és ízanyagok kimutatására termelő halastavakban. XIX. Halászati Tudományos Tanácskozás, Haltenyésztési Kutató Intézet, Szarvas, 1995. május 17-18 Lövell, R. 7', Sackey, L. A. 1973. Absorption by channel catfish of earthy-musty flavor compounds synthesized by cultures of bluegreen algae. Transactions of the American Fisheries Society 102. 774-777. Mallevialle, J., Suffel, I. //. (eds

) 1987. Identification and treatment of tastes and odors in drinking water. American Water Works Association, Denver, 292 pp. Medsker, L. L., Jenkins D., Thomas J. F, Koch C. 1969. Odorous compounds in natural waters. 2-Exohydroxy-2-mcthylbomanc, the major odorous compound produced by several actinomycetes. Environmental Science and Technology, 3: 476-477. Olson, E. H. 1968. Actinomycetes isolation agar. In: DIFCO: Supplementary literature, Difco Lab. Detroit. Pridham, T., Anderson, G, Foley P. C., Lindenfelser L. A., Hesselline C. W„ Benedict R. G. 1957. Antibiotics A. 1956/7, 947-953 Strackebrandt, E., Rainey F. A., Ward-Rainey N. L. 1997. Proposal for a New Hierarchical Classification System, Actinobacteria classis nov. Int. J. Sys. Bact. 47. 2, 479-491. Tucker, C. S., Martin, J. F. 1991. Environment-related off-flavors in fish In: Aquaculture and Water Quality (Brune, D. E. and Tomasso, J. R., eds

) Vol. 3. pp. 133-179 - Proc. of the First International Symposium on Water Quality and Aquaculture held in Los Angeles, 1989. Survey on the occurrence of off-flavour substances of natural origin in Hung, fishponds and natural waters Abstract: 2-Methylisobomool (MIB) and geosmin (GSM) arc off-flavour substances of natural origin that affect adversely the organoleptic properties of water and fish meat. Little information is available concerning the occurrence of these compounds in Hungary. The objective of our study was to survey the levels of MIB and GSM in the water, sediment and fish of the fishponds of different regions of Hungary. The production of M]B and GSM and their accumulation in aquatic invertebrates were also measured in a natural water (the Kákafoki Holt-Körös oxbow) in order to obtain background information. In almost all of the collected and examined fishpond samples measurable, or, sometimes, high levels of off-flavour substances were detected The concentrations of MIB in the water varied between 0,39-435 ig/1, while the levels of GSM, between 0,04-10,95 ig/1. The fish meat samples contained very high levels of MIB (above 1000 (ig/kg) and of GSM (above 8 (ig/kg). On the basis of comparation of the concentrations measured in the sediment and water it seems probable that the main site of production of MIB and GSM is in the sediment. In the studied benthic organisms (bivalves) a significant accumulation of MIB and GSM was measured No information was available earlier regarding the occurrence o( Actinobacteria in Hungarian fishponds. On the basis of our studies these bacteria seem to be present in the fishpond sediments with relatively high numbers (0,3-73 * 10

5 c.f.u./g), while they are not detectable in the water column, with the exception of the experimental lake (55-1700 c.f.u./ml). Keywords

: MIB, geosmin, algae, Actinobacteria, fishponds, sediment