Ultrastructural changes produced in Ehrlich ascites carcinoma cells by ultraviolet-visible radiation in the presence of melanins

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Lea, P.J.; Pawlowski, A.; Persad, S.D.; Menon, I.A.; Haberman, H.F.

1988-01-01

Irradiation of Ehrlich ascites carcinoma (EAC) cells in the presence of pheomelanin, i.e., red hair melanin (RHM), has been reported to produce extensive cell lysis. Irradiation in the presence of eumelanin, i.e., black hair melanin (BHM), or irradiation in the absence of either type of melanin did not produce this effect. We observed that RHM particles penetrated the cell membrane without apparent structural damage to the cell or the cell membrane. Irradiation of the cells in the absence of melanin did not produce any changes in the ultrastructure of the cells. Incubation of the cells in the dark in the presence of RHM produced only minor structural, mainly cytoplasmic changes. Irradiation of the cells in the presence of RHM produced extensive ultrastructural changes prior to complete cell lysis; these changes were more severe than the effects of incubation of the cells in the dark in the presence of RHM. When the cells incubated in the dark or irradiated in the presence of latex particles or either one of the eumelanins particles, viz. BHM or synthetic dopa melanin, these particles did not penetrate into the cells or produce any ultrastructural changes. These particles were in fact not even ingested by the cells.

Melanins Protect Sporothrix brasiliensis and Sporothrix schenckii from the Antifungal Effects of Terbinafine.

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Almeida-Paes, Rodrigo; Figueiredo-Carvalho, Maria Helena Galdino; Brito-Santos, Fábio; Almeida-Silva, Fernando; Oliveira, Manoel Marques Evangelista; Zancopé-Oliveira, Rosely Maria

2016-01-01

Terbinafine is a recommended therapeutic alternative for patients with sporotrichosis who cannot use itraconazole due to drug interactions or side effects. Melanins are involved in resistance to antifungal drugs and Sporothrix species produce three different types of melanin. Therefore, in this study we evaluated whether Sporothrix melanins impact the efficacy of antifungal drugs. Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of two Sporothrix brasiliensis and four Sporothrix schenckii strains grown in the presence of the melanin precursors L-DOPA and L-tyrosine were similar to the MIC determined by the CLSI standard protocol for S. schenckii susceptibility to amphotericin B, ketoconazole, itraconazole or terbinafine. When MICs were determined in the presence of inhibitors to three pathways of melanin synthesis, we observed, in four strains, an increase in terbinafine susceptibility in the presence of tricyclazole, a DHN-melanin inhibitor. In addition, one S. schenckii strain grown in the presence of L-DOPA had a higher MFC value when compared to the control. Growth curves in presence of 2×MIC concentrations of terbinafine showed that pyomelanin and, to a lesser extent, eumelanin were able to protect the fungi against the fungicidal effect of this antifungal drug. Our results suggest that melanin protects the major pathogenic species of the Sporothrix complex from the effects of terbinafine and that the development of new antifungal drugs targeting melanin synthesis may improve sporotrichosis therapies.

Fungal melanins and their interactions with metals.

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Fogarty, R V; Tobin, J M

1996-09-01

Fungal melanins are dark brown or black pigments located in cell walls. They also exist as extracellular polymers. Melanized fungi possess increased virulence and resistance to microbial attack as well as enhanced survival while under environmental stress. Melanins contain various functional groups which provide an array of multiple nonequivalent binding sites for metal ions. Pigmented Cladosporium cladosporoides was shown to biosorb 2.5- to four-fold more Ni, Cu, Zn, Cd, and Pb than albino Penicillium digitatum and at four- to six-fold higher rates. Metal desorption was significantly lower for extracellular melanin than from pigmented or albino biomass which indicated the strength of the melanin-metal bond. At equilibrium, tributyltin chloride (TBTC) concentrations of 2.5 mM, pigmented and albino Aureobasidium pullulans absorbed approximately 0.9 and 0.7 mumol TBTC mg -1 dry wt, respectively, whereas purified extracellular melanin exhibited uptake levels of approximately 22 mumol TBTC mg-1 dry wt at an equilibrium concentration of only 0.4 mM. Addition of melanin to the growth medium reduced the toxic effect of CuSO4 and TBTC due to melanin metal binding and sequestration.

Melanins Protect Sporothrix brasiliensis and Sporothrix schenckii from the Antifungal Effects of Terbinafine.

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Rodrigo Almeida-Paes

Full Text Available Terbinafine is a recommended therapeutic alternative for patients with sporotrichosis who cannot use itraconazole due to drug interactions or side effects. Melanins are involved in resistance to antifungal drugs and Sporothrix species produce three different types of melanin. Therefore, in this study we evaluated whether Sporothrix melanins impact the efficacy of antifungal drugs. Minimal inhibitory concentrations (MIC and minimal fungicidal concentrations (MFC of two Sporothrix brasiliensis and four Sporothrix schenckii strains grown in the presence of the melanin precursors L-DOPA and L-tyrosine were similar to the MIC determined by the CLSI standard protocol for S. schenckii susceptibility to amphotericin B, ketoconazole, itraconazole or terbinafine. When MICs were determined in the presence of inhibitors to three pathways of melanin synthesis, we observed, in four strains, an increase in terbinafine susceptibility in the presence of tricyclazole, a DHN-melanin inhibitor. In addition, one S. schenckii strain grown in the presence of L-DOPA had a higher MFC value when compared to the control. Growth curves in presence of 2×MIC concentrations of terbinafine showed that pyomelanin and, to a lesser extent, eumelanin were able to protect the fungi against the fungicidal effect of this antifungal drug. Our results suggest that melanin protects the major pathogenic species of the Sporothrix complex from the effects of terbinafine and that the development of new antifungal drugs targeting melanin synthesis may improve sporotrichosis therapies.

Melanins Protect Sporothrix brasiliensis and Sporothrix schenckii from the Antifungal Effects of Terbinafine

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Almeida-Paes, Rodrigo; Figueiredo-Carvalho, Maria Helena Galdino; Brito-Santos, Fábio; Almeida-Silva, Fernando; Oliveira, Manoel Marques Evangelista; Zancopé-Oliveira, Rosely Maria

2016-01-01

Terbinafine is a recommended therapeutic alternative for patients with sporotrichosis who cannot use itraconazole due to drug interactions or side effects. Melanins are involved in resistance to antifungal drugs and Sporothrix species produce three different types of melanin. Therefore, in this study we evaluated whether Sporothrix melanins impact the efficacy of antifungal drugs. Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of two Sporothrix brasiliensis and four Sporothrix schenckii strains grown in the presence of the melanin precursors L-DOPA and L-tyrosine were similar to the MIC determined by the CLSI standard protocol for S. schenckii susceptibility to amphotericin B, ketoconazole, itraconazole or terbinafine. When MICs were determined in the presence of inhibitors to three pathways of melanin synthesis, we observed, in four strains, an increase in terbinafine susceptibility in the presence of tricyclazole, a DHN-melanin inhibitor. In addition, one S. schenckii strain grown in the presence of L-DOPA had a higher MFC value when compared to the control. Growth curves in presence of 2×MIC concentrations of terbinafine showed that pyomelanin and, to a lesser extent, eumelanin were able to protect the fungi against the fungicidal effect of this antifungal drug. Our results suggest that melanin protects the major pathogenic species of the Sporothrix complex from the effects of terbinafine and that the development of new antifungal drugs targeting melanin synthesis may improve sporotrichosis therapies. PMID:27031728

The pbrB gene encodes a laccase required for DHN-melanin synthesis in conidia of Talaromyces (Penicillium) marneffei.

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Sapmak, Ariya; Boyce, Kylie J; Andrianopoulos, Alex; Vanittanakom, Nongnuch

2015-01-01

Talaromyces marneffei (Basionym: Penicillium marneffei) is a significant opportunistic fungal pathogen in patients infected with human immunodeficiency virus in Southeast Asia. T. marneffei cells have been shown to become melanized in vivo. Melanins are pigment biopolymers which act as a non-specific protectant against various stressors and which play an important role during virulence in fungi. The synthesis of the two most commonly found melanins in fungi, the eumelanin DOPA-melanin and the allomelanin DHN-melanin, requires the action of laccase enzymes. The T. marneffei genome encodes a number of laccases and this study describes the characterization of one of these, pbrB, during growth and development. A strain carrying a PbrB-GFP fusion shows that pbrB is expressed at high levels during asexual development (conidiation) but not in cells growing vegetatively. The pbrB gene is required for the synthesis of DHN-melanin in conidia and when deleted results in brown pigmented conidia, in contrast to the green conidia of the wild type.

Antiradiation properties of melanin

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Bushmanov A.Ju.

2014-12-01

Full Text Available Aim: to examine the therapeutic efficiency of melanin administered to mice after irradiation at lethal and sublethal doses. Material and methods: Survival and hematological states were studied on CD-1 mice receiving on acute or fractionated whole-body doses on X-rays or gamma-irradiation. Melanin soluble was given with water ad libitum from the first to the 30th-day after irradiation. Results. It was shown that melanin produced a significant therapeutic and protective-therapeutic action against acute radiation injury in the dose range 6,5-7,5 Gy (LD80-LD under our conditions. Cumulative survival melanin treated mice was increased to 14,4%, in control group — 1,9%. After fractionated injury (1 Gy daily, total dose 10 Gy all mice which consumed melanin remained alive, versus 43,7% in control. Melanin decreased radiation-induced damage and stimulated the hematopoiesis recovery after sublethal exposure (5Gy. Conclusion. The results permit to regard melanin as a therapeutic agent for treatment of radiation injuries.

Trichoderma harzianum: Inhibition of mycotoxin producing fungi and toxin biosynthesis.

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Braun, H; Woitsch, L; Hetzer, B; Geisen, R; Zange, B; Schmidt-Heydt, M

2018-04-19

A quarter of the world-wide crop is spoiled by filamentous fungi and their mycotoxins and weather extremes associated with the climate change lead to further deterioration of the situation. The ingestion of mycotoxins causes several health issues leading in the worst case to cancer in humans and animals. Common intervention strategies against mycotoxin producing fungi, such as the application of fungicides, may result in undesirable residues and in some cases to a stress induction of mycotoxin biosynthesis. Moreover, development of fungicide resistances has greatly impacted pre- and postharvest fungal diseases. Hence there is the need to develop alternative strategies to reduce fungal infestation and thus mycotoxin contamination in the food chain. Such a strategy for natural competition of important plant-pathogenic and mycotoxin producing fungi could be Trichoderma harzianum, a mycoparasitic fungus. Especially in direct comparison to certain tested fungicides, the inhibition of different tested fungal species by T. harzianum was comparable, more sustainable and in some cases more effective, too. Besides substantially reduced growth rates, a transcriptional based inhibition of mycotoxin biosynthesis in the competed Aspergillus species could be shown. Furthermore it could be clearly observed by high-resolution Scanning Electron Microscopy (SEM) that T. harzianum actively attaches to the competitor species followed by subsequent enzymatic lysis of those mycelial filaments. The analyzed isolate of T. harzianum MRI349 is not known to produce mycotoxins. In this study it could be successfully proven that T. harzianum as a biological competitor is an effective complement to the use of fungicides. Copyright © 2018 Elsevier B.V. All rights reserved.

Phytotoxins Produced by Fungi Associated with Grapevine Trunk Diseases

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Andolfi, Anna; Mugnai, Laura; Luque, Jordi; Surico, Giuseppe; Cimmino, Alessio; Evidente, Antonio

2011-01-01

Up to 60 species of fungi in the Botryosphaeriaceae family, genera Cadophora, Cryptovalsa, Cylindrocarpon, Diatrype, Diatrypella, Eutypa, Eutypella, Fomitiporella, Fomitiporia, Inocutis, Phaeoacremonium and Phaeomoniella have been isolated from decline-affected grapevines all around the World. The main grapevine trunk diseases of mature vines are Eutypa dieback, the esca complex and cankers caused by the Botryospheriaceae, while in young vines the main diseases are Petri and black foot diseases. To understand the mechanism of these decline-associated diseases and the symptoms associated with them, the toxins produced by the pathogens involved in these diseases were isolated and characterised chemically and biologically. So far the toxins of only a small number of these decline fungi have been studied. This paper presents an overview of the toxins produced by the most serious of these vine wood pathogens: Eutypa lata, Phaeomoniella chlamydospora, Phaeoacremonium aleophilum and some taxa in the Botryosphaeriaceae family, and examines how these toxins produce decline symptoms. The chemical structure of these metabolites and in some cases their vivotoxin nature are also discussed. PMID:22295177

Phytotoxins Produced by Fungi Associated with Grapevine Trunk Diseases

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Antonio Evidente

2011-12-01

Full Text Available Up to 60 species of fungi in the Botryosphaeriaceae family, genera Cadophora, Cryptovalsa, Cylindrocarpon, Diatrype, Diatrypella, Eutypa, Eutypella, Fomitiporella, Fomitiporia, Inocutis, Phaeoacremonium and Phaeomoniella have been isolated from decline-affected grapevines all around the World. The main grapevine trunk diseases of mature vines are Eutypa dieback, the esca complex and cankers caused by the Botryospheriaceae, while in young vines the main diseases are Petri and black foot diseases. To understand the mechanism of these decline-associated diseases and the symptoms associated with them, the toxins produced by the pathogens involved in these diseases were isolated and characterised chemically and biologically. So far the toxins of only a small number of these decline fungi have been studied. This paper presents an overview of the toxins produced by the most serious of these vine wood pathogens: Eutypa lata, Phaeomoniella chlamydospora, Phaeoacremonium aleophilum and some taxa in the Botryosphaeriaceae family, and examines how these toxins produce decline symptoms. The chemical structure of these metabolites and in some cases their vivotoxin nature are also discussed.

Differential Antifungal Activity of Human and Cryptococcal Melanins with Structural Discrepancies.

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Correa, Néstor; Covarrubias, Cristian; Rodas, Paula I; Hermosilla, Germán; Olate, Verónica R; Valdés, Cristián; Meyer, Wieland; Magne, Fabien; Tapia, Cecilia V

2017-01-01

Melanin is a pigment found in all biological kingdoms, and plays a key role in protection against ultraviolet radiation, oxidizing agents, and ionizing radiation damage. Melanin exerts an antimicrobial activity against bacteria, fungi, and parasites. We demonstrated an antifungal activity of synthetic and human melanin against Candida sp. The members of the Cryptococcus neoformans and C. gattii species complexes are capsulated yeasts, which cause cryptococcosis. For both species melanin is an important virulence factor. To evaluate if cryptococcal and human melanins have antifungal activity against Cryptococcus species they both were assayed for their antifungal properties and physico-chemical characters. Melanin extracts from human hair and different strains of C. neoformans ( n = 4) and C. gattii ( n = 4) were investigated. The following minimum inhibitory concentrations were found for different melanins against C. neoformans and C. gattii were (average/range): 13.7/(7.8-15.6) and 19.5/(15.6-31.2) μg/mL, respectively, for human melanin; 273.4/(125->500) and 367.2/(125.5->500) μg/mL for C. neoformans melanin and 125/(62.5-250) and 156.2/(62-250) μg/mL for C. gattii melanin. Using Scanning Electron Microscopy we observed that human melanin showed a compact conformation and cryptococcal melanins exposed an amorphous conformation. Infrared spectroscopy (FTIR) showed some differences in the signals related to C-C bonds of the aromatic ring of the melanin monomers. High Performance Liquid Chromatography established differences in the chromatograms of fungal melanins extracts in comparison with human and synthetic melanin, particularly in the retention time of the main compound of fungal melanin extracts and also in the presence of minor unknown compounds. On the other hand, MALDI-TOF-MS analysis showed slight differences in the spectra, specifically the presence of a minor intensity ion in synthetic and human melanin, as well as in some fungal melanin extracts. We

Differential Antifungal Activity of Human and Cryptococcal Melanins with Structural Discrepancies

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Néstor Correa

2017-07-01

Full Text Available Melanin is a pigment found in all biological kingdoms, and plays a key role in protection against ultraviolet radiation, oxidizing agents, and ionizing radiation damage. Melanin exerts an antimicrobial activity against bacteria, fungi, and parasites. We demonstrated an antifungal activity of synthetic and human melanin against Candida sp. The members of the Cryptococcus neoformans and C. gattii species complexes are capsulated yeasts, which cause cryptococcosis. For both species melanin is an important virulence factor. To evaluate if cryptococcal and human melanins have antifungal activity against Cryptococcus species they both were assayed for their antifungal properties and physico-chemical characters. Melanin extracts from human hair and different strains of C. neoformans (n = 4 and C. gattii (n = 4 were investigated. The following minimum inhibitory concentrations were found for different melanins against C. neoformans and C. gattii were (average/range: 13.7/(7.8–15.6 and 19.5/(15.6–31.2 μg/mL, respectively, for human melanin; 273.4/(125–>500 and 367.2/(125.5–>500 μg/mL for C. neoformans melanin and 125/(62.5–250 and 156.2/(62–250 μg/mL for C. gattii melanin. Using Scanning Electron Microscopy we observed that human melanin showed a compact conformation and cryptococcal melanins exposed an amorphous conformation. Infrared spectroscopy (FTIR showed some differences in the signals related to C-C bonds of the aromatic ring of the melanin monomers. High Performance Liquid Chromatography established differences in the chromatograms of fungal melanins extracts in comparison with human and synthetic melanin, particularly in the retention time of the main compound of fungal melanin extracts and also in the presence of minor unknown compounds. On the other hand, MALDI-TOF-MS analysis showed slight differences in the spectra, specifically the presence of a minor intensity ion in synthetic and human melanin, as well as in some fungal

Evaluation of melanin production by Sporothrix luriei.

