Photometric Determination of Ammonia Nitrogen in Slaughterhouse Wastewater with Nessler's Reagent: Effects of Different Pretreatment Methods

Lin, Yi Miao; Li, Ling Yun; Hu, Ji Wei; Huang, Xianfei; Zhou, Chao; Jia, Miao; Li, Zhi Bin

doi:10.4028/www.scientific.net/amr.955-959.1241

Cited by 11 publications

(8 citation statements)

References 5 publications

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“…The enzymatic activities toward CDHB, BOA, formanilide, acetanilide, and isatin were assessed in buffer A at 55°C for 10 min and detected using the 4-aminoantipyrene chromogenic method described above. The enzymatic activities for benzamide were detected using Nessler's reagent colorimetry (28). The esterase activities against different p-nitrophenyl esters and triglycerides were assessed by titrating the produced fatty acids (29,30).…”

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confidence: 99%

Metabolic Pathway Involved in 6-Chloro-2-Benzoxazolinone Degradation by Pigmentiphaga sp. Strain DL-8 and Identification of the Novel Metal-Dependent Hydrolase CbaA

Dong

Wang

Huang

et al. 2016

Appl Environ Microbiol

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ABSTRACT6-Chloro-2-benzoxazolinone (CDHB) is a precursor of herbicide, insecticide, and fungicide synthesis and has a broad spectrum of biological activity. Pigmentiphaga sp. strain DL-8 can transform CDHB into 2-amino-5-chlorophenol (2A5CP), which it then utilizes as a carbon source for growth. The CDHB hydrolase (CbaA) was purified from strain DL-8, which can also hydrolyze 2-benzoxazolinone (BOA), 5-chloro-2-BOA, and benzamide. The specific activity of purified CbaA was 5,900 U · mg protein ؊1for CDHB, with K m and k cat values of 0.29 mM and 8,500 s ؊1 , respectively. The optimal pH for purified CbaA was 9.0, the highest activity was observed at 55°C, and the inactive metal-free enzyme could be reactivated by Mg 2؉ , Ni 2؉ , Ca 2؉ , or Zn 2؉ . Based on the results obtained for the CbaA peptide mass fingerprinting and draft genome sequence of strain DL-8, cbaA (encoding 339 amino acids) was cloned and expressed in Escherichia coli BL21(DE3). CbaA shared 18 to 21% identity with some metal-dependent hydrolases of the PF01499 family and contained the signature metal-binding motif Q 127 XXXQ 131 XD 133 XXXH 137 . The conserved amino acid residues His288 and Glu301 served as the proton donor and acceptor. E. coli BL21(DE3-pET-cbaA) resting cells could transform 0.2 mM CDHB into 2A5CP. The mutant strain DL-8⌬cbaA lost the ability to degrade CDHB but retained the ability to degrade 2A5CP, consistent with strain DL-8. These results indicated that cbaA was the key gene responsible for CDHB degradation by strain DL-8. IMPORTANCE2-Benzoxazolinone (BOA) derivatives are widely used as synthetic intermediates and are also an important group of allelochemicals acting in response to tissue damage or pathogen attack in gramineous plants. However, the degradation mechanism of BOA derivatives by microorganisms is not clear. In the present study, we reported the identification of CbaA and metabolic pathway responsible for the degradation of CDHB in Pigmentiphaga sp. DL-8. This will provide microorganism and gene resources for the bioremediation of the environmental pollution caused by BOA derivatives. 6-Chloro-2-benzoxazolinone (CDHB) is the precursor of fenoxaprop-p-ethyl (FE) and metamifop synthesis (1). FE is a postemergence aryloxyphenoxy propionate (AOPP) herbicide that is used to control annual and perennial weeds in crops, such as soybean, turf, and wheat (2, 3). Many studies have demonstrated that FE can be hydrolyzed to fenoxaprop acid (FA) and further transformed into CDHB and 2-(4-hydroxyphenoxy)-propionic acid (HPP) by soil microorganisms (4-6). Recently, the hydrolysis of FE to FA by several esterases from different microorganisms has been reported (7-9). However, the underlying genes and the metabolic pathway responsible for the degradation of CDHB in microorganisms are unknown.CDHB is a type of 2-benzoxazolinone (BOA) derivative. BOA is widely used as a synthetic intermediate of related derivatives and is an important group of allelochemicals that respond to tissue damage or pathogen attack in gramineous plants, s...

