A mold or mould is one of the structures that certain fungi can form. The dust-like, colored appearance of molds is due to the formation of spores containing fungal secondary metabolites. The spores are the dispersal units of the fungi. Not all fungi form molds. Some fungi form mushrooms; others grow as single cells and are called microfungi.
Penicillium is a genus of ascomycetous fungi that is part of the mycobiome of many species and is of major importance in the natural environment, in food spoilage, and in food and drug production.
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.
Ochratoxins are a group of mycotoxins produced by some Aspergillus species and some Penicillium species, especially P. verrucosum. Ochratoxin A is the most prevalent and relevant fungal toxin of this group, while ochratoxins B and C are of lesser importance.
Ochratoxin A—a toxin produced by different Aspergillus and Penicillium species — is one of the most-abundant food-contaminating mycotoxins. It is also a frequent contaminant of water-damaged houses and of heating ducts. Human exposure can occur through consumption of contaminated food products, particularly contaminated grain and pork products, as well as coffee, wine grapes, and dried grapes. The toxin has been found in the tissues and organs of animals, including human blood and breast milk. Ochratoxin A, like most toxic substances, has large species- and sex-specific toxicological differences.
Citrinin is a mycotoxin which is often found in food. It is a secondary metabolite produced by fungi that contaminates long-stored food and it can cause a variety of toxic effects, including kidney, liver and cell damage. Citrinin is mainly found in stored grains, but sometimes also in fruits and other plant products.
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.
Brevianamides are indole alkaloids that belong to a class of naturally occurring 2,5-diketopiperazines produced as secondary metabolites of fungi in the genus Penicillium and Aspergillus. Structurally similar to paraherquamides, they are a small class compounds that contain a bicyclo[2.2.2]diazoctane ring system. One of the major secondary metabolites in Penicillium spores, they are responsible for inflammatory response in lung cells.
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 ochraceus is a mold species in the genus Aspergillus known to produce the toxin ochratoxin A, one of the most abundant food-contaminating mycotoxins, and citrinin. It also produces the dihydroisocoumarin mellein. It is a filamentous fungus in nature and has characteristic biseriate conidiophores. Traditionally a soil fungus, has now began to adapt to varied ecological niches, like agricultural commodities, farmed animal and marine species. In humans and animals the consumption of this fungus produces chronic neurotoxic, immunosuppressive, genotoxic, carcinogenic and teratogenic effects. Its airborne spores are one of the potential causes of asthma in children and lung diseases in humans. The pig and chicken populations in the farms are the most affected by this fungus and its mycotoxins. Certain fungicides like mancozeb, copper oxychloride, and sulfur have inhibitory effects on the growth of this fungus and its mycotoxin producing capacities.
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
Penicillium tricolor is a species of fungus in the genus Penicillium which was isolated from wheat in Canada. Penicillium tricolor produces xanthomegnin, viomellein, vioxanthin, terrestric acid, rugulosuvine, verrucofortine, puberuline, and asteltoxin.
Penicillium viridicatum is a psychrophilic species of fungus in the genus, penicillic acid and citrinin. Penicillium viridicatum can spoil grapes and melons.
Penicillium verrucosum is a psychrophilic fungus which was discovered in Belgium and introduced by Dierckx in 1901. Six varieties of this species have been recognized based primarily on differences in colony colour: P. verrucosum var. album, P. verrucosum var. corymbiferum, P. verrucosum var. cyclopium, P. verrucosum var. ochraceum, P. verrucosum var. melanochlorum and P. verrucosum var. verrucosum. This fungus has important implications in food, specifically for grains and other cereal crops on which it grows. Its growth is carefully regulated in order to reduce food spoilage by this fungi and its toxic products. The genome of P. verrucosum has been sequenced and the gene clusters for the biosyntheses of its mycotoxins have been identified.
Aspergillus persii is a species of fungus in the genus Aspergillus which can cause onychomycosis. and otomycosis
Aspergillus insulicola is a species of fungus in the genus Aspergillus. It is from the Circumdati section. The species was first described in 1975. It has been reported to produce xanthomegnin, viomellein, vioxanthin, and penicillic acid.
Aspergillus sesamicola is a species of fungus in the genus Aspergillus. It is from the Circumdati section. The species was first described in 2014. It has been reported to produce xanthomegnin, viomellein, and vioxanthin.
Aspergillus westerdijkiae is a species of fungus in the genus Aspergillus. It is from the Circumdati section. The species was first described in 2004. It has been reported to produce penicillic acid, ochratoxin A, xanthomegnin, viomellein, and vioxanthin.
John Ingram Pitt was an Australian mycologist, known as a leading expert on the role of fungi in food spoilage. He gained an international reputation as a pioneering researcher on the ecology of spoilage molds in extreme environments.
