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: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. 18 samples; Triplicate PHB-enriched bacterial communities recovered from activated sludge were exposed to nanoparticle (TiO2 or Ag) or AgNO3 (as a silver control) or were not exposed to an nanoparticles (control) to determine if the naoparticles affected PHB production.
Project description:Here we report a metatranscriptomic analysis of gene expression and regulation of “Candidatus Accumulibacter”-enriched lab-scale sludge during enhanced biological phosphorus removal (EBPR). Medium density oligonucleotide microarrays were generated with probes targeting most predicted genes hypothesized to be important for the EBPR phenotype. The objectives were to investigate which genes were expressed during EBPR and which genes were differentially expressed between the early stage of anaerobic and aerobic phases (defined as 15 min after acetate addition and 15 min after switching to aeration respectively).
Project description:Apis mellifera workers in temperate climates display two castes; short lived summer bees that engage in nursing, hive maintenance and foraging, and long lived winter bees (diutinus bees) which remain within the hive and are essential for thermoregulation. Label free quantitative proteomic analysis was conducted on A. mellifera workers sampled in June and December to compare the proteomes of summer and winter bees. Proteomic analysis was completed on head, abdominal and venom sac samples which revealed an elevated level of protein abundance in summer bees but and a decrease in protein abundance in winter bees. Head and abdominal samples displayed an increase in cuticular proteins in summer samples whereas an increase in xenobiotic proteins was observed in winter samples. Several carbohydrate metabolism pathways which have been linked to energy production and longevity in insects were observed to be increased in abundance in winter samples in comparison to summer samples. Proteomic analysis of the venom sacs an increased abundance and expression of bee venom associated proteins in comparison to winter workers. These data provides an insight into the adaptions of A. mellifera workers in summer and winter and may aid in future treatment and disease studies on honeybee colonies.
Project description:Apis mellifera workers in temperate climates display two castes; short lived summer bees that engage in nursing, hive maintenance and foraging, and long lived winter bees (diutinus bees) which remain within the hive and are essential for thermoregulation. Label free quantitative proteomic analysis was conducted on A. mellifera workers sampled in June and December to compare the proteomes of summer and winter bees. Proteomic analysis was completed on head, abdominal and venom sac samples which revealed an elevated level of protein abundance in summer bees but and a decrease in protein abundance in winter bees. Head and abdominal samples displayed an increase in cuticular proteins in summer samples whereas an increase in xenobiotic proteins was observed in winter samples. Several carbohydrate metabolism pathways which have been linked to energy production and longevity in insects were observed to be increased in abundance in winter samples in comparison to summer samples. Proteomic analysis of the venom sacs an increased abundance and expression of bee venom associated proteins in comparison to winter workers. These data provides an insight into the adaptions of A. mellifera workers in summer and winter and may aid in future treatment and disease studies on honeybee colonies.
Project description:MicroRNAs (miRNAs) are single strand small non-coding RNAs that regulate target mRNAs at post-transcription level. Winter wheat (Triticum aestivum L.), is an important crop plant all over the world. Long term cold exposure (vernalization) is necessary for winter wheat transition from vegetative growth to reproductive growth, yet the involvement of miRNAs in these stages remains unknown. Therefore, we performed next generation sequencing of small RNAs profiles in crown tissues at three-leaf stage, winter dormancy stage, spring greenup stage and jointing stage.
Project description:Investigation of transcriptome dynamics of Japanese cedar (Cryptomeria japonica) in winter (Dec. 22-23, 2011) and summer (July 30-31, 2012). We investigated seasonal and diurnal transcriptome dynamics of Japanese cedar (Cryptomeria japonica) by analyzing shoot samples collected at four-hour interval for two days in winter and summer, respectively. We first collected sequence data of expressed genes from shoots to designed microarray probes. Microarray analysis revealed the significant difference of transcripts between summer and winter, and the diurnal transcriptome dynamic in summer.Statistical analysis indicated that about 7.7 % of unique genes showed diurnal rhythms with more than two-fold of peak-to-trough amplitude in summer.