Project description:In this experiment, we used advanced proteomics techniques to discern differences in energy allocation between three strains of ammonia oxidizing bacteria: Nitrosomonas europaea, Nitrosomonas ureae, and Nitrosospira multiformis, during ammonia starved and ammonia replete conditions. Replicate cultures in late log phase from the three strains were starved of ammonia for 24 hours and compared to replicate control cultures grown for the same period. All three species were grown with three biological replicates for each condition and species with the exception of two replicates from the N. ureae starved cultures due to sample processing loss. This study has, to our knowledge, produced the first complete proteomes of Nitrosospira multiformis and Nitrosomonas ureae.
Project description:The malate shuttle is traditionally known to maintain the NAD+/NADH balance between the cytosol and mitochondria. Whether the malate shuttle has additional functions was unknown. Here we show that chronic viral infections induced the expression of GOT1, the key enzyme in the malate shuttle, in CD8+ T cells. Got1 deficiency indeed decreased the NAD+/NADH ratio and dampened antiviral CD8+ T cell responses to chronic infection; however, increasing the NAD+/NADH ratio did not restore antiviral T cell responses. Got1 deficiency reduced the production of the ammonia scavenger 2-ketoglutarate and led to toxic ammonia accumulation in CD8+ T cells. Supplementation with 2-ketoglutarate assimilated and detoxified ammonia in Got1-deficient T cells and restored antiviral responses. This study suggests that the major function of the malate shuttle in CD8+ T cells is not to maintain the NAD+/NADH ratio, but rather to detoxify ammonia and enable sustainable ammonia-neutral glutamine catabolism in CD8+ T cells during chronic infections.
Project description:Rhizobium leguminosarum biovar viciae strain 3841 was grown on acetate ammonia AMS and glucose ammonia AMS and gene expression between the two cultures compared
Project description:To elucidate the mechanisms by which ammonia induced the dispersion and proliferation of A. pleuropneumoniae biofilms, NH3·H2O was added to biofilms and planktonic bacteria cultured to the log-phase for short-term stimulation and incubation. Subsequently, planktonic bacteria after ammonia stimulation (PK_NH3, the rapidly proliferating planktonic bacteria after ammonia stimulation), bacteria in the biofilm adhered layer (BF_NH3, adhered biofilm) and the supernatant layer (Up_NH3, bacteria dispersed from the BF layer ) were collected, along with the supernatant layer (Up_DspB) and adhered layer (BF_DspB) treated with DspB, and untreated control groups (PK_Con, Up_Con, BF_Con). RNA was extracted for transcriptome sequencing analysis.
Project description:Ammonia oxidizer community structure were examined in a depth profile from 20 to 2000 m at the Bermuda Atlantic Time-series Study using a functional gene microarray to look at amoA diversity
Project description:Free-living bacteria were grown on succinae ammonia AMS and gene expression was compared to free-living bacteria grown on glucose ammonia AMS.