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Cruz, Ingrid Ludmilla Rodrigues; Figueiredo-Carvalho, Maria Helena Galdino; Zancopé-Oliveira, Rosely Maria; Almeida-Paes, Rodrigo

2018-01-01

There is a paucity of studies on the cell biology of Sporothrix luriei, the less common of the pathogenic Sporothrix species worldwide. The production of DHN-melanin, eumelanin, and pyomelanin were evaluated on the mycelial and yeast forms of the S. luriei ATCC 18616 strain. The mycelial form of this species produced only pyomelanin, which protected the fungus against environmental stressors such as ultraviolet light, heat, and cold. The yeast form was unable to produce any of the tested melanin types. The lack of melanin in the parasitic form of S. luriei may be an explanation for its low frequency in human infections.

Potential biosurfactant producing endophytic and epiphytic fungi ...

African Journals Online (AJOL)

Potential biosurfactant producing endophytic and epiphytic fungi, isolated from macrophytes in the Negro River in Manaus, Amazonas, Brazil. ... Solms and Cyperus ligularis L., macrophytes collected from oil-contaminated waters, were studied to assess their potential for producing biosurfactants; the most promising ones ...

Evaluation of melanin production by Sporothrix luriei

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Ingrid Ludmilla Rodrigues Cruz

Full Text Available There is a paucity of studies on the cell biology of Sporothrix luriei, the less common of the pathogenic Sporothrix species worldwide. The production of DHN-melanin, eumelanin, and pyomelanin were evaluated on the mycelial and yeast forms of the S. luriei ATCC 18616 strain. The mycelial form of this species produced only pyomelanin, which protected the fungus against environmental stressors such as ultraviolet light, heat, and cold. The yeast form was unable to produce any of the tested melanin types. The lack of melanin in the parasitic form of S. luriei may be an explanation for its low frequency in human infections.

Singlet molecular oxygen generation by light-activated DHN-melanin of the fungal pathogen Mycosphaerella fijiensis in black Sigatoka disease of bananas.

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Beltrán-García, Miguel J; Prado, Fernanda M; Oliveira, Marilene S; Ortiz-Mendoza, David; Scalfo, Alexsandra C; Pessoa, Adalberto; Medeiros, Marisa H G; White, James F; Di Mascio, Paolo

2014-01-01

In pathogenic fungi, melanin contributes to virulence, allowing tissue invasion and inactivation of the plant defence system, but has never been implicated as a factor for host cell death, or as a light-activated phytotoxin. Our research shows that melanin synthesized by the fungal banana pathogen Mycosphaerella fijiensis acts as a virulence factor through the photogeneration of singlet molecular oxygen O2 (1Δg). Using analytical tools, including elemental analysis, ultraviolet/infrared absorption spectrophometry and MALDI-TOF mass spectrometry analysis, we characterized both pigment content in mycelia and secreted to the culture media as 1,8-dihydroxynaphthalene (DHN)-melanin type compound. This is sole melanin-type in M. fijiensis. Isolated melanins irradiated with a Nd:YAG laser at 532 nm produced monomol light emission at 1270 nm, confirming generation of O2 (1Δg), a highly reactive oxygen specie (ROS) that causes cellular death by reacting with all cellular macromolecules. Intermediary polyketides accumulated in culture media by using tricyclazole and pyroquilon (two inhibitors of DHN-melanin synthesis) were identified by ESI-HPLC-MS/MS. Additionally, irradiation at 532 nm of that mixture of compounds and whole melanized mycelium also generated O2 (1Δg). A pigmented-strain generated more O2 (1Δg) than a strain with low melanin content. Banana leaves of cultivar Cavendish, naturally infected with different stages of black Sigatoka disease, were collected from field. Direct staining of the naturally infected leaf tissues showed the presence of melanin that was positively correlated to the disease stage. We also found hydrogen peroxide (H2O2) but we cannot distinguish the source. Our results suggest that O2 (1Δg) photogenerated by DHN-melanin may be involved in the destructive effects of Mycosphaerella fijiensis on banana leaf tissues. Further studies are needed to fully evaluate contributions of melanin-mediated ROS to microbial pathogenesis.

Pigmented epidermal cyst with dense collection of melanin: A rare entity - Report of a case with review of the literature.

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Jayalakshmy, P S; Subitha, K; Priya, P V; Johnson, Gerald

2012-05-01

Epidermal cyst is a very common benign cystic lesion of the skin. It is usual to find ulceration of the lining epithelium, rupture of the cyst wall with chronic inflammation and foreign body giant cell reaction. But, it is very rare to see an epidermal cyst with marked accumulation of melanin pigment. Only a few cases of pigmented epidermal cyst with dense collection of melanin pigment have been published in the literature. Here, we are reporting a case of ruptured epidermal cyst with keratin granuloma formation and showing dense collection of melanin pigment.

Different culture media containing methyldopa for melanin production by Cryptococcus species

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Ralciane de Paula Menezes

2011-10-01

Full Text Available INTRODUCTION: Melanin production by species of Cryptococcus is widely used to characterize C. neoformans complex in mycology laboratories. This study aims to test the efficacy of methyldopa from pharmaceutical tablet as a substrate for melanin production, to compare the production of melanin using different agar base added with methyldopa, and to compare the melanin produced in those media with that produced in Niger seed agar and sunflower seed agar by C. neoformans, C. laurentii, and C. albidus. Two isolates of each species, C. neoformans, C. laurentii, and C. albidus, and one of Candida albicans were used to experimentally detect conditions for melanin production. METHODS: The following media were tested: Mueller-Hinton agar (MHA, brain and heart infusion agar (BHIA, blood agar base (BAB, and minimal medium agar (MMA, all added with methyldopa, and the media Niger seed agar (NSA and sunflower seed agar (SSA. RESULTS: All isolates grew in most of the culture media after 24h. Strains planted on media BAB and BHIA showed growth only after 48h. All isolates produced melanin in MMA, MHA, SSA, and NSA media. CONCLUSIONS: Methyldopa in the form pharmaceutical tablet can be used as a substrate for melanin production by Cryptococcus species; minimal medium plus methyldopa was more efficient than the BAB, MHA, and BHIA in the melanin production; and NSA and SSA, followed by MMA added with methyldopa, were more efficient than other media studied for melanin production by all strains studied.

Isolation and characterization of endophytic huperzine A-producing fungi from Huperzia serrata.

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Wang, Ya; Zeng, Qing Gui; Zhang, Zhi Bin; Yan, Ri Ming; Wang, Ling Yun; Zhu, Du

2011-09-01

Huperzia serrata is a producer of huperzine A (HupA), a cholinesterase inhibitor (ChEI). Over 120 endophytic fungi were recovered from this plant and screened for Hup-A and nine were found. These nine represented seven different fungal genera with the most significant producer being Shiraia sp. A total of 127 endophytic fungi isolates obtained from the root, stem, and leaf segments of H. serrata were grouped into 19 genera based on their morphological traits and sequence analysis of the internal transcribed spacers (ITS1-5.8S-ITS2), indicating endophytic fungi in H. serrata are diverse and abundant. Aspergillus, Podospora, Penicillium, Colletotrichum, and Acremonium were the frequent genera, whereas the remaining genera were infrequent groups. Overall, 39 endophytic fungi isolates showed acetylcholinesterase (AChE) inhibition in vitro. Nine endophytic fungi isolates from seven distinct genera were capable of producing HupA verified by thin-layer chromatography and reverse-phase high-performance liquid chromatography (RP-HPLC). Among the HupA-producing fungi, the yield of HupA produced by the Shiraia sp. Slf14 was 327.8 μg/l in potato dextrose broth, and the fungal HupA was further validated by mass spectrometry (ESI-MS). The present study demonstrated that H. serrata was a fascinating fungal reservoir for producing HupA and other ChEIs.

Influence of chitosan and melanin-glucan complex onto gamma-exposure with low doses and acute stressful reaction

International Nuclear Information System (INIS)

Senyuk, O.F.; Tarasenko, P.D.; Pazukhin, Eh.M.; Gorovoj, L.F.; Varlamov, V.P.

2004-01-01

Possibilities of prevention and reduction of consequences of acute exposure on the background of immobilization stress with the help of chitosan preparations and of melanin - glucan complex of highest bazidiomicetes (fungi) were studied. Tested preparations were capable to protect hematological and immunological homeostasis of line BALB/c mice from stressful reaction provoked by acute exposure and two-hour immobilization. The most expressed normalizing and adapting effect had the mixture composed of chitosan and melanin-glucan complex

Expression of melanin and insecticidal protein from Rhodotorula ...

African Journals Online (AJOL)

Both the salmon/red melanin and the insecticidal producing genes of Rhodotorula glutinis was successfully expressed in Escherichia coli using plasmid pZErO-1. This work suggests that in Rhodotorula species melanin and insecticidal toxin are co-expressed and therefore possibly co-evolved. Keywords: Rhodotorula ...

Bio-inspired Structural Colors from Deposition of Synthetic Melanin Nanoparticles by Evaporative Self-assembly

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Xiao, Ming; Li, Yiwen; Deheyn, Dimitri; Yue, Xiujun; Gianneschi, Nathan; Shawkey, Matthew; Dhinojwala, Ali

2015-03-01

Melanin, a ubiquitous black or brown pigment in the animal kingdom, is a unique but poorly understood biomaterial. Many bird feathers contain melanosomes (melanin-containing organelles), which pack into ordered nanostructures, like multilayer or two-dimensional photonic crystal structures, to produce structural colors. To understand the optical properties of melanin and how melanosomes assemble into certain structures to produce colors, we prepared synthetic melanin (polydopamine) particles with variable sizes and aspect ratios. We have characterized the absorption and refractive index of the synthetic melanin particles. We have also shown that we can use an evaporative process to self-assemble melanin films with a wide range of colors. The colors obtained using this technique is modeled using a thin-film interference model and the optical properties of the synthetic melanin nanoparticles. Our results on self-assembly of synthetic melanin nanoparticles provide an explanation as why the use of melanosomes to produce colors is prevalent in the animal kingdom. National science foundation, air force office of scientific research, human frontier science program.

Singlet molecular oxygen generation by light-activated DHN-melanin of the fungal pathogen Mycosphaerella fijiensis in black Sigatoka disease of bananas.

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Miguel J Beltrán-García

Full Text Available In pathogenic fungi, melanin contributes to virulence, allowing tissue invasion and inactivation of the plant defence system, but has never been implicated as a factor for host cell death, or as a light-activated phytotoxin. Our research shows that melanin synthesized by the fungal banana pathogen Mycosphaerella fijiensis acts as a virulence factor through the photogeneration of singlet molecular oxygen O2 (1Δg. Using analytical tools, including elemental analysis, ultraviolet/infrared absorption spectrophometry and MALDI-TOF mass spectrometry analysis, we characterized both pigment content in mycelia and secreted to the culture media as 1,8-dihydroxynaphthalene (DHN-melanin type compound. This is sole melanin-type in M. fijiensis. Isolated melanins irradiated with a Nd:YAG laser at 532 nm produced monomol light emission at 1270 nm, confirming generation of O2 (1Δg, a highly reactive oxygen specie (ROS that causes cellular death by reacting with all cellular macromolecules. Intermediary polyketides accumulated in culture media by using tricyclazole and pyroquilon (two inhibitors of DHN-melanin synthesis were identified by ESI-HPLC-MS/MS. Additionally, irradiation at 532 nm of that mixture of compounds and whole melanized mycelium also generated O2 (1Δg. A pigmented-strain generated more O2 (1Δg than a strain with low melanin content. Banana leaves of cultivar Cavendish, naturally infected with different stages of black Sigatoka disease, were collected from field. Direct staining of the naturally infected leaf tissues showed the presence of melanin that was positively correlated to the disease stage. We also found hydrogen peroxide (H2O2 but we cannot distinguish the source. Our results suggest that O2 (1Δg photogenerated by DHN-melanin may be involved in the destructive effects of Mycosphaerella fijiensis on banana leaf tissues. Further studies are needed to fully evaluate contributions of melanin-mediated ROS to microbial pathogenesis.

Effects of melanin on the accumulation of exopolysaccharides by Aureobasidium pullulans grown on nitrate.

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Zheng, Weifa; Campbell, Bradley S; McDougall, Barbara M; Seviour, Robert J

2008-11-01

Aureobasidium pullulans produced pullulan and melanin when grown in medium containing low nitrate levels. With high nitrate concentrations, however, this fungus produced a mixture of exopolysaccharides (EPS) without melanin synthesis. At 0.78 g l(-1) N as nitrate, where no melanin synthesis occurred, maximum EPS yields reached 6.92 g l(-1) and then decreased to the final yield of 2.36 g l(-1). Following melanin addition (0.1 g l(-1)), yields reached 7.02 g l(-1) at 48 h and fell to a final yield of 5.21 g l(-1). The EPS produced in high nitrate medium contained both pullulan and (1-->3)-beta-glucan, but only pullulan was produced with melanin-supplementation. With melanin addition a doubling of (1-->3)-beta-glucanase activity was observed in high nitrate medium compared to that without supplementation. On the other hand amylolytic activities disappeared in medium with melanin production or addition. Culture filtrates sustained a higher reducing capacity (RC) when melanin was present. Low RC appeared to reduce (1-->3)-beta-glucanase activity and increase amylolytic activities. Thus, higher RC appears to inhibit production/activity of amylose-degrading enzymes capable of degrading pullulan, and stimulates (1-->3)-beta-glucanase synthesis/activity, leading to a preferential accumulation of pullulan.

Metal-chelating compounds produced by ectomycorrhizal fungi collected from pine plantations.

Science.gov (United States)

Machuca, A; Pereira, G; Aguiar, A; Milagres, A M F

2007-01-01

To investigate the in vitro production of metal-chelating compounds by ectomycorrhizal fungi collected from pine plantations in southern Chile. Scleroderma verrucosum, Suillus luteus and two isolates of Rhizopogon luteolus were grown in solid and liquid modified Melin-Norkans (MMN) media with and without iron addition and the production of iron-chelating compounds was determined by Chrome Azurol S (CAS) assay. The presence of hydroxamate and catecholate-type compounds and organic acids was also investigated in liquid medium. All isolates produced iron-chelating compounds as detected by CAS assay, and catecholates, hydroxamates as well as oxalic, citric and succinic acids were also detected in all fungal cultures. Scleroderma verrucosum produced the greatest amounts of catecholates and hydroxamates whereas the highest amounts of organic acids were detected in S. luteus. Nevertheless, the highest catecholate, hydroxamate and organic acid concentrations did not correlate with the highest CAS reaction which was observed in R. luteolus (Yum isolate). Ectomycorrhizal fungi produced a variety of metal-chelating compounds when grown in liquid MMN medium. However, the addition of iron to all fungi cultures reduced the CAS reaction, hydroxamate and organic acid concentrations. Catecholate production was affected differently by iron, depending on the fungal isolate. The ectomycorrhizal fungi described in this study have never been reported to produce metal-chelating compound production. Moreover, apart from some wood-rotting fungi, this is the first evidence of the presence of catecholates in R. luteolus, S. luteus and S. verrucosum cultures.

Mathematical modeling predicts enhanced growth of X-ray irradiated pigmented fungi.

