In vitro evaluation of the safety and probiotic and technological potential of Pediococcus pentosaceus isolated from sheep milk

Six isolates (Ac1Pd, Ac3Pd, Ac4Pd, Ac5Pd, Ac7Pd, and Ac22Pd) of Pediococcus pentosaceus from sheep milk were tested for safety and for probiotic and technological potential. The results showed that none of the isolates were able to produce biogenic amines or virulence factors. The isolates tested showed low hydrophobicities, high auto-aggregation capacities and co-aggregation with L. monocytogenes ATCC 7644, L. sakei ATCC 15521 and E. faecalis ATCC 19444, but none produced ?-galactosidase and bacteriocins. The isolates did not show growth at pH values 3 and 12, while in a pH range from 4 to 10 the growth was variable. In the absence of bile, all the isolates showed growth, with suppression at bile concentrations of 0.1%, 0.3%, 0.6% and 1.0%. In the disc-diffusion test, the isolates tested were resistant to oxacillin, sulfatrimethoprim and vancomycin but were sensitive to chloramphenicol and tetracycline. The isolates showed variable responses to penicillin G and were resistant to most of the drugs tested, except for amoxicillin trihydrate and ibuprofen. All cultures showed a high milk-acidification capacity after 24 hours and none produced exopolysaccharides. The isolates of P. pentosaceus were able to produce diacetyl; however, no culture showed extracellular proteolytic activity and the autolysis varied from 21.3% to 30.5% after 24 h. The isolates grew at NaCl concentrations of 4.0 and 6.0%, but the growth was lower at 10.0%. Finally, all the isolates were found to be safe but had limited application as probiotics and in some technological uses.

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Survival of Bacillus cereus Vegetative Cells and Spores during In Vitro Simulation of Gastric Passage

Journal of Food Protection ◽

10.4315/0362-028x.jfp-11-481 ◽

2012 ◽

Vol 75 (4) ◽

pp. 690-694 ◽

Cited By ~ 22

Author(s):

SIELE CEUPPENS ◽

MIEKE UYTTENDAELE ◽

KATRIEN DRIESKENS ◽

ANDREJA RAJKOVIC ◽

NICO BOON ◽

...

Keyword(s):

Bacillus Cereus ◽

Acid Resistance ◽

In Vitro Experiments ◽

Vegetative Cells ◽

Ph Values ◽

Constant Ph ◽

In Vitro Simulation ◽

Ph Range

The enteric pathogen Bacillus cereus must survive gastric passage in order to cause diarrhea by enterotoxin production in the small intestine. The acid resistance and the survival after gastric passage were assessed by in vitro experiments with acidified growth medium and gastric simulation medium with B. cereus NVH 1230-88 vegetative cells and spores. First, batch incubations at constant pH values for 4 h, which represented different physiological states of the stomach, showed that spores were resistant to any gastric condition in the pH range of 2.0 to 5.0, while vegetative cells were rapidly inactivated at pH values of ≤4.0. Second, a dynamic in vitro gastric experiment was conducted that simulated the continuously changing in vivo conditions due to digestion dynamics by gradually decreasing the pH from 5.0 to 2.0 and fractional emptying of the stomach 30 to 180 min from the start of the experiment. All of the B. cereus spores and 14% (±9%) of the vegetative cells survived the dynamic simulation of gastric passage.

