Combined Effects of pH and Temperature on Listeriolysin O Production by Listeria monocytogenes SLCC 5764

1996 ◽  
Vol 59 (10) ◽  
pp. 1076-1078 ◽  
Author(s):  
LISA S. SCHILLING ◽  
SCOTT E. MARTIN
Keyword(s):  
Acetic Acid ◽  
Listeria Monocytogenes ◽  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Combined Effects ◽  
Listeriolysin O ◽  
Effects Of Ph ◽  
Acidic Conditions ◽  
Effects Of Temperature

Listeria monocytogenes SLCC 5764 was propagated at 4, 25, or 37°C in tryptic soy broth (TSB) acidified with either acetic acid at pH 5.2, 5.7, or 7.0, or hydrochloric acid at pH 5.0, 5.7, or 7.0; or made alkaline with sodium hydroxide at pH 7.5, 8.5, or 9.5. These studies were undertaken to determine the combined effects of temperature and pH on the production of listeriolysin O (LLO). The LLO activity was greatest after the cells were propagated in TSB acidified by either acid to pH 7.0 at 37°C. Very little LLO activity was detected for cells propagated at 4° under acidic conditions. There were no significant differences found between the LLO produced in media acidified with either acid. The LLO activity was highest after the cells were propagated in media at pH 7.5 at 37°C.

Phospholipase C Production of Listeria monocytogenes SLCC 5764 Cultured with Various Salt Concentrations, pHs, and Temperatures

1996 ◽  
Vol 59 (5) ◽  
pp. 472-475
Author(s):  
LISA S. SCHILLING ◽  
LINDA M. MILO ◽  
SCOTT E. MARTIN
Keyword(s):  
Acetic Acid ◽  
Listeria Monocytogenes ◽  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Phospholipase C ◽  
Growth Temperature ◽  
Alkaline Media ◽  
Growth Environment

Listeria monocytogenes SLCC 5764 was propagated at 4, 25, or 37°C in tryptic soy broth (TSB) containing 428, 787, or 1,112 mM NaCl; or adjusted with either acetic acid to pH 5.2, 5.7, or 7.0 or hydrochloric acid to pH 5.0, 5.7, or 7.0; or made alkaline with sodium hydroxide to pH 7.5, 8.5, or 9.5, to determine the effects on the production of phospholipase C (PLC). Altering the growth environment caused alterations in PLC production. The PLC activity was highest after cells were propagated in TSB containing 428 mM NaCl at each growth temperature. Little PLC activity was detected at 4 or 25°C in media with the lowest and highest salt concentrations. Similarly, little PLC activity was detected at 4 or 37°C at each pH from cells grown in media adjusted with either acid. The PLC activity was greater after the cells were grown in media adjusted with either acid at pH 7.0 at 25°C. For growth in alkaline media, the PLC activity was highest after the cells were propagated in media at pH 7.5 at each growth temperature.

Effect of pH, Acidulant, Time, and Temperature on the Growth and Survival of Listeria monocytogenes

1989 ◽  
Vol 52 (8) ◽  
pp. 571-573 ◽  
Author(s):  
KENT M. SORRELLS ◽  
DAVIN C. ENIGL ◽  
JOHN R. HATFIELD
Keyword(s):  
Antimicrobial Activity ◽  
Acetic Acid ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Citric Acid ◽  
Hydrochloric Acid ◽  
Malic Acid ◽  
Incubation Temperature ◽  
Growth And Survival ◽  
Ph Values

The effect of different acids, pH, incubation time, and incubation temperature on the growth and survival of four strains of Listeria monocytogenes in tryptic soy broth was compared. Hydrochloric acid (HCl), acetic acid (AA), lactic acid (LA), malic acid (MA), and citric acid (CA) were used to acidify tryptic soy broth to pH values 4.4, 4.6, 4.8, 5.0, and 5.2 pH. Incubation times were 1, 3, 7, 14, and 28 d at 10, 25, and 35°C. The inhibition of L. monocytogenes in the presence of high acidity appears to be a function of acid and incubation temperature. Based on equal pH values, the antimicrobial activity is AA > LA > CA ≥ MA > HCl at all incubation times and temperatures. When based on equal molar concentration, the activity appeared to be CA ≥ MA > LA ≥ AA > HCl at 35 and 25°C, and MA > CA > AA ≥ LA > HCl at 10°C. Greatest antimicrobial activity occurred at 35°C. Greatest survival occurred at 10°C and greatest growth occurred at 25°C. Final pH of the medium was as low as 3.8 in HCl at 28 d. All strains grew well at pH values lower than the minimum previously reported (5.5–5.6).

