Differential inactivation of three bacteriophages by acid and alkaline pH used in the membrane adsorption–elution method of virus recovery

1980 ◽  
Vol 26 (12) ◽  
pp. 1403-1407 ◽  
Author(s):  
Carolyn M. Sabatino ◽  
Siegfried Maier
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Differential Susceptibility ◽  
Alkaline Ph ◽  
Alkaline Elution ◽  
Adsorption Method ◽  
Acid Ph ◽  
Elution Method ◽  
Virus Recovery ◽  
General Method

The study was prompted by our inability to concentrate phages by a membrane adsorption method effective for polioviruses. Consequently two coliphages, WPK and T4, and F116 of Pseudomonas aeruginosa were tested for their resistance to acid (pH 5.2–3.2) and alkaline (pH 10–11.5) exposures. Only T4 proved acid resistant, allowing for acid adsorption, and only WPK was sufficiently alkaline resistant to allow for alkaline elution. Thus, the differential susceptibility of various phages precludes the use of the acid membrane adsorption–alkaline elution method as a general method for the concentration of phages from large volumes of water.

Effect of environment on sensitivity of Neisseria gonorrhoeae to Pseudomonas aeruginosa bacteriocins

1980 ◽  
Vol 29 (2) ◽  
pp. 507-511
Author(s):  
D C Stein ◽  
B H Hebeler ◽  
F E Young
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Neisseria Gonorrhoeae ◽  
Growth Inhibition ◽  
Environmental Variation ◽  
Clinical Isolates ◽  
Colony Morphology ◽  
Alkaline Ph ◽  
Growth Environment ◽  
Acid Ph ◽  
Apparent Correlation

The effect of environmental variation on the susceptibility of Neisseria gonorrhoeae to pyocin produced by Pseudomonas aeruginosa was examined. Susceptibility to at least one pyocin was demonstrated in strains of N. gonorrhoeae (99%), N. meningitidis (35%), and N. lactamica (47%). The degree of sensitivity to pyocin displayed by N. gonorrhoeae was affected by varying the pH of the growth environment. Gonococcal strains were more sensitive to growth inhibition by pyocins at an alkaline pH and less sensitive to growth inhibition at an acid pH. Inhibitory titers fluctuated during nonselective subculture of fresh clinical isolates. There was no apparent correlation between auxotype and sensitivity to pyocin. Also, no relationship between colony morphology and pyocin sensitivity was seen.

Changes in the acidity and fertility of a red earth soil under wheat–annual pasture rotations

1997 ◽  
Vol 48 (5) ◽  
pp. 561 ◽  
Author(s):  
K. R. Helyar ◽  
B. R. Cullis ◽  
K. Furniss ◽  
G. D. Kohn ◽  
A. C. Taylor
Keyword(s):  
Wheat Crop ◽  
Soil N ◽  
Alkaline Ph ◽  
Waste Products ◽  
Organic C ◽  
Acid Ph ◽  
Rate Of Increase ◽  
Red Earth ◽  
Ph Increase ◽  
Ph Decrease