Directory of Open Access Journals (Sweden)

Igor Shuryak

Full Text Available Ionizing radiation is known for its cytotoxic and mutagenic properties. However, recent evidence suggests that chronic sub-lethal irradiation stimulates the growth of melanin-pigmented (melanized fungi, supporting the hypothesis that interactions between melanin and ionizing photons generate energy useful for fungal growth, and/or regulate growth-promoting genes. There are no quantitative models of how fungal proliferation is affected by ionizing photon energy, dose rate, and presence versus absence of melanin on the same genetic background. Here we present such a model, which we test using experimental data on melanin-modulated radiation-induced proliferation enhancement in the fungus Cryptococcus neoformans, exposed to two different peak energies (150 and 320 kVp over a wide range of X-ray dose rates. Our analysis demonstrates that radiation-induced proliferation enhancement in C. neoformans behaves as a binary "on/off" phenomenon, which is triggered by dose rates 5000 mGy/h. Proliferation enhancement of irradiated cells compared with unirradiated controls occurs at both X-ray peak energies, but its magnitude is modulated by X-ray peak energy and cell melanization. At dose rates <5000 mGy/h, both melanized and non-melanized cells exposed to 150 kVp X-rays, and non-melanized cells exposed to 320 kVp X-rays, all exhibit the same proliferation enhancement: on average, chronic irradiation stimulates each founder cell to produce 100 (95% CI: 83, 116 extra descendants over 48 hours. Interactions between melanin and 320 kVp X-rays result in a significant (2-tailed p-value = 4.8 × 10(-5 additional increase in the number of radiation-induced descendants per founder cell: by 55 (95% CI: 29, 81. These results show that both melanin-dependent and melanin-independent mechanisms are involved in radiation-induced fungal growth enhancement, and implicate direct and/or indirect interactions of melanin with high energy ionizing photons as an important pro

Fluorescent quantification of melanin.

Science.gov (United States)

Fernandes, Bruno; Matamá, Teresa; Guimarães, Diana; Gomes, Andreia; Cavaco-Paulo, Artur

2016-11-01

Melanin quantification is reportedly performed by absorption spectroscopy, commonly at 405 nm. Here, we propose the implementation of fluorescence spectroscopy for melanin assessment. In a typical in vitro assay to assess melanin production in response to an external stimulus, absorption spectroscopy clearly overvalues melanin content. This method is also incapable of distinguishing non-melanotic/amelanotic control cells from those that are actually capable of performing melanogenesis. Therefore, fluorescence spectroscopy is the best method for melanin quantification as it proved to be highly specific and accurate, detecting even small variations in the synthesis of melanin. This method can also be applied to the quantification of melanin in more complex biological matrices like zebrafish embryos and human hair. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Melanin as an active layer in biosensors

Energy Technology Data Exchange (ETDEWEB)

Piacenti da Silva, Marina, E-mail: marinaness@yahoo.com; Congiu, Mirko, E-mail: congiumat@gmail.com; Oliveira Graeff, Carlos Frederico de, E-mail: graeff@fc.unesp.br [Department of Physics, Faculty of Sciences - UNESP, Bauru, SP (Brazil); Fernandes, Jéssica Colnaghi, E-mail: jeziga-cf@yahoo.com.br; Biziak de Figueiredo, Natália, E-mail: natbiziak@yahoo.com.br; Mulato, Marcelo, E-mail: mmulato@ffclrp.usp.br [Department of Physics, Faculty of Philosophy, Science and Letters at Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP (Brazil)

2014-03-15

The development of pH sensors is of great interest due to its extensive application in several areas such as industrial processes, biochemistry and particularly medical diagnostics. In this study, the pH sensing properties of an extended gate field effect transistor (EGFET) based on melanin thin films as active layer are investigated and the physical mechanisms related to the device operation are discussed. Thin films were produced from different melanin precursors on indium tin oxide (ITO) and gold substrates and were investigated by Atomic Force Microscopy and Electrochemical Impedance Spectroscopy. Experiments were performed in the pH range from 2 to 12. EGFETs with melanin deposited on ITO and on gold substrates showed sensitivities ranging from 31.3 mV/pH to 48.9 mV/pH, depending on the melanin precursor and the substrate used. The pH detection is associated with specific binding sites in its structure, hydroxyl groups and quinone imine.

Melanin as an active layer in biosensors

International Nuclear Information System (INIS)

Piacenti da Silva, Marina; Congiu, Mirko; Oliveira Graeff, Carlos Frederico de; Fernandes, Jéssica Colnaghi; Biziak de Figueiredo, Natália; Mulato, Marcelo

2014-01-01

The development of pH sensors is of great interest due to its extensive application in several areas such as industrial processes, biochemistry and particularly medical diagnostics. In this study, the pH sensing properties of an extended gate field effect transistor (EGFET) based on melanin thin films as active layer are investigated and the physical mechanisms related to the device operation are discussed. Thin films were produced from different melanin precursors on indium tin oxide (ITO) and gold substrates and were investigated by Atomic Force Microscopy and Electrochemical Impedance Spectroscopy. Experiments were performed in the pH range from 2 to 12. EGFETs with melanin deposited on ITO and on gold substrates showed sensitivities ranging from 31.3 mV/pH to 48.9 mV/pH, depending on the melanin precursor and the substrate used. The pH detection is associated with specific binding sites in its structure, hydroxyl groups and quinone imine

Lipase-producing fungi for potential wastewater treatment and ...

African Journals Online (AJOL)

Tuoyo Aghomotsegin

2016-05-04

May 4, 2016 ... food, chemical, and pharmaceutical industry means the current global ... be the most convenient biosystem for industrial applications ... Fungi are capable of producing several enzymes for ... strains, and the process results in losses to the isolation ..... technical and economic burdens of lipase production.

Hyperosmotic stress reduces melanin production by altering melanosome formation.

Science.gov (United States)

Bin, Bum-Ho; Bhin, Jinhyuk; Yang, Seung Ha; Choi, Dong-Hwa; Park, Kyuhee; Shin, Dong Wook; Lee, Ai-Young; Hwang, Daehee; Cho, Eun-Gyung; Lee, Tae Ryong

2014-01-01

Many tissues of the human body encounter hyperosmotic stress. The effect of extracellular osmotic changes on melanin production has not yet been elucidated. In this study, we determined that hyperosmotic stress induced by organic osmolytes results in reduced melanin production in human melanoma MNT-1 cells. Under hyperosmotic stress, few pigmented mature melanosomes were detected, but there was an increase in swollen vacuoles. These vacuoles were stained with an anti-M6PR antibody that recognizes late endosomal components and with anti-TA99 and anti-HMB45 antibodies, implying that melanosome formation was affected by hyperosmotic stress. Electron microscopic analysis revealed that the M6PR-positive swollen vacuoles were multi-layered and contained melanized granules, and they produced melanin when L-DOPA was applied, indicating that these vacuoles were still capable of producing melanin, but the inner conditions were not compatible with melanin production. The vacuolation phenomenon induced by hyperosmotic conditions disappeared with treatment with the PI3K activator 740 Y-P, indicating that the PI3K pathway is affected by hyperosmotic conditions and is responsible for the proper formation and maturation of melanosomes. The microarray analysis showed alterations of the vesicle organization and transport under hyperosmotic stress. Our findings suggest that melanogenesis could be regulated by physiological conditions, such as osmotic pressure.

Interactions of fungi from fermented sausage with regenerated cellulose casings.

Science.gov (United States)

Sreenath, Hassan K; Jeffries, Thomas W

2011-11-01

This research examined cellulolytic effects of fungi and other microbes present in cured sausages on the strength and stability of regenerated cellulose casings (RCC) used in the sausage industry. Occasionally during the curing process, RCC would split or fail, thereby leading to loss of product. The fungus Penicillium sp. BT-F-1, which was isolated from fermented sausages, and other fungi, which were introduced to enable the curing process, produced small amounts of cellulases on RCC in both liquid and solid cultivations. During continued incubation for 15-60 days in solid substrate cultivation (SSC) on RCC support, the fungus Penicillium sp isolate BT-F-1 degraded the casings' dry weights by 15-50% and decreased their tensile strengths by ~75%. Similarly commercial cellulase(s) resulted in 20-50% degradation of RCC in 48 h. During incubation with Penicillium sp BT-F-1, the surface structure of RCC collapsed, resulting in loss of strength and stability of casings. The matrix of industrial RCC comprised 88-93% glucose polymer residues with 0.8-4% xylan impurities. Premature casing failure appeared to result from operating conditions in the manufacturing process that allowed xylan to build up in the extrusion bath. The sausage fungus Penicillium sp BT-F-1 produced xylanases to break down soft xylan pockets prior to slow cellulosic dissolution of RCC.

Melanin-Associated Synthesis of SERS-Active Nanostructures and the Application for Monitoring of Intracellular Melanogenesis

OpenAIRE

Haixin Dong; Zhiming Liu; Huiqing Zhong; Hui Yang; Yan Zhou; Yuqing Hou; Jia Long; Jin Lin; Zhouyi Guo

2017-01-01

Melanin plays an indispensable role in the human body. It serves as a biological reducer for the green synthesis of precious metal nanoparticles. Melanin?Ag nanocomposites were successfully produced which exhibited very strong surface-enhanced Raman scattering (SERS) effect because of the reducibility property of melanin. A melanin?Ag composite structure was synthesized in situ in melanin cells, and SERS technique was performed for the rapid imaging and quantitative assay of intracellular mel...

(Pheo)melanin photosensitizes UVA-induced DNA damage in cultured human melanocytes

NARCIS (Netherlands)

Wenczl, E.; Schans, G.P. van der; Roza, L.; Kolb, R.M.; Timmerman, A.J.; Smit, N.P.M.; Pavel, S.; Schothorst, A.A.

1998-01-01

The question of whether melanins are photoprotecting and/or photosensitizing in human skin cells continues to be debated. To evaluate the role of melanin upon UVA irradiation, DNA single-strand breaks (ssb) were measured in human melanocytes differing only in the amount of pigment produced by

Biocompatibility of biodegradable semiconducting melanin films for nerve tissue engineering.

Science.gov (United States)

Bettinger, Christopher J; Bruggeman, Joost P; Misra, Asish; Borenstein, Jeffrey T; Langer, Robert

2009-06-01

The advancement of tissue engineering is contingent upon the development and implementation of advanced biomaterials. Conductive polymers have demonstrated potential for use as a medium for electrical stimulation, which has shown to be beneficial in many regenerative medicine strategies including neural and cardiac tissue engineering. Melanins are naturally occurring pigments that have previously been shown to exhibit unique electrical properties. This study evaluates the potential use of melanin films as a semiconducting material for tissue engineering applications. Melanin thin films were produced by solution processing and the physical properties were characterized. Films were molecularly smooth with a roughness (R(ms)) of 0.341 nm and a conductivity of 7.00+/-1.10 x 10(-5)S cm(-1) in the hydrated state. In vitro biocompatibility was evaluated by Schwann cell attachment and growth as well as neurite extension in PC12 cells. In vivo histology was evaluated by examining the biomaterial-tissue response of melanin implants placed in close proximity to peripheral nerve tissue. Melanin thin films enhanced Schwann cell growth and neurite extension compared to collagen films in vitro. Melanin films induced an inflammation response that was comparable to silicone implants in vivo. Furthermore, melanin implants were significantly resorbed after 8 weeks. These results suggest that solution-processed melanin thin films have the potential for use as a biodegradable semiconducting biomaterial for use in tissue engineering applications.

The effect of melanin on the bystander effect in human keratinocytes

Energy Technology Data Exchange (ETDEWEB)

Mosse, I. [Institute of Genetics and Cytology of the National Academy of Sciences, Academicheskaya Str. 27, Minsk (Belarus)]. E-mail: i.mosse@igc.bas-net.by; Marozik, P. [Institute of Genetics and Cytology of the National Academy of Sciences, Academicheskaya Str. 27, Minsk (Belarus); Radiation and Environmental Science Centre, DIT, Dublin 8 (Ireland); Seymour, C. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ont. (Canada); Mothersill, C. [Department of Medical Physics and Applied Radiation Sciences, McMaster University, Hamilton, Ont. (Canada)

2006-05-11

The influence of melanin on radiation-induced bystander effects has been studied. Melanin is known to be a natural substance with proved radioprotective properties in different organisms and cell lines. It is non-toxic and is effective against acute and chronic irradiation. The lower the radiation dose, the higher the relative impact of melanin protection. In this study influence of melanin on human keratinocytes (HPV-G cells) has been studied using the colony-forming assay. We have shown that bystander donor medium from 0.5 Gy irradiated cells when transferred to unirradiated cells, caused almost the same effect as direct irradiation. Melanin increased the colony-forming ability of bystander recipient cells when it was added into culture medium before irradiation. The effect of melanin added after irradiation was to produce less protection in both the directly irradiated and bystander medium treated groups. The absorption spectrum of the filtered medium is identical to one of the intact culture medium showing that melanin was not present in filtered medium. Thus, it cannot protect recipient cells but reduces the amount of the bystander effect. It is concluded that melanin added before irradiation effectively decreased the radiation dose. The reduction of the impact of the bystander signal on recipient cells when melanin was added to the donor medium after harvest but before filtration, may mean that the bystander signal has a physical component as melanin can absorb all types of physical energy.

The effect of melanin on the bystander effect in human keratinocytes

International Nuclear Information System (INIS)

Mosse, I.; Marozik, P.; Seymour, C.; Mothersill, C.

2006-01-01

The influence of melanin on radiation-induced bystander effects has been studied. Melanin is known to be a natural substance with proved radioprotective properties in different organisms and cell lines. It is non-toxic and is effective against acute and chronic irradiation. The lower the radiation dose, the higher the relative impact of melanin protection. In this study influence of melanin on human keratinocytes (HPV-G cells) has been studied using the colony-forming assay. We have shown that bystander donor medium from 0.5 Gy irradiated cells when transferred to unirradiated cells, caused almost the same effect as direct irradiation. Melanin increased the colony-forming ability of bystander recipient cells when it was added into culture medium before irradiation. The effect of melanin added after irradiation was to produce less protection in both the directly irradiated and bystander medium treated groups. The absorption spectrum of the filtered medium is identical to one of the intact culture medium showing that melanin was not present in filtered medium. Thus, it cannot protect recipient cells but reduces the amount of the bystander effect. It is concluded that melanin added before irradiation effectively decreased the radiation dose. The reduction of the impact of the bystander signal on recipient cells when melanin was added to the donor medium after harvest but before filtration, may mean that the bystander signal has a physical component as melanin can absorb all types of physical energy

Photothermal imaging of melanin

Science.gov (United States)

Kerimo, Josef; DiMarzio, Charles A.

2013-02-01

We present photothermal images of melanin using modulation with two laser beams. Strong melanin absorption followed by efficient nonradiative relaxation caused heating and an increase in temperature. This temperature effect was used as an imaging contrast to detect melanin. Melanin from several samples including Sepia officinalis, black human hair, and live zebra fish, were imaged with a high signal-to-noise ratio. For the imaging, we focused two near infrared laser beams (pump and probe) collinearly with different wavelengths and the pump was modulated in amplitude. The thermally induced variations in the refractive index, at the modulation frequency, were detected by the scattering of the probe beam. The Photothermal method brings several imaging benefits including the lack of background interference and the possibility of imaging for an extended period of time without photodamage to the melanin. The dependence of the photothermal signal on the laser power, modulation frequency, and spatial offset of the probe is discussed. The new photothermal imaging method is promising and provides background-free and label-free imaging of melanin and can be implemented with low-cost CW lasers.

Role of Melanin in Oncogenesis

Science.gov (United States)

2011-08-01

and validating the role of melanin in human melanoma pathobiology. Conclusions  Chronic production of excess melanin caused unique gene...vitro effects in a small sample size.  A long-term study with animal models and human patient specimens is needed to determine if excess melanin ...AD_________________ Award Number: W81XWH-10-1-0066 TITLE: Role of Melanin in Oncogenesis

B16F1 melanoma cells upregulate melanin synthesis after photodynamic therapy

International Nuclear Information System (INIS)

Moder, A.; Gassner, F.; Krammer, B.; Thalhamer, J.; Hammerl, P.

2003-01-01

Full text: The success of photodynamic therapy (PDT) of melanotic tumors is severely limited by insufficient penetration of light into deeper tissue layers. In this study, we analyzed the effect of PDT on the melanin production of the melanoma cell line B16F1. In vitro, these cells produce only little melanin. However, after PDT we found a dramatic elevation in intracellular melanin. Melanin production increased with, both, the concentration of the sensitizing agent and the light dose, and was found to continue for several hours after cell death. PDT-induced melanin synthesis was not prevented by the addition of cycloheximide or actinomycin D prior to irradiation, indicating that de-novo protein synthesis and transcriptional activity are not required for this effect. We also analyzed tyrosinase activity, a key enzyme in melanin biosynthesis, in PDT-treated B16 cells. Tyrosinase activity was found in PDT-treated as well as untreated cells. Cell fractionation experiments showed that tyrosinase was present in the cytosolic as well as the melanosomal fractions of, both, PDT-treated (melanin-high) as well as untreated (melanin-low) cells. These data indicate that PDT-induced production of melanin is not controlled at the transcriptional or translational level and that tyrosinase is not likely an essential regulator in this process. (author)

Keratinocyte-derived laminin-332 protein promotes melanin synthesis via regulation of tyrosine uptake.

