The reduction of formaldehyde by bacterial cells

Formaldehyde is reduced to methyl alcohol by living cells of a creatinine-decomposing strain of Pseudomonas aeruginosa. The amount of HCHO taken up in 30 minutes by 3 x 10¹⁰ cells of this organism is termed its reducing capacity. It was found to be 400 to 480 µg. The reaction takes place over wide pH and temperature ranges, is independent of the concentration of formaldehyde as long as the latter is not high enough to exert a toxic effect on the cell, but depends on the number of bacteria present. In cultures, 3 to 7 days old, there is a decline in reducing capacity without a proportionate decrease in the number of viable cells. On the other hand in cultures, 2 to 4 weeks old, the number of viable cells determines the amount of HCHO taken up. N/100 NaOH depresses the reducing capacity of the organism without affecting bacterial viability. Exposure of bacterial suspensions to temperatures of 46–52°C. for 10 minutes causes a far more rapid decrease in the number of viable cells than in reducing capacity. Incubation of cellular suspensions with nutrient substances, which are able to support adequately the growth of the organism, for 30 minutes prior to the addition of HCHO, induces increases in reducing capacity. The uptake of HCHO by different microorganisms seems to be related to their gaseous and nutritional requirements. Strains of P. aeruginosa and P. fluorescens are predominantly aerobic, least fastidious in their nutritional requirements, most active against HCHO, and least susceptible to the action of aureomycin and chloromycetin. The potential significance of cellular reducing capacity is discussed.

A note on glycerol formal as a solvent in toxicity testing

Twenty-nine organic solvents and emulsifying agents, selected for possible use as injection solvents in toxicity testing, have been submitted to a “range-finding” toxicity screening test on rats. As a result, glycerol formal was examined in greater detail. Glycerol formal is a good inert solvent for a wide range of organic chemicals. It produced no toxic effects or macroscopic pathology when 1500 mg./kg. was administered intraperitoneally to rats, or 1000 mg./kg. to mice or guinea pigs, or 4000 mg./kg. orally to rats, and at high doses the only specific effect found was narcosis. It was correspondingly innocuous subcutaneously or dermally, and was almost non-irritant to the eye surface. There was no detectable effect on the toxicity of parathion. Glycerol formal appears to be a useful addition to the range of solvents suitable for use in toxicity tests.

The use of formalin fixation in the cytochemical demonstration of succinic and DPN- and TPN-dependent dehydrogenases in mitochondria

Brief formalin fixation in the cold prior to histochemical assay of rat liver and pancreas for various dehydrogenases has been used successfully to circumvent the structural damage and enzymatic loss to which mitochondria of frozen sections would otherwise be subject. To obtain an optimal result a single set of conditions has been devised, including fixation prior to freezing of minute (finely diced) organ blocks in graded concentrations (0.7 to 2.0 per cent) of formaldehyde in chilled (1–4°C) Hanks' balanced salt solution, freezing at not higher than -70°C, and use of nitro-BT or, preferably, tetranitro-BT. The present histochemical study of hepatic and acinar cells indicates that not only are succinic and D-β-hydroxybutyric dehydrogenases located exclusively in the mitochondria but so are lactic, malic, and the isocitric dehydrogenases.

Adverse effect of ammonium salts on the antibacterial activity of paraformaldehyde solutions

The antibacterial activity of aqueous solutions of paraformaldehyde in concentrations from 0.1 to 0.4% (w/v) is bacteriostatic rather than bactericidal in the presence or absence of ammonium chloride. The presence of ammonium chloride significantly lengthened the time of exposure to paraformaldehyde necessary for inhibition of growth of the test organism (Staphylococcus aureus FDA 209) when unbuffered solutions were used. Elevation of the pH of the reacting mixture of paraformaldehyde and ammonium chloride by partial buffering lengthened the time of exposure necessary for inhibition of growth of the test organism. Decrease of antibacterial activity was concomitant with the disappearance of paraformaldehyde from the reacting mixture. The reaction of paraformaldehyde with ammonium chloride was rapid at room temperature (25 C) and at pH levels near neutrality. The fate of the reacting paraformaldehyde, including the possibility of the formation of hexamethylenetetramine or methylenimine, is discussed with particular reference to loss of antibacterial activity.

Physicochemical studies on the reaction between formaldehyde and DNA

The reaction between formaldehyde and phage T7 DNA has been studied by optical absorbance and sedimentation measurements. Through the course of denaturation, OD(200) and s(20, w) rise; after the attainment of full hyperchromicity the s(20, w) falls sharply, suggesting a decrease in molecular weight. Conditions in which formaldehyde causes cross-linking are defined. Some experimental applications of the denaturation technique are given. Evidence which suggests that preformed single-strand interruptions may exist in phage DNA is briefly discussed.

