A RAPID BIOASSAY TO DETECT MYCOTOXINS USING A MELANIN PRECURSOR OVERPRODUCER MUTANT OF THE CILIATE<i>TETRAHYMENA THERMOPHILA</i>

González, Alondra

doi:10.1006/cbir.1997.0134

Cited by 14 publications

(5 citation statements)

References 14 publications

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“…Many protozoal species are able to synthesize melanin precursors which may spontaneously polymerize to form the pigment. An interesting example is the "pig" (which stands for "pigmented") mutant of Tetrahymena thermophila, able to secrete huge amounts of allomelanin precursors to the culture medium (Kaney & Knox, 1980;Martin Gonzalez et al, 1997). These compounds, mostly products of catecholamine oxidation, spontaneously polymerize to melanin, which is likely to be a result of hyperactivity of aromatic amino-acids decarboxylase (l-DOPA decarboxylase, EC 4.1.1.26).…”

Section: Protozoamentioning

confidence: 99%

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Melanin synthesis in microorganisms--biotechnological and medical aspects.

Płonka¹,

Grabacka²

2006

Acta Biochim Pol

288

197

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Melanins form a diverse group of pigments synthesized in living organisms in the course of hydroxylation and polymerization of organic compounds. Melanin production is observed in all large taxa from both Pro- and Eukaryota. The basic functions of melanins are still a matter of controversy and speculation, even though their adaptative importance has been proved. Melanogenesis has probably evolved parallel in various groups of free living organisms to provide protection from environmental stress conditions, but in pathogenic microorganisms it correlates with an increased virulence. The genes responsible for melanization are collected in some cases within operons which find a versatile application in genetic engineering. This review summarizes current views on melanogenesis in Pro- and Eukaryotic microorganisms in terms of their biotechnological and biomedical importance.

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Section: Protozoamentioning

confidence: 99%

“…Activity of this enzyme, as in the case of bacteria, can be easily observed and quantified in the culture. Therefore, the "pig" mutant has been employed to test the effectiveness of some eukaryotic antibiotics and mycotoxins (Martin Gonzalez et al, 1997).…”

Section: Protozoamentioning

confidence: 99%

Melanin synthesis in microorganisms--biotechnological and medical aspects.

Płonka¹,

Grabacka²

2006

Acta Biochim Pol

288

197

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“…Melanins are ubiquitous biopolymers found in each group of organisms: Prokaryotes (Drewnowska et al, 2015;Bolognese et al, 2019), plants (Varga, 2016;Shoeva et al, 2020), animals and humans (Barek et al, 2018;Ali & Naaz, 2018;Słominski et al, 2005b), slime molds (Płonka & Rakoczy, 1997) and fungi (Dadachova & Casadevall, 2008;Nosanchuk et al, 2015;Suwannarach et al, 2019). They may be synthesized via enzymatic reaction pathways or by spontaneous oxidative processes (Kaney & Knox, 1980;Martin Gonzalez et al, 1997;Płonka & Garbacka, 2006). Melanins may act as antioxidants (ROS scavengers) (de Cassia R. Goncalves & Bonperio-Sponchiado, 2005;Wang et al, 2006), protective pigments against intense irradiation (Kollias et al, 1991;El-Bialy et al, 2019;Zadlo 2019), chelators for metals (Thaira et al, 2018;Zadlo & Sarna, 2019) and toxins (Karlsson et al, 2009), ecologically and evolu-tionary important pigments supporting cryptic pigmentation (Kelley et al, 2016;Polo-Cavia & Gomez-Mestre, 2017) and mimicry (Hines et al, 2017), as a virulence factor in various fungal species (Polak, 1990;Płonka & Grabacka, 2006) or even as metabolites necessary for proper spore formation (Yu et al, 2015;Zhang et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Detection of a pheomelanin-like pigment by EPR spectroscopy in the mycelium of Plenodomus biglobosus

et al. 2020

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Melanin occurrence in Plenodomus biglobosus was investigated using electron paramagnetic (spin) resonance (EPR, ESR) spectroscopy. The fungus was isolated from living and dead leaves of European ash (Fraxinus excelsior L.). Dark pigmentation of P. biglobosus mycelium in vitro, especially on the reverse, was observed. The black coloration intensified with the age of the culture and inspired us to check if the analyzed fungus species synthesizes melanin. Melanin contains unpaired electrons, thus, EPR spectroscopy was applied, as a specific technique, to verify its presence in P. biglobosus. The EPR spectrum of the mycelium showed a very strong melanin signal, revealing pheomelanin-like features. Thus, the black pigment of P. biglobosus was clearly identified as melanin. However, no melanin was detected in the apparently dark culture medium even when zinc (II) acetate was added to increase the sensitivity of detection. Pheomelanin has many unusual biological functions but it is not commonly found in fungi. Detection of this type of melanin in P. biglobosus, which can be both endophytic or pathogenic, suggests a closer examination of the potential role of this melanin in host-parasite interaction.

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“…It is an important kind of environmental microorganism and can be used as a biological indicator of the state of an aquatic environment [4]. It is a common freshwater eukaryotic original single-cell organism, and one of the highest single-cell forms of biological evolution-a ciliate [5]. Not only can the typical sub-cellular structure be seen in eukaryotic cells but also a complete body of life, such as cilia, mouth parts, mucus, etc.…”

Section: Introductionmentioning

confidence: 99%