The Influence of NaCl and Glucose Content on Growth and Ochratoxin A Production byAspergillus ochraceus,Aspergillus carbonariusandPenicillium nordicum

Ochratoxin A (OTA) is a nephrotoxic mycotoxin, which deserves particular attention for its widespread contamination of a variety of food and feed.Aspergillus ochraceus,Aspergillus carbonarius, andPenicillium nordicumare an important source of OTA in three different kinds of food commodities, including cereals, grape and dried fruit products, and dry-cured meat products. Deeper knowledge of OTA production and mycelium growth related to the high-sugar or NaCl-rich environments was gained in this manuscript.A. ochraceusandP. nordicumwere likely to have greater growth rates in medium supplied with certain concentrations of NaCl (0-80 g/L), and the colony diameter was the largest at the salt content of 40 g/L.P. nordicumwas more suitable to grow in NaCl-riched medium, the OTA production was increased to 316 ppb from 77 ppb when 20 g/L NaCl was added. The capability of OTA production was inhibited when salt content was 40 g/L and 60 g/L inA. ochraceusandP. nordicum, respectively. As the glucose content increased to 250 g/L, the capacity of mycelium growth and sporulation was increased significantly inA. ochraceusandA. carbonarius.A. carbonariuswas more suitable to grow in high-sugar grape products. OTA production was significantly promoted with an added 100 g/L glucose inA. carbonarius. OTA production was inhibited when glucose content was 150 g/L and in 200 g/L inA. ochraceusandA. carbonarius, respectively. NaCl and glucose have an effect on fungal growth and OTA production, and the activation of biosynthetic genes of OtaA. These results would allow designing new strategies to prevent OTA accumulation on sugar or NaCl-riched foodstuffs and achieve the objective to manufacture cereals, dried vine fruits and dry-cured ham, free of OTA.