The relationship between a coiled morphology and Mbl in alkaliphilic Bacillus halodurans C-125 at neutral pH values

Respiring rat heart mitochondria were loaded with Ca2+ and then treated with Ruthenium Red. The factors affecting the subsequent Ca2+-efflux were studied. Addition of rotenone or antimycin led to a decline of efflux except at pH values above 7.2, provided the load was less than about 80 nmol per mg of protein. Oligomycin reversed the effect of the respiratory inhibitors. Independently of respiration, efflux was stimulated by the uncoupler trifluoromethyltetrachlorbenzimadazole, by mersalyl and by thyroid hormones. The stimulated efflux could be diminished by ADP, with Mg2+ as cofactor if efflux was rapid. With respiration in progress, efflux could be stimulated by N-ethylmaleimide and 5,5′-dithiobis-(2-nitrobenzoate). The effects of mersalyl and of thyroid hormones could be diminished with dithiothreitol. In the absence of stimulating agents, the Ca2+ efflux was proportional to the load up to some critical amount, this critical amount was decreased by the agents. Thyroxine and mersalyl caused not only loss of Ca2+, but also simultaneous, but not necessarily proportional, loss of internal adenine nucleotides. Both efflux rates were kept at a low value by bongkrekic acid added before the stimulating agent. It is concluded that Ca2+ efflux is a measure of a permeability controlled by the binding of ADP (an Mg2+) to the inner membrane, and that this in turn depends on the maintenance of certain thiol gropus in a reduced form by a reaction that uses NADH and ATP and the energy-linked transhydrogenase.

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Characterization and comparative study of the rrn operons of alkaliphilic Bacillus halodurans C-125

Extremophiles ◽

10.1007/pl00010713 ◽

2000 ◽

Vol 4 (4) ◽

pp. 209-214 ◽

Cited By ~ 9

Author(s):

K. Nakasone ◽

Noriaki Masui ◽

Yoshihiro Takaki ◽

Rumie Sasaki ◽

G. Maeno ◽

...

Keyword(s):

Comparative Study ◽

Bacillus Halodurans ◽

Alkaliphilic Bacillus ◽

Rrn Operons

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pH Variability and its Relationship with Sarcomere Length and Free Calcium in Beef from Commercial Cattle in Puerto Rico

Meat and Muscle Biology ◽

10.22175/mmb.10684 ◽

2019 ◽

Vol 3 (2) ◽

Author(s):

Y. I. Torres-Burgos ◽

H. Sánchez-Rodríguez ◽

M. Pagán-Morales ◽

A. Casas-Guernica ◽

C. Calkins ◽

...

Keyword(s):