Studies on formalin fixation for electron microscopy and cytochemical staining purposes

A study has been made of the preservation of fine structure, phospholipids, and the activity of acid phosphatase and esterase in rat liver fixed in various solutions containing 4 per cent formaldehyde. Examination of methacrylate-embedded preparations shows that calcium-containing fixatives result in poor preservation of fine structure, whereas veronal-treated or phosphate-buffered formalin gives excellent results if the tonicity of the solutions is suitably adjusted by addition of sucrose. Formol-phosphate, to which Versene has been added, causes deterioration of cellular morphology. Phospholipids are retained almost quantitatively in tissue fixed in formol-calcium, and in phosphate-, collidine-, or triethanolamine-buffered formalin. About 50 per cent of the activity of acid phosphatase and esterase are preserved after 24 hours exposure to these fixatives at 0-2 degrees C, and the distributions of the enzymes and of phospholipids, as judged by cytochemical staining results, are not altered by any of these formalin solutions. Consideration of the morphological and biochemical integrity of the fixed tissue suggests that 4 per cent formaldehyde, buffered at pH 7.2 with 0.067 M phosphate, and containing 7.5 per cent sucrose, is the most suitable of the fixatives for combined cytochemical staining and electron microscopical studies.

AEROBIC DEGRADATION OF CHOLINE. I. FERMENTATION OF CHOLINE BY A MARINE BACTERIUM, ACHROMOBACTER CHOLINOPHAGUM N. SP

A marine bacterium, isolated by an enrichment technique, is able to utilize choline as the sole carbon and nitrogen source in a medium containing various salts. The morphological and biochemical characteristics of the organism indicate that it is a new species. Substrate feeding coupled with culture filtrate analyses indicate that choline is metabolized as follows: choline → betaine → dimethylglycine + formaldehyde → sarcosine + formaldehyde → serine → pyruvate + ammonia without transmethylation being involved. This pathway has not previously been reported for other bacteria or for animal tissues.

SODIUM SULPHOMETHYL DERIVATIVES OF POLYMYXINS

Variations in the treatment of polymyxin B and polymyxin E (colistin) with formaldehyde and sodium bisulphite produce sulphomethyl derivatives which differ quantitatively in acute toxicity and in antibacterial activities in vitro and in vivo. The acute intravenous LD50 values of some sixty samples of these derivatives range from six- to more than eighty-fold those of the parent antibiotics; the in vitro antibacterial activities range from 2 to 12% and the in vivo activities from 20 to 50% of those of the parent antibiotics, with the most toxic derivatives showing the highest activities. When short and prolonged incubation methods are used, assays of the derivatives in solutions of different ages and of blood collected from man and dog after intramuscular injection, show that the antibacterial activities of these sulphomethyl derivatives depend on reversion to the unsubstituted form, and that the differences in the activities are due to variations in stability. These conclusions are supported by comparison of these sulphomethyl derivatives with stable acetyl derivatives. The lower in vivo activity is due, at least partly, to the high renal excretion of the substituted form. Electrophoresis shows that the derivatives are composite, the components corresponding to mono- to pentasulphomethyl polymyxin. Pain at the injection site is the most troublesome side-effect of polymyxin therapy, and this is avoided with these derivatives. In rats injected with quantities some twenty-times the usual human dose, the derivatives cause transitory decrease in urinary output and transitory proteinuria. After intramuscular injection of these derivatives into dogs, no antibiotic is detectable in the cerebrospinal fluid and concentrations present in the bile are not significantly different from those after injection of the parent antibiotic. When injected intracisternally into these animals, derivatives are less toxic than the parent compounds. These studies show that acute intravenous toxicity is a useful index of therapeutic efficiency and that derivatives with intravenous LD50 values of about 100 mg/kg are the most satisfactory ones. Because activity depends on reversion to the parent antibiotic, the use of these derivatives for topical application is contraindicated.

FORMATION OF NORNICOTINE AND OTHER METABOLITES FROM NICOTINE IN VITRO AND IN VIVO

Nornicotine and formaldehyde were formed from nicotine by an enzymatic preparation from rabbit liver. Nornicotine was identified by paper chromatography and was isolated and characterized by physical and chemical methods. Incubation of nornicotine with the same test system gave rise to demethylcotinine. Demethylcotinine was also found in chromatograms of liver extracts following the intravenous administration of nornicotine to the rabbit. Chromatograms from liver, kidney, and urine extracts showed the formation of nornicotine, cotinine, demethylcotinine, and nicotine-1′-oxide, following the intravenous administration of nicotine to the intact rabbit. These metabolic studies indicated that nicotine is demethylated to nornicotine which is further oxidized to demethylcotinine.

