Effects of toluene on microflora and hydrolysis of urea in a black spruce humus

1968 ◽  
Vol 14 (9) ◽  
pp. 999-1003 ◽  
Author(s):  
M. R. Roberge
Keyword(s):  
Picea Mariana ◽  
Phosphate Buffer ◽  
Urease Activity ◽  
Black Spruce ◽  
Urea Hydrolysis ◽  
Viable Bacteria ◽  
Bacteria And Fungi ◽  
Hydrolysis Of ◽  
Lower Production

The value of toluene as an antiseptic in determining the activity of urease in soil was studied in the surface organic horizon of a black spruce (Picea mariana Mill.) forest soil. Toluene was added in various amounts to layers of the humus suspended in water or in phosphate buffer, or sterilized by radiation, and incubated for various periods of time, followed by 8-h treatments with urea. Viable bacteria and fungi were detected by the dilution plate technique and the products of urea hydrolysis were determined by extraction and distillation. By increasing the amount of toluene or the time of contact of toluene with the humus, bacteria and fungi were reduced in number but not completely eliminated. The presence of urea resulted in a larger decrease of bacteria and fungi. With an increase in the amount of toluene, but not in the time of contact of toluene, a decrease was observed in urea hydrolysis. Some of the decrease was due to the inhibition of urease by toluene, and possibly some to the absorption of the products of urea hydrolysis and (or) to a lower production of urease by the surviving microorganisms. The last two possibilities render questionable the use of toluene in the determination of urease activity in soils.

EFFECTS OF CATECHOL AND P-BENZOQUINONE ON THE HYDROLYSIS OF UREA AND ENERGY BARRIERS OF UREASE ACTIVITY IN SOILS

1984 ◽  
Vol 64 (1) ◽  
pp. 51-60 ◽  
Author(s):  
J. S. TOMAR ◽  
A. F. MacKENZIE
Keyword(s):  
Activation Energy ◽  
Organic Matter ◽  
Soil Organic Matter ◽  
Key Words ◽  
Urease Activity ◽  
Urea Hydrolysis ◽  
Urease Inhibitors ◽  
Soil Urease ◽  
Hydrolysis Of ◽  
Hydrolysis Of Urea

The effects of the urease inhibitors, catechol and p-benzoquinone, and temperature on the hydrolysis of urea in five soils were investigated in a laboratory study. Urea hydrolysis decreased significantly with the amount of inhibitors applied and increased significantly with each 5 °C increase in temperature from 5 to 25 °C. The effectiveness of inhibitors generally decreased with increases in temperature from 5 to 25 °C. The correlation of hydrolysis of urea with organic matter contents of the soils was highly significant (r = 0.67** to 0.86**). Both catechol and p-benzoquinone tended to increase the energies and entropies of activation of soil urease and the effect was enhanced with a decrease in soil organic matter. It is suggested that an increase in the activation energy of the soil urease as a result of inhibitor use was related to an increase in the effectiveness of the inhibitor. Key words: Urease inhibitors, urea hydrolysis, energy of activation

scholarly journals Urease testing and yeast taxonomy

1987 ◽  
Vol 33 (5) ◽  
pp. 396-404 ◽  
Author(s):  
J. Leland Booth ◽  
H. S. Vishniac
Keyword(s):  
Urease Activity ◽  
Ethylenediaminetetraacetic Acid ◽  
Chelating Agent ◽  
Maximal Activity ◽  
Urea Hydrolysis ◽  
Basidiomycetous Yeasts ◽  
Urease Production ◽  
Ascomycetous Yeasts ◽  
Hydrolysis Of ◽  
By Products

When urease production was assayed by the hydrolysis of [14C]urea, all basidiomycetous yeasts tested, including the Cryptococcus vishniacii complex (previously reported urease negative), produced significant amounts of 14CO2. The Schizosaccharo-mycetaceae were the only urease-positive ascomycetous yeasts tested. Yarrowia lipolytica was urease negative. The stoichiometry of [14C]urea hydrolysis paralleled by Roberts' rapid urea hydrolysis (RUH) test indicated that causes of anomalous results in conventional urease testing include acidification and alkalinization of the test medium by products of endogenous metabolism and autolysis rather than urease activity. Anomalous results also occurred when cells were grown on media containing the chelating agent ethylenediaminetetraacetic acid (EDTA) prior to RUH. The addition of EDTA to a complex natural medium inhibited urease production in all yeasts reportedly growing at 35 °C (and all other yeasts tested), except Filobasidiella (Cr.) neoformans var. neoformans (NIH 12). The RUH test could differentiate at the varietal level: Fil. (Cr.) neoformans var. neoformans was about 10 times more resistant to EDTA in media used for the growth of cells prior to RUH testing than was Fil. neoformans var. bacillispora (Cr. neoformans var. gattii) (NIH 191). Urease production by Fil. neoformans var. bacillispora was specifically restored to half maximal activity by the addition of 22 μM Ni+2 (as NiCl2) to a growth medium containing 0.100 mM EDTA.