Puerto Rico ◽

Beef Cattle ◽

Dairy Cattle ◽

Calcium Concentration ◽

Sarcomere Length ◽

Free Calcium ◽

Ph Values ◽

And Gender ◽

The University ◽

The Relationship

ObjectivesResearch conducted at the University of Puerto Rico noted that beef with elevated pH values (> 5.86) resulted in more tender meat (P ≤ 0.05). It has been established that proteolytic degradation mechanisms can be influenced by pH and calcium concentration in muscle. Beef with pH values ≥ 5.86 is classified as Dark Firm and Dry (DFD) but there are negative implications associated with greater pH values. However, observations indicating increased tenderness with increased pH raise the question: can variations in pH be associated with differences in sarcomere length (SL) and free calcium concentration (FCC)? Therefore, the objectives of this project were to: (1) document pH distribution; (2) determine the incidence of DFD; and (3) evaluate the relationship between pH, SL, and FCC in commercial cattle harvested in Puerto Rico.Materials and MethodsLongissimus lumborum samples (n = 51) were obtained and background information was noted including number of permanent incisors (PI), type (Dairy or Beef), and gender. The pH values were used to categorize beef into the following groups: Low (≤ 5.40), Normal (5.41 to 5.59), High (5.60 to 5.85) and DFD (≥ 5.86). Meat was flash frozen, powdered, and placed on a microscope slide and a Helium-Neon laser was used to determine SL. A subset of samples was sent off and prepared at the University of Nebraska-Lincoln for FCC quantification (Ward Laboratories; Kearney, NE) with an inductively coupled plasma emission spectrometer (iCAP 6500 Radial; Thermo Electron, Cambridge, UK). All statistical analyses were conducted in SAS (9.4). The Proc FREQ was used to determine pH category distributions and incidence of DFD. The Proc GLIMMIX and Tukey adjustment (α = 0.05) were used to determine the effects of number of PI, type, and gender on pH category, SL and FCC. The Proc CORR was used to evaluate the relationship between pH category, SL and FCC.ResultsThe pH category distribution for the current samples was as follows: 3.92% Low, 41.18% Normal, 35.29% High and 19.61% DFD. The SL ranged from 1.69 to 1.46 mm with an average of 1.53 mm. The FCC ranged from 132.19 to 31.39 mM with an average of 64.23 mM. Longer sarcomeres were detected in cattle with eight and zero PI (1.57 and 1.56 mm, respectively); cattle with two and four PI had intermediate SL (1.53 and 1.52 mm, respectively), and cattle with six PI had the shortest sarcomeres (1.51 mm; P = 0.03). Dairy cattle had longer sarcomeres relative to beef cattle (1.56 vs. 1.52 mm; P = 0.02). Dairy cattle tended to have increased FCC relative to beef cattle (70.72 vs. 58.38 mM; P = 0.08). Also, FCC tended to be greater within the Normal and Low pH categories relative to the High and DFD categories (72.36 vs. 57.31 mM; P = 0.06). The SL and FCC had no relationship (P > 0.05) within the Low, Normal and High pH categories. However, DFD beef had longer SL (0.78; P = 0.01), while having decreased FCC (–0.66; P = 0.04).ConclusionOver half (54.90%) of the beef samples analyzed fell into the High and DFD pH categories, with nearly 20% being classified as DFD. Although, a clear relationship was not established between SL and FCC within the Low, Normal or High pH categories, the results indicate that the increased pH in samples surpassing the DFD threshold correspond to longer sarcomeres and decreased free calcium.

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Inactivation of tyrosine aminotransferase in neutral homogenates and rat liver slices

Biochemical Journal ◽

10.1042/bj1291131 ◽

1972 ◽

Vol 129 (5) ◽

pp. 1131-1138 ◽

Cited By ~ 20

Author(s):

F. Auricchio ◽

L. Mollica ◽

A. Liguori

Keyword(s):

Amino Acid ◽

Rat Liver ◽

Acid Concentration ◽

Tyrosine Aminotransferase ◽

Amino Acid Concentration ◽

Acidic Ph ◽

Ph Values ◽

Neutral Ph ◽

Liver Slices

Inactivation of tyrosine aminotransferase induced in vivo by triamcinolone was studied in a homogenate incubated at neutral pH values. The integrity and the presence of subcellular particles together with a compartment of acidic pH are necessary for inactivation of tyrosine aminotransferase. It is suggested that tyrosine aminotransferase is inactivated inside lysosomes. The system responsible for inactivation of tyrosine aminotransferase was partially purified and identified with lysosomal cathepsins B and B1. Inactivation of tyrosine aminotransferase in liver slices is controlled by the amino acid concentration and strongly stimulated by cysteine. 3,3′,5-Tri-iodo-l-thyronine reversibly and strongly decreases the rate of inactivation of tyrosine aminotransferase. The effect is not due to an increased rate of tyrosine aminotransferase synthesis.

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The Role of Electrochemical Conditions in Near-Neutral pH SCC Initiation Mechanism(s)

2010 8th International Pipeline Conference, Volume 1 ◽

10.1115/ipc2010-31190 ◽

2010 ◽

Author(s):

Abdoulmajid Eslami ◽

Mohammadhassan Marvasti ◽

Weixing Chen ◽

Reg Eadie ◽

Richard Kania ◽

...