This paper reports the effects of 6 wheat–annual pasture rotations over 18 years on soil N, organic C, P, and pH in a red earth soil at Wagga Wagga (35° 03′ S, 147° 21′E), in southern NSW. There were 3 cropping intensities (33, 50, 67%) with pastures dominated by subterranean clover (Trifolium subterraneum L. cv. Bacchus Marsh) and annual ryegrass (Lolium rigidum Gaud. cv. Wimmera). Rotations were long (6-year) or short (2- or 3-year). Initial soil N and organic C concentrations (0–10 cm) were low, 1300–1400 kg N/ha and 0·7–0·9 g organic C/100 g. The rate of increase of total N in the top 20 cm was the same on short and long rotations, and increased with the proportion of pasture in the rotation from 2·0 to 12·1 to 20·7 kg N/ha · year for pasture to crop ratios of 0·33, 0·50, and 0·67. Estimates of the amounts of N fixed and the measured accumulation of N per pasture year varied within the narrow ranges of 95–113 and 45–64 kg N/ha · pasture year. Organic C increased faster as the proportion of pasture in the rotation increased and there was no evidence that steady-state concentrations were achieved by Year 18. Estimates of the average amount of N leached below 30 cm varied in the range 22–29 kg N/ha · year. Analysis of the individual crop and pasture effects on soil N in the surface 10 cm indicated that net nitrate leaching was greatest in the second pasture year or in the first crop year following 1 year of pasture. A significant amount of N leached during the first 2 or 3 pasture years in a rotation was recovered by the first wheat crop or by the third and fourth year pastures. Second to fourth cereal crops depleted soil N by an amount similar to that removed in the grain. Average grain N% for the rotation treatments was closely described (R2 = 0·96) as a function of the length of the pasture phase, the pasture to crop ratio, and the interaction pasture to crop ratio number of preceding wheat crops. In the top 30 cm the pH changed at a rate near –0·04 units/year on all treatments, equivalent to addition of 2·3–2·8 kmol H+/ha · year. The acid addition rate, and hence the long-term lime requirement (50 kg lime/kmol H+), did not vary with pasture to crop ratio or with the length of the rotation. The proportion of the acid added to the top 30 cm of soil that was contributed from the N cycle (nitrification followed by nitrate loss by leaching below 30 cm or by run-off) was 0·65 for rotations with 67% pasture and 0·80 for rotations with 33% pasture. Carbon cycle acids, produced during organic matter accumulation and the synthesis of products that were subsequently removed, accounted for the remainder. Individual crop and pasture effects on soil pH were near the overall mean of –0·04 units except in years preceding and following the transition from pasture to cereal phases of the rotations. In cereal-dominated rotations the last pasture year was strongly acid (pH decrease 0·13–0·17) and the following cereal year was alkaline (pH increase 0·05–0·08). In pasture-dominated rotations the effects were reversed, the last pasture being alkaline (pH increase 0·07–0·12) and the following cereal being acid (pH decrease 0·13–0·19). In the 50% rotations, effects were intermediate. Organic and inorganic forms of soil P in the surface 10 cm increased linearly with time, accounting for 38% of the applied fertiliser P. Of the applied P, 88% was accounted for by the sum of P accumulated in the surface 20 cm of soil and by removal in products and waste products. The remainder may have been lost by erosion or accumulated in forms resistant to extraction by 0·1 M H2SO4 after ignition at 550°C. There was a slightly greater rate of increase of organic P as the proportion of pasture in the rotation increased. The annual addition of 11·8 kg P/ha·year marginally exceeded the amount required to maintain the available P concentration.

Three Novel α-Globin Variants: Hb Itapira [α30(B11) Glu→Val (α1)], Hb Bom Jesus Da Lapa [α30(B11) Glu→Ala (α1)] and Hb Boa Esperança [α16(A14) Lis→Thr (α2)].

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3739-3739
Author(s):  
Maria F. Sonati ◽  
Elza M. Kimura ◽  
Dulcineia M. Albuquerque ◽  
Denise M. Oliveira ◽  
Fernando F. Costa
Keyword(s):  
High Performance ◽  
Globin Gene ◽  
Southeastern Brazil ◽  
Base Substitution ◽  
Alkaline Ph ◽  
Globin Chain ◽  
Chinese Families ◽  
Acid Ph ◽  
Α Chain ◽  
Hematological Manifestations

