On the mechanism of action of maltase of the mould Aspergillus niger I. The effect of temperature on the activation of starch hydrolysis by mould preparations

1957 ◽  
Vol 22 (1) ◽  
pp. 291-298 ◽  
Author(s):  
M. Burger ◽  
K. Beran
Keyword(s):  
Aspergillus Niger ◽  
Mechanism Of Action ◽  
Starch Hydrolysis ◽  
Effect Of Temperature

Growth Modeling of Aspergillus niger Strains Isolated from Citrus Fruit as a Function of Temperature on a Synthetic Medium from Lime (Citrus latifolia T.) Pericarp

2017 ◽  
Vol 80 (7) ◽  
pp. 1090-1098 ◽  
Author(s):  
T. Sandoval-Contreras ◽  
S. Marín ◽  
A. Villarruel-López ◽  
A. Gschaedler ◽  
L. Garrido-Sánchez ◽  
...  
Keyword(s):  
Growth Rate ◽  
Aspergillus Niger ◽  
Phase 1 ◽  
Synthetic Medium ◽  
External Validation ◽  
Citrus Fruit ◽  
Effect Of Temperature ◽  
Lag Phase ◽  
Citrus Fruits ◽  
Appearance Time

ABSTRACT Molds are responsible for postharvest spoilage of citrus fruits. The objective of this study was to evaluate the effect of temperature on growth rate and the time to visible growth of Aspergillus niger strains isolated from citrus fruits. The growth of these strains was studied on agar lime medium (AL) at different temperatures, and growth rate was estimated using the Baranyi and Roberts model (Int. J. Food Microbiol. 23:277–294, 1994). The Rosso et al. cardinal model with inflexion (L. Rosso, J. R. Lobry, S. Bajard, and J. P. Flandrois, J. Theor. Biol. 162:447–463, 1993) was used as a secondary model to describe the effect of temperature on growth rate and the lag phase. We hypothesized that the same model could be used to calculate the time for the mycelium to become visible (tv) by substituting the lag phase (1/λ and 1/λopt) with the time to visible colony (1/tv-opt and 1/tv), respectively, in the Rosso et al. model. High variability was observed at suboptimal conditions. Extremes of temperature of growth for A. niger seem to have a normal variability. For the growth rate and time tv, the model was satisfactorily compared with results of previous studies. An external validation was performed in lime fruits; the bias and accuracy factors were 1.3 and 1.5, respectively, for growth rate and 0.24 and 3.72, respectively, for the appearance time. The discrepancy may be due to the influence of external factors. A. niger grows significantly more slowly on lime fruit than in culture medium, probably because the nutrients are more easily available in medium than in fruits, where the peel consistency may be a physical barrier. These findings will help researchers understand the postharvest behavior of mold on lime fruits, host-pathogen interactions, and environmental conditions infecting fruit and also help them develop guidelines for future work in the field of predictive mycology to improve models for control of postharvest fungi.

Purification and Partial Characterization of Cellulase Produced by Aspergillus niger Cultured on Vitellaria paradoxa shells

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Abdulhakeem Olarewaju Sulyman ◽  
Yusuf A Iyanda ◽  
Afolabi Olaniyi Opasola ◽  
OtunOla Adedayo ◽  
Raliat Abimbola Aladodo
Keyword(s):  
Aspergillus Niger ◽  
Specific Activity ◽  
Gel Filtration ◽  
Inoculum Size ◽  
Partial Characterization ◽  
Effect Of Temperature ◽  
Vitellaria Paradoxa ◽  
Endoglucanase Activity ◽  
Ammonium Sulphate Precipitation

This research investigated the purification and partial characterization of cellulase produced by Aspergillus niger cultured on Vitellaria paradoxa shells. Cellulase (endoglucanase) from A. niger was produced under optimum fermentation conditions at 35 °C, pH 4.7, V. paradoxa, 4 g/L, inoculum size of 10 mm and the fermentation media incubated for 120 hours. The crude endoglucanase obtained were partially purified by subjecting to ammonium sulphate precipitation, dialysis and gel filtration chromatography for further purification. The effect of temperature and pH on the activity of purified endoglucanase was determined. Cellulase was purified to 734.33 folds by Sephadex G-100 column chromatography with a specific activity and yield of 4.406 U/mg and 63.03% respectively. Fractions 4 and 7 contained the highest endoglucanase activity out of 18 fractions collected and the two fractions were pooled for further analysis. The activity of purified endoglucanase was optimum at a temperature of 40 °C and pH 5. Therefore, the purified endoglucanase produced may be explored in detergent industry.

scholarly journals Effect of Temperature on Production of Ochratoxin A by Aspergillus niger in Orange Juice

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Andreana Marino ◽  
Caterina Fiorentino ◽  
Francesca Spataro ◽  
Antonia Nostro
Keyword(s):  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Orange Juice ◽  
Citrus Sinensis ◽  
Effect Of Temperature ◽  
Wild Type ◽  
Different Temperatures ◽  
Strain Dependent ◽  
Intrinsic Strain ◽  
Dependent Mechanism

