scholarly journals Bactericidal effect of hydrogen peroxide is prevented by the lactoperoxidase-thiocyanate system under anaerobic conditions

1980 ◽  
Vol 29 (3) ◽  
pp. 1190-1192
Author(s):  
J Carlsson
Keyword(s):  
Hydrogen Peroxide ◽  
Bactericidal Effect ◽  
Molar Ratio ◽  
Anaerobic Conditions ◽  
Streptococcus Sanguis

Streptococcus sanguis and Peptostreptococcus anaerobius were exposed to various combinations of the components of the lactoperoxidase-thiocyanate-hydrogen peroxide system. The bactericidal effect of hydrogen peroxide was prevented under anaerobic conditions by lactoperoxidase together with thiocyanate, but not by lactoperoxidase or thiocyanate alone. Thiocyanate was effective already at a molar ratio to hydrogen peroxide of 1:100.

Potentiation by L-cysteine of the bactericidal effect of hydrogen peroxide in Escherichia coli

1982 ◽  
Vol 152 (1) ◽  
pp. 81-88
Author(s):  
E H Berglin ◽  
M B Edlund ◽  
G K Nyberg ◽  
J Carlsson
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Metal Ion ◽  
Chelating Agent ◽  
Fold Increase ◽  
Bactericidal Effect ◽  
Anaerobic Conditions ◽  
Dna Breakage ◽  
E Coli ◽  
K 12

Under anaerobic conditions an exponentially growing culture of Escherichia coli K-12 was exposed to hydrogen peroxide in the presence of various compounds. Hydrogen peroxide (0.1 mM) together with 0.1 mM L-cysteine or L-cystine killed the organisms more rapidly than 10 mM hydrogen peroxide alone. The exposure of E. coli to hydrogen peroxide in the presence of L-cysteine inhibited some of the catalase. This inhibition, however, could not fully explain the 100-fold increase in hydrogen peroxide sensitivity of the organism in the presence of L-cysteine. Of other compounds tested only some thiols potentiated the bactericidal effect of hydrogen peroxide. These thiols were effective, however, only at concentrations significantly higher than 0.1 mM. The effect of L-cysteine and L-cystine could be annihilated by the metal ion chelating agent 2,2'-bipyridyl. DNA breakage in E. coli K-12 was demonstrated under conditions where the organisms were killed by hydrogen peroxide.

scholarly journals Bactericidal Effect of Anaerobic Broth Exposed to Atmospheric Oxygen Tested on Peptostreptococcus anaerobius

1977 ◽  
Vol 6 (2) ◽  
pp. 117-123
Author(s):  
Fred Frölander ◽  
Jan Carlsson
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Toxic Effect ◽  
Manganese Dioxide ◽  
Salt Solution ◽  
Death Rate ◽  
Atmospheric Oxygen ◽  
Test Organism ◽  
Bactericidal Effect ◽  
Anaerobic Conditions

Peptostreptococcus anaerobius strain VPI 4330-1 was used as the test organism in an evaluation of the bactericidal effect of anaerobic broth exposed to air. The test organism, grown under anaerobic conditions in Trypticase soy broth, was diluted in buffered salt solution, and about 2 × 10 4 cells were suspended in 10 ml of an aerated broth. Ninety percent of the cells were killed within 15 min in actinomyces broth and within 50 min in Trypticase soy broth. All cells survived for 2 h in fluid thioglycolate medium. Addition of DABCO [1,4-diazabicyclo (2.2.2) octane] or mannitol to Trypticase soy broth did not influence the death rate of the organism, whereas superoxide dismutase decreased the death rate. Addition of catalase or manganese dioxide to the broth kept all the cells viable for 2 h. Of the three broth media tested, actinomyces broth reduced oxygen at the highest rate and Trypticase soy broth reduced it at the slowest rate. Hydrogen peroxide could be demonstrated in actinomyces broth and in Trypticase soy broth but not in fluid thioglycolate medium. In addition to catalase, manganese dioxide also removed all hydrogen peroxide from Trypticase soy broth, and superoxide dismutase significantly decreased the concentration of hydrogen peroxide in the broth. The results suggest that hydrogen peroxide mediated the toxic effect of atmospheric oxygen in these broth media.

scholarly journals The utilization of the mesoporous Ti-SBA-15 catalyst in the epoxidation of allyl alcohol to glycidol and diglycidyl ether in the water medium

2015 ◽  
Vol 17 (4) ◽  
pp. 23-31 ◽  
Author(s):  
Agnieszka Wróblewska ◽  
Edyta Makuch ◽  
Małgorzata Dzięcioł ◽  
Roman Jędrzejewski ◽  
Paweł Kochmański ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Allyl Alcohol ◽  
Water Solution ◽  
Reaction Medium ◽  
Diglycidyl Ether ◽  
Molar Ratio ◽  
Water Medium ◽  
Catalyst Content ◽  
Allyl Alcohol Epoxidation