Science.gov (United States)

Chung, Heesung; Jung, Hyejung; Lee, Jung-Hyun; Oh, Hye Yun; Kim, Ok Bin; Han, Inn-Oc; Oh, Eok-Soo

2014-08-01

Melanocytes, which produce the pigment melanin, are known to be closely regulated by neighboring keratinocytes. However, how keratinocytes regulate melanin production is unclear. Here we report that melanin production in melanoma cells (B16F10 and MNT-1) was increased markedly on a keratinocyte-derived extracellular matrix compared with a melanoma cell-derived extracellular matrix. siRNA-mediated reduction of keratinocyte-derived laminin-332 expression decreased melanin synthesis in melanoma cells, and laminin-332, but not fibronectin, enhanced melanin content and α-melanocyte-stimulating hormone-regulated melanin production in melanoma cells. Similar effects were observed in human melanocytes. Interestingly, however, laminin-332 did not affect the expression or activity of tyrosinase. Instead, laminin-332 promoted the uptake of extracellular tyrosine and, subsequently, increased intracellular levels of tyrosine in both melanocytes and melanoma cells. Taken together, these data strongly suggest that keratinocyte-derived laminin-332 contributes to melanin production by regulating tyrosine uptake. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

Transcription Factor Amr1 Induces Melanin Biosynthesis and Suppresses Virulence in Alternaria brassicicola

Energy Technology Data Exchange (ETDEWEB)

Cho, Yangrae; Srivastava, Akhil; Ohm, Robin A.; Lawrence, Christopher B.; Wang, Koon-Hui; Grigoriev, Igor V.; Marahatta, Sharadchandra P.

2012-05-01

Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. Several A. brassicicola genes have been characterized as affecting pathogenesis of Brassica species. To study regulatory mechanisms of pathogenesis, we mined 421 genes in silico encoding putative transcription factors in a machine-annotated, draft genome sequence of A. brassicicola. In this study, targeted gene disruption mutants for 117 of the transcription factor genes were produced and screened. Three of these genes were associated with pathogenesis. Disruption mutants of one gene (AbPacC) were nonpathogenic and another gene (AbVf8) caused lesions less than half the diameter of wild-type lesions. Unexpectedly, mutants of the third gene, Amr1, caused lesions with a two-fold larger diameter than the wild type and complementation mutants. Amr1 is a homolog of Cmr1, a transcription factor that regulates melanin biosynthesis in several fungi. We created gene deletion mutants of ?amr1 and characterized their phenotypes. The ?amr1 mutants used pectin as a carbon source more efficiently than the wild type, were melanin-deficient, and more sensitive to UV light and glucanase digestion. The AMR1 protein was localized in the nuclei of hyphae and in highly melanized conidia during the late stage of plant pathogenesis. RNA-seq analysis revealed that three genes in the melanin biosynthesis pathway, along with the deleted Amr1 gene, were expressed at low levels in the mutants. In contrast, many hydrolytic enzyme-coding genes were expressed at higher levels in the mutants than in the wild type during pathogenesis. The results of this study suggested that a gene important for survival in nature negatively affected virulence, probably by a less efficient use of plant cell-wall materials. We speculate that the functions of the Amr1 gene are important to the success of A. brassicicola as a competitive saprophyte and plant parasite.

UVA phototransduction drives early melanin synthesis in human melanocytes.

Science.gov (United States)

Wicks, Nadine L; Chan, Jason W; Najera, Julia A; Ciriello, Jonathan M; Oancea, Elena

2011-11-22

Exposure of human skin to solar ultraviolet radiation (UVR), a powerful carcinogen [1] comprising ~95% ultraviolet A (UVA) and ~5% ultraviolet B (UVB) at the Earth's surface, promotes melanin synthesis in epidermal melanocytes [2, 3], which protects skin from DNA damage [4, 5]. UVB causes DNA lesions [6] that lead to transcriptional activation of melanin-producing enzymes, resulting in delayed skin pigmentation within days [7]. In contrast, UVA causes primarily oxidative damage [8] and leads to immediate pigment darkening (IPD) within minutes, via an unknown mechanism [9, 10]. No receptor protein directly mediating phototransduction in skin has been identified. Here we demonstrate that exposure of primary human epidermal melanocytes (HEMs) to UVA causes calcium mobilization and early melanin synthesis. Calcium responses were abolished by treatment with G protein or phospholipase C (PLC) inhibitors or by depletion of intracellular calcium stores. We show that the visual photopigment rhodopsin [11] is expressed in HEMs and contributes to UVR phototransduction. Upon UVR exposure, significant melanin production was measured within one hour; cellular melanin continued to increase in a retinal- and calcium-dependent manner up to 5-fold after 24 hr. Our findings identify a novel UVA-sensitive signaling pathway in melanocytes that leads to calcium mobilization and melanin synthesis and may underlie the mechanism of IPD in human skin. Copyright © 2011 Elsevier Ltd. All rights reserved.

Evidence for the ectopic synthesis of melanin in human adipose tissue.

Science.gov (United States)

Randhawa, Manpreet; Huff, Tom; Valencia, Julio C; Younossi, Zobair; Chandhoke, Vikas; Hearing, Vincent J; Baranova, Ancha

2009-03-01

Melanin is a common pigment in animals. In humans, melanin is produced in melanocytes, in retinal pigment epithelium (RPE) cells, in the inner ear, and in the central nervous system. Previously, we noted that human adipose tissue expresses several melanogenesis-related genes. In the current study, we confirmed the expression of melanogenesis-related mRNAs and proteins in human adipose tissue using real-time polymerase chain reaction and immunohistochemical staining. TYR mRNA signals were also detected by in situ hybridization in visceral adipocytes. The presence of melanin in human adipose tissue was revealed both by Fontana-Masson staining and by permanganate degradation of melanin coupled with liquid chromatography/ultraviolet/mass spectrometry determination of the pyrrole-2,3,5-tricarboxylic acid (PTCA) derivative of melanin. We also compared melanogenic activities in adipose tissues and in other human tissues using the L-[U-(14)C] tyrosine assay. A marked heterogeneity in the melanogenic activities of individual adipose tissue extracts was noted. We hypothesize that the ectopic synthesis of melanin in obese adipose may serve as a compensatory mechanism that uses its anti-inflammatory and its oxidative damage-absorbing properties. In conclusion, our study demonstrates for the first time that the melanin biosynthesis pathway is functional in adipose tissue.

Melanins in Fossil Animals: Is It Possible to Infer Life History Traits from the Coloration of Extinct Species?

Science.gov (United States)

Negro, Juan J; Finlayson, Clive; Galván, Ismael

2018-01-23

Paleo-colour scientists have recently made the transition from describing melanin-based colouration in fossil specimens to inferring life-history traits of the species involved. Two such cases correspond to counter-shaded dinosaurs: dark-coloured due to melanins dorsally, and light-coloured ventrally. We believe that colour reconstruction of fossils based on the shape of preserved microstructures-the majority of paleo-colour studies involve melanin granules-is not without risks. In addition, animals with contrasting dorso-ventral colouration may be under different selection pressures beyond the need for camouflage, including, for instance, visual communication or ultraviolet (UV) protection. Melanin production is costly, and animals may invest less in areas of the integument where pigments are less needed. In addition, melanocytes exposed to UV radiation produce more melanin than unexposed melanocytes. Pigment economization may thus explain the colour pattern of some counter-shaded animals, including extinct species. Even in well-studied extant species, their diversity of hues and patterns is far from being understood; inferring colours and their functions in species only known from one or few specimens from the fossil record should be exerted with special prudence.

Melanins in Fossil Animals: Is It Possible to Infer Life History Traits from the Coloration of Extinct Species?

Science.gov (United States)

Negro, Juan J.; Finlayson, Clive; Galván, Ismael

2018-01-01

Paleo-colour scientists have recently made the transition from describing melanin-based colouration in fossil specimens to inferring life-history traits of the species involved. Two such cases correspond to counter-shaded dinosaurs: dark-coloured due to melanins dorsally, and light-coloured ventrally. We believe that colour reconstruction of fossils based on the shape of preserved microstructures—the majority of paleo-colour studies involve melanin granules—is not without risks. In addition, animals with contrasting dorso-ventral colouration may be under different selection pressures beyond the need for camouflage, including, for instance, visual communication or ultraviolet (UV) protection. Melanin production is costly, and animals may invest less in areas of the integument where pigments are less needed. In addition, melanocytes exposed to UV radiation produce more melanin than unexposed melanocytes. Pigment economization may thus explain the colour pattern of some counter-shaded animals, including extinct species. Even in well-studied extant species, their diversity of hues and patterns is far from being understood; inferring colours and their functions in species only known from one or few specimens from the fossil record should be exerted with special prudence. PMID:29360744

Melanins in Fossil Animals: Is It Possible to Infer Life History Traits from the Coloration of Extinct Species?

Directory of Open Access Journals (Sweden)

Juan J. Negro

2018-01-01

Full Text Available Paleo-colour scientists have recently made the transition from describing melanin-based colouration in fossil specimens to inferring life-history traits of the species involved. Two such cases correspond to counter-shaded dinosaurs: dark-coloured due to melanins dorsally, and light-coloured ventrally. We believe that colour reconstruction of fossils based on the shape of preserved microstructures—the majority of paleo-colour studies involve melanin granules—is not without risks. In addition, animals with contrasting dorso-ventral colouration may be under different selection pressures beyond the need for camouflage, including, for instance, visual communication or ultraviolet (UV protection. Melanin production is costly, and animals may invest less in areas of the integument where pigments are less needed. In addition, melanocytes exposed to UV radiation produce more melanin than unexposed melanocytes. Pigment economization may thus explain the colour pattern of some counter-shaded animals, including extinct species. Even in well-studied extant species, their diversity of hues and patterns is far from being understood; inferring colours and their functions in species only known from one or few specimens from the fossil record should be exerted with special prudence.

Melanin-binding radiopharmaceuticals

International Nuclear Information System (INIS)

Packer, S.; Fairchild, R.G.; Watts, K.P.; Greenberg, D.; Hannon, S.J.

1980-01-01

The scope of this paper is limited to an analysis of the factors that are important to the relationship of radiopharmaceuticals to melanin. While the authors do not attempt to deal with differences between melanin-binding vs. melanoma-binding, a notable variance is assumed

Melanin-Like Pigment Synthesis by Soil Bacillus weihenstephanensis Isolates from Northeastern Poland.

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Justyna M Drewnowska

Full Text Available Although melanin is known for protecting living organisms from harmful physical and chemical factors, its synthesis is rarely observed among endospore-forming Bacillus cereus sensu lato. Here, for the first time, we reported that psychrotolerant Bacillus weihenstephanensis from Northeastern Poland can produce melanin-like pigment. We assessed physicochemical properties of the pigment and the mechanism of its synthesis in relation to B. weihenstephanensis genotypic and phenotypic characteristics. Electron paramagnetic resonance (EPR spectroscopy displayed a stable free radical signal of the pigment from environmental isolates which are consistent with the commercial melanin. Fourier transform infrared spectroscopy (FT-IR and physicochemical tests indicated the phenolic character of the pigment. Several biochemical tests showed that melanin-like pigment synthesis by B. weihenstephanensis was associated with laccase activity. The presence of the gene encoding laccase was confirmed by the next generation whole genome sequencing of one B. weihenstephanensis strain. Biochemical (API 20E and 50CHB tests and genetic (Multi-locus Sequence Typing, 16S rRNA sequencing, and Pulsed-Field Gel Electrophoresis characterization of the isolates revealed their close relation to the psychrotrophic B. weihenstephanensis DSMZ 11821 reference strain. The ability to synthesize melanin-like pigment by soil B. weihenstephanensis isolates and their psychrotrophic character seemed to be a local adaptation to a specific niche. Detailed genetic and biochemical analyses of melanin-positive environmental B. weihenstephanensis strains shed some light on the evolution and ecological adaptation of these bacteria. Moreover, our study raised new biotechnological possibilities for the use of water-soluble melanin-like pigment naturally produced by B. weihenstephanensis as an alternative to commercial non-soluble pigment.

Targeted Disruption of Melanin Biosynthesis Genes in the Human Pathogenic Fungus Lomentospora prolificans and Its Consequences for Pathogen Survival.

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Al-Laaeiby, Ayat; Kershaw, Michael J; Penn, Tina J; Thornton, Christopher R

2016-03-24

The dematiaceous (melanised) fungus Lomentospora (Scedosporium) prolificans is a life-threatening opportunistic pathogen of immunocompromised humans, resistant to anti-fungal drugs. Melanin has been shown to protect human pathogenic fungi against antifungal drugs, oxidative killing and environmental stresses. To determine the protective role of melanin in L. prolificans to oxidative killing (H₂O₂), UV radiation and the polyene anti-fungal drug amphotericin B, targeted gene disruption was used to generate mutants of the pathogen lacking the dihydroxynaphthalene (DHN)-melanin biosynthetic enzymes polyketide synthase (PKS1), tetrahydroxynapthalene reductase (4HNR) and scytalone dehydratase (SCD1). Infectious propagules (spores) of the wild-type strain 3.1 were black/brown, whereas spores of the PKS-deficient mutant ΔLppks1::hph were white. Complementation of the albino mutant ΔLppks1::hph restored the black-brown spore pigmentation, while the 4HNR-deficient mutant ΔLp4hnr::hph and SCD-deficient mutant ΔLpscd1::hph both produced orange-yellow spores. The mutants ΔLppks1::hph and ΔLp4hnr::hph showed significant reductions in spore survival following H₂O₂ treatment, while spores of ΔLpscd1::hph and the ΔLppks1::hph complemented strain ΔLppks1::hph:PKS showed spore survivals similar to strain 3.1. Spores of the mutants ΔLp4hnr::hph and ΔLpscd1::hph and complemented strain ΔLppks1::hph:PKS showed spore survivals similar to 3.1 following exposure to UV radiation, but survival of ΔLppks1::hph spores was significantly reduced compared to the wild-type strain. Strain 3.1 and mutants ΔLp4hnr::hph and ΔLppks1::hph:PKS were resistant to amphotericin B while, paradoxically, the PKS1- and SCD1-deficient mutants showed significant increases in growth in the presence of the antifungal drug. Taken together, these results show that while melanin plays a protective role in the survival of the pathogen to oxidative killing and UV radiation, melanin does not

Antibodies Against Melanin

African Journals Online (AJOL)

1973-01-06

Jan 6, 1973 ... against the exposed protein moiety of incompletely mel- anized melanosomes. When fully melanized the antigenic protein moiety and tyrosinase may be occluded by the non-antigenic melanin. We have no further data to support this suggestion, because we did not, at the time, examine the melanin by ...

Aspergillus fumigatus melanins: Interference with the host endocytosis pathway and impact on virulence

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Thorsten eHeinekamp

2013-01-01

Full Text Available The opportunistic human pathogenic fungus Aspergillus fumigatus produces at least two types of melanin, namely pyomelanin and dihydroxynaphthalene (DHN melanin. Pyomelanin is produced during tyrosine catabolism via accumulation of homogentisic acid. Although pyomelanin protects the fungus against reactive oxygen species and acts as a defense compound in response to cell wall stress, mutants deficient for pyomelanin biosynthesis do not differ in virulence when tested in a murine infection model for invasive pulmonary aspergillosis. DHN melanin is responsible for the characteristic grey-greenish color of A. fumigatus conidia. Mutants lacking a functional polyketide synthase PksP, the enzyme responsible for the initial step in DHN-melanin formation, i.e., the synthesis of naphthopyrone, produce white spores and are attenuated in virulence. The activity of PksP was found to be essential not only for inhibition of apoptosis of phagocytes by interfering with the host PI3K/Akt signaling cascade but also for effective inhibition of acidification of conidia-containing phagolysosomes. These features allow A. fumigatus to survive in phagocytes and thereby to escape from human immune effector cells and to become a successful pathogen.

Melanin-Based Functional Materials

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Marco d’Ischia

2018-01-01

Full Text Available Melanin biopolymers are currently the focus of growing interest for a broad range of applications at the cutting edge of biomedical research and technology. This Special Issue presents a collection of papers dealing with melanin-type materials, e.g., polydopamine, for classic and innovative applications, offering a stimulating perspective of current trends in the field. Besides basic scientists, the Special Issue is directed to researchers from industries and companies that are willing to invest in melanin research for innovative and inspiring solutions.