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Long-term in vitro transformation of 2-line ferrihydrite to goethite/hematite at 4, 10, 15 and 25°C

Clay Minerals ◽

10.1180/0009855043940145 ◽

2004 ◽

Vol 39 (4) ◽

pp. 433-438 ◽

Cited By ~ 88

Author(s):

U. Schwertmann ◽

H. Stanjek ◽

H.-H. Becher

Keyword(s):

Zero Point ◽

Transformation Rate ◽

Ambient Temperatures ◽

Ph Values ◽

In Vitro Transformation ◽

Zero Point Of Charge ◽

Ph Range ◽

Increasing Temperature

Abstract2-line ferrihydrite stored in water at ambient temperatures from 4 to 25°C and at ten different pH values between 2.5 and 12 for up to 10–12 y transformed to both goethite and hematite at all temperatures and pH values except at pH 12 where only goethite was formed. The rate and degree of transformation (20–100%) increased with increasing pH and temperature. The hematite/ (hematite+goethite) ratio varied between 0 and ~0.8, increased with increasing temperature and showed a strong maximum at pH 7–8 which increased from 0.1–0.2 at 4°C to 0.7–0.8 at 25°C. The maximum coincides with the zero point of charge of ferrihydrite where its solubility and, thus, its via-solution transformation rate to goethite are minimal. We assume, therefore, that in this pH-range the (slower) via-solution transformation to hematite can more efficiently compete with that to goethite.

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Toxicity and Resistance Potential of Selected Fungicides to Galactomyces and Penicillium spp. Causing Postharvest Fruit Decays of Citrus and Other Crops

Plant Disease ◽

10.1094/pdis-06-11-0466 ◽

2012 ◽

Vol 96 (1) ◽

pp. 87-96 ◽

Cited By ~ 10

Author(s):

A. H. McKay ◽

H. Förster ◽

J. E. Adaskaveg

Keyword(s):

Mycelial Growth ◽

Single Spore ◽

Ph Values ◽

Highly Active ◽

Green Mold ◽

Dmi Fungicides ◽

Ph Range ◽

Penicillium Spp ◽

Twofold Decrease

A diverse collection of isolates of Galactomyces citri-aurantii and G. geotrichum, the causal pathogens of sour rots of citrus and other fruit crops, respectively, was evaluated for sensitivity to demethylation-inhibiting (DMI) fungicides of the triazole group. Propiconazole was found to be highly effective in reducing mycelial growth of both species in vitro. For 139 isolates of G. citri-aurantii, a mean effective concentration for 50% reduction of mycelial growth (EC50 value) of 0.34 μg/ml was determined; whereas, for 33 isolates of G. geotrichum, this value was 0.14 μg/ml. In a comparison of additional DMI fungicides, mean EC50 values for 60 isolates of G. citri-aurantii and 20 isolates of G. geotrichum, were 0.27 and 0.17 μg/ml for cyproconazole, 0.25 and 0.14 μg/ml for metconazole, and 1.16 and 0.73 μg/ml for tebuconazole, respectively. Propiconazole was also highly active against mycelial growth of imazalil-sensitive isolates of Penicillium digitatum, the pathogen that causes green mold of citrus, with a mean EC50 value of 0.008 μg/ml for 63 isolates. Imazalil-resistant isolates of this fungus were cross-resistant to propiconazole. When G. citri-aurantii and P. digitatum were grown at selected pH values between 3 and 9, inhibition by propiconazole occurred over the entire pH range. The fungicide was most effective at pH 5 when compared with the non-fungicide-amended control grown at the same pH. In laboratory mass platings of single-spore isolates sensitive to propiconazole onto selective media, isolates with an up to 81.6-fold decrease in sensitivity to the fungicide were recovered for P. digitatum. For G. geotrichum, isolates with an approximately twofold decrease in sensitivity were obtained. No isolates with reduced sensitivity were recovered for G. citri-aurantii. Propiconazole is currently being registered for postharvest use on citrus and other crops, and the information provided will be valuable in monitoring of fungicide resistance and in designing effective fungicide application strategies.

