scholarly journals EFFECT OF TEMPERATURE, WATER ACTIVITY AND CINNAMON ESSENTIAL OIL ON THE GROWTH OF ASPERGILLUS FLAVUS LA01 AND ASPERGILLUS NIGER LA04

2018 ◽  
Vol 55 (5A) ◽  
pp. 42
Author(s):  
Phan Thi Kim Lien
Keyword(s):  
Aspergillus Niger ◽  
Essential Oil ◽  
Water Activity ◽  
Aspergillus Flavus ◽  
Effect Of Temperature ◽  
Diffusion Method ◽  
Potato Dextrose Agar Medium ◽  
Sequencing Method ◽  
Cinnamon Essential Oil ◽  
Temperature Water

The aim of the study was to evaluate the influence of temperature, water activity and cinnamon essential oil on the growth of Aspergillus flavus LA01 and Aspergillus niger LA04 and these factors were further optimized to inhibit their growth. Both strains were isolated by Potato Dextrose Agar medium (PDA) and identified by sequencing method from rice collected in Long An province. Evaluating these factors’ inhibition on the fungi growth was based on growth rate at the various points of water activity (aw) (v/v) such as 0.85, 0.90, 0.95, 0.99 and at 25 oC, 30 oC, 37 oC, 42 oC; at various concentrations of the oils 0 %, 1 %, 3 %, 5 %, 7.5 %, 10 % and 15 % at  30 oC incubated for 5 days - the disc diffusion method. The results showed that             30 oC and aw = 0.95 - 0.99 were optimum conditions for Aspergillus flavus LA01 and Aspergillus niger LA04 growth. However, at 42 oC, 37 oC and aw = 0.85 - 0.9 could control Aspergillus flavus LA01 and Aspergillus niger LA04 growth. At concentration of 10 - 15% cinnamon essential oils (EOs), 30 oC and aw = 0.9 - 0.95 could also inhibit them.

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.

scholarly journals Chemical Indices and Antibacterial Properties of Some Essential Oils of Apiaceae and Lauraceae Spices in Southwest of Algeria

2019 ◽  
Author(s):  
Dalila Razni ◽  
Linda Rouisset ◽  
Elhassan Benyagoub
Keyword(s):  
Antibacterial Activity ◽  
Essential Oil ◽  
Essential Oils ◽  
Enterococcus Faecalis ◽  
Antibacterial Properties ◽  
Independent Effect ◽  
Diffusion Method ◽  
Bacterial Strains ◽  
Cinnamon Essential Oil ◽  
The One

This study is a part of the valorization of extract from three most commonly used Algerian spices, namely; caraway and cumin seeds and cinnamon bark. On the one hand, it aims at characterizing the chemical indices of extracted essential oils and evaluating the antibacterial activity of each essential oil by titration and disc diffusion method respectively. On the other hand, it attempts at evaluating the combined action of essential oils against four reference pathogenic bacterial strains, namely Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, and Enterococcus faecalis by well and Chabbert-type diffusion method. The essential oils obtained by the hydrodistillation method have a relatively average extraction about 1.43, 2.3 and 2.5%, respectively for caraway, cumin, and cinnamon. The acid index indicates the behavior and amount of free acids present in the essential oil, in which the acid and saponification indices of cinnamon essential oil indicate a value of 4.48 and 168.56 respectively. It can also inform us about the susceptibility of the oil to undergo alterations. The antibacterial activity results showed that cinnamon essential oil (EO) proved to be the most active against the tested bacterial strains; caraway EO was active against Enterococcus faecalis, and the antibacterial action of cumin EO was the lowest. However, the association of the extracted essential oils has a higher synergistic effect than the independent effect of each essential oil, in which the MIC value found was estimated at 10 to 20 (V/V), 40 to 50 (V/V) and 50 to 70 (V/V) respectively for cinnamon, cumin and caraway. The obtained results show that the response to the antibacterial activity varies according to the plant species used and the extract tested alone or in combination.

Effect of Temperature, Water Activity and Other Toxigenic Mold Species on Growth of Aspergillus flavus and Aflatoxin Production on Corn, Pinto Beans and Soybeans

1988 ◽  
Vol 51 (5) ◽  
pp. 361-363 ◽  
Author(s):  
MARY W. TRUCKSESS ◽  
LEONARD STOLOFF ◽  
PHILIP B. MISLIVEC
Keyword(s):  
Aspergillus Flavus ◽  
Aflatoxin Production ◽  
Aflatoxin Contamination ◽  
Penicillium Citrinum ◽  
Effect Of Temperature ◽  
Mold Growth ◽  
Additional Water ◽  
Pinto Beans ◽  
Native Strains ◽  
Temperature Water

Portions of corn, a commodity in which aflatoxin is frequently found, were held at 16, 26 and 32°C after the moisture contents were adjusted to achieve water activities (aw) ranging from too low to ample for support of mold growth. Suspensions of mold spores from toxigenic cultures of Aspergillus flavus, A. ochraceus, Penicillium citrinum, P. cyclopium and P. urticae were added to the test portions, either as A. flavus alone, as A. flavus with one of the other molds or as a mixture of all 5 species. Additional water was used to obtain the proper moisture levels. A temperature of 16°C was generally too low for aflatoxin production by either the added or native strains of A. flavus, although the mold was able to grow at 16°C at aw values as low as 0.80, 0.77 and 0.85 on corn, soybeans and pinto beans, respectively. Aflatoxin production was essentially the same at 26 and 32° C with limiting aw values in the range of 0.85–0.89. Limiting aw values for mold growth at 26 and 32°C were 0.73, 0.69 and 0.75 for corn, soybeans and pinto beans, respectively. This study provided no evidence that substrate suitability at limiting temperatures and aw levels is a factor in the observed difference in the risk of aflatoxin contamination for these commodities. The study did indicate that the associated mold flora, when the seed is exposed to mold invasion, is a risk determinant.

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