Jujea Valentin

Industrial and household pollution is linked to the alteration of our ecosystems. The presence of large amounts of polluting agents affects oxidation-reduction and acid-base balances systems, causing cascade effects over the microbiota and aquatic environment. In this study we evaluated the biochemical parameters of salt lakes from the protected area of Buzau County, using enzymatic assays in correlation with microbial abundance.

Water and water habitats are essential to life and to the wellness of the communities that rely on them, as the Danube river is subject to human impact and vice versa, periodic surveys are required to determine the status of its pollution levels. In this work we used known microbiological indicators as well as physico-chemical ones to assess the ecotoxicological status of the Danube river from eleven locations partially forming the “Romanian–Bulgarian Danube Sector”. Most of the microbial communities found, and their densities, could be explained by point and diffuse sources scattered along the sector such as discharged household and farm wastewater, as well as nearby agricultural areas where fertilizers have been used and then leaked in the water stream during rainfalls. However, microbial data on non-point sources that lead to diffuse pollution of surface waters could be linked to such parameters and furthermore shown a slight correlation with the current status of fish communities.

The macrophyte plants Lemnaceae are abundant in the tropical and subtropical regions but now present in the Danube Delta. The plant grows in water with high levels of N, P, and K, synthesizing protein at a remarkable rate. Used as food and feed in some regions it is currently attracting interest especially for its ability to metabolize and purify wastewater. Our culture technique of duckweed was standardized in water tanks and a series of analytical methods for determining the chemical parameters of waste water were optimized. Phenotypic biodiversity of the aquatic communities was analyzed using the Biolog Ecoplates system on a total of eight samples, concluding in a symbiosis between the plants and the microbial community that can be linked to Lemnaceae high wastewater purification abilities, that transforms the highly toxic environment into an environment conducive to the development of aerobic organisms.