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Bacteriological studies in sediment from Cerna-Belareca-Danube hydrographic system (SW Romania) with a role in assessing pollution.

2010; University of Oradea Publishing House; Volume: 17; Issue: 1 Linguagem: Inglês

1224-5119

Marioara Nicoleta Filimon, Aurica Breica Borozan, Vasile Daniel Gherman,

Marine Biology and Ecology Research

This paper contains data about the microorganism population in sediment from Cerna-Belareca-Danube hydrographic system. Data allows us to identify possible pollution sources and determine their effect on certain eco physiological group of microorganisms. Bacteriological studies had in view to establish three eco physiological groups of microorganism: nitrifying bacteria, iron-reducing bacteria and anaerobic sulfate-reducing bacteria. Determination has been made using serial dilutions and specific culture environment for each eco physiological group. Based on absolute values of those 3 microorganism groups, the bacterial indicator of sediment quality has been established (BISQ). Sediment analyses have values between 1.274 (Orsova upstream) and 1.296 (Mehadia downstream) in spring. These are the values for winter: 1.286 (Topleţ downstream) and 1.310 (Orsova upstream). Additional contribution of organic sulfur compounds and microorganisms involved in the sulfur cycle have relatively close values for both seasons in Herculane sample point. Sampling points Mehadia downstream and Topleţ downstream represent the endpoint of BISQ. Lowest values had been recorded here in autumn and the highest values had been recorded in spring. BISQ lower values from Orsova harbor and Orsova shipyard is due to oil pollution, varnishes, paints, detergents and metals. BISQ has seasonal variations, depending on the sampling point of the studied aquatic ecosystem.