scholarly journals The Effect of Incubation Temperature, Substrate and Initial pH Value on Plantaricin Activity and the Relative Transcription of pln Genes of Six Sourdough Derived Lactiplantibacillus plantarum Strains

Fermentation ◽  
2021 ◽  
Vol 7 (4) ◽  
pp. 320
Author(s):  
Maria K. Syrokou ◽  
Panagiota Stasinopoulou ◽  
Spiros Paramithiotis ◽  
Loulouda Bosnea ◽  
Marios Mataragas ◽  
...  
Keyword(s):  
Incubation Temperature ◽  
Ph Value ◽  
Marginal Effect ◽  
Growth Substrate ◽  
Weak Correlation ◽  
Transcriptomic Response ◽  
Time Points ◽  
Ph Values ◽  
Initial Ph ◽  
Strain Dependent

The aim of the present study was to assess the effect of sourdough related parameters on the growth and plantaricin activity of six Lactiplantibacillus plantarum strains against a mixture of 5 Listeria monocytogenes strains and to analyze the transcriptomic response of their pln genes. Parameters included 3 substrates (MRS broth, mMRS broth, WFE), 3 temperatures (20, 30, 37 °C), 2 initial pH values (5.0, 6.0), 2 NaCl concentrations (0.0, 1.8%) and 12 time points (ranging from 0 to 33 h). The transcriptomic response of the plantaricin genes to the aforementioned parameters was assessed after 21 h of growth. In general, plantaricin activity was strain dependent with that of Lp. plantarum strains LQC 2422, 2441, 2485 and 2516, harboring four pln genes, namely, pln423 (plαΑ), plαΒ, plαC and plαD, reaching 2560 AU/mL. However, strains LQC 2320 and 2520, in which 18 pln genes were detected, namely, plNC8a, plNC8b, plNC8c, plnL, plnR, plnJ, plnK, plnE, plnF, plnH, plnS, plnY, plNC8-IF, plNC8-HK, plnD, plnI, plnM and plnG, exhibited plantaricin activity barely reaching 160 AU/mL. Substrate, temperature, initial pH value and strains significantly affected plantaricin activity, while NaCl had only a marginal effect. Similarly, growth substrate and temperature had a more pronounced effect than initial pH value on gene transcription. A strong correlation between the transcription of the genes belonging to the same locus was observed; however, only a weak correlation, if any, was observed between plantaricin activity and the transcription of the genes assessed.

Study on the Factors and Degradation of Cellulose Degradation Bacteria

2013 ◽  
Vol 864-867 ◽  
pp. 40-43
Author(s):  
Song Liu
Keyword(s):  
Filter Paper ◽  
Loss Rate ◽  
Incubation Temperature ◽  
Ph Value ◽  
Cellulose Degradation ◽  
Weight Loss Rate ◽  
High Efficient ◽  
Initial Ph ◽  
Congo Red Staining ◽  
Single Factor Experiment

This study obtained 12 microbial degradation of cellulose from perennial accumulation of cellulose waste soil, through Congo red staining, isolated high efficient bacteria N4 degradation of cellulose. The N4 strain degradation single factor experiment showed that: carbon concentration, incubation temperature and initial pH value influence on the degradation of filter paper. Through the orthogonal experimental study obtained: when the concentration of filter paper is 0.5%, culture temperature is 30 °C, initial pH is 8, N4 strain filter paper degradation rate reached optimal, filter paper weight loss rate of 68.92%.

Growth and Aflatoxin Production by Aspergillus parasiticus NRRL 2999 in the Presence of Lactic Acid and at Different Initial pH values

1987 ◽  
Vol 50 (11) ◽  
pp. 940-944 ◽  
Author(s):  
FATHY E. EL-GAZZAR ◽  
GULAM RUSUL ◽  
ELMER H. MARTH
Keyword(s):  
Lactic Acid ◽  
Aflatoxin B1 ◽  
High Performance ◽  
Aspergillus Parasiticus ◽  
Ph Value ◽  
Aflatoxin Production ◽  
Reversed Phase ◽  
Ph Values ◽  
Initial Ph ◽  
Medium Weight