Keyword(s):

Cathodic Protection ◽

Pipeline Steel ◽

Synergistic Effects ◽

Co2 Concentration ◽

Initiation Mechanism ◽

Ph Values ◽

Neutral Ph ◽

Comprehensive Test ◽

Disbonded Coating

In order to improve our understanding of near-neutral pH SCC initiation mechanism(s), a comprehensive test setup was used to study the electrochemical conditions beneath the disbonded coatings in cracking environments. In this setup the synergistic effects of cyclic loading, coating disbondment, and cathodic protection were considered. Our previous results showed that there can be a significant variation in the pH of the localized environment under the disbonded coating of pipeline steel. The pH inside the disbondment can change significantly from near-neutral to high pH values, strongly depending on the level of cathodic protection and CO2 concentration. Both of these variables affected the electrochemical conditions on the steel surface and therefore the initiation mechanisms. This work highlights the role of electrochemical conditions in near-neutral pH SCC initiation mechanisms.

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Factors Affecting Lead Leaching from Microwavable Plastic Ware Made with Lead-Containing Pigments

Journal of Food Protection ◽

10.4315/0362-028x-65.7.1166 ◽

2002 ◽

Vol 65 (7) ◽

pp. 1166-1171 ◽

Cited By ~ 2

Author(s):

D. INTHORN ◽

O. LERTSUPOCHAVANICH ◽

S. SILAPANUNTAKUL ◽

D. SUJIRARAT ◽

B. INTARAPRASONG

Keyword(s):

Public Health ◽

Acetic Acid ◽

Extraction Time ◽

Prolonged Heating ◽

Factors Affecting ◽

Ph Values ◽

Lead Leaching ◽

Decreasing Ph ◽

The Relationship ◽

Made In

Although food contact polymers do not normally contain lead, it is suspected that lead may be leached from some microwavable plastic ware items made in Thailand with lead-containing pigments. The purpose of this study was to examine relationships with regard to lead leached from microwavable plastic ware. Four factors were studied: pH, heat level, extraction time, and number of repeated extractions. A total of 243 samples of microwavable plastic ware items locally manufactured in Thailand were used. This study used three pH values (3.5, 4.5, and 6.5) and three heat levels (levels 3, 6, and 9 [170, 500, and 850 W, respectively]). Acetic acid was used both as the extracting agent and for adjusting the pH. Samples were collected at each level at 1, 3, and 5 min, and the amount of leached lead was measured with an atomic adsorption spectrometer. The results of this study show that pH, heat, and extraction time affected the amount of lead leaching from microwavable plastic ware. The amount of lead leaching increased with decreasing pH but increased with increasing heat level and extraction time. On the basis of these three factors, the results of this study indicate that the pH of the extractant (r = −0.592, P < 0.01), the heat level of extraction (r = 0.293, P < 0.01), the extraction time (r = 0.226, P < 0.01), and the number of extractions (r = −0.153, P < 0.01) are related to lead leaching from microwavable plastic ware. The relationship between the pH of the extractant, the heat level of extraction, and the extraction time significantly moderated lead leaching from microwavable plastic ware (R2 = 0.511, P < 0.001). For all factors, the amount of lead leaching was lower than the permissible level of 1 mg/liter specified by the Minister of Public Health. In conclusion, a combination of high acid, prolonged heating, and extraction time accelerated the amount of lead leaching from microwavable plastic ware, but the incidence of lead leaching was negligible.

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Studies on the relationship of saliva to rumen function of sheep on low feed intakes

Australian Journal of Agricultural Research ◽

10.1071/ar9620907 ◽

1962 ◽

Vol 13 (5) ◽

pp. 907 ◽

Cited By ~ 11

Author(s):

WR McManus

Keyword(s):

