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15 recordsLinked to original sources
PubMed2026

Prophage Activation as an Overlooked Mechanism Underlying the Biocidal Effect of Free Nitrous Acid in Sewers.

Biogenic hydrogen sulfide produced in sewer systems causes odor nuisance and concrete corrosion, necessitating effective biocidal control. Free nitrous acid (FNA) has emerged as a promising biocide, but its unclear mechanisms complicate dosage optimization and risk assessment. Here, using Desulfovibrio vulgaris as a model lysogenic bacterium, we demonstrate that low-dose FNA (0.2-4.0 mg N/L) induces bacterial inactivation via prophage activation-associated lysis in addition to chemical oxidation. Reactive nitrogen species (RNS) scavenging tests revealed that RNS-mediated oxidative stress was closely associated with prophage activation. Activated phages further infected new hosts, reducing the viability of freshly cultured D. vulgaris cells by 25.7% and increasing total phage production 15.2-fold. The phenomenon was further validated in real sewage biofilms, where increased phage production and decreased bacterial viability were observed at a low FNA dose of 0.2 mg N/L, below the dose required for cell destruction by chemical oxidation. Furthermore, metagenomic analysis of 896 sewage samples worldwide revealed that 71.9% of recovered sewage-derived microbial genomes harbor prophages, indicating a widespread genomic basis for prophage activation-mediated bacterial inactivation. Overall, this study expands current understanding of the biocidal mechanisms of FNA and contributes to the development of environmentally sustainable biocidal strategies.

Nitrous Acid↗
PubMed1978

[Pharmacological effect of pentacyanonitrosylferrate and similar complex compounds].

Comparative studies were performed on the spasmolytic and hypotensive effects of pentacyanoferrates with different ligands (NO, NO2, NOS, NH3, H2O) and of hexacyanoferrates and other nitrosyl compounds. Besides sodium nitroprusside, the nitro and thionitro complexes in equimolar doses were found to cause hypotension and relaxation of the aortic strip of rabbits contracted by adrenaline and spasmolytic effects on the contracted guinea pig ileum. The liberated nitrosyl cation or its secondary product, nitrous acid, is thought to be responsible for the pharmacodynamic effects of these complex compounds. This is in agreement with the fact that also other nitrosyl compounds (nitrosyl perchlorate, nitrosyl-bis(dimethylglyoximato)cobaltIII) and free undissociated nitrous acid produce transient spasmolytic effects. Pentacyanoaquoferrate and hexacyanoferrateIII exert, presumably because of the oxydation of sulfhydryl groups, spasmolytic effects in vitro. Accordingly, their effects are prevented in the presence of sulfhydryl compounds such as glutathion or dithioerythrit.

Animals↗
PubMed1978

A new biochemical subtype of the Sanfilippo syndrome: characterization of the storage material in cultured fibroblasts of Sanfilippo C patients.

Fibroblasts cultured from the skin of three unrelated patients with the clinical symptoms of the Sanfilippo syndrome (mucopolysaccharidosis III) accumulated intracellularly excessive amounts of heparan sulfate and showed a lengthened turnover time for this mucopolysaccharide. They exhibited, however, neither a deficiency of heparan sulfate sulfamidase or alpha-N-acetylglucosaminidase nor of any other known glycosaminoglycan-degrading hydrolase. This new mucopolysaccharidosis was therefore designated as type C of the Sanfilippo syndrome. The abnormal heparan sulfate metabolism of Sanfilippo C fibroblasts could not be normalized by addition of crude urinary proteins or concentrated secretions from normal fibroblasts to the culture medium or by cocultivation with normal fibroblasts. The accumulated heparan sulfate was characterized by a reduced negative net charge. A small proportion of it could be adsorbed onto a cation exchange resin. It was sensitive to nitrous acid degradation under conditions where glucosamine residues with free amino groups are attacked. It is therefore suggested that the primary defect in this new mucopolysaccharidosis concerns the step which follows the hydrolysis of N-sulfonate groups in heparan sulfate degradation.

Adolescent↗
PubMed1976

Effect of sodium nitrite inhibition on intracellular thiol groups and on the activity of certain glycolytic enzymes in Clostridium perfringens.