scholarly journals Molecular Profiling of Rhizosphere Microbial Communities Associated with Healthy and Diseased Black Spruce (Picea mariana) Seedlings Grown in a Nursery

2004 ◽  
Vol 70 (6) ◽  
pp. 3541-3551 ◽  
Author(s):  
M. Filion ◽  
R. C. Hamelin ◽  
L. Bernier ◽  
M. St-Arnaud
Keyword(s):  
Picea Mariana ◽  
Root Rot ◽  
Black Spruce ◽  
Restriction Analysis ◽  
Phylogenetic Analyses ◽  
Methodological Approach ◽  
Rrna Gene ◽  
Wide Range ◽  
Bacteria And Fungi ◽  
Evenness Indices

ABSTRACT Bacterial and fungal populations associated with the rhizosphere of healthy black spruce (Picea mariana) seedlings and seedlings with symptoms of root rot were characterized by cloned rRNA gene sequence analysis. Triplicate bacterial and fungal rRNA gene libraries were constructed, and 600 clones were analyzed by amplified ribosomal DNA restriction analysis and grouped into operational taxonomical units (OTUs). A total of 84 different bacterial and 31 different fungal OTUs were obtained and sequenced. Phylogenetic analyses indicated that the different OTUs belonged to a wide range of bacterial and fungal taxa. For both groups, pairwise comparisons revealed that there was greater similarity between replicate libraries from each treatment than between libraries from different treatments. Significant differences between pooled triplicate samples from libraries of genes from healthy seedlings and pooled triplicate samples from libraries of genes from diseased seedlings were also obtained for both bacteria and fungi, clearly indicating that the rhizosphere-associated bacterial and fungal communities of healthy and diseased P. mariana seedlings were different. The communities associated with healthy and diseased seedlings also showed distinct ecological parameters as indicated by the calculated diversity, dominance, and evenness indices. Among the main differences observed at the community level, there was a higher proportion of Acidobacteria, Gammaproteobacteria, and Homobasidiomycetes clones associated with healthy seedlings, while the diseased-seedling rhizosphere harbored a higher proportion of Actinobacteria, Sordariomycetes, and environmental clones. The methodological approach described in this study appears promising for targeting potential rhizosphere-competent biological control agents against root rot diseases occurring in conifer nurseries.

FACTORS AFFECTING UREASE ACTIVITY IN A BLACK SPRUCE HUMUS STERILIZED BY GAMMA RADIATION

1968 ◽  
Vol 48 (3) ◽  
pp. 355-361 ◽  
Author(s):  
M. R. Roberge ◽  
R. Knowles
Keyword(s):  
Picea Mariana ◽  
Maximum Rate ◽  
Urease Activity ◽  
Radiation Flux ◽  
Ph Value ◽  
Black Spruce ◽  
Factors Affecting ◽  
Measured Activity ◽  
Rate Of Hydrolysis ◽  
Sterilization Dose

Factors affecting the activity of urease were studied in a black spruce (Picea mariana (Mill.) B S P.) humus sampled at Baie-Comeau, Quebec, and sterilized with a Co-60 source. The enzyme was almost completely inactivated by 4–5,000 kr (about four times the sterilization dose). For a given dose, the measured activity was somewhat lower when a lower radiation flux was used with a longer exposure time. A substrate concentration of 50–100 mg/g urea-N was required for maximum rate of hydrolysis. Even at a much lower concentration (3.5 mg/g), hydrolysis was linear during the first 12 hr of reaction at 20 °C. Urease activity was approximately proportional to temperature in the range 10–40 °C. Activity showed a slight decrease as water content was increased from 60 to 140% of maximum holding capacity. In humus buffered at different pH's, the activity was at a maximum at about pH 7.0. In the absence of buffer, however, activity was higher than when buffered at either the initial or the final pH value of the unbuffered system. Activity did not change as buffer concentration in the samples was increased from 0.25 to 1.00 M.