The hydrolytic enzymes produced by fungi strains isolated from the sand and soil of recreational areas

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Kurnatowski, Piotr; Wójcik, Anna; Błaszkowska, Joanna; Góralska, Katarzyna

2016-10-01

The pathogenicity of fungi depends on, inter alia, the secretion of hydrolytic enzymes. The aim of this study was to determine the enzymatic activity of yeasts and yeast-like fungi isolated from children’s recreation areas, and compare the results with literature data of strains obtained from patients with mycoses. The enzymatic activity of 96 strains was assessed using an API ZYM kit (bioMerieux, France) and their biotypes were established. The fungal species were found to produce from 16 to 19 hydrolases: the most active were: leucine arylamidase (e5), acid phosphatase (e10), alkaline phosphatase (e1), naphthol-AS-BI-phosphohydrolase (e11), esterase – C4 (e2), β-galac - tosidase (e13) and β-glucosidase (e16). In addition, 13 biotypes characteristic of particular species of fungi were defined. Most strains could be categorized as biotypes C2 – 39.5% and A – 26%. The examined fungal strains isolated from recreational areas have selected biochemical characteristics i.e. production of hydrolases, which demonstrate their pathogenicity. They produce a number of enzymes which are also present in strains isolated from patients with mycoses, including: leucine arylamidase (e5), acid phosphatase (e10), naphthol-AS-BI-phosphohydrolase (e11) and alkaline phosphatase (e1). The biotypes identified in the course of this study (A, B3, B4, C1, C6 and D3) have been also reported in cases of fungal infection. Therefore, the fungi present in the sand and soil of recreational have pathogenic properties and are possible factors of fungal infection among children.

Increased metabolite production by deletion of an HDA1-type histone deacetylase in the phytopathogenic fungi, Magnaporthe oryzae (Pyricularia oryzae) and Fusarium asiaticum.

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Maeda, K; Izawa, M; Nakajima, Y; Jin, Q; Hirose, T; Nakamura, T; Koshino, H; Kanamaru, K; Ohsato, S; Kamakura, T; Kobayashi, T; Yoshida, M; Kimura, M

2017-11-01

Histone deacetylases (HDACs) play an important role in the regulation of chromatin structure and gene expression. We found that dark pigmentation of Magnaporthe oryzae (anamorph Pyricularia oryzae) ΔMohda1, a mutant strain in which an orthologue of the yeast HDA1 was disrupted by double cross-over homologous recombination, was significantly stimulated in liquid culture. Analysis of metabolites in a ΔMohda1 mutant culture revealed that the accumulation of shunt products of the 1,8-dihydroxynaphthalene melanin and ergosterol pathways were significantly enhanced compared to the wild-type strain. Northern blot analysis of the ΔMohda1 mutant revealed transcriptional activation of three melanin genes that are dispersed throughout the genome of M. oryzae. The effect of deletion of the yeast HDA1 orthologue was also observed in Fusarium asiaticum from the Fusarium graminearum species complex; the HDF2 deletion mutant produced increased levels of nivalenol-type trichothecenes. These results suggest that histone modification via HDA1-type HDAC regulates the production of natural products in filamentous fungi. Natural products of fungi have significant impacts on human welfare, in both detrimental and beneficial ways. Although HDA1-type histone deacetylase is not essential for vegetative growth, deletion of the gene affects the expression of clustered secondary metabolite genes in some fungi. Here, we report that such phenomena are also observed in physically unlinked genes required for melanin biosynthesis in the rice blast fungus. In addition, production of Fusarium trichothecenes, previously reported to be unaffected by HDA1 deletion, was significantly upregulated in another Fusarium species. Thus, the HDA1-inactivation strategy may be regarded as a general approach for overproduction and/or discovery of fungal metabolites. © 2017 The Society for Applied Microbiology.

Variation of Human Hairiness: A Possible Adaptation to Solar Radiation and Melanin

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Dhugga Amrita

2014-07-01

Full Text Available Many theories have been advanced to explain human hairlessness, however, there is no consensus. This study of 76 males observed that skin reflectance measuring skin colouration and melanin pigmentation correlated with hair size and follicle density. Individuals with a greater concentration of melanin within the superficial layer of the skin had a lower follicle density and smaller sizes of hairs. In contrast, individuals with a lower melanin concentration and lighter skin colour had a full range of hairiness. This leads to the suggestion that over the course of human evolution, high concentrations of melanin in consistently exposed to ultraviolet radiation areas developed first and that hair loss was a consequence of competition in the skin between melanin production and hair growth. Darker pigmented skin and lower follicle density are significantly correlated (R2=0.283; p<0.05. Individuals with darker skin had a mean of 4.91 follicles per cm2 whereas those with lighter skin reflectance had 11.20 follicles per cm2. This suggests that increased concentrations of melanin in the basal layer of the epidermis may limit hairiness by negatively influencing the skin's ability to produce hair.

[Peculiarities of linear growth of the melanin-containing fungi Cladosporium sphaerospermum Penz. and Alternaria alternata (Fr.) Keissler].

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Vember, V V; Zhdanova, N N

2001-01-01

Results on determination of radial (linear) growth rate of melanin-containing fungi Cladosporium sphaerospermum Penz. and Alternaria alternata (Fr.) Keissler concerning place of their isolation and ecologic peculiarities are presented in the paper. Essential differences, as to all studied indices of the strains of C. sphaerospermum strains, isolated from premices of the ChNPP 4th unit from the control strains of this species have been established. Only strain 34 of C. sphaerospermum, isolated from the cable driving region of the "Shelter" object, which did not differ from the control strains as to all the studied indices, made the exception. The radial growth rate was 2-4 times as low and variability amplitude 10-30 times as high in strains 60 and 5-1 of C. sphaerospermum, (which suffered high radiation load), as in the control strains of this species. The radial growth rate of C. sphaerospermum studied strains was an order lower as a whole than that of A. alternata strains. All the above said evidence for implementation of K-type vital strategy by C. sphaerospermum species and in this connection one can suppose its active growth on the surface of walls and ferroconcrete structures of the ChNPP 4th unit. Absence of differences, as to the studied radial growth indices, between A. alternata strains isolated from the ChNPP 4th unit premices and control strains of the species can evidence for the existence of A. alternata species under the conditions of high radioactivity in the surviving state.

EFFECT OF CADMIUM(II) ON FREE RADICALS IN DOPA-MELANIN TESTED BY EPR SPECTROSCOPY.

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Zdybel, Magdalena; Pilawa, Barbara; Chodurek, Ewa

2015-01-01

Electron paramagnetic resonance (EPR) spectroscopy may be applied to examine interactions of melanin with metal ions and drugs. In this work EPR method was used to examination of changes in free radical system of DOPA-melanin--the model eumelanin after complexing with diamagnetic cadmium(II) ions. Cadmium(II) may affect free radicals in melanin and drugs binding by this polymer, so the knowledge of modification of properties and free radical concentration in melanin is important to pharmacy. The effect of cadmium(II) in different concentrations on free radicals in DOPA-melanin was determined. EPR spectra of DOPA-melanin, and DOPA-melanin complexes with cadmium(II) were measured by an X-band (9.3 GHz) EPR spectrometer produced by Radiopan (Poznań, Poland) and the Rapid Scan Unit from Jagmar (Krak6w, Poland). The DOPA (3,4-dihydroxyphenylalanine) to metal ions molar ratios in the reaction mixtures were 2:1, 1:1, and 1: 2. High concentrations of o-semiquinone (g ~2.0040) free radicals (~10(21)-10(22) spin/g) characterize DOPA-melanin and its complexes with cadmium(II). Formation of melanin complexes with cadmium(II) increase free radical concentration in DOPA-melanin. The highest free radical concentration was obtained for DOPA-melanin-cadmium(II) (1:1) complexes. Broad EPR lines with linewidths: 0.37-0.73 mT, were measured. Linewidths increase after binding of cadmium(II) to melanin. Changes of integral intensities and linewidths with increasing microwave power indicate the homogeneous broadening of EPR lines, independently on the metal ion concentration. Slow spin-lattice relaxation processes existed in all the tested samples, their EPR lines saturated at low microwave powers. Cadmium(II) causes fastening of spin-lattice relaxation processes in DOPA-melanin. The EPR results bring to light the effect of cadmium(II) on free radicals in melanin, and probably as the consequence on drug binding to eumelanin.

Molecular identification of fungi trichothecens producing in seeds madder and detection of their nivalenol gene synthesis using PCR

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Seyyed Alireza Esmailzadeh Hosseini

2018-01-01

Full Text Available Madder is one of the most important crops that used for medical and industrial applications and is widely cultivated in Yazd province. During 2012, sampling was done form seeds madder in important areas planted in Yazd province, including Bafq and Ardakan. After culturing and purification of fungal isolates in PDA and CLA media, additional identification was performed by PCR with specific primers for each species. Detection of fungi mycotoxins producing potential such as Nivalenol (NIV using Tri13 primers was done. High-performance liquid chromatography (HPLC was used to confirm the produce NIV mycotoxins potential in Fusarium species. 249 fungal strains were isolated from madder seed belonging to 6 genera of fungi including Fusarium spp., Aspergillus spp., Penicillium spp., Alternaria spp., Rhizoctonia solani and Rhizpous spp., that Fusarium isolates with 71 percent was the most frequency among fungi isolated. Among Fusarium fungi isolated, F. solani (55 isolates and F. oxysporum (41 isolates were the most frequency. F. poae, F. semitectum and F. equiseti ability to produce mycotoxins such as Nivalenol (NIV that are harmful to human health and animals as well as effect on the quantity and quality of madder color production. Tri13 gene involved in production NIV was detected in three Fusarium species that all isolates produce NIV. The results of HPLC showed that all studied Fusarium fungi, have the potential to produce NIV mycotoxins. The results of this study showed that fungi associated with seeds madder are able to produce trichothecene mycotoxins that they can be dangerous for consumers. Given that, this is the first report of fungi mycotoxins producing on seeds madder in Yazd province, thus should be measures to control and reduce fungal agents in these products.

Transcription factor Amr1 induces melanin biosynthesis and suppresses virulence in Alternaria brassicicola.

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Yangrae Cho

Full Text Available Alternaria brassicicola is a successful saprophyte and necrotrophic plant pathogen. Several A. brassicicola genes have been characterized as affecting pathogenesis of Brassica species. To study regulatory mechanisms of pathogenesis, we mined 421 genes in silico encoding putative transcription factors in a machine-annotated, draft genome sequence of A. brassicicola. In this study, targeted gene disruption mutants for 117 of the transcription factor genes were produced and screened. Three of these genes were associated with pathogenesis. Disruption mutants of one gene (AbPacC were nonpathogenic and another gene (AbVf8 caused lesions less than half the diameter of wild-type lesions. Unexpectedly, mutants of the third gene, Amr1, caused lesions with a two-fold larger diameter than the wild type and complementation mutants. Amr1 is a homolog of Cmr1, a transcription factor that regulates melanin biosynthesis in several fungi. We created gene deletion mutants of Δamr1 and characterized their phenotypes. The Δamr1 mutants used pectin as a carbon source more efficiently than the wild type, were melanin-deficient, and more sensitive to UV light and glucanase digestion. The AMR1 protein was localized in the nuclei of hyphae and in highly melanized conidia during the late stage of plant pathogenesis. RNA-seq analysis revealed that three genes in the melanin biosynthesis pathway, along with the deleted Amr1 gene, were expressed at low levels in the mutants. In contrast, many hydrolytic enzyme-coding genes were expressed at higher levels in the mutants than in the wild type during pathogenesis. The results of this study suggested that a gene important for survival in nature negatively affected virulence, probably by a less efficient use of plant cell-wall materials. We speculate that the functions of the Amr1 gene are important to the success of A. brassicicola as a competitive saprophyte and plant parasite.

Intraocular distribution of melanin in human, monkey, rabbit, minipig and dog eyes.

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Durairaj, Chandrasekar; Chastain, James E; Kompella, Uday B

2012-05-01

The purpose of this study was to quantify the melanin pigment content in sclera, choroid-RPE, and retina, three tissues encountered during transscleral drug delivery to the vitreous, in human, rabbit, monkey, minipig, and dog models. Strain differences were assessed in NZW × NZR F1 and Dutch belted rabbits and Yucatan and Gottingen minipigs. The choroid-RPE and retina tissues were divided into central (posterior pole area) and peripheral (away from posterior pole) regions while the sclera was analyzed without such division. Melanin content in the tissues was analyzed using a colorimetric assay. In all species the rank order for pigment content was: choroid-RPE >retina ≥ sclera, except in humans, where scleral melanin levels were higher than retina and central choroid. The melanin content in a given tissue differed between species. Further, while the peripheral tissue pigment levels tended to be generally higher compared to the central regions, these differences were significant in human in the case of choroid-RPE and in human, monkey, and dogs in the case of retina. Strain difference was observed only in the central choroid-RPE region of rabbits (NZW × NZR F1 >Dutch Belted). Species, strain, and regional differences exist in the melanin pigment content in the tissues of the posterior segment of the eye, with Gottingen minipig being closest to humans among the animals assessed. These differences in melanin content might contribute to differences in drug binding, delivery, and toxicity. Copyright © 2012 Elsevier Ltd. All rights reserved.

Targeted Disruption of Melanin Biosynthesis Genes in the Human Pathogenic Fungus Lomentospora prolificans and Its Consequences for Pathogen Survival

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Ayat Al-Laaeiby

2016-03-01

Full Text Available The dematiaceous (melanised fungus Lomentospora (Scedosporium prolificans is a life-threatening opportunistic pathogen of immunocompromised humans, resistant to anti-fungal drugs. Melanin has been shown to protect human pathogenic fungi against antifungal drugs, oxidative killing and environmental stresses. To determine the protective role of melanin in L. prolificans to oxidative killing (H2O2, UV radiation and the polyene anti-fungal drug amphotericin B, targeted gene disruption was used to generate mutants of the pathogen lacking the dihydroxynaphthalene (DHN-melanin biosynthetic enzymes polyketide synthase (PKS1, tetrahydroxynapthalene reductase (4HNR and scytalone dehydratase (SCD1. Infectious propagules (spores of the wild-type strain 3.1 were black/brown, whereas spores of the PKS-deficient mutant ΔLppks1::hph were white. Complementation of the albino mutant ΔLppks1::hph restored the black-brown spore pigmentation, while the 4HNR-deficient mutant ΔLp4hnr::hph and SCD-deficient mutant ΔLpscd1::hph both produced orange-yellow spores. The mutants ΔLppks1::hph and ΔLp4hnr::hph showed significant reductions in spore survival following H2O2 treatment, while spores of ΔLpscd1::hph and the ΔLppks1::hph complemented strain ΔLppks1::hph:PKS showed spore survivals similar to strain 3.1. Spores of the mutants ΔLp4hnr::hph and ΔLpscd1::hph and complemented strain ΔLppks1::hph:PKS showed spore survivals similar to 3.1 following exposure to UV radiation, but survival of ΔLppks1::hph spores was significantly reduced compared to the wild-type strain. Strain 3.1 and mutants ΔLp4hnr::hph and ΔLppks1::hph:PKS were resistant to amphotericin B while, paradoxically, the PKS1- and SCD1-deficient mutants showed significant increases in growth in the presence of the antifungal drug. Taken together, these results show that while melanin plays a protective role in the survival of the pathogen to oxidative killing and UV radiation, melanin does not

EPR studies of melanin from Cladosporium cladosporioides

International Nuclear Information System (INIS)

Pilawa, B.; Buszman, E.; Latocha, M.; Wilczok, T.

1996-01-01

Free radical properties of Cladosporium cladosporioides mycelium and melanin, and synthetic eumelanin and pheomelanin were studied by electron paramagnetic resonance method. Single EPR line and complex EPR spectrum with hyperfine splitting were measured for model DOPA-melanin and cysteinyldopa-melanin, respectively. EPR spectra of Cladosporium cladosporioides samples and pheomelanin show the same character. The concentration of paramagnetic centers in melanins isolated from Cladosporium cladosporioides is considerably higher than that of crude mycelium, whereas the EPR line widths are lower for mycelium than for melanin samples. For all analyzed samples the increase of EPR signals intensity with the increase of microwave power, and the decrease of intensities after saturation were observed the low values of microwave power sufficient for EPR lines saturation demonstrate that the spin-lattice relaxation times of unpaired electrons in melanins are long. (author)

Low-melanin containing pullulan production from sugarcane bagasse hydrolysate by Aureobasidium pullulans in fermentations assisted by light-emitting diode.