Activities of glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12) (GAP-DH) and aldolase (EC 4.1.2.13) in cells of Clostridium perfringens that had been inhibited with sodium nitrite were investigated. A complete loss in GAP-DH activity and a 67% decrease in aldolase activity were observed when growth of C. perfringens was inhibited. There was also a 91% decrease in the concentration of free sulfhydryl groups of soluble cellular components. Dithiothreitol restored some activity to inactive GAP-DH from sodium nitrite-inhibited cells, indicating that a loss of reduced sulfhydryl groups was involved in the inactivation of the enzyme. The evidence presented suggests that sodium nitrite inhibition of C. perfringens may involve an interaction of sodium nitrite as nitrous acid with sulfhydryl-containing constituents of the bacterial cell.

Cell Wall↗
PubMed1979

Nitroalkane oxidation by streptomycetes.

Crude cell-free extracts of nine strains of Streptomyces tested for nitroalkane-oxidizing activity showed production of nitrous acid from 2-nitropropane, 1-nitropropane, nitroethane, nitromethane, and 3-nitropropionic acid. These substrates were utilized in most strains but to a decreasing extent in the order given, and different strains varied in their relative efficiency of oxidation. p-Nitrobenzoic acid, p-aminobenzoic acid, enteromycin, and omega-nitro-l-arginine were not attacked. d-Amino acid oxidase, glucose oxidase, glutathione S-transferase, and xanthine oxidase, enzymes potentially responsible for the observed oxidations in crude cellfree extracts, were present at concentrations too low to play any significant role. A nitroalkane-oxidizing enzyme from streptozotocin-producing Streptomyces achromogenes subsp. streptozoticus was partially purified and characterized. It catalyzes the oxidative denitrification of 2-nitropropane as follows: 2CH(3)CH(NO(2))CH(3) + O(2) --> 2CH(3)COCH(3) + 2HNO(2). At the optimum pH of 7.5 of the enzyme, 2-nitropropane was as good a substrate as its sodium salt; t-nitrobutane was not a substrate. Whereas Tiron, oxine, and nitroxyl radical acted as potent inhibitors of this enzyme, superoxide dismutase was essentially without effect. Sodium peroxide abolished a lag phase in the progress curve of the enzyme and afforded stimulation, whereas sodium superoxide did not affect the reaction. Reducing agents, such as glutathione, reduced nicotinamide adenine dinucleotide, and nicotinamide adenine dinucleotide phosphate, reduced form, as well as thiol compounds, were strongly inhibitory, but cyanide had no effect. The S. achromogenes enzyme at the present stage of purification is similar in many respects to the enzyme 2-nitropropane dioxygenase from Hansenula mrakii. The possible involvement of the nitroalkane-oxidizing enzyme in the biosynthesis of antibiotics that contain a nitrogen-nitrogen bond is discussed.

Alkanes↗
PubMed1975

The non-enzymic reduction of nitrite by benzyl viologen (free-radical) in the presence and absence of ammonium sulphate.

Some similarity is inferred between the reaction or reduced benzyl viologen with undissociated nitrous acid, which is significant at pH values below 7 and that with the undissociated product of nitrite ion and ammonium sulphate; presumably ammonium nitrite. This would explain why the presence of ammonium sulphate appreciably offsets the effects of decreasing pH and also the exponential relationship between rate of nitrite loss and ammonium sulphate concentration. There are other features of the reaction which cannot be explained at present, especially with regard to the degree of reduction of benzyl viologen. It is nevertheless apparent that a complex non-enzymic reaction yielding several products occurs when ammonium sulphate is present and that the presence of likely residual quantities after its use in enzyme purification may cause serious errors in enzyme assay.

Ammonium Sulfate↗
PubMed1976

Beta-hydroxynorleucine: separation of its isomers and biological studies.

