Influence of Temperature, pH, Water Activity and Antifungal Agents on Growth of Aspergillus flavus and A. parasiticus

Abstract

Effect of temperature, pH, water activity, and nine antifungal agents on growth of Aspergihs flavus and A. parasiticus was determined on Sabouraud-Dextrose Agar and on corn. Maximal growth of the two molds occurred at 33"C, the highest temperature used, pH of 5.0 and a, of 0.99. At 15'C, growth was observed at a, of 0.95 but not 0.90. Slight growth was observed at an a, of 0.85 at 27°C and 33°C. Nine antifungal agents (Botran, Orthocide, Polyram 80, Topsin-M, Thiram, Imazalil, sodium propionate, sodium sulfite and DDVP) were tested for inhibition of growth. Activity of the antifungals increased as the a, was decreased. All antifungals showed inhibitory activity, but Imazalil and DDVP were the most effective agents at the lowest concentrations.

Colonization of wounded peanut seeds by soil fungi: selectivity for species from Aspergillus section Flavi

“…Interactions of water activity and temperature.-Conditions for peanut seed colonization by section Flavi species in the current study (ranges: A w ϭ 0.82-0.98 and 15-37 C; optima: A w ϭ 0.92-0.96 at 22-37 C) were similar to conditions reported for spore germination and growth in pure culture (Holmquist et al 1983, Pitt and Miscamble 1995, Mislivec et al 1975, Sautour et al 2002. The observation of greater tolerance for low water activities at temperatures optimal for growth also has been reported from controlled culture conditions (Ayerst 1969, Holmquist et al 1983, Mislivec et al 1975, Pitt and Miscamble 1995.…”

Colonization of wounded peanut seeds by soil fungi: selectivity for species fromAspergillussectionFlavi

“…The observation of greater tolerance for low water activities at temperatures optimal for growth also has been reported from controlled culture conditions (Ayerst 1969, Holmquist et al 1983, Mislivec et al 1975, Pitt and Miscamble 1995. Water activities Ն0.98 are suboptimal for growth of section Flavi species (Pitt andMiscamble 1995, Sautour et al 2002), which was evident in the current experiments at the highest seed water activity of 0.98.…”

Effects of Growth Parameters on the Analysis of Aspergillus flavus Volatile Metabolites

“…Relative humidity, temperature, substrate (growth medium), number of fungal spores inoculated and oxidation stress are the main factors influencing fungal growth, metabolism and MVOCs' production in a laboratory setting [20][21][22]. For example, López-Malo et al [23] studied the effect of incubation temperature (10-30˝C), pH (3.0-4.0) and vanillin concentration (350-1200 ppm) on the growth of A. flavus.…”