Aspergillus tubingensis

Aspergillus tubingensis was first discovered by Raoul Mosseray in 1934. The conidia are heavily roughened, 3-5 μm in diameter. Whitish to pink sclerotia ranging from 0.5 to 0.8 mm in diameter are often produced. A. tubingensis exists exclusively as an asexual fungus but is understood to be phylogenetically closely related to the other so-called black Aspergilli and sexual states in the genus Petromyces. The production of Ochratoxin A (OTA) was previously thought to be a variable character dependent on strain; however, the production of OTA is thought to be a consistent feature with prior reports of variation arising from the inclusion of misidentified strains (e.g., A. niger) or inconsistencies in test conditions such as incubation time, temperature, and growth medium. Other extrolites produced by this fungus include: asperazine, pyranoigrin A, pyrophen, funalenone, and kotanins. When cultured on creatine sucrose agar (CREA) culture medium, A. tubingensis demonstrates good acid production (strong yellow colour change) and a moderate growth rate. A. tubingensis and A. niger have similar morphology and are difficult to distinguish without resorting to more advanced methods. One rapid test that is useful in distinguishing the two taxa, the Ehrlich reaction, queries the presence of indole. In this test, A. tubingensis is negative in contrast to A. niger which produces a positive result. Sequences of protein coding genes such as Calmodulin and β-tubulin also reliable differentiate the two taxa. The production of asperazine by A. tubingensis also separates this species from other morphologically similar Aspergilli. ==Habitat and ecology==

Aspergillus tubingensis exhibits high resistance to ultraviolet light and can grow in elevated temperatures between , with optimal growth between . In the temperature range of , this species is able to produce the mycotoxin, ochratoxin A (OTA). The fungus is tolerant of low pH and has a preference for environments of relatively low water activity. Originally recognized from Chiang Mai, Thailand and China, A. tubingensis is found worldwide in warm climate regions. It is often seen in indoor environments of Croatia and Turkey, with some appearances in the Netherlands, Hungary, Thailand, and Algeria. This species is commonly isolated from soil and plant debris as well as agricultural crops such as grapes, cocoa, coffee, and cereal, and as an agent of rot on apples, grapes, and cereals. == Commercial uses ==

Because of the paucity of mycotoxin production by A. tubingensis, it has been explored for use in biotechnology and industrial applications. "The plastic-busting potential was discovered last year by a team of scientists from China and Pakistan, who sought to isolate the fungi that were degrading polyurethane at a waste disposal site in Islamabad. The fungi were identified as aspergillus tubingensis and the scientists observed how it broke down bonds between the different polymers in weeks, rather than the decades it can take plastic to naturally disintegrate." ==Opportunistic disease==

Fungal keratitis (corneal infection) can be caused by members of the black Aspergilli including A. tubingensis. Aspergillus tubingensis has also been implicated in the infection of maxillary bone following a tooth extraction. ==References==