Abstract Three new Hb variants were found in four blood donors, which we named Hb Itapira [α30(B11) Glu→Val)], Hb Bom Jesus da Lapa [α30(B11) Glu→Ala)] and Hb Boa Esperança [α16 (A14) Lis→Thr], according to their carriers’ origin. The first one was detected in a Caucasian man from Southeastern Brazil; electrophoresis at alkaline pH showed a low proportion Hb S-like band (5,5%), which was not distinguished from Hb A at acidic pH. High performance liquid chromatography-HPLC exhibited a short peak at D-Window. The abnormal α-globin was demonstrated by globin-chain electrophoresis at acid pH, with a slower migration than the normal α-chain. The α genes were sequenced (ABI PRISM-377-DNA automated sequencer, Applied Biosystems, CA, USA) and a base substitution found at the 30th codon of the α1-gene (GAG→GTG), in heterozygosis, causing Glu→Val replacement in the α-chain. Familial analysis revealed that the carrier’s mother and brother have the same alteration. All the affected members of this family are also heterozygous for the α-globin gene triplication (αααanti3.7), explaining the low percentage of the variant and suggesting an association of the mutation with the triplicate haplotype. Hb Bom Jesus da Lapa results of a mutation at the same gene and position: α1, 30th codon (GAG→GCG), causing Glu→Ala replacement. It was detected in an African descendant woman from the northeastern region of Brazil; the electrophoretic behaviour was similar to that of Hb Itapira, but it eluted with Hb A2 on HPLC, in a total of 24.8%, and the mutant did not separate from normal α-chain at the acidic globin electrophoresis. Two other variants with replacement of the α-chain 30th residue have been described [Hb O-Padova (Glu→Lys), found in Italian, Turkish and Spanish families, and Hb G-Chinese (or G-Honolulu, G-Hong Kong, G-Singapore) (Glu→Gln), encountered in Chinese families], none of them with clinical or hematological manifestations although this residue is involved in the αlβ1 contacts of the molecule. Hb Boa Esperança was detected in two apparently not-related individuals, one of them of African descent, both originate from the state of Minas Gerais, Southeast Brazil. This variant moved faster than Hb A at alkaline pH, was not distinguished at acid pH, and eluted as an additional peak at P3 on HPLC (25%); globin-chain electrophoresis showed a slower α-chain. Sequencing revealed a base substitution at the 16th codon of the α2-gene, in heterozygosis (AAG→ACG; Lys→Thr). Although the carriers have different surnames and do not know each other, β-cluster haplotypes are suggestive of a common ancestor. Three other mutations have already been described in this position [Hb I (Lys→Glu), Hb Beijing (Lys→Asn), in asymptomatic heterozigotes, and Hb Harbin (Lys→Met), slightly unstable, resulting in anemia to its carrier. All the three variants described here showed normal instability and solubility tests.

Distribution of Non-Rubber Substances in Preserved Latex Part II. Acids

1943 ◽  
Vol 16 (2) ◽  
pp. 365-380
Author(s):  
H. C. Baker
Keyword(s):  
Particle Size ◽  
Present Author ◽  
Acetone Extract ◽  
Alkaline Ph ◽  
Protein Distribution ◽  
Active Materials ◽  
Different Types ◽  
Surface Active ◽  
Rubber Phase ◽  
General Method

Abstract In a previous paper by the present author, a general method for determining the distribution of the nonrubber substances between the rubber-and-water phases in latex was described and results were given of its application to the study of the distribution of nitrogen and materials extractable with acetone. It was shown that the nitrogen associated with the rubber phase is of two different types, a small amount (about 0.02 per cent) being independent of particle size and consequently distributed throughout the mass of the rubber, whereas the remainder is a function of particle size, replaceable by surface-active materials, such as soaps, and is, consequently, situated at the surface of the particles. The surface nitrogen in ammoniated latex was variable, decreased with age of latex, could be partially desorbed at an alkaline pH by washing the latex, for instance, by dilution or repeated creaming, and is considered to represent the protective protein covering of the latex globules. The total variation experienced in unconcentrated ammoniated latices of varying ages was from 0.11 to 0.18 per cent, but in latex of good quality about six months old, surface nitrogen was 0.15 per cent, corresponding to about 1 per cent protein. Distribution experiments on the acetone extract showed that there is from 2 to 3 per cent of acetone-soluble substances associated with the rubber, of which less than one-half represents ammonium soaps at the surface of the particles. The surface of the rubber particles is, therefore, composed largely of protein and fat acids, and it was thought probable that the ratio between them might change, both during the life of a single latex and from one latex to another.