Twenty-five milliliters of glucose-yeast-salts medium containing 0, 0.5, 0.75, 1.0, 1.5 and 2.0% lactic acid with an initial pH of 3.5 or 4.5 were inoculated with 1 ml of a spore suspension containing 106 conidia of Aspergillus parasiticus NRRL 2999 and incubated at 28°C for 10 d. The pH of the medium, weight of mycelium and aflatoxin production were determined after 3, 7, and 10 d of incubation. Amounts of aflatoxin produced were determined using reversed-phase high-performance liquid chromatography. Cultures grown in the presence of 0.5 and 0.75% lactic acid at an initial pH of 4.5 produced more aflatoxin B1 than did the other cultures at the end of 3 d of incubation. This was not true for aflatoxin G1; with increasing concentrations of lactic acid, cultures produced decreasing amounts of aflatoxin G1. Also, cultures growing in the medium with an initial pH of 3.5 produced more aflatoxin B1 in the presence of lactic acid at the end of 3 d of incubation than did control cultures. Cultures growing in the presence of 0.5 and 0.75% lactic acid produced the most aflatoxin. Maximum amounts of aflatoxin G1 were produced after 7 d of incubation, with cultures growing in the presence of 0.5 and 0.75% lactic acid producing the most. Lactic acid did not inhibit growth (mycelium weight) of cultures in the medium with initial pH values of 3.5 or 4.5 except there was a slight decrease in mycelial weight when the medium contained 0.5% lactic acid and had an initial pH value of 3.5.

scholarly journals Characterizing the impact of MnO2 addition on the efficiency of Fe0/H2O systems

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Viet Cao ◽  
Ghinwa Alyoussef ◽  
Nadège Gatcha-Bandjun ◽  
Willis Gwenzi ◽  
Chicgoua Noubactep
Keyword(s):  
Ph Value ◽  
Iron Corrosion ◽  
Dissolved Iron ◽  
Ph Values ◽  
Solid Iron ◽  
Initial Ph ◽  
Fixation Capacity ◽  
Co Precipitation ◽  
The Impact

AbstractThe role of manganese dioxide (MnO2) in the process of water treatment using metallic iron (Fe0/H2O) was investigated in quiescent batch experiments for t ≤ 60 d. MnO2 was used as an agent to control the availability of solid iron corrosion products (FeCPs) while methylene blue (MB) was an indicator of reactivity. The investigated systems were: (1) Fe0, (2) MnO2, (3) sand, (4) Fe0/sand, (5) Fe0/MnO2, and (6) Fe0/sand/MnO2. The experiments were performed in test tubes each containing 22.0 mL of MB (10 mg L−1) and the solid aggregates. The initial pH value was 8.2. Each system was characterized for the final concentration of H+, Fe, and MB. Results show no detectable level of dissolved iron after 47 days. Final pH values varied from 7.4 to 9.8. The MB discoloration efficiency varies from 40 to 80% as the MnO2 loading increases from 2.3 to 45 g L−1. MB discoloration is only quantitative when the operational fixation capacity of MnO2 for Fe2+ was exhausted. This corresponds to the event where adsorption and co-precipitation with FeCPs is intensive. Adsorption and co-precipitation are thus the fundamental mechanisms of decontamination in Fe0/H2O systems. Hybrid Fe0/MnO2 systems are potential candidates for the design of more sustainable Fe0 filters.

scholarly journals The Proliferation Rule of Microcystis Aeruginosa Under Different Initial pH Conditions and its Influence on the pH Value of the Environment

2021 ◽  
Author(s):  
Sijie Wei ◽  
Guanjie Zhuang ◽  
Lirijian Cheng ◽  
Shoubing Wang
Keyword(s):  
Microcystis Aeruginosa ◽  
Ph Value ◽  
Control Strategies ◽  
Scientific Basis ◽  
Cyanobacterial Blooms ◽  
Ph Values ◽  
Inoculation Density ◽  
Initial Ph ◽  
Ph Conditions ◽  
Optimal Ph

Abstract This study investigated the characteristics of the proliferation process of Microcystis aeruginosa and its changes to environmental pH values under different initial pH values and different initial inoculation densities. The results showed that although the initial pH value or the initial inoculation density was different, the pH values of the culture systems fluctuated up and down throughout the proliferation of M. aeruginosa, both on a daily and hourly time scale, and then tended to stabilize around the same value of 10.0 at the end of proliferation. The optimal pH value for the proliferation of M. aeruginosa was 9.56. This study creatively proposes that the period when the environmental pH value starts to rise rapidly toward 9.0 could be selected as an early warning period for a cyanobacterial outbreak, and the environmental pH value could be adjusted to below 8.0 to delay the outbreak. These results provide a scientific basis for further understanding the mechanism of cyanobacterial blooms and formulating pH-based control strategies.

