Chemical & Biological Dynamics

1998

"In fact, the chemical reaction rate of traditional chlorine dioxide bleaching of pulp is too fast to observe the intermediate process. The mechanism behind the reaction of 4-hydroxy-3-methoxyacetophenone (APO), a phenolic lignin model compound, with high concentrations of chlorine dioxide was investigated. Individual solutions of each compound and a mixture of the two were analyzed by UV–vis spectrophotometry, and an absorbance band at 260 nm was observed for the stable benzoquinone intermediates at room temperature. Free chlorine dioxide displayed an absorbance at 360 nm and changes in this absorbance were studied with different APO concentrations. A fixed molar ratio of 1:3 was obtained between APO and chlorine dioxide consumption. The intermediate absorbance demonstrated a linear relationship with the APO concentration. The reaction path between APO and chlorine dioxide at high concentrations was speculated, and it was observed that the activity of C1, C2, C3, C5, and C6 on the APO benzene ring was enhanced when high concentrations of chlorine dioxide were present. From these results, a new method for efficient and clean chlorine dioxide bleaching can be developed."

{ChlordioX Plus}

1985

{Powder capsule for generating Chlorine Dioxide. Includes recommended use in refrigerators.}

"Our KyroCAPS represent an innovative and patented capsule system that does not affect the smell, taste or pH value of the water."

"The process is particularly suitable to treat feedstocks used in biorefining processes, such as in ethanol fermentation."

"A liquid biocide containing stabilized chlorine dioxide and hypochlorous acid for various uses, including use as a teat dip or dairy animals. The stable, prophylactic biocide consists essentially of 0.10-20.0% by weight of a chlorite salt, 0.1-3.0% by weight of an acid, 0.10-2.0% by weight of an alkaline agent, and the balance water. Chlorite salt reacts with the acid to form germicidal chlorine dioxide and hypochlorous acid. The acid constituency and the alkaline agent constituency regulate the pH of the solution such that the biocide is stable when mixed for a period greater than two months. The present disclosure also includes a method of producing a stable, prophylactic biocide for dairy cattle, the method comprising 0.10-20.0% by weight of a chlorite salt, 0.10-3.0% by weight of an acid, 0.10-2.0% by weight of an alkaline agent, and the balance water in a container, and sealing the container. In the method, the acid and alkaline agent constituencies regulate the pH of the solution such that the formation of hydronium ions from the acid is correspondingly regulated to stabilize the solution for a period greater than two months from the date of sealing."

***!!!!***!!*** {Includes useful explanation of ppm} "Unit of ppm: ppm (parts per million) represents the ratio of 1 part per million. The weight ratio (mg / L = ppm, 1 L water is approximately equal to 1 kg) is used for liquids, and the volume ratio is used for gas. The ppm of this test applies the weight ratio in aqueous solution."

{Taiko} "A pure chlorine dioxide solution includes a chlorine dioxide gas dissolved therein, a chlorite, and a pH adjuster which is an acid or a salt thereof having a buffering property whose pH is 2.5 to 6.8 as a 5% aqueous solution at 25° C."

A pure chlorine dioxide solution includes a chlorine dioxide gas dissolved therein, a chlorite, and a pH adjuster which is an acid or a salt thereof having a buffering property whose pH is 2.5 to 6.8 as a 5% aqueous solution at 25° C.

"Chlorine dioxide (ClO2) inactivation experiments were conducted with adenovirus type 40 (AD40) and feline calicivirus (FCV). Experiments were carried out in buffered, disinfectant demand-free water under high- and low-pH and -temperature conditions. Ct values (the concentration of ClO2 multiplied by …"

****!!!!****!!!!**** "optimum conditions for the production of gaseous chlorine dioxide (ClO2) from aqueous ClO2 (HCl+NaClO2). When 1 N HCl was reacted with various concentrations of NaClO2 (50,000-500,000 mg/mL), the highest concentration (695 mg/L) of gaseous ClO2 was obtained from the aqueous ClO2 containing 100,000 µg/mL NaClO2. Next, the effects of relative humidity (RH; 43, 85, and 100%) and temperature (4, 12, and 25ºC) on the production of gaseous ClO2 were investigated. It was observed that the concentration of gaseous ClO2 was increased as RH was decreased, or the temperature was increased. Finally, it was confirmed that the amount of gaseous ClO2 was highly correlated (R2=0.9546-0.9992) with the volume of aqueous ClO2."