Hydrogen Sulphide Production at Alkaline, Neutral and Acid pH by a Bacterial Consortium Isolated from Peruvian Mine Tailing and Wetland

2013 ◽  
Vol 825 ◽  
pp. 384-387
Author(s):  
Juliet Mormontoy ◽  
Jasmin E. Hurtado
Keyword(s):  
Mixed Culture ◽  
Hydrogen Sulphide ◽  
Mine Tailings ◽  
Bacterial Consortium ◽  
Mixed Cultures ◽  
No Production ◽  
Alkaline Ph ◽  
Dissolved Metals ◽  
Biochemical Tests ◽  
Acid Ph

The gol aim of this study is to optimize the ability to produce hydrogen sulphide (H2S) in pure and mixed cultures of sulfate reducing bacteria (SRB) at pH variations from 9 to 5. Hydrogen sulphide produced by SRB reacts with dissolved metals in water or tailings generating highly insoluble metal sulfides and therefore the selective immobilization of different metals. Three strains of SRB were isolated from Orcopampa mine tailings and from the Pantanos de Villa wetlands, both located in Peru. Cultures were identified by microscopy, cultural characteristics and biochemical tests as production of desulfoviridin and growth in different substrates. The production of H2S by pure and mixed cultures was evaluated at: acid pH (5), neutral pH (7) and alkaline pH (9). The mixed culture consisted of all three isolated species:Desulfobactersp. from mine tailings andDesulfovibrio desulfuricansandDesulfovibrio sapovorans from wetland sludges. Pure cultures of these three strains grew and produced H2S at both neutral or alkaline pH. At low pH no pure culture was able to grow and no production of H2S was detected. A mixed culture formed by the three isolated SRB was the only culture that grew and produced sulphide at the three different pH tested in shorter time (24 hours). The improvement of bacterial activity can be based in the metabolic diversity of the mixed culture able to use lactate and acetate as a result of the joint activity of these species. Energy obtained from the substrate is thus used more efficiently.

scholarly journals Digestibilities of casein and soya-bean protein in relation to their effects on serum cholesterol in rabbits

1985 ◽  
Vol 54 (2) ◽  
pp. 355-366 ◽  
Author(s):  
Christopher J. H. Woodward ◽  
Kenneth K. Carroll
Keyword(s):  
Heat Treatment ◽  
Serum Cholesterol ◽  
Soya Bean ◽  
Pancreatic Enzymes ◽  
Alkaline Ph ◽  
Acid Ph ◽  
Ph Dependent ◽  
Low Solubility ◽  
Bean Protein

1. Diets containing isolated soya-bean protein induce lower levels of serum cholesterol in animals than diets containing casein. Experiments were conducted to investigate whether differences in digestibility of the proteins might explain this effect.2. At pH 8 with pancreatic enzymes or intestinal peptidase, soya-bean protein was hydrolysed in vitro much less rapidly than casein. However, with pepsin (EC3. 4. 23. 1) at acid pH, soya-bean protein was hydrolysed more rapidly than casein.3. These differences in digestibility may be due to pH-dependent changes in solubility of the proteins. Casein and soya-bean protein were most soluble at alkaline and acid pH respectively.4. Heat treatment of the proteins resulted in lower solubilities and digestibilities. Sonication of soya-bean protein at pH 7.8 increased solubility but only slightly raised digestibility.5. When fed to rabbits, enzymically hydrolysed soya-bean protein induced a 2.3-fold higher concentration of serum cholesterol than did intact soya-bean protein. The hypocholesterolaemic effect of soya-bean protein may be partly attributable to its low solubility and digestibility at alkaline pH.

scholarly journals Molecular Basis of pH and Ca2+ Regulation of Aquaporin Water Permeability