Manganese waste water treatment by fungi derived from manganese slag

2010 ◽  
Vol 62 (5) ◽  
pp. 1183-1189
Author(s):  
Yu-Zhu Ou-yang ◽  
Jian-Bing Cao ◽  
Xiao-Ming Li ◽  
Wei Zheng ◽  
Dong-Bo Wang ◽  
...  
Keyword(s):  
Waste Water ◽  
Water Treatment ◽  
Incubation Temperature ◽  
Rotation Speed ◽  
Ph Value ◽  
Water Solution ◽  
Waste Water Treatment ◽  
High Adsorption ◽  
Initial Ph ◽  
Manganese Slag

The aim of this study was to isolate a mould from the surface of manganese slag which had strong resistance and high adsorption of Mn2 + , and to determine the effects of initial Mn2 +  concentration, incubation temperature, rotation speed and inoculation amount on adsorption of Mn2 +  from manganese waste water solution. The result showed that a mould (A5) which was isolated from manganese slag had the adsorption rate of Mn2 +  to 97.5% at the initial pH value 6, inoculation amount 2%, rotation speed 150 r/min, a concentration of Mn2 +  500 mg/L, and a temperature of 28°C cultivated for 50 h. As there is no research on adsorption of Mn2 +  from manganese waste water by fungi before, this research showed a theoretical guidance on this field.

Adsorption of As (v) from Water by Activated Aluminum Oxide

2012 ◽  
Vol 476-478 ◽  
pp. 1965-1968
Author(s):  
Da Lei Zhang ◽  
Fan Qiao ◽  
Mou Lv ◽  
Ying Jie Sun ◽  
Qing Yuan Guo
Keyword(s):  
Aluminum Oxide ◽  
Adsorption Equilibrium ◽  
Ph Value ◽  
Adsorption Properties ◽  
Operating Conditions ◽  
Optimum Operating ◽  
Ph Values ◽  
Initial Ph ◽  
Langmuir Isotherm Model ◽  
Activated Aluminum Oxide

In this paper the adsorption properties of activated aluminum oxide (AAO ) to As(V) were researched. The effect of operating factors such as pH, contact time and initial As(V) concentration was investigated and the optimum operating conditions were established. Experimental results indicated that the optimal pH value adsorption of As(V)by activated aluminum oxide was from 4 to 6, and the optimum initial pH values was 5.5.The adsorption equilibrium was achieved within 5h.The adsorption capacity for As(V)increased with increasing concentration and the adsorption date was well fit by the Langmuir isotherm model. It is believed that activated aluminum oxide (AAO) is environmentally acceptable and industrially application for utilization in arsenic-containing wastewater treatment.

scholarly journals Changes in the composition and properties of biochar after one-year application

2020 ◽  
Vol 217 ◽  
pp. 10009
Author(s):  
Marya Bovsun ◽  
Оlga Nesterova ◽  
Viktoriia Semal ◽  
Аlexandra Khokhlova ◽  
Nikolay Sakara
Keyword(s):  
Volatile Compounds ◽  
Water Retention ◽  
Ph Value ◽  
Water Retention Capacity ◽  
Retention Capacity ◽  
Noticeable Change ◽  
Growing Period ◽  
Ph Values ◽  
Initial Ph ◽  
One Year

The study examines the change in the properties of biochar obtained from Betula alba tree residues after its application in a field growing experiment for two growing periods in the areas with different water-air conditions (both with and without drainage). The results obtained after the first growing period showed a noticeable change in the indicators. The pH values in the biochar sample after the first growing period decreased sharply by 1.3 and 0.7 units in the areas with and without drainage, respectively, compared to the initial pH value of 8.09. After the second growing period, the change in pH value was not significant. The values of ash elements increased sharply, the content of volatile compounds decreased slightly. Water retention capacity improved. After the first growing period, water retention capacity almost doubled and it changed slightly in the sample with the biochar after its application in the second growing period.