DETERMINATION OF MICRO-AMOUNTS OF 5β-PREGNAN-3α-OL-20-ONE IN URINE USING INFRARED-SPECTROMETRY

1962 ◽  
Vol 41 (2) ◽  
pp. 234-246 ◽  
Author(s):  
H. J. van der Molen
Keyword(s):  
Infrared Spectrum ◽  
Quantitative Determination ◽  
Acid Hydrolysis ◽  
Chromatographic Separation ◽  
Pure Form ◽  
Infrared Spectrometry ◽  
Hydrolysis Of

ABSTRACT A procedure for the quantitative determination of 5β-pregnan-3α-ol-20-one in urine is described. After acid hydrolysis of the pregnanolone-conjugates in urine, the free steroids are extracted with toluene. Pregnanolone is isolated in a pure form as its acetate; after chromatographic separation of the free steroids on alumina, the fraction containing pregnanolone is acetylated and rechromatographed on alumina. Quantitative determination of the isolated pregnanolone-acetate is carried out with the aid of the infrared spectrum recorded by a micro KBr-wafermethod. The reliability of the method under various conditions is discussed under the headings, specificity, accuracy, precision and sensitivity. It is possible to determine 30–40 μg pregnanolone in a 24-hours urine portion with a precision of 25%.

EINE CHEMISCHE METHODE ZUR BESTIMMUNG VON 16-EPI-ÖSTRIOL IM URIN DES MENSCHEN

1963 ◽  
Vol 44 (1) ◽  
pp. 47-66 ◽  
Author(s):  
W. Nocke ◽  
H. Breuer
Keyword(s):  
Melting Point ◽  
Phosphoric Acid ◽  
Aqueous Alkali ◽  
Percentage Error ◽  
Organic Layer ◽  
Maximum Percentage ◽  
Chemical Determination ◽  
Routine Assay ◽  
Hydrolysis Of

ABSTRACT A method for the chemical determination of 16-epi-oestriol in the urine of nonpregnant women with a qualitative sensitivity of less than 0.5 μg/24 h is described. The separation of 16-epi-oestriol and oestriol is accomplished by converting 16-epi-oestriol into its acetonide, a reaction which is stereoselective for cis-glycols and therefore not undergone by oestriol as a trans-glycol. Following partition between chloroform and aqueous alkali, the acetonide of 16-epi-oestriol is completely separated with the organic layer whereas oestriol as a strong phenol remains in the alkaline phase. 16-epi-oestriol is chromatographed on alumina as the acetonide and determined as a Kober chromogen. This procedure can easily be incorporated into the method of Brown et al. (1957 b) thus making possible the simultaneous routine assay of oestradiol-17β, oestrone, oestriol and 16-epi-oestriol from one sample of urine. The specificity of the method was established by separation of 16-epi-oestriol from nonpregnancy urine as the acetonide, hydrolysis of the acetonide by phosphoric acid, isolation of the free compound by microsublimation and identification by micro melting point, colour reactions and chromatography. The accuracy of the method is given by a mean recovery of 64% for pure crystalline 16-epi-oestriol when added to hydrolysed urine in 5–10 μg amounts. The precision is given by s = 0.24 μg/24 h. For the duplicate determination of 16-epi-oestriol the qualitative sensitivity is 0.44 μg/24 h, the maximum percentage error being ± 100% The quantitative sensitivity (±25% error) is 1.7 μg/24 h.

INDIREKTE PAPIERCHROMATOGRAPHISCHE METHODE ZUR BESTIMMUNG DER HARNOESTROGENE

1961 ◽  
Vol 38 (4) ◽  
pp. 545-562 ◽  
Author(s):  
L. Kecskés ◽  
F. Mutschler ◽  
I. Glós ◽  
E. Thán ◽  
I. Farkas ◽  
...  
Keyword(s):  
Pregnant Women ◽  
Granulosa Cell ◽  
Iron Content ◽  
List Type ◽  
Granulosa Cell Tumour ◽  
Hydrolysis Of ◽  
Phenol Fraction ◽  
Qualitative Determination

ABSTRACT 1. An indirect paperchromatographic method is described for separating urinary oestrogens; this consists of the following steps: acidic hydrolysis, extraction with ether, dissociation of phenol-fractions with partition between the solvents. Previous purification of phenol fraction with the aid of paperchromatography. The elution of oestrogen containing fractions is followed by acetylation. Oestrogen acetate is isolated by re-chromatography. The chromatogram was developed after hydrolysis of the oestrogens 'in situ' on the paper. The quantity of oestrogens was determined indirectly, by means of an iron-reaction, after the elution of the iron content of the oestrogen spot, which was developed by the Jellinek-reaction. 2. The method described above is satisfactory for determining urinary oestrogen, 17β-oestradiol and oestriol, but could include 16-epioestriol and other oestrogenic metabolites. 3. The sensitivity of the method is 1.3–1.6 μg/24 hours. 4. The quantitative and qualitative determination of urinary oestrogens with the above mentioned method was performed in 50 pregnant and 9 non pregnant women, and also in 2 patients with granulosa cell tumour.