Separation of the four isomers of beta-hydroxynorleucine was accomplished by partition column chromatography and asymmetric enzymatic hydrolysis of the N-chloroacetyl derivatives. From these, the corresponding N-chloroacetyl derivatives were made. The purity and configuration of each isomer of the free acid and N-chloroacetylated derivative were ascertained by: (a) paper chromatography in five solvent systems, (b) elemental analysis, (c) Van Slyke nitrous acid determination of alpha-carbonyl carbon, and (d) Van Slyke ninhydrin determination of alpha-carbonyl carbon, and (e) optical rotation. Comparison of the rate of enzymatic hydrolysis by hog renal acylase I of the N-chloroacetyl derivative of the L-isomers of each diastereomer showed that the acyl B isomer is a better substrate than the acyl A isomer, where A denotes the faster moving diastereomer and B denotes the slower moving diastereomer in a defined chromatographic solvent system. Microbiological assay using Lactobacillus casei in a system selected for screening for possible antitumor activity indicated that while none of the isomers as free amino acids had any growth inhibitory action, the N-acylated isomers showed modest but significant activity. The N-chloroacetyl derivative of the D-enantiomorph of diastereomer B exhibited the greatest growth inhibitory activity, showing about twice the activity of the other three isomers.

Aminocaproates↗
PubMedDate not supplied

[Role of the thyroid gland in the effects of parenteral feeding].

In 82 albino rats with experimental thyrotoxicosis the assimilation of parenterally administered amino acid mixture of mori-amine S-2 was investigation. In thyrotoxicosis the assimilation of the amino acid mixture was found to be down. It is only a combination of mori-amine S-2 with vitamins, hormones and 6-methyluracil that facilitates the utilization of free amino acids by the tissues (this being borne out by a falling level of aminic nitrogen in the blood, skeletal muscles, heart and liver), persistently upholds the positive nitrous balance, prevents losses of the body weight and foces down oxygen consumption.

Amino Acids↗
PubMed1979

Isolation and characterization of mucopolysaccharides from rat liver mitochondria.

Mucopolysaccharides were isolated from rat liver mitochondria which had been labeled with 35S-sulfate. They were prepared from trichloroacetic acid (TCA)-insoluble and -soluble fractions of lipid-free mitochondria. These fractions were digested with pronase exhaustively, and the mucopolysaccharides were recovered in the void volume fractions of gel filtration of the pronase digests on Sephadex G-50, monitored by radioactivity determination. Identification of these mucopolysaccharides was based on electrophoresis on cellulose acetate film using three different media, enzymatic and chemical degradations specific to each type of mucopolysaccharide, using chondroitinases, heparitinase, and nitrous acid. From the TCA-insoluble fraction, chondroitin sulfate A and dermatan sulfate were obtained in a ratio of about 1 : 2, based on 35S-radioactivities, whereas the TCA-soluble fraction yielded chondroitin sulfates A/C, dermatan sulfate, and heparan sulfate in a ratio of about 1 : 3 : 12. The total amount of mitochondrial mucopolysaccharides was about 3 mg/g protein, distributed between the TCA-insoluble and -soluble fractions in a ratio of about 1 : 3.

Animals↗
PubMed1978

The radiolysis of glyceraldehyde-3-phosphate dehydrogenase.

The yields in molecules per 100 eV for active-site and sulphydryl loss from glyceraldehyde-3-phosphate dehydrogenase have been determined in nitrous-oxide-saturated, aerated and argon-saturated solutions. Molecular hydrogen peroxide produces a sulphenic acid product, which can be repaired by post-irradiation treatment with dithiothreitol. Comparison of the yields under various conditions showed that in aerated solutions both .OH and .O2-radicals inactivated the enzyme with an efficiency of about 26 per cent. However, the efficiency of .OH in air-free solutions was less, and inactivation by .H and eaq- did not appear to be appreciable. There is a correlation between SH loss and loss of active sites.

Air↗
PubMed1978

Erythroglycan, a high molecular weight glycopeptide with the repeating structure [galactosyl-(1 leads to 4)-2-deoxy-2-acetamido-glucosyl(1 leads to 3)] comprising more than one-third of the protein-bound carbohydrate of human erythrocyte stroma.