Growth and Aflatoxin Production by Aspergillus parasiticus NRRL 2999 in the Presence of Potassium Benzoate or Potassium Sorbate and at Different Initial pH Values

1987 ◽  
Vol 50 (10) ◽  
pp. 820-825 ◽  
Author(s):  
GULAM RUSUL ◽  
ELMER H. MARTH
Keyword(s):  
High Performance ◽  
Aspergillus Parasiticus ◽  
Ph Value ◽  
Aflatoxin Production ◽  
Reversed Phase ◽  
Potassium Sorbate ◽  
Lag Phase ◽  
Ph Values ◽  
Initial Ph ◽  
Potassium Benzoate

Experiments were done to determine how different concentrations of potassium benzoate or potassium sorbate in a glucose-yeast extract-salts medium with an initial pH value of 3.5, 4.5 or 5.5 affected growth and aflatoxin production by Aspergillus parasiticus NRRL 2999. The pH of the medium, weight of mycelium and amount of aflatoxin produced were determined after 3 and 7 d of incubation. Aflatoxin was determined using reversed-phase high-performance liquid chromatography. Maximum concentrations of potassium sorbate and potassium benzoate that permitted growth were 0.2% and 0.4%, respectively, in a medium with an initial pH of 5.5. When the initial pH was 4.5, the maximum concentrations of potassium sorbate and potassium benzoate that permitted growth were 0.05% and 0.10%, respectively, but there was an extended lag phase. Increasing concentrations of potassium benzoate or potassium sorbate decreased amounts of aflatoxin B1 and G1 produced after 3 d in a medium with initial pH values of 5.5 or 4.5. Cultures growing in the medium containing 0.1, 0.15 or 0.20% potassium benzoate or potassium sorbate and with an initial pH of 5.5 were somewhat inhibited at 3 d of incubation, which was characterized by a slow decrease in pH, low mycelium dry weight and small amounts of accumulated aflatoxins. After 7 d these cultures overcame the initial inhibition and produced substantial amounts of aflatoxins and mycelium. This was also true for cultures growing in a medium with an initial pH of 4.5 and containing potassium benzoate or potassium sorbate. By decreasing the initial pH of the medium from 5.5 to 4.5, amounts of potassium benzoate or potassium sorbate required to achieve inhibition decreased by a factor of 10.

scholarly journals Hydrothermal Synthesis of Various Shape-Controlled Europium Hydroxides

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 529
Author(s):  
Hongjuan Zheng ◽  
Kongjun Zhu ◽  
Ayumu Onda ◽  
Kazumichi Yanagisawa
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Ph Value ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Hydrothermal Reactions ◽  
Starting Solution ◽  
Initial Ph ◽  
Shape Controlled ◽  
Scanning Electron

Eu(OH)3 with various shape-controlled morphologies and size, such as plate, rod, tube, prism and nanoparticles was successfully synthesized through simple hydrothermal reactions. The products were characterized by XRD (X-Ray Powder Diffraction), FE-SEM (Field Emission- Scanning Electron Microscopy) and TG (Thermogravimetry). The influence of the initial pH value of the starting solution and reaction temperature on the crystalline phase and morphology of the hydrothermal products was investigated. A possible formation process to control morphologies and size of europium products by changing the hydrothermal temperature and initial pH value of the starting solution was proposed.

scholarly journals Bonding of Selected Hardwoods with PVAc Adhesive

2020 ◽  
Vol 11 (1) ◽  
pp. 67
Author(s):  
Ján Iždinský ◽  
Ladislav Reinprecht ◽  
Ján Sedliačik ◽  
Jozef Kúdela ◽  
Viera Kučerová
Keyword(s):  
Adhesion Strength ◽  
Cold Water ◽  
Ph Value ◽  
Water Extract ◽  
Solid Wood ◽  
Contact Angles ◽  
Water Contact ◽  
Ph Values ◽  
Positive Tendency ◽  
The Impact

The bonding of wood with assembly adhesives is crucial for manufacturing wood composites, such as solid wood panels, glulam, furniture parts, and sport and musical instruments. This work investigates 13 hardwoods—bangkirai, beech, black locust, bubinga, ipé, iroko, maçaranduba, meranti, oak, palisander, sapelli, wengé and zebrano—and analyzes the impact of their selected structural and physical characteristics (e.g., the density, cold water extract, pH value, roughness, and wettability) on the adhesion strength with the polyvinyl acetate (PVAc) adhesive Multibond SK8. The adhesion strength of the bonded hardwoods, determined by the standard EN 205, ranged in the dry state from 9.5 MPa to 17.2 MPa, from 0.6 MPa to 2.6 MPa in the wet state, and from 8.5 MPa to 19.2 MPa in the reconditioned state. The adhesion strength in the dry state of the bonded hardwoods was not influenced by their cold water extracts, pH values, or roughness parallel with the grain. On the contrary, the adhesion strength was significantly with positive tendency influenced by their higher densities, lower roughness parameters perpendicular to the grain, and lower water contact angles.

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