scholarly journals The microbial metabolism of acetophenone. Metabolism of acetophenone and some chloroacetophenones by an Arthrobacter species

1975 ◽  
Vol 152 (2) ◽  
pp. 233-241 ◽  
Author(s):  
Roger E. Cripps
Keyword(s):  
Pure Culture ◽  
Sole Source ◽  
Insertion Reaction ◽  
Phenyl Acetate ◽  
Growth Substrate ◽  
Environmental Implications ◽  
Acetate Esterase ◽  
Oxygen Insertion ◽  
Arthrobacter Species ◽  
Hydrolysis Of

1. An organism that utilizes acetophenone as sole source of carbon and energy was isolated in pure culture and tentatively identified as an Arthrobacter sp. 2. Cell-free extracts of the acetophenone-grown organism contained an enzyme, acetophenone oxygenase, that catalysed an NADPH-dependent consumption of O2 in the presence of the growth substrate; approx. 1mol of O2 and 1mol of NADPH were consumed per mol of acetophenone oxidized. 3. Cell-free extracts also contained an enzyme capable of the hydrolysis of phenyl acetate to phenol and acetate. The amount of this esterase was increased markedly by growth on acetophenone. 4. The observed products of the acetophenone oxygenase reaction by crude cell-free extracts were phenol and acetate. However, inhibition of the phenyl acetate esterase by paraoxon resulted in the formation of phenyl acetate from acetophenone. 5. A degradative sequence is proposed in which acetophenone is metabolized by an oxygen-insertion reaction to form phenyl acetate. Further metabolism occurs by hydrolysis of this ester. 6. The organism and extracts were shown to metabolize chlorinated acetophenones. The environmental implications of this observation are discussed.

Mn-catalyzed radical initiated domino transformation of alkynylated cyclohexadienones with TMSN3 and O2 to bicyclic azido alcohols

2020 ◽  
Vol 56 (23) ◽  
pp. 3453-3456 ◽  
Author(s):  
Pranesh Pal ◽  
Prathama S. Mainkar ◽  
Kiranmai Nayani ◽  
Srivari Chandrasekhar
Keyword(s):  
Radical Addition ◽  
Insertion Reaction ◽  
Mild Conditions ◽  
Oxygen Insertion

An efficient cascade radical addition/cyclization/oxygen insertion reaction of alkyne-tethered cyclohexadienones with TMSN3 was carried out under mild conditions to generate bicyclic azido alcohol scaffolds.

Description of bacteria able to degrade isoquinoline in pure culture

1994 ◽  
Vol 40 (7) ◽  
pp. 555-560 ◽  
Author(s):  
J. Aislabie ◽  
N. K. Richards ◽  
T. C. Lyttle
Keyword(s):  
Heterocyclic Compound ◽  
Pure Culture ◽  
Sole Source ◽  
Broth Culture ◽  
Gram Negative ◽  
Carbon And Nitrogen ◽  
The Family ◽  
Nitrogen Heterocyclic

Isoquinoline is a nitrogen heterocyclic compound that is associated with coal- and oil-derived wastes. Four strains of bacteria able to degrade isoquinoline in pure culture were isolated from sites known to be contaminated with oil. Isoquinoline was used as the sole source of carbon and nitrogen by these isolates. Isoquinoline was initially transformed to 1-hydroxyisoquinoline, which accumulated in the broth culture, and then disappeared. The four strains isolated were Gram negative, aerobic, rod-shaped bacteria with polar flagella. The strains have been presumptively identified as members of the family Comamonadaceae.Key words: isoquinoline degradation, Comamonadaceae.not available

scholarly journals Affinity of extracellular phosphatases for ELF97 phosphate in aquatic environments

2007 ◽  
Vol 58 (5) ◽  
pp. 454 ◽  
Author(s):  
Jiří Nedoma ◽  
France Van Wambeke ◽  
Alena Štrojsová ◽  
Martina Štrojsová ◽  
Solange Duhamel
Keyword(s):  
Pure Culture ◽  
Marine Bacterium ◽  
Aquatic Environments ◽  
Kinetic Properties ◽  
Michaelis Constant ◽  
Lower Affinity ◽  
Saturation Kinetics ◽  
Elf97 Phosphate ◽  
Hydrolysis Of ◽  
Phosphatase Substrate