Science.gov (United States)

Terán Hilares, Ruly; Orsi, Camila Ayres; Ahmed, Muhammad Ajaz; Marcelino, Paulo Franco; Menegatti, Carlos Renato; da Silva, Silvio Silvério; Dos Santos, Júlio César

2017-04-01

Pullulan is a polymer produced by Aureobasidium pullulans and the main bottleneck for its industrial production is the presence of melanin pigment. In this study, light-emitting diodes (LEDs) of different wavelengths were used to assist the fermentation process aiming to produce low-melanin containing pullulan by wild strain of A. pullulans LB83 with different carbon sources. Under white light using glucose-based medium, 11.75g.L -1 of pullulan with high melanin content (45.70UA 540nm .g -1 ) was obtained, this production improved in process assisted by blue LED light, that resulted in 15.77g.L -1 of pullulan with reduced content of melanin (4.46UA 540nm .g -1 ). By using sugarcane bagasse (SCB) hydrolysate as carbon source, similar concentration of pullulan (about 20g.L -1 ) was achieved using white and blue LED lights, with lower melanin contents in last. Use of LED light was found as a promising approach to assist biotechnological process for low-melanin containing pullulan production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Monitoring, genomic study and control of patulin producing fungi in Korean fruits

International Nuclear Information System (INIS)

Kim, Dongho; Lim, Sangyong; Joe, Minho; Yun, Hyejung; Kim, Suhyun; Park, Jongchun

2008-07-01

This study was intended to apply irradiation technology for the degradation of patulin from apples and apple juices by investigating their physical, mechanical, biological, and pharmacochemical properties in view of potential uses in the bio-industry. The patulin producing fungi was separated from in Korean apples. Totally, 16 morphological types of fungi were isolated from the apples and a patulin producing fungi was identified. The isolated patulin producing fungus was found to a represent species of Penicillium crustosum. The patulin, dissolved in distilled water at a concentration of 50 ppm was practically degraded by the gamma irradiation at the dose of 1.0 kGy, while 33% of the patulin was remained at apple juice. In conclusion, it was suggested that 1 kGy of gamma irradiation (recommended radiation doses for radicidation and/or quarantine in fruits) is effective for the reduction of patulin, but the nutritional elements should be considered because the radio-degradation effects are environment dependant. The effects of a gamma irradiation on the physiochemical and physical characteristics of apple was investigated during a post-irradiation storage at 4 and 25. Gamma irradiation dose not affect stability of the nutritional contents, functional properties and physical characteristics of apples, especially in the condition of a cold storage after a radiation treatment. The degradation condition characteristics of patulin in apple juice and functional properties of corresponding condition were monitored by response surface methodology (RSM)

Monitoring, genomic study and control of patulin producing fungi in Korean fruits

Energy Technology Data Exchange (ETDEWEB)

Kim, Dongho; Lim, Sangyong; Joe, Minho; Yun, Hyejung [KAERI, Daejeon (Korea, Republic of); Kim, Suhyun [KBSI, Daejeon (Korea, Republic of); Park, Jongchun [Seonam Univ., Asan (Korea, Republic of)

2008-07-15

This study was intended to apply irradiation technology for the degradation of patulin from apples and apple juices by investigating their physical, mechanical, biological, and pharmacochemical properties in view of potential uses in the bio-industry. The patulin producing fungi was separated from in Korean apples. Totally, 16 morphological types of fungi were isolated from the apples and a patulin producing fungi was identified. The isolated patulin producing fungus was found to a represent species of Penicillium crustosum. The patulin, dissolved in distilled water at a concentration of 50 ppm was practically degraded by the gamma irradiation at the dose of 1.0 kGy, while 33% of the patulin was remained at apple juice. In conclusion, it was suggested that 1 kGy of gamma irradiation (recommended radiation doses for radicidation and/or quarantine in fruits) is effective for the reduction of patulin, but the nutritional elements should be considered because the radio-degradation effects are environment dependant. The effects of a gamma irradiation on the physiochemical and physical characteristics of apple was investigated during a post-irradiation storage at 4 and 25. Gamma irradiation dose not affect stability of the nutritional contents, functional properties and physical characteristics of apples, especially in the condition of a cold storage after a radiation treatment. The degradation condition characteristics of patulin in apple juice and functional properties of corresponding condition were monitored by response surface methodology (RSM)

Leaf-cutting ant fungi produce cell wall degrading pectinase complexes reminiscent of phytopathogenic fungi.

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Schiøtt, Morten; Rogowska-Wrzesinska, Adelina; Roepstorff, Peter; Boomsma, Jacobus J

2010-12-31

Leaf-cutting (attine) ants use their own fecal material to manure fungus gardens, which consist of leaf material overgrown by hyphal threads of the basidiomycete fungus Leucocoprinus gongylophorus that lives in symbiosis with the ants. Previous studies have suggested that the fecal droplets contain proteins that are produced by the fungal symbiont to pass unharmed through the digestive system of the ants, so they can enhance new fungus garden growth. We tested this hypothesis by using proteomics methods to determine the gene sequences of fecal proteins in Acromyrmex echinatior leaf-cutting ants. Seven (21%) of the 33 identified proteins were pectinolytic enzymes that originated from the fungal symbiont and which were still active in the fecal droplets produced by the ants. We show that these enzymes are found in the fecal material only when the ants had access to fungus garden food, and we used quantitative polymerase chain reaction analysis to show that the expression of six of these enzyme genes was substantially upregulated in the fungal gongylidia. These unique structures serve as food for the ants and are produced only by the evolutionarily advanced garden symbionts of higher attine ants, but not by the fungi reared by the basal lineages of this ant clade. Pectinolytic enzymes produced in the gongylidia of the fungal symbiont are ingested but not digested by Acromyrmex leaf-cutting ants so that they end up in the fecal fluid and become mixed with new garden substrate. Substantial quantities of pectinolytic enzymes are typically found in pathogenic fungi that attack live plant tissue, where they are known to breach the cell walls to allow the fungal mycelium access to the cell contents. As the leaf-cutting ant symbionts are derived from fungal clades that decompose dead plant material, our results suggest that their pectinolytic enzymes represent secondarily evolved adaptations that are convergent to those normally found in phytopathogens.

Leaf-cutting ant fungi produce cell wall degrading pectinase complexes reminiscent of phytopathogenic fungi

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Boomsma Jacobus J

2010-12-01

Full Text Available Abstract Background Leaf-cutting (attine ants use their own fecal material to manure fungus gardens, which consist of leaf material overgrown by hyphal threads of the basidiomycete fungus Leucocoprinus gongylophorus that lives in symbiosis with the ants. Previous studies have suggested that the fecal droplets contain proteins that are produced by the fungal symbiont to pass unharmed through the digestive system of the ants, so they can enhance new fungus garden growth. Results We tested this hypothesis by using proteomics methods to determine the gene sequences of fecal proteins in Acromyrmex echinatior leaf-cutting ants. Seven (21% of the 33 identified proteins were pectinolytic enzymes that originated from the fungal symbiont and which were still active in the fecal droplets produced by the ants. We show that these enzymes are found in the fecal material only when the ants had access to fungus garden food, and we used quantitative polymerase chain reaction analysis to show that the expression of six of these enzyme genes was substantially upregulated in the fungal gongylidia. These unique structures serve as food for the ants and are produced only by the evolutionarily advanced garden symbionts of higher attine ants, but not by the fungi reared by the basal lineages of this ant clade. Conclusions Pectinolytic enzymes produced in the gongylidia of the fungal symbiont are ingested but not digested by Acromyrmex leaf-cutting ants so that they end up in the fecal fluid and become mixed with new garden substrate. Substantial quantities of pectinolytic enzymes are typically found in pathogenic fungi that attack live plant tissue, where they are known to breach the cell walls to allow the fungal mycelium access to the cell contents. As the leaf-cutting ant symbionts are derived from fungal clades that decompose dead plant material, our results suggest that their pectinolytic enzymes represent secondarily evolved adaptations that are convergent to

Melanocyte biology and function with reference to oral melanin hyperpigmentation in HIV-seropositive subjects.

Science.gov (United States)

Feller, Liviu; Chandran, Rakesh; Kramer, Beverley; Khammissa, Razia A G; Altini, Mario; Lemmer, Johan

2014-09-01

The color of normal skin and of oral mucosa is not determined by the number of melanocytes in the epithelium but rather by their melanogenic activity. Pigmented biopolymers or melanins are synthesized in melanosomes. Tyrosinase is the critical enzyme in the biosynthesis of both brown/black eumelanin and yellow/red pheomelanin. The number of the melanosomes within the melanocytes, the type of melanin within the melanosomes, and the efficacy of the transfer of melanosomes from the melanocytes to the neighboring keratinocytes all play an important role in tissue pigmentation. Melanin production is regulated by locally produced factors including proopiomelanocortin and its derivative peptides, particularly alpha-melanocyte-stimulating hormone (α-MSH), melanocortin 1 receptor (MC1R), adrenergic and cholinergic agents, growth factors, cytokines, and nitric oxide. Both eumelanin and pheomelanin can be produced by the same melanocytes, and the proportion of the two melanin types is influenced by the degree of functional activity of the α-MSH/MC1R intracellular pathway. The cause of HIV oral melanosis is not fully understood but may be associated with HIV-induced cytokine dysregulation, with the medications commonly prescribed to HIV-seropositive persons, and with adrenocortical dysfunction, which is not uncommon in HIV-seropositive subjects with AIDS. The purpose of this article is to discuss some aspects of melanocyte biology and HIV-associated oral melanin hyperpigmentation.

The gene encoding the melanin-concentrating hormone receptor 1 is associated with schizophrenia in a Danish case-control sample

DEFF Research Database (Denmark)

Demontis, Ditte; Nyegaard, Mette; Christensen, Jane H

2012-01-01

OBJECTIVE: The MCHR1 gene encoding the melanin-concentrating hormone receptor 1 is located on chromosome 22q13.2 and has previously been associated with schizophrenia in a study of cases and controls from the Faroe Islands and Scotland. Herein we report an association between variations in the MCHR...

EPR examination of Zn2+ and Cu2+ binding by pigmented soil fungi Cladosporium cladosporioides

International Nuclear Information System (INIS)

Buszman, Ewa; Pilawa, Barbara; Zdybel, Magdalena; Wilczynski, Slawomir; Gondzik, Anna; Witoszynska, Teresa; Wilczok, Tadeusz

2006-01-01

The purpose of this study was to examine the usefulness of electron paramagnetic resonance spectroscopy (EPR) to estimate zinc and copper ions biosorption from the environment by pigmented soil fungi Cladosporium cladosporioides. The existence of a low amount of pheomelanin, besides eumelanin, in C. cladosporioides samples was proved by the analysis of shape of their EPR spectra. Concentration of o-semiquinone free radicals in crude mycelium was 2.4 x 10 17 spin/g. Changes in free radicals system of C. cladosporioides cultured in the presence of Zn 2+ and Cu 2+ were analysed. Both magnetic and chemical interactions of zinc and copper ions with free radicals in C. cladosporioides melanin were found. Magnetically interacting diamagnetic Zn 2+ ions increased the concentration of o-semiquinone free radicals in melanin existing in C. cladosporioides mycelium, whereas paramagnetic Cu 2+ ions decreased this concentration. Chemical interactions of Zn 2+ and Cu 2+ ions decreased the free radical concentrations in C. cladosporioides melanin. Homogeneously distributed free radicals in C. cladosporioides melanin rise its activity in biosorption processes

Evolution of structural diversity of trichothecenes, a family of toxins produced by plant pathogenic and entomopathogenic fungi.

Science.gov (United States)

Proctor, Robert H; McCormick, Susan P; Kim, Hye-Seon; Cardoza, Rosa E; Stanley, April M; Lindo, Laura; Kelly, Amy; Brown, Daren W; Lee, Theresa; Vaughan, Martha M; Alexander, Nancy J; Busman, Mark; Gutiérrez, Santiago

2018-04-01

Trichothecenes are a family of terpenoid toxins produced by multiple genera of fungi, including plant and insect pathogens. Some trichothecenes produced by the fungus Fusarium are among the mycotoxins of greatest concern to food and feed safety because of their toxicity and frequent occurrence in cereal crops, and trichothecene production contributes to pathogenesis of some Fusarium species on plants. Collectively, fungi produce over 150 trichothecene analogs: i.e., molecules that share the same core structure but differ in patterns of substituents attached to the core structure. Here, we carried out genomic, phylogenetic, gene-function, and analytical chemistry studies of strains from nine fungal genera to identify genetic variation responsible for trichothecene structural diversity and to gain insight into evolutionary processes that have contributed to the variation. The results indicate that structural diversity has resulted from gain, loss, and functional changes of trichothecene biosynthetic (TRI) genes. The results also indicate that the presence of some substituents has arisen independently in different fungi by gain of different genes with the same function. Variation in TRI gene duplication and number of TRI loci was also observed among the fungi examined, but there was no evidence that such genetic differences have contributed to trichothecene structural variation. We also inferred ancestral states of the TRI cluster and trichothecene biosynthetic pathway, and proposed scenarios for changes in trichothecene structures during divergence of TRI cluster homologs. Together, our findings provide insight into evolutionary processes responsible for structural diversification of toxins produced by pathogenic fungi.

Identification of ochratoxin A producing fungi associated with fresh and dry liquorice.

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Amanda Juan Chen

Full Text Available The presence of fungi on liquorice could contaminate the crop and result in elevated levels of mycotoxin. In this study, the mycobiota associated with fresh and dry liquorice was investigated in 3 producing regions of China. Potential toxigenic fungi were tested for ochratoxin A (OTA and aflatoxin B1 (AFB1 production using liquid chromatography/mass spectrometry/mass spectrometry. Based on a polyphasic approach using morphological characters, β-tubulin and RNA polymerase II second largest subunit gene phylogeny, a total of 9 genera consisting of 22 fungal species were identified, including two new Penicillium species (Penicillium glycyrrhizacola sp. nov. and Penicillium xingjiangense sp. nov.. The similarity of fungal communities associated with fresh and dry liquorice was low. Nineteen species belonging to 8 genera were detected from fresh liquorice with populations affiliated with P. glycyrrhizacola, P. chrysogenum and Aspergillus insuetus comprising the majority (78.74%, 33.33% and 47.06% of total of the community from Gansu, Ningxia and Xinjiang samples, respectively. In contrast, ten species belonging to 4 genera were detected from dry liquorice with populations affiliated with P. chrysogenum, P. crustosum and Aspergillus terreus comprising the majority (64.00%, 52.38% and 90.91% of total of the community from Gansu, Ningxia and Xinjiang samples, respectively. Subsequent LC/MS/MS analysis indicated that 5 fungal species were able to synthesize OTA in vitro including P. chrysogenum, P. glycyrrhizacola, P. polonicum, Aspergillus ochraceus and A. westerdijkiae, the OTA concentration varied from 12.99 to 39.03 µg/kg. AFB1 was absent in all tested strains. These results demonstrate the presence of OTA producing fungi on fresh liquorice and suggest that these fungi could survive on dry liquorice after traditional sun drying. Penicillium chrysogenum derived from surrounding environments is likely to be a stable contributor to high OTA level in

Melanin and Melanin-Related Polymers as Materials with Biomedical and Biotechnological Applications-Cuttlefish Ink and Mussel Foot Proteins as Inspired Biomolecules.

Science.gov (United States)

Solano, Francisco

2017-07-18

The huge development of bioengineering during the last years has boosted the search for new bioinspired materials, with tunable chemical, mechanical, and optoelectronic properties for the design of semiconductors, batteries, biosensors, imaging and therapy probes, adhesive hydrogels, tissue restoration, photoprotectors, etc. These new materials should complement or replace metallic or organic polymers that cause cytotoxicity and some adverse health effects. One of the most interesting biomaterials is melanin and synthetic melanin-related molecules. Melanin has a controversial molecular structure, dependent on the conditions of polymerization, and therefore tunable. It is found in animal hair and skin, although one of the common sources is cuttlefish (Sepia officinalis) ink. On the other hand, mussels synthesize adhesive proteins to anchor these marine animals to wet surfaces. Both melanin and mussel foot proteins contain a high number of catecholic residues, and their properties are related to these groups. Dopamine (DA) can easily polymerize to get polydopamine melanin (PDAM), that somehow shares properties with melanin and mussel proteins. Furthermore, PDAM can easily be conjugated with other components. This review accounts for the main aspects of melanin, as well as DA-based melanin-like materials, related to their biomedical and biotechnological applications.