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In Vitro Interaction between Venous Blood Clots and Radiopharmaceuticals

Nuklearmedizin ◽

10.1055/s-0038-1624299 ◽

1985 ◽

Vol 24 (04) ◽

pp. 173-179 ◽

Cited By ~ 1

Author(s):

B. R. R. Persson ◽

V. Kempi

Keyword(s):

Room Temperature ◽

Venous Blood ◽

Gel Chromatography ◽

Time Intervals ◽

Ph Values ◽

Blood Clots ◽

Glass Tubes ◽

Ph Range ◽

In Vitro Interaction

SummaryClots of 1 ml venous blood formed in glass tubes after 10 min at room temperature were incubated at 37° C with the radiopharmaceutical to be studied. Methods for quality control of the radiopharmaceuticals were compared. Gel chromatography scanning was found to give reliable information. The incorporation into the clot was studie’d at different pH values and after various time intervals. The highest incorporation was found for 125I-fibrinogen and for 99mTc-mac-roaggregates of albumin, followed by 99mTc-sulphur colloid and 99mTc-strep-tokinase at pH less than 2. The titrated initial dose of 99mTc-streptoki-nase was studied at various pH levels. The lysing effect was less in the pH range 1-2.5, where the best labeling yield was obtained. The inactivation of streptokinase by the labeling procedure was also studied with im-munoelectrophoresis and decomposition of casein. In vitro studies of the interaction of radiopharmaceuticals with clots add information for the clinical use of radiopharmaceuticals for thrombus localization.

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Influence of Selected Restorative Materials on the Environmental pH: In Vitro Comparative Study

Applied Sciences ◽

10.3390/app112411975 ◽

2021 ◽

Vol 11 (24) ◽

pp. 11975

Author(s):

Anna Lehmann ◽

Kacper Nijakowski ◽

Michalina Nowakowska ◽

Patryk Woś ◽

Maria Misiaszek ◽

...

Keyword(s):

Dental Caries ◽

Glass Ionomer Cements ◽

Glass Ionomer ◽

Bacterial Colonisation ◽

Ph Values ◽

Caries Treatment ◽

Restorative Materials ◽

Initial Ph ◽

Ph Range

In dental caries treatment, it is worth using such restorative materials that may limit plaque accumulation. The pH of the filling seems to be an important factor affecting the potential bacterial colonisation. Our study aimed to assess how selected restorative materials influence the environmental pH. A total of 150 specimens (30 of each: Ketac Molar, Riva LC, Riva SC, Filtek Bulk Fill, and Evetric) were placed in 100 sterile hermetic polyethene containers with saline and stored in 37 °C. The pH of each sample was measured using the electrode Halo HI13302 (Hanna Instruments, Poland) at specific points in time for 15 days. The initial pH levels were significantly lower for glass ionomer cements (3.9–4.7) compared to composites (5.9–6.0). With time, the pH increased for samples with glass ionomer cements (by nearly 1.5), whereas it decreased for samples with composites (maximally by 0.8). In the end, all materials were in the pH range between 5.3 and 6.0. The highest final pH was obtained with Ketac Molar at about 5.9. Double samples had lower pH values than single samples, irrespective of the type of material. In conclusion, immediately after application, restorative materials decreased the environmental pH, especially light-cured glass ionomer cements. For glass ionomers, within two weeks, the pH increased to levels comparable with composites.

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Effects of incubation fluid pH and fibrolytic enzymes on the in vitro fermentation of pure substrates, assessed using the Reading Pressure Technique (RPT)

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200008644 ◽

2002 ◽

Vol 2002 ◽

pp. 208-208 ◽

Cited By ~ 1

Author(s):

D. Colombatto ◽

F. L. Mould ◽

M. K. Bhat ◽

E. Owen

Keyword(s):

In Vitro Fermentation ◽

Commercial Enzyme ◽

Fibrolytic Enzymes ◽

Optimum Activity ◽

Ph Values ◽

Optimum Ph ◽

Ph Conditions ◽

Ph Range ◽

Optimum Ph Range

Modern feeding practices often lead to ruminal conditions being sub-optimal for fibre digestion. It has been speculated that fibrolytic enzymes, which usually show optimum activity at pH values below 6.0, may be of benefit when applied to diets of high producing animals. This study used a commercial enzyme mixture (EM), already identified as effective; to investigate its optimum pH range with respect to activity and its impact on the fermentation profiles of pure substrates, under differing pH conditions.