**** "We concluded, then, that chlorine dioxide inactivated poliovirus by reacting with the viral RNA and impairing the ability of the viral genome to act as a template for RNA synthesis"

"over 30 min, chlorine dioxide did not change the Raman spectrum or the spore structure"

This work investigated degradation (measured by qPCR) and biological deactivation (measured by culture-based natural transformation) of extra- and intracellular antibiotic resistance genes (eARGs and iARGs) by free available chlorine (FAC), NH2Cl, O3, ClO2, and UV light (254 nm), and of eARGs by •OH, using a chromosomal ARG (blt) of multidrug-resistant Bacillus subtilis 1A189. Rate constants for degradation of four 266–1017 bp amplicons adjacent to or encompassing the acfA mutation enabling blt overexpression increased in proportion to #AT+GC bps/amplicon, or in proportion to #5′-GG-3′ or 5′-TT-3′ doublets/amplicon, with respective values ranging from 0.59 to 2.3 (×1011 M–1 s–1) for •OH, 1.8–6.9 (×104 M–1 s–1) for O3, 3.9–9.2 (×103 M–1 s–1) for FAC, 0.35–1.2(×101 M–1 s–1) for ClO2, and 2.0–8.8 (×10–2 cm2/mJ) for UV at pH 7, and from 1.7–4.4 M–1 s–1 for NH2Cl at pH 8. For FAC, NH2Cl, O3, ClO2, and UV, ARG deactivation paralleled degradation of amplicons approximating a ∼800–1000 bp acfA-flanking sequence required for natural transformation in B. subtilis, whereas deactivation outpaced degradation for •OH. At practical disinfectant exposures, eARGs and iARGs were ≥90% degraded/deactivated by FAC, O3, and UV, but recalcitrant to NH2Cl and ClO2. iARG degradation/deactivation always lagged cell inactivation. These findings provide a quantitative framework for evaluating ARG fate during disinfection/oxidation, and support using qPCR as a proxy for tracking ARG deactivation under carefully selected circumstances.

1980. This study was conducted to examine the effects of chlorine dioxide on dehydrogenase enzymes, protein synthesis, and deoxyribonucleic acid of bacteria…

"short-lived acidified sodium chlorite (ASC) which has potent decontaminating properties. Upon mixing the main active ingredient, chlorous acid is produced in equilibrium with chlorite anion. The proportion varies with pH, temperature, and other factors, ranging from approximately 5–35% chlorous acid with 65–95% chlorite, more acidic solutions result in a higher proportion of chlorous acid. Chlorous acid breaks down to chlorine dioxide which in turn breaks down to chlorite anion and ultimately chloride anion. ASC is used for sanitation of the hard surfaces which come in contact with food and as a wash or rinse for a variety of foods... Because the oxo-chlorine compounds are unstable when properly prepared, there should be no measurable residue on food if treated appropriately. "

Low molecular weight (LMW) thiols function as thiol-redox buffers to maintain the reduced state of the cytoplasm. The best studied LMW thiol is the tripeptide glutathione (GSH) present in all eukaryotes and Gram-negative bacteria. Firmicutes bacteria, including Bacillus and Staphylococcus species utilize the redox buffer bacillithiol (BSH) while Actinomycetes produce the related redox buffer mycothiol (MSH). In eukaryotes, proteins are post-translationally modified to S-glutathionylated proteins under conditions of oxidative stress. S-glutathionylation has emerged as major redox-regulatory mechanism in eukaryotes and protects active site cysteine residues against overoxidation to sulfonic acids. First studies identified S-glutathionylated proteins also in Gram-negative bacteria. Advances in mass spectrometry have further facilitated the identification of protein S-bacillithiolations and S-mycothiolation as BSH- and MSH-mixed protein disulfides formed under oxidative stress in Firmicutes and Actinomycetes, respectively. In Bacillus subtilis, protein S-bacillithiolation controls the activities of the redox-sensing OhrR repressor and the methionine synthase MetE in vivo. In Corynebacterium glutamicum, protein S-mycothiolation was more widespread and affected the functions of the maltodextrin phosphorylase MalP and thiol peroxidase (Tpx). In addition, novel bacilliredoxins (Brx) and mycoredoxins (Mrx1) were shown to function similar to glutaredoxins in the reduction of BSH- an...

"exogenous glutathione added to glutathione-deficient E. coli in amounts equal to those which would be present in a similar suspension of the wild-type bacteria fully restored resistance of glutathione-deficient bacteria to chlorine-based oxidants" "oxidized glutathione is almost as effective as reduced glutathione, implying that the tripeptide and/or oxidized thiol undergo further reactions with chlorine compounds. Indeed, in vitro, 1 mol of reduced glutathione will react with approximately 3.5 to 4.0 mol of hypochlorous acid."

Abstract Strawberries are highly sensitive to deterioration by microbial decay after harvest and Botrytis cinerea is one of the most common diseases that infect them. Previous work has reported successful extension of strawberry shelf life through the use of chlorine dioxide (ClO2) gas treatments. In this study, California strawberries purchased at retail stores were treated with continuously generated ClO2 gas over concentrations ranging from 0.01 to 5.0 mg/L for durations ranging from 7 to 1000 min to determine how ClO2 gas impacts fungal mortality and fruit quality as a function of treatment concentration, treatment duration, and ClO2 absorption by the fruit. Repeated measures and Gompertz models were used to infer on the efficacy of the ClO2 gas, and a novel method was used to quantify the ClO2 absorption by fresh produce. It was found that ClO2 gas treatments have minimal effect at delaying the onset or growth rate of Botrytis cinerea for treatments followed by incubation at 4 or 22 °C even when corrected for natural variability of Botrytis cinerea presence among batches of strawberries, indicating that treatments are not sufficient for shelf-life extension.

The effect of chlorine dioxide (ClO2) on Penicillium expansum growth and patulin production in vitro and on its disease severity in apples was investi…

Journal of Food Science 54: 57-60