Project description:Biological treatments to degrade cyanide are a powerful technology for cyanide removal from industrial wastewaters. It has been previously demonstrated that the alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 is able to use free cyanide and several metal-cyanide complexes as the sole nitrogen source. In this work, the strain CECT5344 has been used for detoxification of the different chemical forms of cyanide that are present in alkaline wastewaters from the jewelry industry. This liquid residue also contains large concentrations of metals like iron, copper and zinc, making this wastewater even more toxic. To elucidate the molecular mechanisms involved in the bioremediation process, a quantitative sRNA sequencing analysis has been carried out in P. pseudoalcaligenes CECT5344 cells grown with the jewelry residue, free cyanide and ammonium as sole nitrogen sources.
Project description:Transcriptional analysis of the cyanotroph Pseudomonas pseudoalcaligenes CECT5344 in response to cyanide present in wastewaters from industrial activities, such as jewelry and electroplating activities Four-conditions experiment, including three different nitrogen sources (ammonium, sodium cyanide or a cyanide-containing wastewater). One experiment without nitrogen added to the media (nitrogen limited condition). Four biological replicates for each condition (added nitrogen source to the media) plus the experiment without nitrogen source added.
Project description:Biological treatments to degrade cyanide have shown to be a powerful technology for cyanide removal from industrial wastewaters. It has been previously demonstrated that the alkaliphilic bacterium Pseudomonas pseudoalcaligenes CECT5344 is able to use free cyanide and several metal−cyanide complexes as the sole nitrogen source. The strain CECT5344 has been used for detoxification of the different chemical forms of cyanide that are present in alkaline wastewaters from the electroplating process of the jewelry industry. This liquid residue also contains large concentrations of metals like iron, copper and zinc, making this wastewater even more toxic. A proteomic analysis by LC-MS/MS has been applied to elucidate the molecular mechanisms involved in this bioremediation process in P. pseudoalcaligenes CECT5344. Among others, different proteins related to cyanide and cyanate assimilation, as well as other proteins involved in transport and resistance to metals were induced by the cyanide-containing jewelry residue have been identified.
Project description:Microbial Community Responses to Cyanide Loading in A Biological Cyanide-containing Wastewater Treatment Reactor for Gold Mill Effluent
Project description:Pure cultures of ammonia oxidizing bacterium, Nitrosomonas europaea, are exposed to cyanide in pseudo-steady state batch reactor in presence of ammonia. Nitrosomonas europaea are generally regarded as the most sensitive organism to various inhibitors commonly encountered in the wastewater treatment plants (WWTP). To find stress genes of Nitrosomonas europaea to cyanide known as inhibitor of respiratory process, whole-genome transcript response to cyanide was determined in this research using microarray and qRT-PCR. When 1 uM NaCN inhibits nitrification about 50 %, transcript levels of 35 genes were increased while transcript levels of 29 genes were decreased, showing more than 2-fold in total 2460 genes. moeZ (NE2353), homologue with rhodanases related to detoxification of CN-, showed 7-fold up regulation and gene cluster including moeZ also showed significant up regulation. Keywords: cyanide, stress response, moeZ
Project description:Pure cultures of ammonia oxidizing bacterium, Nitrosomonas europaea, are exposed to cyanide in pseudo-steady state batch reactor in presence of ammonia. Nitrosomonas europaea are generally regarded as the most sensitive organism to various inhibitors commonly encountered in the wastewater treatment plants (WWTP). To find stress genes of Nitrosomonas europaea to cyanide known as inhibitor of respiratory process, whole-genome transcript response to cyanide was determined in this research using microarray and qRT-PCR. When 1 uM NaCN inhibits nitrification about 50 %, transcript levels of 35 genes were increased while transcript levels of 29 genes were decreased, showing more than 2-fold in total 2460 genes. moeZ (NE2353), homologue with rhodanases related to detoxification of CN-, showed 7-fold up regulation and gene cluster including moeZ also showed significant up regulation. Keywords: cyanide, stress response, moeZ The 1 uM NaCN caused more than 50 % inhibition in physiological response for 1 hour incubation. Transcriptional levels of the cells inhibited by cyanide were compared with the cells under control condition.
Project description:Manufactured nanomaterials (MNMs) are increasingly incorporated into consumer products that are disposed into sewage. In wastewater treatment, MNMs adsorb to activated sludge biomass where they may impact biological wastewater treatment performance, including nutrient removal. Here, we studied MNM effects on bacterial polyhydroxyalkanoate (PHA), specifically polyhydroxybutyrate (PHB), biosynthesis because of its importance to enhanced biological phosphorus (P) removal (EBPR). Activated sludge was sampled from an anoxic selector of a municipal wastewater treatment plant (WWTP), and PHB-containing bacteria were concentrated by density gradient centrifugation. After starvation to decrease intracellular PHB stores, bacteria were nutritionally augmented to promote PHB biosynthesis while being exposed to either MNMs (TiO2 or Ag) or to Ag salts (each at a concentration of 5 mg L-1). Cellular PHB concentration and PhyloChip community composition were analyzed. The final bacterial community composition differed from activated sludge, demonstrating that laboratory enrichment was selective. Still, PHB was synthesized to near-activated sludge levels. Ag salts altered final bacterial communities, although MNMs did not. PHB biosynthesis was diminished with Ag (salt or MNMs), indicating the potential for Ag-MNMs to physiologically impact EBPR through the effects of dissolved Ag ions on PHB producers.
Project description:Characterization of microbial communities at the genomic, transcriptomic, proteomic and metabolomic levels, with a special interest on lipid accumulating bacterial populations, which are naturally enriched in biological wastewater treatment systems and may be harnessed for the conversion of mixed lipid substrates (wastewater) into biodiesel. The project aims to elucidate the genetic blueprints and the functional relevance of specific populations within the community. It focuses on within-population genetic and functional heterogeneity, trying to understand how fine-scale variations contribute to differing lipid accumulating phenotypes. Insights from this project will contribute to the understanding the functioning of microbial ecosystems, and improve optimization and modeling strategies for current and future biological wastewater treatment processes. This project contains datasets derived from the same biological wastewater treatment plant. The data includes metagenomes, metatranscriptomes, metaproteomes and organisms isolated in pure cultures. Characterization of microbial communities at the genomic, transcriptomic, proteomic and metabolomic levels, with a special interest on lipid accumulating bacterial populations, which are naturally enriched in biological wastewater treatment systems and may be harnessed for the conversion of mixed lipid substrates (wastewater) into biodiesel. The project aims to elucidate the genetic blueprints and the functional relevance of specific populations within the community. It focuses on within-population genetic and functional heterogeneity, trying to understand how fine-scale variations contribute to differing lipid accumulating phenotypes. Insights from this project will contribute to the understanding the functioning of microbial ecosystems, and improve optimization and modeling strategies for current and future biological wastewater treatment processes. This project contains datasets derived from the same biological wastewater treatment plant. The data includes metagenomes, metatranscriptomes, metaproteomes and organisms isolated in pure cultures.