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Influence of Potassium and pH on the PG-mediated Hydrolysis of Pectin in Tomato Fruit Cell Wall

HortScience ◽

10.21273/hortsci.32.3.478c ◽

1997 ◽

Vol 32 (3) ◽

pp. 478C-478

Author(s):

Jong-Pil Chun ◽

Donald J. Huber

Keyword(s):

Cell Wall ◽

Tomato Fruit ◽

In Vitro Assays ◽

Ph Values ◽

Ph Range ◽

Hydrolysis Of ◽

Ionic Effects ◽

Catalytic Capacity

The catalytic capacity of tomato polygalacturonase (PG) toward soluble pectic polymers is in excess of activity expressed in vivo; however, in vitro assays of PG have traditionally been performed under conditions (pH 4.0 to 4.5, 150 mM NaCl) that likely do not reflect the apoplastic environment of ripening tomato fruit. In this study, hydrolysis of pectin by purified tomato PG (isozyme 2) was examined in response to K+ (the predominate apoplastic cation) and over the pH range from 3.0 to 6.0. In the presence of K+, PG activity toward polygalacturonic acid measured reductometrically increased nearly 3.5-fold from pH 4.0 to pH 5.5. In the presence of Na+, activity decreased 90% over the same pH range. PG-mediated degradation of cell wall from mature-green fruit showed divergent hydrolytic patterns in response to pH and K+. At pH 4.5 in the presence of K+ (as KCl), catalysis resulted in both solubilization and extensive depolymerization of cell wall pectin, with oligomers accounting for a significant portion of the hydrolysis products. At pH 5.5, the total quantity of wall pectin released in response to PG2 was similar to that at pH 4.5; however, oligomer production was strongly suppressed at the higher pH. At pH values favoring extensive depolymerization, low mol mass products were produced at 5 mM K+ and increased to a maximum at 100 mM K+. At higher pH, hydrolysis patterns were not affected by [K+]. pH and ionic effects may contribute to the distinctive patterns of pectin hydrolysis observed for different fruits.

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The Malachite Green Biodegradation in Bioreactors on Various pH Domains

Revista de Chimie ◽

10.37358/rc.19.8.7472 ◽

2019 ◽

Vol 70 (8) ◽

pp. 2996-2999

Author(s):

Viorel Gheorghe ◽

Catalina Gabriela Gheorghe ◽

Andreea Bondarev ◽

Vasile Matei ◽

Mihaela Bombos

Keyword(s):

Malachite Green ◽

Contact Time ◽

Dominant Species ◽

Wastewater Treatment Plants ◽

Organic Substances ◽

Biological Degradation ◽

Growth Promoters ◽

Ph Values ◽

Biological Sludge ◽

Ph Range

In the experimental study was studied the malachite green colorant biodegradation in biological sludge with biological activity. The biodegradability tests were carried out in laboratory bioreactors, on aqueous solutions of green malachite contacted with microorganisms in which the dominant species is Paramecium caudatum, in a pH range between 8 and 12, temperatures in the ranges 25-350C, using pH neutralizing substances and biomass growth promoters. The colorant initial concentrations and those obtained after biological degradation depending on the contact time, at certain pH values, were established through UV-Vis spectrometry. The studies have shown the measure of possible biological degradation of some organic substances with extended uses, with largely aromatic structure, resistance to biodegradation of microorganisms, commonly used in wastewater treatment plants.

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Pharmacokinetic Drug-drug Interaction of Antibiotics Used in Sepsis Care in China

Current Drug Metabolism ◽

10.2174/1389200221666200929115117 ◽

2020 ◽

Vol 21 ◽

Author(s):

Xuan Yu ◽

Zixuan Chu ◽

Jian Li ◽

Rongrong He ◽

Yaya Wang ◽

...

