Molds are a large and taxonomically diverse number of fungal species where the growth of hyphae results in discoloration and a fuzzy appearance, especially on food. The network of these tubular branching hyphae, called a nuclei. The dusty texture of many molds is caused by profuse production of asexual spores (conidia) formed by differentiation at the ends of hyphae. The mode of formation and shape of these spores is traditionally used to classify molds. Many of these spores are colored, making the fungus much more obvious to the human eye at this stage in its life-cycle.
Molds are considered to be microbes and do not form a specific taxonomic or phylogenetic grouping, but can be found in the divisions Zygomycota and Ascomycota. In the past, most molds were classified within the Deuteromycota.
Molds cause biodegradation of natural materials, which can be unwanted when it becomes food spoilage or damage to property. They also play important roles in biotechnology and food science in the production of various foods, beverages, antibiotics, pharmaceuticals and enzymes. Some diseases of animals and humans can be caused by certain molds: disease may result from allergic sensitivity to mold spores, from growth of pathogenic molds within the body, or from the effects of ingested or inhaled toxic compounds (mycotoxins) produced by molds.
- Biology 1
- Common molds 2
- Food production 3
- Pharmaceuticals from molds 4
- Health effects 5
- Growth in buildings and homes 6
- Molds in art 7
- See also 8
- References 9
- External links 10
There are thousands of known species of molds, which have diverse life-styles including
- The EPA's guide to mold
- Moore D; Robson GD; Trinci APJ (editors). (2011). 21st Century Guidebook to Fungi (1st ed.). Cambridge University Press.
- Madigan M; Martinko J (editors). (2005). Brock Biology of Microorganisms (11th ed.). Prentice Hall.
- Morgan, Mike. "Moulds". Microscopy UK. Retrieved 26 June 2012.
- Chiba University, Japan. "Fungus and Actinomycetes Gallery". Chiba University Medical Mycology Research Center. Retrieved 26 June 2012.
- Hibbett DS, Binder M, Bischoff JF, Blackwell M, Cannon PF, Eriksson OE, et al. (2007). "Fungi"A higher level phylogenetic classification of the (PDF). Mycological Research 111 (5): 509–547.
- Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed.). McGraw Hill. pp. 633–8.
- Wareing, Peter. "The Fungal Infection of Agricultural Produce and the Production of Mycotoxins". European Mycotoxins Awareness Network. Retrieved 3 August 2013.
- Malloch, D. (1981). Moulds : their isolation, cultivation and identification. Toronto Canada: Univ. of Toronto Press.
- Pitt JI, Hocking AD (2009). Fungi and Food Spoilage. London: Springer.
- "Red yeast rice (Monascus purpureus)".
- "Study: Red Rice Yeast Helps Cut Bad Cholesterol".
- L. H. Stahnke, L. O. Sunesen; Stahnke, L.H (November 2003). "Mould starter cultures for dry sausages—selection, application and effects". Meat Science 65 (3): 935–948.
- "The Nobel Prize website". Retrieved 27 June 2012.
- "Award Ceremony Speech". Nobel Prizes and Laureates. Nobel Media. Retrieved 26 May 2014.
- ACS Chemistry for Life. "The discovery of penicillin". Retrieved 27 June 2012.
- Money, Nicholas (2004). Carpet Monsters and Killer Spores: A Natural History of Toxic Mold. Oxford, UK: Oxford University Press. p. 178.
- Indoor Environmental Quality: Dampness and Mold in Buildings. National Institute for Occupational Safety and Health. August 1, 2008.
- Saunders Comprehensive Veterinary Dictionary, Blood and Studdert, 1999
Various artists have used molds in artistic fashion. Daniele Del Nero creates creepy, decaying architectural models of houses that are mold-covered. Antoine Bridier-Nahmias deliberately grows molds in Petri dishes that grows symmetrically and with somewhat attractive colors, and places photos on the blog Magical Contamination.
Molds in art
Mold growth in buildings can lead to a variety of health problems. Various practices can be followed to mitigate mold issues in buildings, the most important of which is to reduce moisture levels that can facilitate mold growth. Removal of affected materials after the source of moisture has been reduced and/or eliminated may be necessary for remediation.
Growth in buildings and homes
Molds can also pose a hazard to human and animal health when they are consumed following the growth of certain mold species in stored food. Some species produce toxic secondary metabolites, collectively termed penicillin adversely affects the growth of Gram-positive bacteria (e.g. Clostridium species), certain spirochetes and certain fungi.
Mold in the home can usually be found in damp, dark or steamy areas e.g. bathroom or kitchen, cluttered storage areas, recently flooded areas, basement areas, plumbing spaces, areas with poor ventilation and outdoors in humid environments. Symptoms caused by mold allergy are watery, itchy eyes, a chronic cough, headaches or migraines, difficulty breathing, rashes, tiredness, sinus problems, nasal blockage and frequent sneezing.
