Effect of temperature and water activity on gene expression and aflatoxin biosynthesis in Aspergillus flavus on almond medium

Comparative study of toxigenic potential of Aspergillus flavus and Aspergillus niger isolated from Barley as affected by temperature, water activity and carbon source

“…Differently, Gallo et al (2016) found that 28 C and 0.96 a W were the optimal conditions for the highest production of AFB1 by A. flavus on almond based medium. According to Klich (2007), the differences found in literature about the optimal conditions supporting aflatoxin production are likely due to the differences in media used and in fungal strain studied.…”

“…At 21 C/97% RH and 30 C/ 85% RH, the populations of A. flavus increased significantly and aflatoxins were produced. Gallo et al, 2016, found an optimal conditions for the greatest accumulation of fungal biomass of A. flavus on almond medium to be 28 C and 0.96 a w , after 15 days of incubation; whereas no fungal growth was observed at 20 C at the driest conditions examined (0.90 and 0.93 a w ).…”

“…With regard to aflatoxin production, several reports have established the optimal conditions for A. flavus at 0.99 a W and 25e30 C (Giorni et al, 2007;Kheiralla et al, 1992). Differently, Gallo et al (2016) found that 28 C and 0.96 a W were the optimal conditions for the highest production of AFB1 by A. flavus on almond based medium.…”

“…Changes in pH, composition of culture media, trace metals, and carbon (C) sources can have a remarkable influence (Medina et al, 2008(Medina et al, , 2004Mühlencoert et al, 2004). Although several surveys have investigated the influence of environmental factors on growth and mycotoxigenic capacity on toxigenic Aspergillus species (Bellí et al, 2004a(Bellí et al, , 2004bLeong et al, 2006;Astoreca et al, 2007aAstoreca et al, , 2007bGallo et al, 2016;Choi et al, 2015;Esteban et al, 2006;Giorni et al, 2007;Abdollahi and Buchanan, 1981;Liu and Chu, 1998;Kheiralla et al, 1992;Medina et al, 2008), none has interested a comparison between species producing different mycotoxins cultured in the same environmental and cultural conditions. In the current study, we want to gain information on how OTA and AFB1 production is influenced by the nature of the carbohydrate, temperature and water availability in the cultural medium trying to emphasize the difference in behavior of two species, Aspergillus niger and A. flavus, isolated from a same substrate and producing different mycotoxins.…”

Aflatoxins: biosynthesis, prevention and eradication

“…Aflatoxins (AF) are mycotoxins that belong to a group of highly oxygenated polyketides mainly produced by Aspergillus flavus and Aspergillus parasiticus, even though some studies recently demonstrated the importance of species such as Aspergillus nomius, Aspergillus minisclerotigenes and Aspergillus arachidicola as AF producers (Gallo et al, 2016). It is estimated that at least a quarter of the world's food crops is contaminated by mycotoxins; leading to a large economical loss worldwide (Kumar et al, 2008;Njobeh et al, 2009).…”