Keyword(s):

Drug Interaction ◽

Drug Interactions ◽

Penicillin G ◽

Literature Mining ◽

Human Pharmacokinetics ◽

P450 Enzyme ◽

Drug Drug Interaction ◽

Pharmacokinetic Drug ◽

Sepsis Care

Background: Many antibiotics have a high potential for having an interaction with drugs, as perpetrator and/or victim, in critically ill patients, and particularly in sepsis patients. Methods: The aim of this review is to summarize the pharmacokinetic drug-drug interaction (DDI) of 45 antibiotics commonly used in sepsis care in China. Literature mining was conducted to obtain human pharmacokinetics/dispositions of the antibiotics, their interactions with drug metabolizing enzymes or transporters, and their associated clinical drug interactions. Potential DDI is indicated by a DDI index > 0.1 for inhibition or a treated-cell/untreated-cell ratio of enzyme activity being > 2 for induction. Results: The literature-mined information on human pharmacokinetics of the identified antibiotics and their potential drug interactions is summarized. Conclusion: Antibiotic-perpetrated drug interactions, involving P450 enzyme inhibition, have been reported for four lipophilic antibacterials (ciprofloxacin, erythromycin, trimethoprim, and trimethoprim-sulfamethoxazole) and three lipophilic antifungals (fluconazole, itraconazole, and voriconazole). In addition, seven hydrophilic antibacterials (ceftriaxone, cefamandole, piperacillin, penicillin G, amikacin, metronidazole, and linezolid) inhibit drug transporters in vitro. Despite no reported clinical PK drug interactions with the transporters, caution is advised in the use of these antibacterials. Eight hydrophilic antibacterials (all β-lactams; meropenem, cefotaxime, cefazolin, piperacillin, ticarcillin, penicillin G, ampicillin, and flucloxacillin), are potential victims of drug interactions due to transporter inhibition. Rifampin is reported to perpetrate drug interactions by inducing CYP3A or inhibiting OATP1B; it is also reported to be a victim of drug interactions, due to the dual inhibition of CYP3A4 and OATP1B by indinavir. In addition, three antifungals (caspofungin, itraconazole, and voriconazole) are reported to be victims of drug interactions because of P450 enzyme induction. Reports for other antibiotics acting as victims in drug interactions are scarce.

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Trans-sialidase Associated with Atherosclerosis: Defining the Identity of a Key Enzyme Involved in the Pathology

Current Drug Targets ◽

10.2174/1389450120666190308111619 ◽

2019 ◽

Vol 20 (9) ◽

pp. 938-941

Author(s):

Victor Y. Glanz ◽

Veronika A. Myasoedova ◽

Andrey V. Grechko ◽

Alexander N. Orekhov

Keyword(s):

Acid Metabolism ◽

Research Subject ◽

Disease Pathogenesis ◽

Sialidase Activity ◽

Ph Values ◽

Ldl Particles ◽

Optimum Ph ◽

Key Enzyme ◽

St6gal I

Atherosclerosis is associated with the increased trans-sialidase activity, which can be detected in the blood plasma of atherosclerosis patients. The likely involvement in the disease pathogenesis made this activity an interesting research subject and the enzyme that may perform such activity was isolated and characterized in terms of substrate specificity and enzymatic properties. It was found that the enzyme has distinct optimum pH values, and its activity was enhanced by the presence of Ca2+ ions. Most importantly, the enzyme was able to cause atherogenic modification of lowdensity lipoprotein (LDL) particles in vitro. However, the identity of the discovered enzyme remained to be defined. Currently, sialyltransferases, mainly ST6Gal I, are regarded as major contributors to sialic acid metabolism in human blood. In this mini-review, we discuss the possibility that atherosclerosis- associated trans-sialidase does, in fact, belong to the sialyltransferases family.

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