ABSTRACT
Organics,sulfide and nitrogen compounds in industrial wastewater are significant challenges for wastewater treatment. These pollutants could be removed simultaneously from wastewater treatment system using biological technologies. In this study, a heterotrophic denitrifying sulfur bacterial strain HDD1 was isolated from wastewater treatment bioreactor. Strain HDD1 was identified as Thauera sp. based on the 16S rRNA gene phylogenetic analysis and physiological characteristics. Acetate and sulfide could be utilized as electron donors and nitrate as electron acceptor for respiration in Thauera sp. HDD1. The acetate (300 mg·L-1), sulfide (200 mg·L-1) and nitrate (487 mg·L-1) were completely metabolized and removed within 15 hours. The main product of sulfide oxidation was elemental sulfur as identified by scanning electron microscope and energy dispersive spectrometer. These results suggest that the newly isolated Thauera sp. HDD1 could be used for simultaneous industrial wastewater treatment and elemental sulfur resource recovery.
Subject(s)
Nitrates/metabolism , Phylogeny , Sulfur-Reducing Bacteria/classification , Sulfur/metabolism , Bioreactors/microbiology , Denitrification , Heterotrophic Processes , RNA, Ribosomal, 16S/genetics , Sulfides , Sulfur-Reducing Bacteria/isolation & purification , Wastewater/microbiologyABSTRACT
A Gram-staining-negative, rod-shaped, motile and facultatively anaerobic bacterial strain, designated X2(T), was isolated from the sludge of an anaerobic, denitrifying, sulfide-removal bioreactor, and found to oxidize sulfide anaerobically with nitrate as electron acceptor. The strain grew at salinities of 0-3% (w/v) NaCl (optimum, 0-1%). Growth occurred at pH 6.0-10.0 (optimum, pH 8.0) and 10-37 °C (optimum, 30 °C). The genomic DNA G+C content was 59 mol%. Q-8 and Q-9 were detected as the respiratory quinones. The major fatty acids (>10â%) were C16:1ω7c and/or C16:â1ω6c, C18:â1ω7c and C16:0. The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and one unidentified phospholipid. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain X2(T) formed a novel clade within the family Pseudomonadaceae, with the highest sequence similarity to Pseudomonas caeni KCTC 22292(T) (93.5%). On the basis of phenotypic, chemotaxonomic and phylogenetic characteristics, it is proposed that this strain represents novel genus and species within the family Pseudomonadaceae, for which the name Thiopseudomonas denitrificans gen. nov., sp. nov. is proposed. The type strain is X2(T) (â=CCTCC M 2013362(T)â=DSM 28679(T)â=âKCTC 42076(T)).
Subject(s)
Phylogeny , Pseudomonadaceae/classification , Sewage/microbiology , Bacterial Typing Techniques , Base Composition , Bioreactors , DNA, Bacterial/genetics , Fatty Acids/chemistry , Molecular Sequence Data , Phospholipids/chemistry , Pseudomonadaceae/genetics , Pseudomonadaceae/isolation & purification , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Ubiquinone/chemistryABSTRACT
Biocatalyzed electrolysis systems (BES) have been the topic of a great deal of research. However, the biocathodes formed in single-chamber BES without extra inocula have not previously been researched. Along with the formation of biocathodes, the polarization current increased to 1.76 mA from 0.35 mA of abio-cathodes at -1.2 V (vs. SCE). Electrochemical impedance spectroscopy (EIS) results also indicated that the charge transfer resistance (Rct) was decreased to 148.9 Ω, less than 1978 Ω of the abio-cathodes cleared. The performance of the biocathodes was tested for azo dye decolorization, and the dye removal efficiency was 13.3±3.2% higher than abio-cathodes with a 0.5 V direct current (DC) power supply. These aspects demonstrate that biocathode accelerates the rate of electrode reaction in BES and comparing with noble metal catalysts, biocathodes have low toxicity or non-toxic and reproducible properties, which can be widely applied in bioelectrochemical field in the future.
Subject(s)
Azo Compounds/chemistry , Coloring Agents/chemistry , Dielectric Spectroscopy/methods , Amido Black/chemistry , Bioelectric Energy Sources , Biofilms , Bioreactors , Catalysis , Electrochemistry/methods , Electrodes , Electrolysis , Electrons , Time FactorsABSTRACT
OBJECTIVE: To study the protection of Corn Shuang on hyperlipidemic rats vascular wall and its mechanism of action. METHODS: Thirty Wistar rats were randomly divided into control group, model group and test group (n = 10). Feeding rats according to the experiment requirement, after 15 weeks,the content of lipids, superoxide dismutase (SOD), serum glutathione peroxidase (GSH-Px), malondialdehyde (MDA), nitric oxide (NO) and nitric oxide synthase (NOS) were measured in each group rats serum, morphological changes of rat aortic wall tissue were observed by light microscopy. RESULTS: The concentration of total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL-C) and MDA increased significantly in model group (P < 0.01), the concentration of high density lipoprotein (HDL-C), SOD, GSH-Px, NO and NOS decreased significantly (P < 0.01); Corn Shuang could reduce the concentration of TC, TG, LDL-C and MDA in hyperlipidemia rats serum (P < 0.01), promote the content of HDL-C, SOD, GSH-Px, NO and NOS (P < 0.01); Aortic wall showed typical atherosclerotic lesion in model group; Corn shuang could improve significantly damages of artery wall. CONCLUSION: Corn Shuang had obvious protective effect on the vessel wall, its mechanism might be related to regulation of blood lipid, antioxidant, maintenance of NO metabolism.
