Time filter

Source Type

Che J.,Dalian University of Technology | Xu M.,Center for Food Safety of Animal Origin | Yang G.,Dalian University of Technology | Wang L.,Dalian University of Technology | And 5 more authors.
Chinese Journal of Environmental Engineering | Year: 2014

In the present study, effects of aerobic activated sludge with diatomite carrier in sequencing batch reactor (SBR) on removal of ammonia-nitrogen(NH4 +-N), nitrite-nitrogen(NO2 --N) and chemical oxygen demand(COD)in mariculture wastewater with high nitrogen and low carbon were evaluated, and the property of sludge settling and characteristics of nitrifying bacteria in sludge were analyzed. The results indicated that the reactor could provide a less than 0.028 mg/L NO2 --N effluent concentration and about 98.93% and over 76.62% removal rate of NH4 +-N and COD respectively in mariculture wastewater containing 50 mg/L NH4 +-N after purification with conditions of room temperature, over 4.5 mg/L dissolved oxygen (DO), pH around 7.0 ~ 8.0, 11 hours HRT and 10 min settling time. The images of granular sludge with diatomite as well as scanning electron microscopy (SEM) revealed that the time of maturation stage of granular sludge was reduced and the stability and settling property of granular sludge were greatly improved after diatomite carrier was added. With successful and stable operation of the system, the FISH analysis showed that the ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) were dominant microflora, AOB accounted for about 33.5% of the total bacteria, and the ratio of the number of AOB and NOB was 1:1.33, two dominant bacteria accounted for about 77.2% of the total bacteria. ©, 2014, Science Press. All right reserved. Source

Wang T.,Dalian University of Technology | Wang T.,Dalian SEM Bio Engineering Technology Co. | Sun Y.,Liaoning Academy of Agricultural science | Jin L.,Dalian University of Technology | And 5 more authors.
Fish and Shellfish Immunology | Year: 2013

The nuclear factor κB (NF-κB) has been evolutionary conserved from insects to mammals and plays a major regulatory role in the initiation of physiological responses. In this study, we identified and characterized a primitive and functional NF-κB pathway active in the immune defence of the sea cucumber (Apostichopus japonicus). The ancient NF-κB homologues, Aj-rel and Aj-p105, share numerous signature motifs with their vertebrate orthologues, notably the Rel Homology Domain, Rel Protein Signature DNA Binding Motif, Nuclear Localization Signal and the Ankyrin Repeats for Aj-p105. Phylogenetic analyses indicate that these homologues belong to class I and II of NF-κB respectively. We examined the dimerization of Aj-rel and Aj-p105 and our results demonstrated that Aj-rel forms heterdimers with Aj-p105 and the degradation product of Aj-p105, namely Aj-p50. We further observed that LPS stimulation led to the degradation of Aj-p105 and the nuclear translocation of Aj-rel and Aj-p50. Taken together, our data indicate that the NF-κB signaling cascade is active in sea cucumber and plays a crucial role in regulating their immune defence. Our results increase the available information on sea cucumber immunity and provide new information for use in the study of the comparative and evolutionary aspects of immunity. © 2012 Elsevier Ltd. Source

Che J.,Dalian University of Technology | Wang L.L.,Dalian University of Technology | Wang L.L.,Center for Food Safety of Animal Origin | Wang X.T.,Dalian University of Technology | And 5 more authors.
Israeli Journal of Aquaculture - Bamidgeh | Year: 2015

Sequencing batch reactors (SBR) have been used in the biological treatment of aquaculture wastewater. In this study, we investigated the microbial community of a SBR that used diatomite earth (20 g/L) as the sludge carrier material. Marine wastewater in which ammonia content was 42.08 to 55.88 mg/L was supplied to the SBR every 12 h over a treatment period of 65 days. During the first 20 days, the concentration of NH4-N decreased gradually, while nitrite (NO2-N) became the major nitrogen compound, reminiscent of the development of an ammonia-oxidizing process. Over the next 20 days, the concentration of NH4-N decreased further due to conversion to NO3-N. More than 99% of the NH4-N was converted to NO3-N over a period of 40-65 days. Denaturing gradient gel electrophoresis (DGGE) assay showed that bacteria of the genus Flavobacterium were present during the entire treatment period, while α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria, and Sphingobacteriia started to accumulate after the first 20 days. Fluorescence in situ hybridization (FISH) assay identified Nitrobacter and Nitrosomonas as the main bacteria involved in the conversion of NH4-N to NO3-N. Diatomite earth therefore acted as an efficient sludge carrier by shortening the settling time and facilitating bacterial colonization. This SBR was capable of rapid removal of NH4-N. This warrants further investigation at the pilot-scale in an actual mariculture farm. © 2015 Israeli Journal of Aquaculture - Bamidgeh. All rights reserved. Source

Discover hidden collaborations