This challenging study was carried out to evaluate the temporal production of ochratoxin A (OTA) by Aspergillus niger ATCC 16404 and wild type A. niger AM at different temperatures in fresh squeezed orange juice (Citrus sinensis [L.] Osbeck cv Tarocco). Each strain, inoculated into the filtered orange juice, was incubated at 4°C, 20°C, and 26°C for 28 days. In the juice, at 26°C and 20°C, the concentration of A. niger ATCC 16404 increased by more than 2 log10 up to the 21st day. At 4°C it remained constant. The microbial load of A. niger AM decreased at all temperatures. At 26°C, the maximum OTA accumulation found was 3.44 ng/mL on the 21st day for A. niger ATCC 16404 and 8. 44 ng/mL on the 7th day for A. niger AM. The OTA synthesis seemed to be an intrinsic strain-dependent mechanism. A. niger ATCC 16404 produced OTA in accordance with the higher temperatures and the biomass concentrations, whereas A. niger AM produced the toxin at all temperatures regardless of its biomass. These results showed that fresh orange juice contaminated with Aspergillus niger aggregate strains may contain OTA levels.

scholarly journals Determination of Activation Energies and the Optimum Temperatures of Hydrolysis of Starch by α-Amylase from Porcine Pancreas

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4117
Author(s):  
Justyna Miłek
Keyword(s):  
Pancreatic Insufficiency ◽  
Pharmaceutical Preparations ◽  
Activation Energies ◽  
Enzyme Concentration ◽  
Starch Hydrolysis ◽  
Effect Of Temperature ◽  
Porcine Pancreas ◽  
Hydrolysis Of ◽  
Deactivation Process

The present paper reports the determination of the activation energies and the optimum temperatures of starch hydrolysis by porcine pancreas α-amylase. The parameters were estimated based on the literature data on the activity curves versus temperature for starch hydrolysis by α-amylase from porcine pancreas. It was assumed that both the hydrolysis reaction process and the deactivation process of α-amylase were first-order reactions by the enzyme concentration. A mathematical model describing the effect of temperature on porcine pancreas α-amylase activity was used. The determine deactivation energies Ea were from 19.82 ± 7.22 kJ/mol to 128.80 ± 9.27 kJ/mol, the obtained optimum temperatures Topt were in the range from 311.06 ± 1.10 K to 326.52 ± 1.75 K. In turn, the values of deactivation energies Ed has been noted in the range from 123.57 ± 14.17 kJ/mol to 209.37 ± 5.17 kJ/mol. The present study is related to the starch hydrolysis by α-amylase. In the industry, the obtained results the values Ea, Ed, Topt can be used to design and optimize starch hydrolysis by α-amylase porcine pancreas. The obtained results might also find application in research on the pharmaceutical preparations used to treat pancreatic insufficiency or prognosis of pancreatic cancer.

scholarly journals Activity of α-amylase Produced by Aspergillus niger at Different pH, Temperature and Incubation Time Using Solid-state Fermentation Process of Corn and Wheat Wastes

2021 ◽  
pp. 1-11
Author(s):  
Musa Sale Makeri ◽  
Muntari Bala ◽  
Solomon Peter Wante ◽  
Kwaya Vawanje Bitrus ◽  
Habiba Usman Aliyu
Keyword(s):  
Solid State ◽  
Aspergillus Niger ◽  
Solid State Fermentation ◽  
Incubation Time ◽  
Environmental Sustainability ◽  
Extracellular Enzymes ◽  
Effect Of Temperature ◽  
Anthropogenic Activity ◽  
Use Of Resources ◽  
By Products

In Nigeria, agro by-products have not been fully utilized by many and often discarded at the dumping site. This anthropogenic activity is contributing to an increase in pollution and is a threat to public health. Environmental sustainability requires the wise use of resources that include agro by-products. Therefore, there is a need to utilize the agro by-product for the production of enzymes such as α-amylase. α -amylase is one of the important extracellular enzymes with several uses. The development of suitable technology to produce enzymes at a very lower cost is significant. The solid-state fermentation (SSF) process using corn and wheat wastes as a substrate have been utilized. In this study, Aspergillus niger from abattoir effluent was identified, isolated and used for the production of an enzyme (α-amylase). The study evaluated the effect of temperature, pH and incubation period on the activities of α-amylase produced by Aspergillus niger. The activity of α-amylase was found to be higher at pH 6.5 and temperature above 50oC. At 4 days incubation of the solid-state fermentation of corn and wheat wastes, α-amylase activities produced were 90.61 Unit/mL and 87.34 Unit/mL respectively. Also in this study, 3-dimensional presentation of the pH, temperature and incubation time were evaluated. The result presented an optimal condition for amylase activity produced by Aspergillus niger.

