The work presents novel metagenomic tools to study the diversity and distribution of bacterial laccases in natural and polluted environments. The results show that bacterial genes for laccases are widely distributed in soil, waste water biofilters and river sediments. Furthermore, this work presents the first study on distribution of putative laccases in bacteria using bioinformatic search of over 2,000 bacterial genomes. The search , which was performed utilizing custom profile Hidden Markov models (pHMMs), revealed two and three domain laccases in virtually all bacterial phyla. Suprisingly, these also include strict anaerobes and autotrophs, indicating that bacteria may use laccases for processes other than substrate utilization. In addition work presents possible strategies to find novel lacasses using this data base and then express their genes in heterologous hosts.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 3953272Antidepressant and tranquilizing pharmaceuticals are two major categories of drugs primarily affecting mental processes, i.e. psychoactive pharmaceuticals. This is also our experimental model system in which we will study the influence of pharmaceutycals on expresion and diversity of bacterial laccases. Our research focused on the occurrence and fate of psychoactive pharmaceuticals in the aqueous environment and during water treatment. We describe two analytical methods for trace level determination in aqueous environmental matrices. We further discuss the results of experiments investigating the fate of diazepam and oxazepam using laboratory scale flow-through bioreactors with activated sludge under aerobic and anoxic conditions. To improve the removal of poorly biodegradable diazepam and oxazepam the aerobic and anoxic treatment are combined with abiotic experiments including photolytic and photocatalytic breakdown. While the photolysis did not show promising results in view of removal of target pharmaceuticals, the monochromatic 254nm UV lamp in the presence of 0.5% hydrogen peroxide reached up to 97% removal in biologically treated wastewater. Finally the aerobic-anoxic-photocatalytical treatment is coupled to the adsorption to activated carbon, where the residual pharmaceuticals are removed, which makes this technology potentially useful for treatment of pharmaceutical wastewaters.
B.03 Paper at an international scientific conference
COBISS.SI-ID: 25057319