Organic sulfur compounds. VII. Some reactions of benzothiazine hydroxamic acids

1970 ◽  
Vol 48 (23) ◽  
pp. 3727-3732 ◽  
Author(s):  
R. T. Coutts ◽  
Sharon J. Matthias ◽  
E. Mah ◽  
N. J. Pound
Keyword(s):  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Unsaturated Acid ◽  
Hydroxamic Acids ◽  
Sulfur Compounds ◽  
The Other ◽  
Complex Reaction ◽  
Organic Sulfur Compounds ◽  
Derivatives Of

Treatment of (3,4-dihydro-4-hydroxy-3-oxo-2H-1,4-benzothiazin-2-yl)acetic acid (1a) with sodium hydroxide yields the corresponding lactam, i.e. (3,4-dihydro-3-oxo-2H-1,4-benzothiazin-2-yl)acetic acid, together with the α,β-unsaturated acid, 3,4-dihydro-3-oxo-2H-1,4-benzothiazine-Δ2,α-acetic acid. The 6-methyl- and 6-bromo-derivatives of 1a behaved similarly when reacted with sodium hydroxide but when 3,4-dihydro-4-hydroxy-3-oxo-2H-1,4-benzothiazine was so treated a more complex reaction occurred.Methyl (6-bromo-3,4-dihydro-4-hydroxy-3-oxo-2H-1,4-benzothiazin-2-yl)acetate was also treated with hydrochloric acid. The two products isolated were (6-bromo-3,4-dihydro-3-oxo-2H-1,4-benzothiazin-2-yl)acetic acid and (6-bromo-7-chloro-3,4-dihydro-3-oxo-2H-1,4-benzothiazin-2-yl)acetic acid.The action of hydrochloric acid on 3,4-dihydro-4-hydroxy-7-methyl-3-oxo-2H-1,4-benzothiazine also gave two products. One was the corresponding lactam; the other was unexpected and has been tentatively identified as bis[2-(3,4-dihydro-7-methyl-3-oxo-2H-1,4-benzothiazine].

scholarly journals Study of protein extraction from residues of tambatinga amazon fish

2020 ◽  
Vol 42 ◽  
pp. e10
Author(s):  
Sumária Sousa e Silva ◽  
Danieli Alini Pettenon ◽  
José Wilson Pires Carvalho ◽  
Sumaya Ferreira Guedes ◽  
Raquel Aparecida Loss
Keyword(s):  
Acetic Acid ◽  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Protein Extraction ◽  
Physicochemical Characterization ◽  
Waste Utilization ◽  
Moisture Determination ◽  
Forced Circulation ◽  
Fish Waste ◽  
Powder Samples

The present work aimed to extract proteins from tambatinga fish residue with physicochemical characterization, a hybrid of the crossing between the female tambaqui (Colossoma macropomum) and the male pirapitinga (Piaractus brachypomus). Protein extraction was performed by the following methods: acid (hydrochloric acid, acetic acid) and basic (sodium hydroxide). The protein fraction was characterized in relation to moisture content, ash, protein and yield. The moisture determination was performed with powder samples, submitted to drying at 40 ° C, in a forced circulation oven, which presented values of 7.29; 11.42 and 3.14% respectively. Regarding the fixed mineral residue (ash), the samples differed from each other, with values between 81.52; 50.65 and 44.76%. The samples obtained by the different processes presented protein contents of 3.63; 9.36 and 39.55% respectively. And the yield of protein extraction was 8.96; 3.64 and 6.43% for hydrochloric acid, acetic acid and sodium hydroxide, respectively. The obtained results indicate that it is possible to perform protein extraction for fish waste utilization, mainly by the basic extraction method.

Catalase, Superoxide Dismutase and Listeriolysin O Production by Listeria monocytogenes in Broth Containing Acetic and Hydrochloric Acids

1994 ◽  
Vol 57 (7) ◽  
pp. 626-628 ◽  
Author(s):  
LISA K. DIMMIG ◽  
ERIC R. MYERS ◽  
SCOTT E. MARTIN
Keyword(s):  
Superoxide Dismutase ◽  
Listeria Monocytogenes ◽  
Hydrochloric Acid ◽  
Enzyme Production ◽  
Growth Media ◽  
Listeriolysin O ◽  
Weak Acids ◽  
Sod Activity ◽  
Strong Acids

Cells of Listeria monocytogenes 10403S were propagated at 37°C in media acidified with either acetic or hydrochloric acid to determine the effect on the production of catalase (CA), superoxide dismutase (SOD) and listeriolysin O (LLO). The CA and LLO activities decreased while SOD activity increased as the pH of the growth media was decreased. Comparison of the acids indicated that neither acid caused significant differences in enzyme production except for SOD activity at pH 5.7. These results suggest that growth of L. monocytogenes in acid environments may influence the production of these enzymes, while growth in strong acids versus weak acids may not be significantly different.