The chemical mechanism of action of glucose oxidase from Aspergillus niger

2004 ◽  
Vol 260 (1) ◽  
pp. 69-83 ◽  
Author(s):  
Gerd Wohlfahrt ◽  
Svetlana Trivić ◽  
Jasmina Zeremski ◽  
Draginja Peričin ◽  
Vladimir Leskovac
Keyword(s):  
Aspergillus Niger ◽  
Glucose Oxidase ◽  
Mechanism Of Action ◽  
Chemical Mechanism

Effect of Temperature, Water Activity, and pH on Growth and Production of Ochratoxin A by Aspergillus niger and Aspergillus carbonarius from Brazilian Grapes

2014 ◽  
Vol 77 (11) ◽  
pp. 1947-1952 ◽  
Author(s):  
FABIANA REINIS FRANCA PASSAMANI ◽  
THAIS HERNANDES ◽  
NOELLY ALVES LOPES ◽  
SABRINA CARVALHO BASTOS ◽  
WILDER DOUGLAS SANTIAGO ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Ochratoxin A ◽  
Water Activity ◽  
Fungal Growth ◽  
Grape Juice ◽  
Effect Of Temperature ◽  
Aspergillus Carbonarius ◽  
Optimal Conditions ◽  
Wide Range ◽  
Temperature Water

The growth of ochratoxigenic fungus and the presence of ochratoxin A (OTA) in grapes and their derivatives can be caused by a wide range of physical, chemical, and biological factors. The determination of interactions between these factors and fungal species from different climatic regions is important in designing models for minimizing the risk of OTA in wine and grape juice. This study evaluated the influence of temperature, water activity (aw), and pH on the development and production of OTA in a semisynthetic grape culture medium by Aspergillus carbonarius and Aspergillus niger strains. To analyze the growth conditions and production of OTA, an experimental design was conducted using response surface methodology as a tool to assess the effects of these abiotic variables on fungal behavior. A. carbonarius showed the highest growth at temperatures from 20 to 33°C, aw between 0.95 and 0.98, and pH levels between 5 and 6.5. Similarly, for A. niger, temperatures between 24 and 37°C, aw greater than 0.95, and pH levels between 4 and 6.5 were optimal. The greatest toxin concentrations for A. carbonarius and A. niger (10 μg/g and 7.0 μg/g, respectively) were found at 15°C, aw 0.99, and pH 5.35. The lowest pH was found to contribute to greater OTA production. These results show that the evaluated fungi are able to grow and produce OTA in a wide range of temperature, aw, and pH. However, the optimal conditions for toxin production are generally different from those optimal for fungal growth. The knowledge of optimal conditions for fungal growth and production of OTA, and of the stages of cultivation in which these conditions are optimal, allows a more precise assessment of the potential risk to health from consumption of products derived from grapes.

Effect of temperature shift on production of xylanase by Aspergillus niger

2005 ◽  
Vol 40 (10) ◽  
pp. 3255-3257 ◽  
Author(s):  
Qi-peng Yuan ◽  
Jian-dong Wang ◽  
Huai Zhang ◽  
Zhong-ming Qian
Keyword(s):  
Aspergillus Niger ◽  
Temperature Shift ◽  
Effect Of Temperature

scholarly journals Biosorption of mercury (II) from aqueous solution onto biomass of Aspergillus niger

2018 ◽  
Vol 3 (3) ◽  
pp. 15-25
Author(s):  
Ismael Acosta Rodríguez ◽  
Nancy Cecilia Pacheco-Castillo ◽  
Juan Fernando Cárdenas-González ◽  
Maria de Guadalupe Moctezuma Zarate ◽  
Víctor Manuel Martínez-Juárez ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Aspergillus Niger ◽  
Fungal Biomass ◽  
Industrial Wastewater ◽  
Absorption Spectrometry ◽  
Effect Of Temperature ◽  
Contaminated Water ◽  
Spectrometry Method ◽  
Removal Capacity

Mercury (II) removal capacity in aqueous solution by Aspergillus niger biomass was analyzed by the atomic absorption spectrometry method. The fungus grew in 2000 ppm of the metal (20.3%). Biosorption was evaluated at different pH (3.5, 4.5, and 5.5) at different times. In addition, the effect of temperature in the range of 28°C to 45oC and removal at different initial concentrations of Hg (II) from 100 to 500 mg/L were also studied. The highest biosorption (83.2% with 100 mg/L of the metal, and 1 g of biomass) was 24 h at pH of 5.5 and 28oC. With regard to temperature, the highest removal was to 28oC, with an 83.2% removal at 24 h, and at higher biomass concentrations, the removal was most efficient (100% in 12 h with 5 g of biomass). Fungal biomass showed good removal capacity of the metal in situ, 69% removal in contaminated water, after 7 days of incubation and 5 g of biomass (100 mL water), so it can be used to remove industrial wastewater.

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