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confidence: 99%

Metabolic Pathway Involved in 6-Chloro-2-Benzoxazolinone Degradation by Pigmentiphaga sp. Strain DL-8 and Identification of the Novel Metal-Dependent Hydrolase CbaA

Dong

Wang

Huang

et al. 2016

Appl Environ Microbiol

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“…The third method is based on the Neßler reaction (Eq. 1) 17.

true \begin{matrix} left {normalNH}_{4}^{+} + 2 {normalK}_{2} [Hg I_{4}] + 3 normalNaOH + normalO {normalH}^{-} \to \\ left [H g_{2} N] normalI false↓ + 4 normalKI + 3 normalNaI + 4 {normalH}_{2} normalO \end{matrix}

…”

Section: Methodsmentioning

confidence: 99%

Optimization of Gas Scrubbing in the Calcination of Struvite

Thumeyer

Bertau

Fröhlich

2021

Chemie Ingenieur Technik

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During the calcination of magnesium ammonium phosphate hexahydrate (struvite) in the process of recycling to obtain phosphoric acid, ammonia is released in addition to water and carbon dioxide. With a gas scrubber, e.g., in the form of a bubble column reactor, ammonia can be recovered as a usable valuable material. With water as an inexpensive and effective absorbent, almost complete absorption (92 %) of the ammonia from the exhaust air can be achieved.

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“…The ammonia nitrogen content in each sample was determined by comparison with a standard curve ( Lin et al, 2014 ). A stock solution of ammonia nitrogen was prepared with ammonium chloride (Guaranteed reagent; INESA, Shanghai, China).…”

Section: Methodsmentioning

confidence: 99%

Formation of sclerotia inSclerotinia ginsengand composition of the sclerotial exudate

Wang

Zhou

et al. 2018

PeerJ

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BackgroundSclerotinia ginseng is a major devastating soil-borne pathogen of ginseng that can cause irreparable damage and large economic losses. This pathogen produces sclerotia, which are among the most persistent resting structures produced by filamentous fungi. The production of an exudate is a common feature of sclerotial development.MethodsS. ginseng was cultured on 10 different media and the following parameters were measured: mycelial growth rate (mm/day), initial formation time of exudate droplets, total quantity of exudate, number of sclerotia per dish, and sclerotial fresh/dry weight. The composition of the sclerotial exudate was analyzed using four methods (high performance liquid chromatography, gas chromatography-mass spectrometry, flame atomic absorption spectrometry, and Nessler’s reagent spectrophotometry).ResultsWe found that PDA was the optimal medium for exudate production, while SDA medium resulted in the highest mycelial growth rate. The earliest emergence of exudate droplets from sclerotia was on OA-YE and V8 media. The largest amount of sclerotia and the smallest sclerotia were produced on V8 medium. The maximum and minimum dry/fresh weight were obtained on MEA medium and V8 medium, respectively. The exudate contained organic acids (oxalic acid, gallic acid, ferulic acid, vanillic acid, caffeic acid, and tannic acid), carbohydrates (inositol, glucose, and trehalose), various ions (potassium, sodium, and magnesium), and ammonia.DiscussionThe functions of the identified compounds are discussed within the context of pathogenicity, sclerotial development, and antimicrobial activity. Our findings provide information about the production of sclerotia and the composition of sclerotial exudate that may be useful to develop strategies to control this disease.

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Photometric Determination of Ammonia Nitrogen in Slaughterhouse Wastewater with Nessler's Reagent: Effects of Different Pretreatment Methods

Cited by 11 publications

References 5 publications

Metabolic Pathway Involved in 6-Chloro-2-Benzoxazolinone Degradation by Pigmentiphaga sp. Strain DL-8 and Identification of the Novel Metal-Dependent Hydrolase CbaA

Metabolic Pathway Involved in 6-Chloro-2-Benzoxazolinone Degradation by Pigmentiphaga sp. Strain DL-8 and Identification of the Novel Metal-Dependent Hydrolase CbaA

Optimization of Gas Scrubbing in the Calcination of Struvite

Formation of sclerotia inSclerotinia ginsengand composition of the sclerotial exudate

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