Aflatoxins are various poisonous carcinogens and mutagens that are produced by certain molds, particularly Aspergillus species mainly by Aspergillus flavus and Aspergillus parasiticus. According to the USDA, "They are probably the best known and most intensively researched mycotoxins in the world." The fungi grow in soil, decaying vegetation and various staple foodstuffs and commodities such as hay, maize, peanuts, coffee, wheat, millet, sorghum, cassava, rice, chili peppers, cottonseed, tree nuts, sesame seeds, sunflower seeds, and various cereal grains and oil seeds. In short, the relevant fungi grow on almost any crop or food. When such contaminated food is processed or consumed, the aflatoxins enter the general food supply. They have been found in both pet and human foods, as well as in feedstocks for agricultural animals. Animals fed contaminated food can pass aflatoxin transformation products into milk, milk products, and meat. For example, contaminated poultry feed is the suspected source of aflatoxin-contaminated chicken meat and eggs in Pakistan.
Aspergillus niger is a mold classified within the Nigri section of the Aspergillus genus. The Aspergillus genus consists of common molds found throughout the environment within soil and water, on vegetation, in fecal matter, on decomposing matter, and suspended in the air. Species within this genus often grow quickly and can sporulate within a few days of germination. A combination of characteristics unique to A. niger makes the microbe invaluable to the production of many acids, proteins and bioactive compounds. Characteristics including extensive metabolic diversity, high production yield, secretion capability, and the ability to conduct post-translational modifications are responsible for A. niger's robust production of secondary metabolites. A. niger's capability to withstand extremely acidic conditions makes it especially important to the industrial production of citric acid.
A mycotoxin is a toxic secondary metabolite produced by fungi and is capable of causing disease and death in both humans and other animals. The term 'mycotoxin' is usually reserved for the toxic chemical products produced by fungi that readily colonize crops.
Fumonisin B1 is the most prevalent member of a family of toxins, known as fumonisins, produced by multiple species of Fusarium molds, such as Fusarium verticillioides, which occur mainly in maize (corn), wheat and other cereals. Fumonisin B1 contamination of maize has been reported worldwide at mg/kg levels. Human exposure occurs at levels of micrograms to milligrams per day and is greatest in regions where maize products are the dietary staple.
Zearalenone (ZEN), also known as RAL and F-2 mycotoxin, is a potent estrogenic metabolite produced by some Fusarium and Gibberella species. Specifically, the Gibberella zeae, the fungal species where zearalenone was initially detected, in its asexual/anamorph stage is known as Fusarium graminearum. Several Fusarium species produce toxic substances of considerable concern to livestock and poultry producers, namely deoxynivalenol, T-2 toxin, HT-2 toxin, diacetoxyscirpenol (DAS) and zearalenone. Particularly, ZEN is produced by Fusarium graminearum, Fusarium culmorum, Fusarium cerealis, Fusarium equiseti, Fusarium verticillioides, and Fusarium incarnatum. Zearalenone is the primary toxin that binds to estrogen receptors, causing infertility, abortion or other breeding problems, especially in swine. Often, ZEN is detected together with deoxynivalenol in contaminated samples and its toxicity needs to be considered in combination with the presence of other toxins.
The fumonisins are a group of mycotoxins derived from Fusarium and their Liseola section. They have strong structural similarity to sphinganine, the backbone precursor of sphingolipids.
Mycotoxicology is the branch of mycology that focuses on analyzing and studying the toxins produced by fungi, known as mycotoxins. In the food industry it is important to adopt measures that keep mycotoxin levels as low as practicable, especially those that are heat-stable. These chemical compounds are the result of secondary metabolism initiated in response to specific developmental or environmental signals. This includes biological stress from the environment, such as lower nutrients or competition for those available. Under this secondary path the fungus produces a wide array of compounds in order to gain some level of advantage, such as incrementing the efficiency of metabolic processes to gain more energy from less food, or attacking other microorganisms and being able to use their remains as a food source.
Fermented tea is a class of tea that has undergone microbial fermentation, from several months to many years. The exposure of the tea leaves to humidity and oxygen during the process also causes endo-oxidation and exo-oxidation. The tea leaves and the liquor made from them become darker with oxidation. Thus, the various kinds of fermented teas produced across China are also referred to as dark tea, not be confused with black tea, which is actually referred to as "red tea" in Chinese. The most famous fermented tea is pu'er produced in Yunnan province.
Fusarium verticillioides is the most commonly reported fungal species infecting maize. Fusarium verticillioides is the accepted name of the species, which was also known as Fusarium moniliforme. The species has also been described as mating population A of the Fusarium fujikuroi species complex. F. verticllioides produces the mutagenic chemical compound fusarin C. F. verticillioides produces a group of disease-causing mycotoxins—fumonisins—on infected kernels.
Mycotoxins are secondary metabolites produced by filamentous fungi, commonly detected as contaminants in agricultural commodities globally. Exposure to these toxins can be very detrimental to both humans and animal, and can lead to mycotoxicosis, which can be a variety of medical conditions. In animals, exposure through feed can disrupt nutrient digestion, absorption, metabolism, and even affect animal physiology. The most common fungi that produce mycotoxins include Fusarium, Aspergillus, and Penicillium.
Aspergillus rambellii is a species of fungus in the genus Aspergillus. It is from the Ochraceorosei section. The species was first described in 2005. It accumulates very large amounts of sterigmatocystin, 3-O-methylsterigmatocystin and aflatoxin B1.
Aspergillus glaucus is a filamentous fungus which is known to have a wide environmental distribution due to its physiological hardiness under extreme conditions. Like many other fungi belonging to the genus Aspergillus, it can be mildly pathogenic but has a number of useful potential applications in medicine and the production of foodstuffs.
Penicillium nordicum is an anamorph species of fungus in the genus Penicillium which produces ochratoxin A. Penicillium nordicum contaminates protein rich foods and foods with high NaCl-konzentration. It is mostly found on dry-cured meat products and cheese products
Aspergillus tubingensis is a darkly pigmented species of fungus in the genus Aspergillus section Nigri. It is often confused with Aspergillus niger due to their similar morphology and habitat. A. tubingensis is often involved in food spoilage of fruits and wheat, and industrial fermentation. This species is a rare agent of opportunistic infection.
Aspergillus acidus is a species of fungus in the genus Aspergillus. Aspergillus acidus can be used in food fermentation for tea.
Aspergillus astellatus is a species of the genus of Aspergillus. It is from the Nidulantes section. Aspergillus astellatus produces Aflatoxin B1, Aflatoxin B2 and sterigmatocystin.
Xeromyces is a monotypic genus of fungus in the family Monascaceae. Its only species, Xeromyces bisporus, was first described by L.R. Fraser in 1954. No subspecies are listed in the Catalogue of Life.
Aspergillus aculeatinus is a species of fungus in the genus Aspergillus. It belongs to the group of black Aspergilli, which are important industrial workhorses. A. aculeatinus belongs to the Nigri section. The species was first described in 2008 and has been isolated from Thai coffee beans. It has been shown to produce neoxaline, secalonic acid D and F, and aculeacins.
Aspergillus parvisclerotigenus is a species of fungus in the genus Aspergillus. It is from the Flavi section. The species was first described in 2005. A. parvisclerotigenus has been isolated in Nigeria and has been found to produce aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, aflatrem, aflavarin, aspirochlorin, cyclopiazonic acid, kojic acid, and paspaline.
Fumonisin B4 is a fumonisin mycotoxin produced mainly by the fungi Fusarium proliferatum, Fusarium verticillioides. Recently FB4 has been detected in fungi Aspergillus niger and in several Tolypocladium species.