Effects of Temperature on the Conductivity of Microemulsions:  Influence of Sodium Hydroxide and Hydrochloric Acid

1999 ◽  
Vol 44 (4) ◽  
pp. 846-849 ◽  
Author(s):  
E. Alvarez ◽  
L. García-Río ◽  
J. C. Mejuto ◽  
J. M. Navaza ◽  
J. Pérez-Juste
Keyword(s):  
Hydrochloric Acid ◽  
Sodium Hydroxide ◽  
Effects Of Temperature

Wet-Etching Characteristics of SiCN Films Deposited by HWCVD Method

2012 ◽  
Vol 81 ◽  
pp. 34-38
Author(s):  
H. Nakanishi ◽  
T. Ogata ◽  
Y. Kadotani ◽  
Akira Izumi
Keyword(s):  
Acetic Acid ◽  
Sulfuric Acid ◽  
Sodium Chloride ◽  
Hydrochloric Acid ◽  
Phosphoric Acid ◽  
Sodium Hydroxide ◽  
Potassium Hydroxide ◽  
Wet Etching ◽  
Chemical Agents ◽  
Acid Etch

We investigated the wet-etching properties of SiCN films using chemical agents. Our results show that sodium hydroxide, potassium hydroxide and phosphoric acid etch SiCN films, while hydrochloric acid, sulfuric acid, acetic acid, ammonium chloride and sodium chloride cannot etch SiCN films.

Use of Double-Gradient Plates To Study Combined Effects of Salt, pH, Monolaurin, and Temperature on Listeria monocytogenes†

1996 ◽  
Vol 59 (6) ◽  
pp. 601-607 ◽  
Author(s):  
M. FARID A. BAL'A ◽  
DOUGLAS L. MARSHALL
Keyword(s):  
Listeria Monocytogenes ◽  
Salt Tolerance ◽  
Incubation Temperature ◽  
Combined Effects ◽  
Initial Inoculum ◽  
Neutral Ph ◽  
Gradient Diffusion ◽  
Diffusion Technique ◽  
Effects Of Ph ◽  
Ph Range

This study evaluated the combined effects of pH, NaCl, incubation temperature, and sublethal concentrations of monolaurin on the survival of Listeria monocytogenes using the double-gradient diffusion technique. L. monocytogenes tolerance to NaCl was greatest (>78 g/liter) at neutral pH (6.8 to 7.2) and increased in the pH range 7.0 to 5.4 as the incubation temperature was lowered. Monolaurin at 2 μg/ml lowered the salt tolerance of L. monocytogenes to 60 g/liter independently of pH. At 4 μg of monolaurin per ml, salt tolerance was reduced to approximately 40 g/liter with no growth occurring at pH 6.0 to 5.4 and 25 g of NaCl per liter. At 8 μg of monolaurin per ml, only a subpopulation of the initial inoculum tolerated 25 g of NaCl per liter at neutral pH (6.5 to 7.5). Monolaurin reduced the tolerance of L. monocytogenes to NaCl and low pH.

Differentiation of the Effects of pH and Lactic or Acetic Acid Concentration on the Kinetics of Listeria Monocytogenes Inactivation

1993 ◽  
Vol 56 (6) ◽  
pp. 474-478 ◽  
Author(s):  
R. L. BUCHANAN ◽  
M. H. GOLDEN ◽  
R. C. WHITING
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Acid Concentration ◽  
Brain Heart Infusion ◽  
Acetic Acid Concentration ◽  
Effects Of Ph ◽  
Lag Period ◽  
D Values ◽  
Acetic Acids

The effects of pH and lactic acid or acetic acid concentration on Listeria monocytogenes inactivation were studied in brain heart infusion broth using a three strain mixture. Combinations of lactic acid/sodium lactate and acetic acid/sodium acetate were used to achieve concentrations of 0.1, 0.5, 1.0, and 2,0 M in conjunction with pH values of 4.0, 5.0, 6.0, and 7.0. Cultures adjusted with HCl to pH 3.0 to 7.0 in 0.5 pH unit intervals were used as 0.0 M controls. Each pH/concentration combination was inoculated to a level of 108 CFU/ml and incubated at 28°C for up to 60 d. Bacterial populations were determined periodically by plate counts. Inactivation was exponential after an initial lag period. Survivor curves (log# versus time) were fitted using a linear model that incorporated a lag period. The model was subsequently used to calculate D values and “time to a 4-D (99.99%) inactivation” (t4-D); t4-D values were directly related to pH and inversely related to acid concentration. At acid/pH combinations that supported growth, the level of the organism increased slightly (2- to 10-fold) before declining. In the HCl-adjusted controls with pH's ≤5.5, the rate of inactivation was linearly related to pH. In the presence of the monocarboxylic acids, the duration of the lag period and the rate of inactivation were dependent on the pH, as well as the identity and concentration of acid. 4-D inactivation times were related to the level of undissociated lactic and acetic acids. That relationship was described by the equations, t4-D = exp (−0.1773*LA0.5 + 7.3482) and t4-D = exp (−0.1468*AA0.5 + 7.3905) for lactic and acetic acids, respectively, where LA and AA are mM of undissociated acid. These relationships were used in conjunction with the Henderson-Hasselback equation to develop a model for predicting the rate of inactivation as a function of pH and total organic acid concentration.

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