Abstract This work presents the studies on the optimization the process of allyl alcohol epoxidation over the Ti-SBA-15 catalyst. The optimization was carried out in an aqueous medium, wherein water was introduced into the reaction medium with an oxidizing agent (30 wt% aqueous solution of hydrogen peroxide) and it was formed in the reaction medium during the processes. The main investigated technological parameters were: the temperature, the molar ratio of allyl alcohol/hydrogen peroxide, the catalyst content and the reaction time. The main functions the process were: the selectivity of transformation to glycidol in relation to allyl alcohol consumed, the selectivity of transformation to diglycidyl ether in relation to allyl alcohol consumed, the conversion of allyl alcohol and the selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed. The analysis of the layer drawings showed that in water solution it is best to conduct allyl alcohol epoxidation in direction of glycidol (selectivity of glycidol 54 mol%) at: the temperature of 10–17°C, the molar ratio of reactants 0.5–1.9, the catalyst content 2.9–4.0 wt%, the reaction time 2.7–3.0 h and in direction of diglycidyl ether (selectivity of diglycidyl ether 16 mol%) at: the temperature of 18–33°C, the molar ratio of reactants 0.9–1.65, the catalyst content 2.0–3.4 wt%, the reaction time 1.7–2.6 h. The presented method allows to obtain two very valuable intermediates for the organic industry.

Antimicrobial Effects of Novel H2O2-Ag+ Complex on Membrane Damage to Staphylococcus aureus,Escherichia coli and Salmonella typhimurium

2021 ◽  
Author(s):  
Bing Han ◽  
Xiaoyu Han ◽  
Mengmeng Ren ◽  
Yilin You ◽  
Jicheng Zhan ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Hydrogen Peroxide ◽  
Staphylococcus Aureus ◽  
Salmonella Typhimurium ◽  
Membrane Damage ◽  
Bactericidal Effect ◽  
E Coli ◽  
Bacterial Cell Membrane ◽  
Time Kill ◽  
Environmental Disinfection

Diseases caused by harmful microorganisms pose a serious threat to human health. Safe and environment-friendly disinfectants are, therefore, essential in preventing and controlling such pathogens. This study aimed to investigate the antimicrobial activity and mechanism of a novel hydrogen peroxide and silver (H 2 O 2 -Ag + ) complex (HSC) in combatting Staphylococcus aureus ATCC 29213, Escherichia coli O157:H7 NCTC 12900 and Salmonella typhimurium SL 1344. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values against S. aureus were found to be 0.014 % H 2 O 2 -3.125 mg/L Ag + , while 0.028 % H 2 O 2 -6.25 mg/L Ag + for both E. coli and S. typhimurium . Results of the growth curve assay and time-kill trial suggest that the HSC could inhibit the growth of the tested bacteria, as 99.9 % of viable cells were killed following treatment at the 1 MIC for 3 h. Compared with Oxytech D10 disinfectant (0.25 % H 2 O 2 -5 mg/L Ag + ), the HSC exhibited better antibacterial efficacy at a lower concentration (0.045 % H 2 O 2 -10 mg/L Ag + ). The mechanism of antibacterial action of HSC was found including the disruption of the bacterial cell membrane, followed by entry into the bacteria cell to reduce intracellular adenosine triphosphate (ATP) concentration, and inhibit the activity of antioxidases, superoxide dismutase (SOD) and catalase (CAT). The enhanced bactericidal effect of hydrogen peroxide combined with silver indicates a potential for its application in environmental disinfection, particularly in the food industry.

scholarly journals A facile and effective method for preparation of 2.5-furandicarboxylic acid via hydrogen peroxide direct oxidation of 5-hydroxymethylfurfural

2017 ◽  
Vol 19 (1) ◽  
pp. 11-16 ◽  
Author(s):  
Shuang Zhang ◽  
Long Zhang
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Oxidation Mechanism ◽  
Molar Ratio ◽  
Alkaline Condition ◽  
Optimal Parameters ◽  
Direct Oxidation ◽  
Reaction Parameters ◽  
Alkaline Conditions ◽  
Furandicarboxylic Acid

Abstract In this paper, 2,5-furandicarboxylic acid (FDCA) was efficiently prepared by the direct oxidation of 5-hydroxymethylfurfural (5-HMF) using hydrogen peroxide (H2O2) in alkaline conditions without any catalysts. The effects of reaction parameters on the process were systematically investigated and the optimal parameters were obtained as follows: molar ratio of 5-HMF:KOH:H2O2 was 1:4:8, reaction temperature and reaction time were determined as 70°C and 15 minutes, respectively. Under these conditions, the yield of FDCA was 55.6% and the purity of FDCA could reach 99%. Moreover, we have speculated the detailed oxidation mechanism of 5-HMF assisted by hydrogen peroxide in alkaline condition to synthesize FDCA.

