Table 5.

Toxins in bioprocess media that could contaminate the initial product prior to downstream processing (see Table 2)

Toxin or precursor	Example of source
Aflatoxin (causes liver damage, and is a very potent carcinogen)	Mouldy groundnuts – contaminated by Aspergillus flavus (aflatoxin is removed in oil manufacture)
Cyanogens (can form cyanide)	Untreated cassava almond nut kernels
Mutagens and carcinogens such as benzo(a)pyrene (cause damage to DNA)*	They form in burnt feedstocks and foods
Solanins (neurotoxins)	Skins of potatoes greened by light exposure
Patulin	Mouldy apples
Bacterial toxins	Foods contaminated with for example E. coli O157, Salmonella spp., Shigella spp.
Algal toxins	Red algal blooms
Ochratoxins	Mouldy feedstocks
Heavy metals such as mercury	Some feedstocks of microbial, plant and fish origin

*Benzo(a)pyrene can be activated to the ultimate (proximate) carcinogen by cytochromes P450 1A1.