Glycopeptides of molecualr weight range 7,000 to 11,000, unusual in size and structure, have been partially purified from pronase digests of lipid-free human erythrocyte ghosts; we term this fraction "erythroglycan." These substances comprise about one-third of the galactose and glucosamine of the ghost. Methylation analysis of erythroglycan yields mainly 4-linked glucosamine, 3-linked galactose, and 3,6-linked galactose, along with mannose and fucose derivatives. Hydrazinolysis and nitrous acid deamination degrade erythroglycan to galactosyl-2,5-anhydromannose, indicating a repeating structure of galactosyl, (1 leads to 4)-2deoxy-2-acetamidoglucosyl (1 leads to 3). Digestion with the endo-beta-galactosidase from Escherichia freundii gives only partial cleavage of the erythroglycan, probably because of the arborized structure indicated by the branched galactose. Since sphingosine is not detectable after methanolysis by chemical ionization mass spectrometry, and since amino acids are present, we conclude that these substances are probably glycopeptidic in origin and are not "macroglycolipids." Erythroglycan may have the same type of keratan-like core structure as the long chain blood group glycolipids from human erythrocytes and could be a protein-bound carrier of the ABO determinants.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1979

Presence of heparan sulfate in the glomerular basement membrane.

The glomerular basement membrane was subjected to digestion with specific enzymes to determine the chemical nature (sialoglycoproteins, collagenous peptides, or glycosaminoglycans) of the anionic sites previously demonstrated in the laminae rarae. Enzyme digestion was carried out both in situ and in vitro. Kidneys were perfused in situ with enzyme solutions followed by perfusion with fixative containing the cationic dye, ruthenium red, to detect the anionic sites. Glomerular basement membranes were isolated by detergent treatment of glomeruli and incubated with enzyme solutions, followed by incubation with cationized ferritin (pI 7.3-7.5) to label the anionic sites. Only highly purified enzymes free of proteolytic activity were used. The findings were the same both in situ and in vitro. The anionic sites were unaffected by treatment with neuraminidase, chondroitinase ABC, and testicular or leech hyaluronidase. However, they could no longer be demonstrated after digestion with crude heparinase, purified heparitinase, or Pronase or after nitrous acid oxidation. The results demonstrate that the sites contain heparan sulfate since they are removed by treatment with heparitinase and by nitrous acid oxidation-procedures specific for heparan sulfate; and that sialoglycoproteins or other glycosaminoglycans do not represent major components of these sites since the latter are not affected by digestion with neuraminidase and other glycosaminoglycan-specific enzymes. Identical findings were obtained on basement membranes in other locations (Bowman's capsule, tubule epithelium, and endothelium of peritubular capillaries). The presence of heparan sulfate in the glomerular basement membrane is discussed in relation to the charge-selective properties of the glomerular filter and in relation to its potential involvement in various types of glomerular injury.

Animals↗
PubMed1978

Improved yields of daunomycinone glycosides in developmental mutants of Streptomyces coeruleorubidus.

When improving Streptomyces coeruleorubidus JA 10092, a producer of antibiotics of the daunomycinone complex, the most active variants were found among isolates of morphological types bld-1 (with a suppressed production of the aerial mycelium on organic media containing glucose) and whi (with an asporogenic aerial mycelium on glucose media and with the bald phenotype on media containing starch). Submerged cultures of the whi mutants produced increased quantities of daunomycinone glycosides in the antibiotic complex, the amount of free anthracyclinones being simultaneously decreased. The whi strains differed from the wild type also in higher demands for aeration, concentration of glucose and in an increased production capacity in starch media. The overall antibiotic activity increased more than 40 times after a six-step selection (application of UV light, gamma-radiation, nitrous acid and natural spreads) combined with an altered fermentation technology.

Culture Media↗
PubMed1979

Epidural analgesia and the metabolic response to surgery.

The effect of epidural blockade on the metabolic and hormonal responses to pelvic surgery was investigated in 14 female patients. Central venous blood samples were collected every 30 minutes and analysed for free fatty acids, glycerol, beta-hydroxybutyrate, acetoacetate, glucose, lactate, pyruvate, cortisol and growth hormone concentrations. There was no change in fat and glucose metabolism except for a transient decrease in lipolysis after 30 minutes of surgery. Cortisol and growth hormone values were significantly increased (p less than 0.01) after 60 minutes. A small but statistically significant increase in blood lactate concentration was observed (p less than 0.01) and the concept of a "metabolic V/Q" abnormality is postulated to explain the lacticacidaemia.

Adult↗