scholarly journals Bactericidal Effect of Hydrogen Peroxide on Spacecraft Isolates

1975 ◽  
Vol 30 (4) ◽  
pp. 710-711 ◽  
Author(s):  
M. D. Wardle ◽  
G. M. Renninger
Keyword(s):  
Hydrogen Peroxide ◽  
Bactericidal Effect

Bactericidal effect of hydroxyl radicals generated by the sonolysis and photolysis of hydrogen peroxide for endodontic applications

2017 ◽  
Vol 103 ◽  
pp. 65-70 ◽  
Author(s):  
Haruna Ibi ◽  
Makoto Hayashi ◽  
Fumihiko Yoshino ◽  
Muneaki Tamura ◽  
Ayaka Yoshida ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radicals ◽  
Bactericidal Effect

Biosynthesis of glucosyl monophosphoryl undecaprenol and its role in lipoteichoic acid biosynthesis

1982 ◽  
Vol 152 (2) ◽  
pp. 616-625
Author(s):  
D J Mancuso ◽  
T H Chiu
Keyword(s):  
Thin Layer ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Deae Cellulose ◽  
Lipoteichoic Acid ◽  
Molar Ratio ◽  
Streptococcus Sanguis ◽  
Chromatographic Profile ◽  
Hydrolysis Of ◽  
Cellulose Column

A glucophospholipid was detected in an incubation mixture containing UDP-glucose, MgCl2, ATP, and a particulate enzyme prepared from Streptococcus sanguis. The synthesis of this lipid was inhibited strongly by UDP and moderately by UMP. The molar ratio of glucose to phosphate in the purified lipid was found to be 1:1. Glucose and glucose 1-phosphate were released by mild alkaline hydrolysis of the glucophospholipid. The lipid produced by mild acid degradation of the purified lipid yielded a thin-layer chromatographic profile similar to that of acid-treated undecaprenol. One of the minor components exhibited the same mobility as untreated undecaprenol. To characterize further the lipid moiety of the glucophospholipid, a polyisoprenol was purified from the neutral lipid of S. sanguis. The polyisoprenol was converted in the presence of ATP, UDP-glucose, and the particulate enzyme into a lipid which exhibited the same thin-layer chromatographic mobility as the glucophospholipid. The structure of the polyisoprenol was determined by nuclear magnetic resonance and mass spectrometry to be an undecaprenol with an internal cis-trans ratio of 7:2. These results indicate that the glucophospholipid is glucosyl monophosphoryl undecaprenol. The glucosyl moiety of the glucophospholipid was shown to be incorporated in the presence of the particulate enzyme into a macromolecule which was characterized as a lipoteichoic acid by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and DEAE-cellulose column chromatography. This result indicates that glucosyl monophosphoryl undecaprenol is the direct glucosyl donor in the synthesis of lipoteichoic acid.

Evaluation of the tribological properties and oxidative stability of epoxidized and ring opened products of pure rice bran oil

2020 ◽  
pp. 135065012095053
Author(s):  
Ananthan D Thampi ◽  
Abhishek R John ◽  
M Muhammed Arif ◽  
S Rani
Keyword(s):  
Hydrogen Peroxide ◽  
Vegetable Oils ◽  
Rice Bran ◽  
Rice Bran Oil ◽  
Research Work ◽  
Viscosity Index ◽  
Oxidation Stability ◽  
High Viscosity ◽  
Molar Ratio ◽  
Four Levels

Vegetable oils constitute a potential base stock for bio-lubricants, which has good biodegradability, high flash point, high viscosity index and excellent boundary lubrication properties. They also possess some limitations like low thermal and oxidation stability, poor low temperature properties and narrow range of viscosities. These limitations can be altered by modifying the vegetable oils chemically or by providing additives into the oils. This research work focused on the chemical modification of pure rice bran oil by epoxidation process using 30% hydrogen peroxide and glacial acetic acid. The epoxidized rice bran oil was then subjected to ring opening process using butanoic acid. The epoxidation process was optimized with four factors (Temperature, Time, Weight % of Catalyst, Hydrogen Peroxide molar ratio), each factors having four levels. The lubricant properties of pure rice bran oil (RBO), epoxidized rice bran oil (ERBO) and ring opened rice bran oil (RRBO) were studied. It was noted that the lubricant properties of ERBO and RRBO were better compared to pure RBO.

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