2004 ◽  
Vol 123 (5) ◽  
pp. 573-580 ◽  
Author(s):  
Karin L. Németh-Cahalan ◽  
Katalin Kalman ◽  
James E. Hall
Keyword(s):  
Water Permeability ◽  
Xenopus Oocytes ◽  
Ph Regulation ◽  
Ph Dependence ◽  
Ph Sensitivity ◽  
Alkaline Ph ◽  
Acid Ph ◽  
Outer Vestibule ◽  
Calmodulin Mutant ◽  
Aquaporin Family

Aquaporins facilitate the diffusion of water across cell membranes. We previously showed that acid pH or low Ca2+ increase the water permeability of bovine AQP0 expressed in Xenopus oocytes. We now show that external histidines in loops A and C mediate the pH dependence. Furthermore, the position of histidines in different members of the aquaporin family can “tune” the pH sensitivity toward alkaline or acid pH ranges. In bovine AQP0, replacement of His40 in loop A by Cys, while keeping His122 in loop C, shifted the pH sensitivity from acid to alkaline. In the killifish AQP0 homologue, MIPfun, with His at position 39 in loop A, alkaline rather than acid pH increased water permeability. Moving His39 to His40 in MIPfun, to mimic bovine AQP0 loop A, shifted the pH sensitivity back to the acid range. pH regulation was also found in two other members of the aquaporin family. Alkaline pH increased the water permeability of AQP4 that contains His at position 129 in loop C. Acid and alkaline pH sensitivity was induced in AQP1 by adding histidines 48 (in loop A) and 130 (in loop C). We conclude that external histidines in loops A and C that span the outer vestibule contribute to pH sensitivity. In addition, we show that when AQP0 (bovine or killifish) and a crippled calmodulin mutant were coexpressed, Ca2+ sensitivity was lost but pH sensitivity was maintained. These results demonstrate that Ca2+ and pH modulation are separable and arise from processes on opposite sides of the membrane.

scholarly journals Toxicity reduction and biodegradability enhancement of cork processing wastewaters by ozonation

2013 ◽  
Vol 68 (10) ◽  
pp. 2214-2219 ◽  
Author(s):  
A. C. Gomes ◽  
L. Silva ◽  
R. Simões ◽  
N. Canto ◽  
A. Albuquerque
Keyword(s):  
Biological Treatment ◽  
Treatment Options ◽  
Oxygen Demand ◽  
Successful Implementation ◽  
Alkaline Ph ◽  
Acid Ph ◽  
Ozone Dose ◽  
Toxicity Reduction ◽  
High Oxidation ◽  
Pre Treatment

Biodegradability enhancement and detoxification of cork boiling wastewater (CBW) are required for the successful implementation of biological treatment options. We studied the possibility of achieving these goals through ozonation pre-treatment by experimenting on the effect of ozone dose and pH. The CBW used had a pH of 5.81, a chemical oxygen demand (COD) of 1,865 mg L−1, a biochemical oxygen demand (BOD5) of 498 mg L−1 and total phenol (TP) and tannin compounds concentrations of 523 and 399 mg L−1, respectively. The ozone doses ranged from 0.27 to 2.63 for the O3(applied)/COD0 ratios with samples at natural pH and set to 3.33 and 9.96. Ozonation allowed the BOD20/COD ratio (biodegradability index) to increase from 0.37 to 0.63 and a toxicity reduction from 3.08 to 1.24 TU (Microtox). The corresponding removals obtained were 15.2–62.0%, 38.4–83.2% and 56.7–92.1% for COD, TP and colour, respectively. The best outcome of ozonation pre-treatment requires O3(applied)/COD0 ratios over 1.5 and an acid pH. The increase of TP removals with ozone dose at acid pH led to biodegradability enhancement and CBW detoxification. However, for similar conditions the highest COD removals were obtained at alkaline pH due to the hydroxyl radicals’ high oxidation ability but lack of selectivity.

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