Project description:Screening and Identification of Heterotrophic Nitrification-Aerobic Denitrification Bacteria in the Culture Ponds of Whiteleg Shrimp
| PRJNA1270744 | ENA
Project description:Screening and Identification of Heterotrophic Nitrification-Aerobic Denitrification Bacteria in the Culture Ponds of Whiteleg Shrimp
| PRJNA1270847 | ENA
Project description:Screening and Identification of Heterotrophic Nitrification-Aerobic Denitrification Bacteria in the Culture Ponds of Whiteleg Shrimp
| PRJNA1272770 | ENA
Project description:Screening and Identification of Heterotrophic Nitrification-Aerobic Denitrification Bacteria in the Culture Ponds of Whiteleg Shrimp
Project description:Roothans et al., analyzed heterotrophic denitrification processes that can be an important source of nitrous oxide. We employed planktonic nitrification-inhibited denitrifying enrichment cultures under alternating oxic-anoxic conditions. The dynamic conditions resulted in a general presence of the denitrifying enzymes. Overall, we show that aerobic denitrification should not be neglected as an ecologically relevant process. Contact author: m.laureni@tudelft.nl
2024-07-17 | PXD042057 | Pride
Project description:Heterotrophic nitrification aerobic denitrification bacteria for high salt wastewater treatment
Project description:Nitrogen and arsenic contaminants often coexist in groundwater, and microbes show the potential for simultaneous removal of nitrogen and arsenic. Here, we reported that Hydrogenophaga sp. H7 was heterotrophic nitrification and aerobic denitrification (HNAD) and arsenite [As(III)] oxidation bacterium. Strain H7 presented efficient capacities for simultaneous NH4+-N, NO3--N, or NO2--N removal with As(III) oxidation during aerobic cultivation. Strikingly, the bacterial ability to remove nitrogen and oxidize As(III) has remained high across a wide range of temperatures, pH values, and shaking speeds, exceeding that of the most commonly reported HNAD bacteria. Additionally, the previous HNAD strains exhibited a high denitrification efficiency, but a suboptimal concentration of nitrogen remained in the wastewater. Here, strain H7 combined with FeCl3 efficiently removed 96.14% of NH4+-N, 99.08% of NO3--N, and 94.68% of total nitrogen (TN), and it oxidized 100% of As(III), even at a low nitrogen concentration (35 mg/L). The residues in the wastewater still met the Surface Water Environmental Quality Standard of China after five continuous wastewater treatment cycles. Furthermore, genome and proteomic analyses led us to propose that the shortcut nitrification-denitrification pathway and As(III) oxidase AioBA are the key pathways that participate in simultaneous nitrogen removal and As(III) oxidation.
Project description:Acute hepatopancreatic necrosis disease (AHPND) is a shrimp farming disease, caused by a pathogenic Vibrio parahaemolyticus carrying a plasmid encoding Vp_PirAB-like toxin (VpAHPND). Whiteleg shrimp, Litopenaeus vannamei were fed food pellets containing formalin-killed VpAHPND (FKC-VpAHPND) to select for toxin resistance. To identify genes associated with Vp_PirAB-like toxin resistance, total RNA was sequenced to identify differentially expressed genes (DEGs) in the stomach and hepatopancreas among surviving shrimp (sur-FKC), AHPND-infected shrimp (Vp-inf) and normal shrimp (control). From a total of 79,591 genes, 194 and 224 DEGs were identified in the stomach and hepatopancreas transcriptomes, respectfully. The expressions of DEGs were validated by qPCR of ten genes. Only one gene, a gene homologous to L vannamei anti-lipopolysaccharide factor AV-R isoform (LvALF AV-R), was expressed significantly more strongly in sur-FKC than in the other groups. The association of LvALF AV-R expression and toxin resistance was affirmed from the surviving shrimp in a second-trial of FKC-VpAHPND feeding. These results suggest that LvALF AV-R may be involved in shrimp defense mechanisms against Vp_PirAB-like toxin virulence.
Project description:World aquaculture production of the Pacific white shrimp (Litopenaeus vannamei) is estimated to account for 80% of the total shrimp produce worldwide. The global demand for shrimp has driven the industry to utilize and rely on semi-intensive and intensive shrimp systems. In the United States, Pacific white shrimp production can take place in semi-intensive earthen ponds, recirculating aquaculture systems (RAS), biofloc technology and green water. In this study, the effects of lowering dissolved oxygen conditions in outdoor green water tanks on global gene expression is examined. Tissue samples from the gill and intestine were collected for gene expression analysis via RNA sequencing. Among all comparisons, RNA sequencing revealed the up-regulation of a single gene: hydroxyacid oxidase 1 gene. The HOA1 gene was found to be 7-fold higher in the intestine sample at the medium aeration level compare to that of the high (control) level. The HAO1 gene, also known as glycolate oxidase 1 (GOX1) is a gene related to the 2-hydroxyacid oxidase enzyme that is part of the oxidoreductase family and plays a role in glyoxylate and dicarboxylate metabolism. The identification of a single differentially expressed gene across all analyzed samples suggests that Pacific white shrimp exposed to lowering dissolved oxygen set points does not induce global changes in gene expression at these levels.