Recently, the phosphatase substrate ELF97 phosphate (ELFP) has been employed to study the presence of extracellular phosphatases in different plankton populations in natural aquatic environments. Kinetic properties of ELFP hydrolysis by natural extracellular phosphatases are, however, mostly unknown. We indirectly studied the affinity of extracellular phosphatases for ELFP in different aquatic environments through its ability to inhibit the hydrolysis of 4-methylumbelliferyl phosphate (4MUP). Values of inhibition constants, Ki, which correspond to the concentrations necessary for half saturation of phosphatases by ELFP, were lowest (0.18–4.5 µmol L–1) in the oligotrophic Mediterranean Sea. We found higher values (i.e. lower affinity) in oligo- to mesotrophic acidified lakes (5.2–14 µmol L–1), in a eutrophic reservoir (13–35 µmol L–1) and in a pure culture of the marine bacterium Alteromonas infernus (29 µmol L–1). ELFP had a pronounced effect on the parameter KM (Michaelis constant) of 4MUP saturation kinetics, while its effect on the parameter Vmax was low. This behaviour is compatible with the assumption of competitive interaction between 4MUP and ELFP. Our experiments indicated that the assay ELFP concentration in the detection kit used was 250–500 µmol L–1 (after the recommended dilution to a ratio of 1:20), which would ensure >99% saturation of extracellular phosphatases in marine environments and >90% saturation in the studied fresh waters.

Gas-phase hydrolysis of phenyl acetate and phenyl benzoate by superoxide ion

1983 ◽  
Vol 105 (7) ◽  
pp. 2091-2092 ◽  
Author(s):  
Carolyn L. Johlman ◽  
Robert L. White ◽  
Donald T. Sawyer ◽  
Charles L. Wilkins
Keyword(s):  
Gas Phase ◽  
Phenyl Acetate ◽  
Superoxide Ion ◽  
Phenyl Benzoate ◽  
Hydrolysis Of

scholarly journals Growth of Escherichia coli Coexpressing Phosphotriesterase and Glycerophosphodiester Phosphodiesterase, Using Paraoxon as the Sole Phosphorus Source

2004 ◽  
Vol 70 (1) ◽  
pp. 404-412 ◽  
Author(s):  
Sean Yu McLoughlin ◽  
Colin Jackson ◽  
Jian-Wei Liu ◽  
David L. Ollis
Keyword(s):  
Escherichia Coli ◽  
Enterobacter Aerogenes ◽  
Sole Source ◽  
Limiting Factor ◽  
E Coli ◽  
Dimethyl Phosphate ◽  
Genes Encoding ◽  
Phosphorus Source ◽  
Hydrolysis Of ◽  
Methyl Phosphate

ABSTRACT Phosphotriesterases catalyze the hydrolytic detoxification of phosphotriester pesticides and chemical warfare nerve agents with various efficiencies. The directed evolution of phosphotriesterases to enhance the breakdown of poor substrates is desirable for the purposes of bioremediation. A limiting factor in the identification of phosphotriesterase mutants with increased activity is the ability to effectively screen large mutant libraries. To this end, we have investigated the possibility of coupling phosphotriesterase activity to cell growth by using methyl paraoxon as the sole phosphorus source. The catabolism of paraoxon to phosphate would occur via the stepwise enzymatic hydrolysis of paraoxon to dimethyl phosphate, methyl phosphate, and then phosphate. The Escherichia coli strain DH10B expressing the phosphotriesterase from Agrobacterium radiobacter P230 (OpdA) is unable to grow when paraoxon is used as the sole phosphorus source. Enterobacter aerogenes is an organism capable of growing when dimethyl phosphate is the sole phosphorus source. The enzyme responsible for hydrolyzing dimethyl phosphate has been previously characterized as a nonspecific phosphohydrolase. We isolated and characterized the genes encoding the phosphohydrolase operon. The operon was identified from a shotgun clone that enabled E. coli to grow when dimethyl phosphate is the sole phosphorus source. E. coli coexpressing the phosphohydrolase and OpdA grew when paraoxon was the sole phosphorus source. By constructing a short degradative pathway, we have enabled E. coli to use phosphotriesters as a sole source of phosphorus.

Hydrolysis of fenamiphos and its oxidation products by a soil bacterium in pure culture, soil and water

2003 ◽  
Vol 61 (3) ◽  
pp. 252-256 ◽  
Author(s):  
M. Megharaj ◽  
N. Singh ◽  
R. S. Kookana ◽  
R. Naidu ◽  
N. Sethunathan
Keyword(s):  
Pure Culture ◽  
Soil Bacterium ◽  
Oxidation Products ◽  
Hydrolysis Of ◽  
Soil And Water

scholarly journals Heats of Hydrolysis of Phenyl Acetate and Phenyl Thiolacetate.

1960 ◽  
Vol 14 ◽  
pp. 561-565 ◽  
Author(s):  
Ingemar Wadsö ◽  
Torkild Thurmann-Moe ◽  
Edgar F. Westrum, Jr ◽  
Norman E. Levitin ◽  
Gertrud Westin
Keyword(s):  
Phenyl Acetate ◽  
Hydrolysis Of
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