Some molds also produce mycotoxins that can pose serious health risks to humans and animals. Some studies claim that exposure to high levels of mycotoxins can lead to neurological problems and in some cases death. Prolonged exposure, e.g. daily home exposure, may be particularly harmful. Research on the health impacts of mold has not been conclusive. The term "toxic mold" refers to molds that produce mycotoxins, such as Stachybotrys chartarum, and not to all molds in general.
Molds are ubiquitous, and mold spores are a common component of household and workplace dust; however, when mold spores are present in large quantities, they can present a health hazard to humans, potentially causing allergic reactions and respiratory problems.
The immunosuppressant drug Tolypocladium inflatum.
Several statin cholesterol-lowering drugs (such as lovastatin, from Aspergillus terreus) are derived from molds.
 As this was during the Second World War, Florey sought USA Government involvement. With research teams in the UK and some in the US, industrial-scale production of crystallised penicillin was developed during 1941-1944 by the USDA and by Pfizer.
Alexander Fleming's accidental discovery of the antibiotic penicillin involved a Penicillium mold called Penicillium notatum (although the species identity is disputed as possibly being Penicillium chrysogenum or Penicillium rubens). Fleming continued to investigate Penicillin, showing that it could inhibit various types of bacteria found in infections and other ailments, but he was unable to produce the compound in large enough amounts necessary for production of a medicine. His work was expanded by a team at Oxford University; Clutterbuck, Lovell, and Raistrick, who began to work on the problem in 1931. This team was also unable to produce the pure compound in any large amount, and found that the purification process diminished its effectiveness and negated the anti-bacterial properties it had.
Pharmaceuticals from molds
- Fusarium venenatum – quorn
- Geotrichum candidum – cheese
- Neurospora sitophila – oncom
- Penicillium spp. – various cheeses including Brie and Blue cheese
- Rhizomucor miehei – microbial rennet for making vegetarian and other cheeses
- Rhizopus oligosporus – tempeh
Other molds that have been used in food production include:
Some sausages, such as salami, incorporate starter cultures of molds  to improve flavour and reduce bacterial spoilage during curing. Penicillium nalgiovense, for example, may appear as a powdery white coating on some varieties of dry-cured sausage.
Red rice yeast is a product of the mold Monascus purpureus grown on rice, and is common in Asian diets. The yeast contains several compounds collectively known as monacolins, which are known to inhibit cholesterol synthesis. A study has shown that red rice yeast used as a dietary supplement, combined with fish oil and healthy lifestyle changes, may help reduce "bad" cholesterol as effectively as certain commercial statin drugs.
The Kōji (麹) molds are a group of Aspergillus species, notably Aspergillus oryzae, and secondarily A. sojae, that have been cultured in eastern Asia for many centuries. They are used to ferment a soybean and wheat mixture to make soybean paste and soy sauce. Koji molds break down the starch in rice, barley, sweet potatoes, etc., a process called saccharification, in the production of sake, shōchū and other distilled spirits. Koji molds are also used in the preparation of Katsuobushi.
Few molds can begin growing at temperatures of 4 °C (39 °F) or below, so food is typically refrigerated at this temperature. When conditions do not enable growth to take place, molds may remain alive in a dormant state depending on the species, within a large range of temperatures. The many different mold species vary enormously in their tolerance to temperature and humidity extremes. Certain molds can survive harsh conditions such as the snow-covered soils of Antarctica, refrigeration, highly acidic solvents, anti-bacterial soap and even petroleum products such as jet fuel.:22
Although molds can grow on dead organic matter everywhere in nature, their presence is visible to the unaided eye only when they form large mycelium. All growth occurs at hyphal tips, with cytoplasm and organelles flowing forwards as the hyphae advance over or through new food sources. Nutrients are absorbed at the hyphal tip. In artificial environments such as buildings, humidity and temperature are often stable enough to foster the growth of mold colonies, commonly seen as a downy or furry coating growing on food or other surfaces.
Molds reproduce by producing large numbers of small spores, which may contain a single nucleus or be multinucleate. Mold spores can be asexual (the products of mitosis) or sexual (the products of meiosis); many species can produce both types. Some molds produce small, hydrophobic spores that are adapted for wind dispersal and may remain airborne for long periods; in some the cell walls are darkly pigmented, providing resistance to damage by ultraviolet radiation. Other mold spores have slimy sheaths and are more suited to water dispersal. Mold spores are often spherical or ovoid single cells, but can be multicellular and variously shaped. Spores may cling to clothing or fur; some are able to survive extremes of temperature and pressure.
(salting, pickling, jams, bottling, freezing, drying) are to prevent or slow mold growth as well as growth of other microbes. food preservation Many strategies for