| Mold Metabolism | Two-tier:
primary - energy production and mold growth
secondary - occurs when mold growth slows down or stops, produces mycotoxins |
| Mycotoxins | - mold toxins produced as secondary metabolites
- formed at the end of experimental growth of molds
- some are mutagenic and carcinogenic
- no known significance to mold's metabolism or growth --> assumed as a way to dispose of metabolic intermediates or increase competitive advantage in microbial community |
| Factors affecting mycotoxin production | - moisture (water activity: aw)
- relative humidity
- temperature
- pH
- competing microbes
- stress on plants
- damage to seeds |
| Aflatoxin | - most widely studied
- Aspergillus flavus, parasiticus, and nominus also produce aflatoxin
- at least 18 closely related aflatoxins are known
- fluoresce under UV light
- most potent: Aflatoxin B1
- in order of toxicity: B1 > M1 > G1 > B2 > M2 = G2 |
| Fumonisins | - produced by Fusarium spp in corn and other grains
- Fusarium monoliforme
- at least 7 fumonisins are known
- linked to esophageal cancer in humans, pulmonary edema in pigs, leukoencephalomalacia in horses
- can cause liver cancer |
| Patulin | - produced by some Penicillium spp, Aspergillus spp, Byssochlamys spp
- P. patulin, P. expansum, P. claviforme
- toxin produced mostly in fruits, fruit juices, bread, and sausage
- high levels (440 ug/L) found in apple juice
- up to 45 ppm found in apple cider
- carcinogenic |