THE ISOLATION OF OLIGOSACCHARIDES FROM THE CELL-WALL POLYSACCHARIDE OF LACTOBACILLUS CASEI, SEROLOGICAL GROUP C

1. A number of disaccharides and oligosaccharides have been isolated from the products of mild acid hydrolysis of the specific substance from Lactobacillus casei, serological group C. 2. The major disaccharide is O-beta-d-glucopyranosyl-(1-->3)-N-acetyl- d-galactosamine (B4) and evidence is presented for the structure of a tetrasaccharide composed of O-beta-d-glucopyranosyl-(1-->6)-d-galactose (B1) joined through its reducing end group to B4. 3. Disaccharide B1 is also a component of a trisaccharide O-beta-d-glucopyranosyl-(1-->6)-O-beta- d-galactopyranosyl-(1-->6)-N-acetyl-d-glucosamine (A7). 4. A number of other oligosaccharides have been shown to be related structurally. 5. The ability of certain of the oligosaccharides to inhibit the precipitin reaction has been studied. The disaccharide B1 is more effective as an inhibitor than gentiobiose and the trisaccharide A7 is considerably more effective than B1. 6. These results have been compared with those obtained previously for the composition of the cell wall.

PRESERVATION OF TOTAL, LYO-, AND DESMOENZYME ACTIVITY IN MAMMALIAN SALIVARY GLANDS FOLLOWING CHLORAL HYDRATE FORMALIN FIXATION

Acid phosphatase, alkaline phosphatase, nonspecific esterase, pseudocholinesterase, leucine aminopeptidase, and β-d-galactosidase activities of parotid and submandibular salivary glands were evaluated in six animal species. Assays for total enzyme, lyoenzyme, and demoenzyme were performed on unfixed and chloral hydrate formalin (CHF) fixed frozen cryostat sections.

Following fixation lyoenzyme (soluble fraction) activity exhibited extreme reduction for all enzymes except pseudocholinesterase, while the demoenzyme (insoluble fraction) activity of acid phosphatase, nonspecific esterase, pseudocholinesterase, and β-d-galactosidase was maintained at a high level or increased. Since removal of lyoenzyme activity and retention of desmoenzyme activity are requisites in histochemical localization, this fixative may be the preferred method for handling tissues prior to the localization of the above cited enzymes.

Several hypotheses are proposed to explain the increased desmoenzyme (nonspecific esterase and β-d-galactosidase) noted subsequent to fixation.

THE USE OF ACETYLETHYLENEIMINE IN THE PRODUCTION OF INACTIVATED FOOT-AND-MOUTH DISEASE VACCINES

Suspensions of FMD virus treated with 0·05% formalin at 26° C. for periods up to 144 hr. remained infective for cattle, although the infectivity could not be detected in the presence of aluminium hydroxide. Infectivity was detected in similar virus suspensions which had been treated with 0·05% AEI at 37° C. for 8 hr. but not in suspensions treated for 12 hr.

Vaccines prepared from these suspensions were antigenically potent and serum neutralization tests demonstrated the development and regression of serum antibody. The AEI vaccines were at least as potent as the corresponding formalin vaccines.

A CYTOCHEMICAL STUDY OF THE SOLUBILITIES OF THE HISTONES OF FIXED NECTURUS LIVER

Evidence for heterogeneity in solubility properties of the histones of fixed Necturus liver was obtained by extracting freeze-methanol-substituted tissue with 2-10% perchloric acid, ethanol-HCl, or 0.02 N HCl, postfixing in formaldehyde then staining with the Alfert-Geschwind method for basic proteins and measuring the dye bound to nuclei by microspectrophotometry.

Data was obtained which can be interpreted as indicating that each of the acids extracts a discrete portion of the histone. Information from experiments based on sequential extractions with two different reagents suggests that the portions extracted may represent different subfractions, perhaps corresponding to histone subtypes differing in relative content of arginine and lysine and in other properties.

CHEMICAL AND IMMUNOLOGICAL COMPOSITION OF SURFACE STRUCTURES OF LISTERIA MONOCYTOGENES

Osebold, John W. (University of California, Davis), Ole Aalund, and Clarence E. Chrisp. Chemical and immunological composition of surface structures of Listeria monocytogenes. J. Bacteriol. 89:84-88. 1965.-A proteinlike surface substance was demonstrated on Listeria monocytogenes when an explanation was sought for the inagglutinability of some somatic antigens. The serological behavior of live bacteria and organisms subjected to heat, formalin, and trypsin was compared. The agglutination-inhibiting phenomenon was most pronounced with heat-killed (100 C) antigens. Trypsinization eliminated inagglutinability and increased sensitivity. Substances released by the enzyme had an ultraviolet-absorption peak at 260 mmu and showed a spot on paper chromatograms compatible with polypeptide. Inagglutinable cells combined with antibody because they could readily absorb antibodies from serum. After reaction with anti-Listeria serum, inagglutinable cells could be agglutinated by the addition of antiglobulin serum. It was hypothesized that heat inactivation of cells denatured the proteinaceous surface layer which interferred with the formation of a visible agglutination product but did not eliminate antigen-antibody reaction.