Effective and characteristics of anthraquinone-2,6-disulfonate (AQDS) on denitrification byParacoccus versutussp.GW1

Abstract

The effects of anthraquinone-2,6-disulfonate (AQDS) on microbial populations and the biocatalysing characteristics of AQDS on denitrifying strain GW1 are discussed. The results showed that microbial population abundances were 30, 6, 12 and 18% during the different periods (1st, 5th, 10th and 20th days). Strain GW1 utilized AQDS as an electron acceptor in the respiration chain and reduced AQDS to hydroquinone (QH2). The nitrate removal efficiency of strain GW1 was increased 1.14-1.63 fold with 0.04-0.32 mmol/L AQDS. A linear correlation was found between the nitrate removal reaction constant k[gNO3(-)- N/(gVSS x d)] (where VSS is volatile suspended solids) and AQDS concentration (CAQDS), which was k = 19.332 C(AQDS) + 11.115 (R2 = 0.9749). The stabilized oxidation-reduction potential (ORP) values with AQDS were lower 22-92 mv than the control during the denitrification process. The concentration of nitrite sequentially accumulated up to around 250 mg/L when nitrate have removed completely. The results suggested that AQDS as redox mediator was capable of biocatalysing the nitrate and nitrite removal rate.

Isolation and Cr(VI) reduction characteristics of quinone respiration in Mangrovibacter plantisponsor strain CR1

“…A similar result with AQDS was reported by Li et al. previously . According to the research of Field et al.…”

“…Quinones accept electrons from the respiration chain because of their carbonyl groups , and the concentration of AQS greatly influenced the Cr(VI) reduction rate. Experiments were conducted with 0–1.12 mM AQS at 35 °C, pH 6.5 and 1 mM Cr(VI).…”

The Selenoproteome as a Dynamic Response Mechanism to Oxidative Stress in Hydrogenotrophic Methanogenic Communities

“…Proteomic sampling occurred on days 20 (a) and 21 (b), at which both cultures had sufficiently adapted and exhibited similar methane yields (Figure SI 2A of the Supporting Information). The addition of 25 mM AQDS proved effective at generating an optimal redox environment for methanogenesis, , with reduced AQDS serving as a redox buffer to lower ORP variability (Figure C). To act as a redox buffer, AQDSH – has been proposed to react with oxygen to form AQDSHO 2 – at neutral pH (Figure A), where AQDS recovery from AQDSHO 2 – was identified as a rate-limiting step .…”

Study of the dynamics and material transformation characteristics of nitrite denitrification in UASB

“…Denitrifying sludge was acclimated in this reactor by 50 mg L ¡1 NO 3 -N. The composition of the acclimated synthetic wastewater [21] ¡1 . During the set-up and steady-state processes, the change in the denitrifying bacteria population was evaluated by fluorescence in situ hybridization (FISH).…”

“…FISH steps were as follows [21]: (1) the defined amount of nitrite denitrification granular sludge was placed in a 1.5 mL centrifuge tube and soaked with 4% paraformaldehyde for 4 h at 4 C; (2) the granular sludge sample was washed three times by 1£ PBS (phosphate buffered saline); (3) the sample was spotted on a gelatincoated slide, treated with 50%, 80% and 100% ethanol, as a process of dehydration, for 3 min, respectively, and allowed to air dry as previously described; (4) the sludge sample was covered with 10 mL of hybridization buffer (0.9 mol L ¡1 NaCl, 0.01% sodium dodecyl sulphate (SDS), 20 mmol L ¡1 TrisÀHCl (pH 7.2), 20% deionized formamide) containing 10 nmol L ¡1 of EUB338 probe; (5) the hybridization was performed for 3 h at 46 C; then the sludge sample was washed in pre-warmed washing buffer (20 mmol L ¡1 TrisÀHCl (pH 7.2), 0.01% SDS, Figure 1. Diagram of experimental equipment.…”