Melanin and Melanin-Related Polymers as Materials with Biomedical and Biotechnological Applications—Cuttlefish Ink and Mussel Foot Proteins as Inspired Biomolecules

Science.gov (United States)

2017-01-01

The huge development of bioengineering during the last years has boosted the search for new bioinspired materials, with tunable chemical, mechanical, and optoelectronic properties for the design of semiconductors, batteries, biosensors, imaging and therapy probes, adhesive hydrogels, tissue restoration, photoprotectors, etc. These new materials should complement or replace metallic or organic polymers that cause cytotoxicity and some adverse health effects. One of the most interesting biomaterials is melanin and synthetic melanin-related molecules. Melanin has a controversial molecular structure, dependent on the conditions of polymerization, and therefore tunable. It is found in animal hair and skin, although one of the common sources is cuttlefish (Sepia officinalis) ink. On the other hand, mussels synthesize adhesive proteins to anchor these marine animals to wet surfaces. Both melanin and mussel foot proteins contain a high number of catecholic residues, and their properties are related to these groups. Dopamine (DA) can easily polymerize to get polydopamine melanin (PDAM), that somehow shares properties with melanin and mussel proteins. Furthermore, PDAM can easily be conjugated with other components. This review accounts for the main aspects of melanin, as well as DA-based melanin-like materials, related to their biomedical and biotechnological applications. PMID:28718807

Melanin and Melanin-Related Polymers as Materials with Biomedical and Biotechnological Applications—Cuttlefish Ink and Mussel Foot Proteins as Inspired Biomolecules

Directory of Open Access Journals (Sweden)

Francisco Solano

2017-07-01

Full Text Available The huge development of bioengineering during the last years has boosted the search for new bioinspired materials, with tunable chemical, mechanical, and optoelectronic properties for the design of semiconductors, batteries, biosensors, imaging and therapy probes, adhesive hydrogels, tissue restoration, photoprotectors, etc. These new materials should complement or replace metallic or organic polymers that cause cytotoxicity and some adverse health effects. One of the most interesting biomaterials is melanin and synthetic melanin-related molecules. Melanin has a controversial molecular structure, dependent on the conditions of polymerization, and therefore tunable. It is found in animal hair and skin, although one of the common sources is cuttlefish (Sepia officinalis ink. On the other hand, mussels synthesize adhesive proteins to anchor these marine animals to wet surfaces. Both melanin and mussel foot proteins contain a high number of catecholic residues, and their properties are related to these groups. Dopamine (DA can easily polymerize to get polydopamine melanin (PDAM, that somehow shares properties with melanin and mussel proteins. Furthermore, PDAM can easily be conjugated with other components. This review accounts for the main aspects of melanin, as well as DA-based melanin-like materials, related to their biomedical and biotechnological applications.

Skip areas of retained melanin: A clue to the histopathological diagnosis of idiopathic guttate hypomelanosis

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Rajiv Joshi

2014-01-01

Full Text Available Biopsy findings in 55 cases of idiopathic guttate hypomelanosis (IGH are reported. Most cases had a flat epidermis with loss of the rete pattern and a thickened orthokeratotic basket weave stratum corneum. The epidermis had markedly decreased to absent melanin in the basal layer and reduced numbers of melanocytes at the dermoepidermal junction. One-third of patients had a sparse perivascular lymphocytic infiltrate, whereas the rest had no significant dermal inflammation. These findings are in concordance with current literature.However, small foci of retained melanin in the basal layer (skip areas alternating with larger areas of melanin loss were present in almost 80% of cases. This finding has not been reported earlier and appears to be quite specific to IGH and may be used as a clue to differentiate IGH from other similar conditions such as vitiligo and guttate morphea.

Enzyme and biochemical producing fungi

DEFF Research Database (Denmark)

Lübeck, Peter Stephensen; Lübeck, Mette; Nilsson, Lena

2010-01-01

factories for sustainable production of important molecules. For developing fungi into efficient cell factories, the project includes identification of important factors that control the flux through the pathways using metabolic flux analysis and metabolic engineering of biochemical pathways....

Condition-dependence, pleiotropy and the handicap principle of sexual selection in melanin-based colouration.

Science.gov (United States)

Roulin, Alexandre

2016-05-01

The signalling function of melanin-based colouration is debated. Sexual selection theory states that ornaments should be costly to produce, maintain, wear or display to signal quality honestly to potential mates or competitors. An increasing number of studies supports the hypothesis that the degree of melanism covaries with aspects of body condition (e.g. body mass or immunity), which has contributed to change the initial perception that melanin-based colour ornaments entail no costs. Indeed, the expression of many (but not all) melanin-based colour traits is weakly sensitive to the environment but strongly heritable suggesting that these colour traits are relatively cheap to produce and maintain, thus raising the question of how such colour traits could signal quality honestly. Here I review the production, maintenance and wearing/displaying costs that can generate a correlation between melanin-based colouration and body condition, and consider other evolutionary mechanisms that can also lead to covariation between colour and body condition. Because genes controlling melanic traits can affect numerous phenotypic traits, pleiotropy could also explain a linkage between body condition and colouration. Pleiotropy may result in differently coloured individuals signalling different aspects of quality that are maintained by frequency-dependent selection or local adaptation. Colouration may therefore not signal absolute quality to potential mates or competitors (e.g. dark males may not achieve a higher fitness than pale males); otherwise genetic variation would be rapidly depleted by directional selection. As a consequence, selection on heritable melanin-based colouration may not always be directional, but mate choice may be conditional to environmental conditions (i.e. context-dependent sexual selection). Despite the interest of evolutionary biologists in the adaptive value of melanin-based colouration, its actual role in sexual selection is still poorly understood. �

GAMMA RADIATION INTERACTS WITH MELANIN TO ALTER ITS OXIDATION-REDUCTION POTENTIAL AND RESULTS IN ELECTRIC CURRENT PRODUCTION

Energy Technology Data Exchange (ETDEWEB)

Turick, C.; Ekechukwu, A.; Milliken, C.

2011-05-17

The presence of melanin pigments in organisms is implicated in radioprotection and in some cases, enhanced growth in the presence of high levels of ionizing radiation. An understanding of this phenomenon will be useful in the design of radioprotective materials. However, the protective mechanism of microbial melanin in ionizing radiation fields has not yet been elucidated. Here we demonstrate through the electrochemical techniques of chronoamperometry, chronopotentiometry and cyclic voltammetry that microbial melanin is continuously oxidized in the presence of gamma radiation. Our findings establish that ionizing radiation interacts with melanin to alter its oxidation-reduction potential. Sustained oxidation resulted in electric current production and was most pronounced in the presence of a reductant, which extended the redox cycling capacity of melanin. This work is the first to establish that gamma radiation alters the oxidation-reduction behavior of melanin, resulting in electric current production. The significance of the work is that it provides the first step in understanding the initial interactions between melanin and ionizing radiation taking place and offers some insight for production of biomimetic radioprotective materials.

Polyextremotolerant black fungi: oligotrophism, adaptive potential and a link to lichen symbioses

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Cene eGostinčar

2012-11-01

Full Text Available Black meristematic fungi can survive high doses of radiation and are resistant to desiccation. These adaptations help them to colonize harsh oligotrophic habitats, e.g. on the surface and subsurface of rocks. One of their most characteristic stress-resistance mechanisms is the accumulation of melanin in the cell walls. This, production of other protective molecules and a plastic morphology further contribute to ecological flexibility of black fungi. Increased growth rates of some species after exposure to ionizing radiation even suggest yet unknown mechanisms of energy production. Other unusual metabolic strategies may include harvesting UV or visible light or gaining energy by forming facultative lichen-like associations with algae or cyanobacteria. The latter is not entirely surprising, since certain black fungal lineages are phylogenetically related to clades of lichen-forming fungi. Similar to black fungi, lichen-forming fungi are adapted to growth on exposed surfaces with low availability of nutrients. They also efficiently use protective molecules to tolerate frequent periods of extreme stress. Traits shared by both groups of fungi may have been important in facilitating the evolution and radiation of lichen-symbioses.

Mechanical and photo-fragmentation processes for nanonization of melanin to improve its efficacy in protecting cells from reactive oxygen species stress

International Nuclear Information System (INIS)

Liu, Yi-Cheng; Chen, Sih-Min; Liu, Jhong-Han; Hsu, Hsiang-Wei; Lin, Hoang-Yan; Chen, Szu-yuan

2015-01-01

It has been well established ex vivo that melanin has the ability of scavenging free radicals and reactive oxygen species (ROS), besides other functions. Therefore, we propose to utilize nanonized melanin as medication against acute oxidative stress. For this purpose, we developed and characterized two techniques based on mechanical stir and photo-fragmentation using femtosecond laser pulses, respectively, for disintegration of suspended melanin powder to produce nanometer-sized and water-dispersible melanin. This resolves a major obstacle in the medical and industrial applications of melanin. The viabilities of cultured retinal pigment epithelium (RPE) cells exposed to exogenous H 2 O 2 stress and treated with various conditions of melanin and irradiation were compared. It was found that melanin could be nanonized very effectively with the techniques, and nanonized melanin exhibited a much stronger effect than unprocessed melanin on raising the viability of cultured RPE cells under acute ROS stress. The effect was even more prominent without simultaneous light irradiation, promising for effective in vivo application to the whole body

Mechanical and photo-fragmentation processes for nanonization of melanin to improve its efficacy in protecting cells from reactive oxygen species stress

Energy Technology Data Exchange (ETDEWEB)

Liu, Yi-Cheng [Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Chen, Sih-Min [Graduate Institute of Biophysics, National Central University, Jhongli 32001, Taiwan (China); Liu, Jhong-Han; Hsu, Hsiang-Wei [Department of Physics, National Central University, Jhongli 32001, Taiwan (China); Lin, Hoang-Yan [Graduate Institute of Photonics and Optoelectronics, and Department of Electrical Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Chen, Szu-yuan, E-mail: sychen@ltl.iams.sinica.edu.tw [Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan (China); Graduate Institute of Biophysics, National Central University, Jhongli 32001, Taiwan (China); Department of Physics, National Central University, Jhongli 32001, Taiwan (China)

2015-02-14

It has been well established ex vivo that melanin has the ability of scavenging free radicals and reactive oxygen species (ROS), besides other functions. Therefore, we propose to utilize nanonized melanin as medication against acute oxidative stress. For this purpose, we developed and characterized two techniques based on mechanical stir and photo-fragmentation using femtosecond laser pulses, respectively, for disintegration of suspended melanin powder to produce nanometer-sized and water-dispersible melanin. This resolves a major obstacle in the medical and industrial applications of melanin. The viabilities of cultured retinal pigment epithelium (RPE) cells exposed to exogenous H{sub 2}O{sub 2} stress and treated with various conditions of melanin and irradiation were compared. It was found that melanin could be nanonized very effectively with the techniques, and nanonized melanin exhibited a much stronger effect than unprocessed melanin on raising the viability of cultured RPE cells under acute ROS stress. The effect was even more prominent without simultaneous light irradiation, promising for effective in vivo application to the whole body.

Does melanin matter in the dark?

Science.gov (United States)

Płonka, Przemysław M; Picardo, Mauro; Slominski, Andrzej T

2017-07-01

In living cells, melanin pigment is formed within melanosomes, which not only protect the cells from autodestruction, but also serve as second messenger organelles regulating important skin functions, with melanocytes acting as primary sensory and regulatory cells of the epidermis. Yet, one can argue that skin melanin, which may negatively affect cellular homeostasis in melanoma, really exerts protective functions. Consequently, the actual functions of melanin and the melanogenic pathway in skin biology remains enigmatic. Yet, the solution of this riddle seems simple - to check the actual influence of natural melanin on skin cells in the dark. Since many interesting hypotheses and theories put forward in this respect did not survive confrontation with the experiment, a leading pigment research group from Naples was brave to "jump off the cliff" by confronting theory with experimental reality. They showed that, in the dark, human hair-derived melanin promotes inflammatory responses in keratinocytes, lowers their viability, promotes oxidative stress, and that pheomelanin does so more strongly than eumelanin. Thus, pheomelanin hardly protects red-haired individuals, even when avoiding the sun. Black hairs do not do much better either, unless they undergo graying. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Bird Integumentary Melanins: Biosynthesis, Forms, Function and Evolution

Science.gov (United States)

Galván, Ismael; Solano, Francisco

2016-01-01

Melanins are the ubiquitous pigments distributed in nature. They are one of the main pigments responsible for colors in living cells. Birds are among the most diverse animals regarding melanin-based coloration, especially in the plumage, although they also pigment bare parts of the integument. This review is devoted to the main characteristics of bird melanins, including updated views of the formation and nature of melanin granules, whose interest has been raised in the last years for inferring the color of extinct birds and non-avian theropod dinosaurs using resistant fossil feathers. The molecular structure of the two main types of melanin, eumelanin and pheomelanin, and the environmental and genetic factors that regulate avian melanogenesis are also presented, establishing the main relationship between them. Finally, the special functions of melanin in bird feathers are also discussed, emphasizing the aspects more closely related to these animals, such as honest signaling, and the factors that may drive the evolution of pheomelanin and pheomelanin-based color traits, an issue for which birds have been pioneer study models. PMID:27070583

Bird Integumentary Melanins: Biosynthesis, Forms, Function and Evolution

Directory of Open Access Journals (Sweden)

Ismael Galván

2016-04-01

Full Text Available Melanins are the ubiquitous pigments distributed in nature. They are one of the main pigments responsible for colors in living cells. Birds are among the most diverse animals regarding melanin-based coloration, especially in the plumage, although they also pigment bare parts of the integument. This review is devoted to the main characteristics of bird melanins, including updated views of the formation and nature of melanin granules, whose interest has been raised in the last years for inferring the color of extinct birds and non-avian theropod dinosaurs using resistant fossil feathers. The molecular structure of the two main types of melanin, eumelanin and pheomelanin, and the environmental and genetic factors that regulate avian melanogenesis are also presented, establishing the main relationship between them. Finally, the special functions of melanin in bird feathers are also discussed, emphasizing the aspects more closely related to these animals, such as honest signaling, and the factors that may drive the evolution of pheomelanin and pheomelanin-based color traits, an issue for which birds have been pioneer study models.

Melanins in Fossil Animals: Is It Possible to Infer Life History Traits from the Coloration of Extinct Species?

OpenAIRE

Negro, Juan J.; Fynlayson, Clive; Galván, Ismael

2018-01-01

Paleo-colour scientists have recently made the transition from describing melanin-based colouration in fossil specimens to inferring life-history traits of the species involved. Two such cases correspond to counter-shaded dinosaurs: dark-coloured due to melanins dorsally, and light-coloured ventrally. We believe that colour reconstruction of fossils based on the shape of preserved microstructures—the majority of paleo-colour studies involve melanin granules—is not without risks. In addition, ...

1,8-Dihydroxynaphthalene monoglucoside, a new metabolite of Sclerotinia sclerotiorum, and the effect of tricyclazole on its production.

Science.gov (United States)

Starratt, A N; Ross, L M; Lazarovits, G

2002-04-01

Isolate SS7 of Sclerotinia sclerotiorum was previously shown to produce and excrete into agar medium copious amounts of the melanin precursor 1,8-dihydroxynaphthalene. Much reduced quantities of this product were produced in the presence of tricyclazole, an inhibitor of pentaketide melanin biosynthesis. In this study, we demonstrate that young cultures of isolate SS7 produce 1,8-dihydroxynaphthalene monoglucoside, a new natural product not previously reported from fungi. When cultured in the presence of tricyclazole, such young cultures also accumulated two new monoglucosides of 1,3,8-trihydroxynaphthalene, which, as well as 1,8-dihydroxynaphthalene monoglucoside, were also obtained from cultures of two other isolates of S. sclerotiorum. It is proposed that rapid glucosylation of 1,3,8-trihydroxynaphthalene in young tricyclazole-inhibited S. sclerotiorum cultures accounts for the failure to observe 2-hydroxyjuglone or other metabolites usually associated with blockage of the pentaketide pathway to melanin in fungi.

Antibacterial Activity of Melanin from Cuttlefish and Squid Ink

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Yuspihana Fitrial

2017-08-01

Full Text Available Marine environment comprises of many organism which are known to posses bioactive compound as a common means of self-defense or for the protection of eggs and embryos. Class Cephalopods (such as squidand cuttlefish are notable for their defences, such as jetting escape movements, changes in colouration, toxic venom and inking.This study aims to compare the antibacterial activity of melanin from cuttlefish ink (Sepia sp. with squid ink (Loligo sp. against E. coli. Extraction and purification studies were carried out on Sepia and Loligo melanin using a hydrochloric acid 0,5M treatment under mechanical.The melanins were obtained and further evaluated their activity by direct contact methods between melanin and E. coli in nutrient broth.Total microbes was counted by total plate count.Both inks also was tested their activity against E. coli. The results showed that melanin from cuttlefish and squid inks had inhibitory activity at concentrations of 10 mg / ml and 20 mg / mL, respectively reaching 99.99% against E. coli.The inks of both Cephalopods at the same concentration as melanin, did not show any inhibitory activity against E. coli.  The melanin of Sepia sp. have a higher antibacterial activity than the melanin of Loligo sp.

