Water activity, temperature, and pH effects on growth of Fusarium moniliforme and Fusarium proliferatum isolates from maize

1995 ◽  
Vol 41 (12) ◽  
pp. 1063-1070 ◽  
Author(s):  
Sonia Marin ◽  
Vicente Sanchis ◽  
Naresh Magan
Keyword(s):  
Water Activity ◽  
Fusarium Moniliforme ◽  
Potential Temperature ◽  
Fusarium Proliferatum ◽  
Ph Effects ◽  
Optimum Ph ◽  
Effects Of Ph ◽  
Activity Temperature ◽  
Optimum Ph And Temperature

The effects of water activity (aw, 0.994–0.90 ≡ 0.4–14.0 (–)MPa water potential), temperature (4–45 °C), and pH (3.6, 5.5, 7.0), and their interactions on growth of isolates of Fusarium moniliforme and Fusarium proliferatum were determined in vitro on a maize extract agar medium. Growth of two isolates of F. moniliforme and four isolates of F. proliferatum were significantly influenced by water activity regardless of solute type used (NaCl, glycerol, or glucose). However, at steady-state aw levels, growth was optimum at 0.994–0.98 aw and reduced significantly at 0.92 aw. Further detailed studies with one isolate of F. moniliforme (25N) and two isolates of F. proliferatum (73N, 13 IN) showed that growth occurred over the range of 0.994–0.90 aw in the temperature range 20–35 °C with slight differences between species. Growth did occur at 4 °C and 0.994–0.96 aw, but no growth was recorded at 40 and 45 °C regardless of aw. Profiles of aw × temperature relations for growth of these two species were constructed from these data for the first time. Optimum pH and temperature for growth was 5.5 and 25 °C for both isolates of F. proliferatum, and pH 7.0 and 30 °C for the isolate of F. moniliforme. However, for the latter isolate at <0.98 aw, optimum pH and temperature for growth changed. The effects of pH, temperature, and aw for single, two-way and three-way interactions were all found to be statistically significant for these three isolates. The ecological significance of this information for understanding these important fumonisin-producing fungi is discussed.Key words: water activity, temperature, fumonisin-producing, Fusarium moniliforme, Fusarium proliferatum, maize.

Water and temperature relations and microconidial germination of Fusarium moniliforme and Fusarium proliferatum from maize

1996 ◽  
Vol 42 (10) ◽  
pp. 1045-1050 ◽  
Author(s):  
Sonia Marín ◽  
V. Sanchis ◽  
A. Teixido ◽  
R. Saenz ◽  
A. J. Ramos ◽  
...  
Keyword(s):  
Water Activity ◽  
Fusarium Moniliforme ◽  
Potential Temperature ◽  
Gompertz Model ◽  
Linear Increase ◽  
Fusarium Proliferatum ◽  
Activity Temperature ◽  
Lag Times ◽  
Lag Phases

The effects of water activity (aw, 0.994–0.85 = 0.4–21.0 (−)MPa water potential), temperature (5–42 °C), and their interactions on microconidial germination of three isolates each of Fusarium moniliforme and Fusarium proliferatum were determined in vitro on a maize meal extract medium. Temporal germination rates of microconidia of isolates of both species were significantly influenced by both aw and temperature. Germination was very rapid at >0.94 aw with an almost linear increase with time. Germination rates of microconidia of F. moniliforme were slower than those of F. proliferatum isolates at marginal aw levels and 5–25 °C, while at higher temperature (30–37 °C), the former germinated more rapidly than the latter. The aw minima for germination of isolates of both species was 0.88, with none occurring at 0.85 aw over a 40-day incubation period. At 37 °C, isolates of F. moniliforme had slightly lower aw minima than those of F. proliferatum. The narrowest range of aw for germination was at 5 °C, and none occurred at 42 °C. The effect of aw × temperature interactions on the lag phases (h) prior to germination and the germination rates (h−1) were estimated using the Gompertz model and the Zwietering equation. This showed that lag phases were shorter at 25–30 °C and 0.994–0.98 aw, and were increased to 10–500 h at marginal temperatures (5–10 °C) for F. proliferatum and longer for F. moniliforme. At marginal aw levels (0.92–0.90), lag times were increased to >250 h. Germination rates (h−1) were different for the two species. Microconidia of F. moniliforme germinated optimally at 25–37 °C and 0.96–0.98 aw, but this changed to 30 °C at 0.90–0.94 aw, while germination of microconidia of F. proliferatum remained optimum at 30 °C, regardless of aw. There were statistically significant (P < 0.01) effects of aw, temperature, isolate, and two- and three-way interactions for F. proliferatum, but there were no intraisolate effects for F. moniliforme. The ecological significance of these data for understanding colonization patterns of these important fumonisin-producing fungi are discussed.Key words: water activity, temperature, germination, fumonisin producing, Fusarium spp.

