The bacterial metabolism of 4,4′-dichlorobiphenyl,and its suppression by alternative carbon sources

The metabolism of 4,4′-dichlorobiphenyl by mixed cultures of bacteria, isolated from activated sludge, was studied in shake cultures and in soil, both in presence and absence of alternative carbon sources. When 4,4′-dichlorobiphenyl was used as sole carbon source, 4-chlorobenzoic acid and 4,4′-dichloro-2,3-biphenyldiol could be isolated from the culture medium. Polar metabolites however, could not be detected in soil and in media in which alternative carbon sources such as glucose, glycerol, peptone, yeast-extract, humic acid or activated sludge were present. No hydroxylated or carboxylic acid derivatives could be isolated when 2,4′, 5-tri-, 2,2′,5,5′,-textra-, 2,2′,3,4,5′-penta-, 2,2′,3,4,5,5′-hexa- and decachlorobiphenyl were used as the sole carbon sources for incubation with bacteria in shake culture.     

Developing sustainable water management scenarios by using thorough hydrologic analysis and environmental criteria

Wetlands constitute a significant source of life since they incorporate unique habitats with endemic and migrant species. They also contribute to the preservation of high global biodiversity and they are under protection according to EU legislation. Nevertheless, during the last century, significant degradation has been observed in wetlands, mainly due to intensification of agriculture and poor water management practices. Calcareous fens habitat with the endangered species Cladium mariscus and Carex spp. is an ecologically significant wetland that undergoes great ecological stresses globally, due to the irrational use of water resources. In Trichonis lake, Western Greece, this habitat has been under deterioration during the last 50 years due to the lack of a sustainable water management plan that has caused destabilization of the hydrologic balance and high water level fluctuations. This human induced hydrologic regime has led to seasonal shifting between drought and flooding which constitute unfavorable conditions for this fen habitat and as a result significant elimination of this ecosystem extent has occurred. This study has adopted technologically advanced scientific methods such as GIS applications and remote sensing techniques to quantify the existing water resources and formulate a sustainable management scheme by considering both anthropogenic water uses and environmental protection.