Determination of δ-hexadecansultone in sodium α-olefinesulphonates and liquid detergents using gas chromatography-mass spectrometry (GC/MS)

2019 ◽  
Vol 85 (7) ◽  
pp. 16-21
Author(s):  
Liliya R. Mubarakova ◽  
German K. Budnikov
Keyword(s):  
Multicomponent Mixture ◽  
Operating Mode ◽  
Complete Separation ◽  
Gas Chromatography Mass Spectrometry ◽  
Liquid Detergent ◽  
Cyclic Esters ◽  
Alcohol Water ◽  
Household Chemicals ◽  
Hydrolysis Of

Sultones are cyclic esters of hydroxysulfonic acids, which are formed in the process of sulfonation of α-olefins with sulfur trioxide gas. More stable sultones may be present in the final product — an anionic surfactant — sodium α-olefin sulfonate (AOC-Na). AOC-Na is widely used in the production of household chemicals and cosmetic products, including liquid dishwashing detergents. Sultones are strong skin sensitizers, their level in AOC-Na should be strictly controlled and not exceed 5 ppm. Operational and strict control of the sultone content upon AOC-Na production allows timely adjustment at the stage of hydrolysis, which leads to a more complete disclosure of the sultone cycle with the formation of the corresponding olefin sulfonates and hydroxyalkanesulfonates. We propose a method for determining δ-hexadecansultone in liquid dishwashing detergents and sodium α-olefinsulfonates obtained on the basis of α-olefins of C14 – C16 fractions using GC/MS, which provides shortening of sample preparation and keeps the sensitivity with a detection limit of 0.02 mg/kg. The effect of various weakly polar and non-polar organic solvents used for Sultone extraction from AOC-Na and liquid detergent on liquid extraction based on the dispersion of the extractant in an alcohol/water phase is studied. When selecting the solvent we have shown that the use of diethyl ether provided the best extraction of the analyte. Determination of the analyte extraction recovery was performed using the reaction of hydrolysis of the extracted mixture. We specified the operating mode of the device which provided complete separation of the components of the analyzed compounds including the samples of liquid detergent for dishes being a multicomponent mixture of complex composition.

Determination of the prevalence of helicobacter pylori oral infection in smoking patients with chronic generalized periodontitis on the background of chronic hyperacidal gastritis during treatment

2020 ◽  
Vol 40 (4) ◽  
pp. 50-54
Author(s):  
O. L. Zolotukhina ◽  
◽  
Ju. G. Romanova ◽  
O. V. Maslov ◽  
◽  
...  
Keyword(s):  
Risk Factors ◽  
Helicobacter Pylori ◽  
Oral Cavity ◽  
Urease Activity ◽  
Rapid Test ◽  
Oral Infection ◽  
Helicobacter Pylori Infection ◽  
Natural Origin ◽  
Periodontal Tissues

Diseases of periodontal tissues occupy one of the leading positions among modern dental problems, namely the multifactorial nature of these diseases. In modern dental science, the issue of the development of periodontal pathology against the background of somatic pathology and risk factors remains relevant. Pathology of periodontal tissues in 68–90 % of cases is accompanied by chronic diseases of the gastrointestinal tract. Today, there is no doubt that Helicobacter pylori infection can be present in the biotopes of the oral cavity and can affect the course of periodontal pathology. As you know, smoking is one of the important risk factors for the development of inflammatory-dystrophic diseases of periodontal tissues, which can aggravate the course of the latter. The purpose of the work is to determine the prevalence of oral Helicobacter pylori infection in tobacco-dependent patients with chronic generalized periodontitis on the background of chronic hyperacid gastritis during treatment. Patients who received the proposed therapeutic and prophylactic complex (ultraphonophoresis procedures with the created gel «Apisan», and probiotic drug BioGaia ProDentis and angioprotective drug of natural origin — Detralex) showed a gradual decrease in the level of total urease activity and, as a consequence, a decrease the prevalence of Helicobacter pylori infection in the oral cavity according to the results of a urease rapid test with material from the oral cavity, both in the presence of a risk factor — smoking, and in its absence. The use of the proposed therapeutic and prophylactic complex proved to be effective in reducing the prevalence of oral Helicobacter pylori infection in smoking patients and patients who do not smoke, with chronic generalized periodontitis against the background of chronic hyperacidal gastritis associated with Helicobacter pylori.

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