Water activity, temperature, and pH effects on growth of the biocontrol agentPantoea agglomeransCPA-2

2002 ◽  
Vol 48 (12) ◽  
pp. 1082-1088 ◽  
Author(s):  
E Costa ◽  
J Usall ◽  
N Teixidó ◽  
J Delgado ◽  
I Viñas
Keyword(s):  
Water Activity ◽  
Bacterial Growth ◽  
Biocontrol Agent ◽  
Great Influence ◽  
Ph Effects ◽  
Sucrose Medium ◽  
Activity Temperature ◽  
Ph Conditions ◽  
Yeast Extract Sucrose

The growth response of the biocontrol agent Pantoea agglomerans to changes in water activity (aw), temperature, and pH was determined in vitro in nutrient yeast extract-sucrose medium. The minimum temperature at which P. agglomerans was able to grow was 267–272 kelvins (–6 to –1°C), and growth of P. agglomerans did not change at varying pH levels (4.5–8.6). The minimum awfor growth was 0.96 in media modified with glycerol and 0.95 in media modified with NaCl or glucose. Solute used to reduce water activity had a great influence on bacterial growth, especially at unfavourable conditions (e.g., low pH or temperature). NaCl stimulated bacterial growth under optimum temperatures but inhibited it under unfavourable pH conditions (4.5 or 8.6). In contrast, the presence of glucose in the medium allowed P. agglomerans to grow over a broad range of temperature (3–42°C) or pH (5–8.6) regimes. This study has defined the range of environmental conditions (aw, pH, and temperature) over which the bacteria may be developed for biological control of postharvest diseases.Key words: biocontrol, ecophysiology response, stress.

scholarly journals Investigation of Optimum pH and Temperature for In-Vitro Crystallization of Urinary Cystine

2019 ◽  
Vol 6 (1) ◽  
pp. 25
Author(s):  
A. D. U. R. Gunawardana ◽  
K. N. L. Amarasingha ◽  
A. M. B. Priyadarshani
Keyword(s):  
Optimum Ph ◽  
Optimum Ph And Temperature

Biodegradation of Direct Red 28 and Direct Yellow 12 by a Novel Bacterial Consortium

2014 ◽  
Vol 651-653 ◽  
pp. 215-219
Author(s):  
Ling Yu Zhu ◽  
Xue Hui Xie ◽  
Na Liu ◽  
Hong Jiang ◽  
Fang Yang ◽  
...  
Keyword(s):  
Bacterial Consortium ◽  
Complete Degradation ◽  
Ms Analysis ◽  
Optimum Ph ◽  
Effects Of Ph ◽  
Direct Red 28 ◽  
Optimum Ph And Temperature

Studies were carried out on the decolorization of Direct Red 28 (DR) and Direct Yellow 12 (DY) by developed bacterial consortium. Effects of pH, temperature, and NaCl concentrations on degradation were studied. GC-MS was used to detect the intermediates produced in the effluents of anaerobic step. The optimum pH and temperature for the degradation of DR and DY were pH 7 and 6, and 37°Cand 45°C, respectively. We observed the peak of benzenamine in GC-MS analysis. The products formed during the reduction of DY12 were benzenamine and 2-Amino-1-hydroxybenzene. The results showed a complete degradation of DY12 by the bacterial consortium.

Effect of pH and inhibitors on beta-amyloid fibril assembly

1996 ◽  
Vol 54 ◽  
pp. 752-753
Author(s):  
Beverly E. Maleeff ◽  
Timothy K. Hart ◽  
Stephen J. Wood ◽  
Ronald Wetzel
Keyword(s):  
Amyloid Fibril ◽  
Peptide Fragment ◽  
Hydrophobic Peptides ◽  
Amyloid Fibril Formation ◽  
Effects Of Ph ◽  
Severity Of The Disease ◽  
Kinetics Of ◽  
The Brain

Alzheimer's disease is characterized post-mortem in part by abnormal extracellular neuritic plaques found in brain tissue. There appears to be a correlation between the severity of Alzheimer's dementia in vivo and the number of plaques found in particular areas of the brain. These plaques are known to be the deposition sites of fibrils of the protein β-amyloid. It is thought that if the assembly of these plaques could be inhibited, the severity of the disease would be decreased. The peptide fragment Aβ, a precursor of the p-amyloid protein, has a 40 amino acid sequence, and has been shown to be toxic to neuronal cells in culture after an aging process of several days. This toxicity corresponds to the kinetics of in vitro amyloid fibril formation. In this study, we report the biochemical and ultrastructural effects of pH and the inhibitory agent hexadecyl-N-methylpiperidinium (HMP) bromide, one of a class of ionic micellar detergents known to be capable of solubilizing hydrophobic peptides, on the in vitro assembly of the peptide fragment Aβ.

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

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.

scholarly journals A Novel In Vitro Model for Determining the Optimum pH and Dose Volume of New Liquid Alginate for Infant Reflux Suppression

Drugs in R&D ◽  
2021 ◽  
Author(s):  
Jeanine Fisher ◽  
Fiona McLaughlin ◽  
Neil Fawkes ◽  
Hannah Tipple ◽  
Cathal Coyle ◽  
...  
Keyword(s):  
In Vitro Model ◽  
Dose Volume ◽  
Optimum Ph ◽  
Vitro Model

Influence of water activity and temperature on growth and fumonisin production by Fusarium proliferatum strains on irradiated wheat grains

2018 ◽  
Vol 266 ◽  
pp. 158-166 ◽  
Author(s):  
Eugenia Cendoya ◽  
María del Pilar Monge ◽  
Stella Maris Chiacchiera ◽  
María Cecilia Farnochi ◽  
María Laura Ramirez
Keyword(s):  
Water Activity ◽  
Fusarium Proliferatum ◽  
Wheat Grains ◽  
Influence Of Water
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