Volatile Fatty Acid ◽

Ph Values ◽

In Vivo Experiments ◽

Rumen Ph ◽

Conscious Sheep ◽

Mixed Saliva ◽

Relationship Of ◽

The Relationship ◽

Standard Ration

Seven in vivo experiments are reported in which the effects of diverting alkaline mixed saliva from the actively fermenting contents of the rumen of anaesthetized and conscious sheep fed on a standard ration were studied for periods up to 6 hr. The absence of various quantities of saliva (225–1349 ml) was associated with profound alterations in the rumen environment: rumen liquor volatile fatty acid (V.F.A.) levels were consistently and substantially elevated, and rumen pH levels depressed. These changes in the rumen environment began about 40–60 min after saliva diversion commenced, and were sustained long after such values for the control animals had inflected towards fasting levels. Rumen movements were recorded in two experiments. Rumen movement was reduced, but not entirely suppressed, some 60 min after the minimal pH values obtained. It is suggested that this reduction in rumen movement was a consequence of depressed pH values. The rumen pH-rumen V.F.A. relationship was, in six such cases, altered but the strength of this relationship was not significantly changed. It was concluded that these effects on rumen pH-V.F.A. levels and relationship were due, directly or indirectly, to the changed buffering or osmotic regime, or both, of the saliva-depleted rumen liquor. Implications of these findings are discussed in the light of rumen physiology and the field use of oesophageally fistulated sheep.

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Multiple α-mannosidase activities in mammalian tissues as shown by metal-ion activation

Biochemical Journal ◽

10.1042/bj1630557 ◽

1977 ◽

Vol 163 (3) ◽

pp. 557-564 ◽

Cited By ~ 7

Author(s):

S M Snaith

Keyword(s):

Metal Ions ◽

Metal Ion ◽

Active Enzyme ◽

Thiol Groups ◽

Ion Activation ◽

Ph Values ◽

Neutral Ph ◽

Mammalian Tissues ◽

Different Types ◽

Metal Ion Activation

1. Four different types of alpha-mannosidase activity were shown to occur in several tissues from the rat. There is the Zn2+-dependent enzyme, active at acidic pH, and three enzymes that are active near to neutral pH. 2. The ‘neutral’ enzymes are activated by Fe2+, Co2+ or Mn2+. 3. Optimum activities for these three enzymes are shown at pH values of 5.2, 6.5 and 7.3. The activity at pH6.5 is the only one evident without metal-ion activation, but activity is enhanced by all three metal ions. The activity at pH 5.2 is seen only in the presence of Fe2+ or Co2+, and the activity at pH7.3 is seen only in the presence of Co2+ or Mn2+ and in a non-chelating buffer medium. 4. The pH6.5-active enzyme is inactivated by EDTA, but activity is restored by excess of metal ion. 5. The enzymes differ markedly in their stability. The pH6.5-active enzyme is very labile and the pH7.3-active enzyme is the most stable. 6. Tissue preparations vary widely in their activity at pH6.5, but where activity is low it can be increased by incubation with one of the activating metal cations. 7. All the enzymes active at neutral pH are inhibited by heavy-metal ions and stabilized to some extent by thiol groups.

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THE EFFECT OF CELLULOSE ADDITIONS AND MOISTURE LEVEL ON MYCOFLORA OF SOIL

Canadian Journal of Microbiology ◽

10.1139/m63-071 ◽

1963 ◽

Vol 9 (4) ◽

pp. 555-561 ◽

Cited By ~ 5

Author(s):

Zofia Maciejowska ◽

E. B. Williams

Keyword(s):

Water Holding Capacity ◽

Moisture Level ◽

High Moisture ◽

Fungus Flora ◽

Amended Soils ◽

Cellulose Decomposition ◽

Ph Values ◽

Neutral Ph ◽

Major Factors ◽

Water Holding

The fungus flora developing in cellulose-amended and non-amended soils of neutral pH at moisture levels of 60, 70, and 80% water-holding capacity (WHC) was investigated. A distinct, successive development of three species, Staphylotrichum coccosporum, Coccospora agricola, and Sependonium sp., was observed in soil held at 60% WHC. More species developed in soil held at 70% WHC, and they could effectively coexist during cellulose decomposition. S. coccosporum developed in smaller numbers at 80% WHC than at 60 and 70% WHC. Sepedonium sp. was associated with cellulose decomposition only at 80% WHC. Species of Trichoderma, Monilia, and Fusarium developed better at high moisture levels. It was concluded that available inoculum and the moisture of soils of similar pH values are major factors in determining composition of the microflora of cellulose-amended soil.

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