Control of ergosterol producer fungi contaminating cereal grains by certain environmental conditions and gamma rays

International Nuclear Information System (INIS)

Shahin, A.A.M.

2007-01-01

Existence of ergosterol in grains usually gives an indication that these grains are contaminated by ergosterol producing fungi. So, ergosterol concentration could be a suitable marker for estimation of fungal contamination range in cereal grains. Thirty eight fungal isolates were isolated from maize, sorghum and barley grains. Alternaria, Cladosporium and Aspergillus were the most common fungal genera among these isolates and they were tested for ergosterol production. The highest ergosterol producing fungi were identified as Alternaria alternaria, Cladosporium herbarum and Aspergillus niger var.niger. The present results indicate that the most suitable conditions for producing ergosterol by these strains in maize grains were found to be at 25 degree C for 30 days. Exposing the artificially contaminated maize grains by the above three strains (10 7 CFU/ml) to increasing dose levels of gamma rays up to 10 kGy and storing for 30 days, gradually decreased the production of ergosterol to 7.9, 6.2 and 1.5 mg/g dry weight of grains by A. alternata and C.herbarum and A. niger var. niger, respectively. D 10 values of the tested three isolates in maize grains were found to be 2, 1.61, and 1.2 kGy, respectively. The results showed that cold storage (10 degree C) clearly decreased the activity of the tested fungi for producing ergosterol during the storage periods, and a dose level of 15 kGy was quite enough to free the grains from A. alternata, Cladosporium herbarum and A. niger var. niger, regardless the contamination level of grains with these ergosterol producer fungus

Thermophilic Fungi to Dominate Aflatoxigenic/Mycotoxigenic Fungi on Food under Global Warming.

Science.gov (United States)

Paterson, Robert Russell M; Lima, Nelson

2017-02-17

Certain filamentous fungi produce mycotoxins that contaminate food. Mycotoxin contamination of crops is highly influenced by environmental conditions and is already affected by global warming, where there is a succession of mycotoxigenic fungi towards those that have higher optimal growth temperatures. Aflatoxigenic fungi are at the highest limit of temperature although predicted increases in temperature are beyond that constraint. The present paper discusses what will succeed these fungi and represents the first such consideration. Aflatoxins are the most important mycotoxins and are common in tropical produce, much of which is exported to temperate regions. Hot countries may produce safer food under climate change because aflatoxigenic fungi will be inhibited. The same situation will occur in previously temperate regions where these fungi have recently appeared, although decades later. Existing thermotolerant and thermophilic fungi (TTF) will dominate, in contrast to the conventional mycotoxigenic fungi adapting or mutating, as it will be quicker. TTF produce a range of secondary metabolites, or potential mycotoxins and patulin which may become a new threat. In addition, Aspergillus fumigatus will appear more frequently, a serious human pathogen, because it is (a) thermotolerant and (b) present on crops: hence this is an even greater problem. An incubation temperature of 41 °C needs employing forthwith to detect TTF. Finally, TTF in crops requires study because of the potential for diseases in humans and animals under climate change.

Potential of volatile compounds produced by fungi to influence sensory quality of coffee beverage

DEFF Research Database (Denmark)

Iamanaka, B. T.; Teixeira, A. A.; Teixeira, A. R. R.

2014-01-01

Fungi are known producers of a large number of volatile compounds (VCs). Several VCs such as 2,4,6 trichloroanisole (TCA), geosmin and terpenes have been found in coffee beverages, and these compounds can be responsible for off-flavor development. However, few studies have related the fungal...... contamination of coffee with the sensory characteristics of the beverage. The aim of this research was to investigate the production of VCs by fungi isolated from coffee and their potential as modifiers of the sensory coffee beverage quality. Three species were isolated from coffee from the southwest of São...... Paulo state and selected for the study: Penicillium brevicompactum, Aspergillus luchuensis (belonging to section Nigri) and Penicillium sp. nov. (related to Penicillium crustosum). VCs produced by the fungal inoculated in raw coffee beans were extracted and tentatively identified by SPME...

SEARCH PRODUCERS OF POLYPHENOLS AND SOME PIGMENTS AMONG BASIDIOMYCETES

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Fedotov О. V.

2014-02-01

Full Text Available General content of polyphenols, carotenoids and melanin in basidiomycetes carpophorus was determined. 50 species were studied, 27 of which belong to the Polyporales form and 23 are to the Agaricales form. In order to determine the total content of phenolic substances spectrophotometric methods were used. Polyphenols were studied in alcoholic extracts through the modified Folin-Chokalteu procedure; melanin — by alkaline hydrolysis and calculated using a calibration curve (by pyrocatechol, carotenoids were studied in acetone extracts and calculated by the Vetshteyn formula. Statistical and cluster analysis of the data enabled to identify species of basidiomycetes that are perspective for biotechnology. The most promising in terms of total polyphenols, carotenoids and melanins of poliporal basidiomycetes are species Fomes fomentarius, Ganoderma applanatum, Ganoderma lucidum and Laetiporus sulphureus, and among agarikal fungi — Fistulina hepatica, Flammulina velutipes, Pleurotus ostreatus, Stropharia rugosoannulata, Agrocybe cylindracea and Tricholoma flavovirens. These species of Basidiomycetes were isolated in pure mycelia culture to find out their biosynthetic activity.

Redox Active Transition Metal ions Make Melanin Susceptible to Chemical Degradation Induced by Organic Peroxide.

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Zadlo, Andrzej; Pilat, Anna; Sarna, Michal; Pawlak, Anna; Sarna, Tadeusz

2017-12-01

With aging, retinal pigment epithelium melanosomes, by fusion with the age pigment lipofuscin, form complex granules called melanolipofuscin. Lipofuscin granules may contain oxidized proteins and lipid hydroperoxides, which in melanolipofuscin could chemically modify melanin polymer, while transition metal ions present in melanin can accelerate such oxidative modifications. The aim of this research was to examine the effect of selected transition metal ions on melanin susceptibility to chemical modification induced by the water-soluble tert-butyl hydroperoxide used as an oxidizing agent. Synthetic melanin obtained by DOPA autooxidation and melanosomes isolated from bovine retinal pigment epithelium were analyzed. To monitor tert-butyl hydroperoxide-induced oxidative changes of DMa and BMs, electron paramagnetic resonance spectroscopy, UV-vis absorption spectroscopy, dynamic light scattering, atomic force microscopy and electron paramagnetic resonance oximetry were employed. These measurements revealed that both copper and iron ions accelerated chemical degradation induced by tert-butyl hydroperoxide, while zinc ions had no effect. Strong prooxidant action was detected only in the case of melanosomes and melanin degraded in the presence of iron. It can be postulated that similar chemical processes, if they occur in situ in melanolipofuscin granules of the human retinal pigment epithelium, would modify antioxidant properties of melanin and its reactivity.

Surface structure characterization of Aspergillus fumigatus conidia mutated in the melanin synthesis pathway and their human cellular immune response.

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Bayry, Jagadeesh; Beaussart, Audrey; Dufrêne, Yves F; Sharma, Meenu; Bansal, Kushagra; Kniemeyer, Olaf; Aimanianda, Vishukumar; Brakhage, Axel A; Kaveri, Srini V; Kwon-Chung, Kyung J; Latgé, Jean-Paul; Beauvais, Anne

2014-08-01

In Aspergillus fumigatus, the conidial surface contains dihydroxynaphthalene (DHN)-melanin. Six-clustered gene products have been identified that mediate sequential catalysis of DHN-melanin biosynthesis. Melanin thus produced is known to be a virulence factor, protecting the fungus from the host defense mechanisms. In the present study, individual deletion of the genes involved in the initial three steps of melanin biosynthesis resulted in an altered conidial surface with masked surface rodlet layer, leaky cell wall allowing the deposition of proteins on the cell surface and exposing the otherwise-masked cell wall polysaccharides at the surface. Melanin as such was immunologically inert; however, deletion mutant conidia with modified surfaces could activate human dendritic cells and the subsequent cytokine production in contrast to the wild-type conidia. Cell surface defects were rectified in the conidia mutated in downstream melanin biosynthetic pathway, and maximum immune inertness was observed upon synthesis of vermelone onward. These observations suggest that although melanin as such is an immunologically inert material, it confers virulence by facilitating proper formation of the A. fumigatus conidial surface. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Red blood cell membrane-camouflaged melanin nanoparticles for enhanced photothermal therapy.

Science.gov (United States)

Jiang, Qin; Luo, Zimiao; Men, Yongzhi; Yang, Peng; Peng, Haibao; Guo, Ranran; Tian, Ye; Pang, Zhiqing; Yang, Wuli

2017-10-01

Photothermal therapy (PTT) has represented a promising noninvasive approach for cancer treatment in recent years. However, there still remain challenges in developing non-toxic and biodegradable biomaterials with high photothermal efficiency in vivo. Herein, we explored natural melanin nanoparticles extracted from living cuttlefish as effective photothermal agents and developed red blood cell (RBC) membrane-camouflaged melanin (Melanin@RBC) nanoparticles as a platform for in vivo antitumor PTT. The as-obtained natural melanin nanoparticles demonstrated strong absorption at NIR region, higher photothermal conversion efficiency (∼40%) than synthesized melanin-like polydopamine nanoparticles (∼29%), as well as favorable biocompatibility and biodegradability. It was shown that RBC membrane coating on melanin nanoparticles retained their excellent photothermal property, enhanced their blood retention and effectively improved their accumulation at tumor sites. With the guidance of their inherited photoacoustic imaging capability, optimal accumulation of Melanin@RBC at tumors was achieved around 4 h post intravenous injection. Upon irradiation by an 808-nm laser, the developed Melanin@RBC nanoparticles exhibited significantly higher PTT efficacy than that of bare melanin nanoparticles in A549 tumor-bearing mice. Given that both melanin nanoparticles and RBC membrane are native biomaterials, the developed Melanin@RBC platform could have great potential in clinics for anticancer PTT. Copyright © 2017 Elsevier Ltd. All rights reserved.

Thermophilic Fungi to Dominate Aflatoxigenic/Mycotoxigenic Fungi on Food under Global Warming

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Robert Russell M. Paterson

2017-02-01

Full Text Available Certain filamentous fungi produce mycotoxins that contaminate food. Mycotoxin contamination of crops is highly influenced by environmental conditions and is already affected by global warming, where there is a succession of mycotoxigenic fungi towards those that have higher optimal growth temperatures. Aflatoxigenic fungi are at the highest limit of temperature although predicted increases in temperature are beyond that constraint. The present paper discusses what will succeed these fungi and represents the first such consideration. Aflatoxins are the most important mycotoxins and are common in tropical produce, much of which is exported to temperate regions. Hot countries may produce safer food under climate change because aflatoxigenic fungi will be inhibited. The same situation will occur in previously temperate regions where these fungi have recently appeared, although decades later. Existing thermotolerant and thermophilic fungi (TTF will dominate, in contrast to the conventional mycotoxigenic fungi adapting or mutating, as it will be quicker. TTF produce a range of secondary metabolites, or potential mycotoxins and patulin which may become a new threat. In addition, Aspergillus fumigatus will appear more frequently, a serious human pathogen, because it is (a thermotolerant and (b present on crops: hence this is an even greater problem. An incubation temperature of 41 °C needs employing forthwith to detect TTF. Finally, TTF in crops requires study because of the potential for diseases in humans and animals under climate change.

Natural melanin composites by layer-by-layer assembly

Science.gov (United States)

Eom, Taesik; Shim, Bong Sub

2015-04-01

Melanin is an electrically conductive and biocompatible material, because their conjugated backbone structures provide conducting pathways from human skin, eyes, brain, and beyond. So there is a potential of using as materials for the neural interfaces and the implantable devices. Extracted from Sepia officinalis ink, our natural melanin was uniformly dispersed in mostly polar solvents such as water and alcohols. Then, the dispersed melanin was further fabricated to nano-thin layered composites by the layer-by-layer (LBL) assembly technique. Combined with polyvinyl alcohol (PVA), the melanin nanoparticles behave as an LBL counterpart to from finely tuned nanostructured films. The LBL process can adjust the smart performances of the composites by varying the layering conditions and sandwich thickness. We further demonstrated the melanin loading degree of stacked layers, combination nanostructures, electrical properties, and biocompatibility of the resulting composites by UV-vis spectrophotometer, scanning electron microscope (SEM), multimeter, and in-vitro cell test of PC12, respectively.

N-acetylglucosamine affects Cryptococcus neoformans cell-wall composition and melanin architecture.

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Camacho, Emma; Chrissian, Christine; Cordero, Radames J B; Liporagi-Lopes, Livia; Stark, Ruth E; Casadevall, Arturo

2017-11-01

Cryptococcus neoformans is an environmental fungus that belongs to the phylum Basidiomycetes and is a major pathogen in immunocompromised patients. The ability of C. neoformans to produce melanin pigments represents its second most important virulence factor, after the presence of a polysaccharide capsule. Both the capsule and melanin are closely associated with the fungal cell wall, a complex structure that is essential for maintaining cell morphology and viability under conditions of stress. The amino sugar N-acetylglucosamine (GlcNAc) is a key constituent of the cell-wall chitin and is used for both N-linked glycosylation and GPI anchor synthesis. Recent studies have suggested additional roles for GlcNAc as an activator and mediator of cellular signalling in fungal and plant cells. Furthermore, chitin and chitosan polysaccharides interact with melanin pigments in the cell wall and have been found to be essential for melanization. Despite the importance of melanin, its molecular structure remains unresolved; however, we previously obtained critical insights using advanced nuclear magnetic resonance (NMR) and imaging techniques. In this study, we investigated the effect of GlcNAc supplementation on cryptococcal cell-wall composition and melanization. C. neoformans was able to metabolize GlcNAc as a sole source of carbon and nitrogen, indicating a capacity to use a component of a highly abundant polymer in the biospherenutritionally. C. neoformans cells grown with GlcNAc manifested changes in the chitosan cell-wall content, cell-wall thickness and capsule size. Supplementing cultures with isotopically 15 N-labelled GlcNAc demonstrated that the exogenous monomer serves as a building block for chitin/chitosan and is incorporated into the cell wall. The altered chitin-to-chitosan ratio had no negative effects on the mother-daughter cell separation; growth with GlcNAc affected the fungal cell-wall scaffold, resulting in increased melanin deposition and assembly. In

Melanin-Covered Nanoparticles for Protection of Bone Marrow During Radiation Therapy of Cancer

International Nuclear Information System (INIS)

Schweitzer, Andrew D.; Revskaya, Ekaterina; Chu, Peter; Pazo, Valeria; Friedman, Matthew; Nosanchuk, Joshua D.; Cahill, Sean; Frases, Susana; Casadevall, Arturo; Dadachova, Ekaterina

2010-01-01

Purpose: Protection of bone marrow against radiotoxicity during radioimmunotherapy and in some cases external beam radiation therapy such as hemi-body irradiation would permit administration of significantly higher doses to tumors, resulting in increased efficacy and safety of treatment. Melanin, a naturally occurring pigment, possesses radioprotective properties. We hypothesized that melanin, which is insoluble, could be delivered to the bone marrow by intravenously administrated melanin-covered nanoparticles (MNs) because of the human body's 'self-sieving' ability, protecting it against ionizing radiation. Methods and Materials: The synthesis of MNs was performed via enzymatic polymerization of 3,4-dihydroxyphenylalanine and/or 5-S-cysteinyl-3,4-dihydroxyphenylalanine on the surface of 20-nm plain silica nanoparticles. The biodistribution of radiolabeled MNs in mice was done at 3 and 24 h. Healthy CD-1 mice (Charles River Laboratories International, Inc., Wilmington, MA) or melanoma tumor-bearing nude mice were given MNs intravenously, 50 mg/kg of body weight, 3 h before either whole-body exposure to 125 cGy or treatment with 1 mCi of 188 Re-labeled 6D2 melanin-binding antibody. Results: Polymerization of melanin precursors on the surface of silica nanoparticles resulted in formation of a 15-nm-thick melanin layer as confirmed by light scattering, transmission electron microscopy, and immunofluorescence. The biodistribution after intravenous administration showed than MN uptake in bone marrow was 0.3% and 0.2% of injected dose per gram at 3 and 24 h, respectively, whereas pre-injection with pluronic acid increased the uptake to 6% and 3% of injected dose per gram, respectively. Systemic MN administration reduced hematologic toxicity in mice treated with external radiation or radioimmunotherapy, whereas no tumor protection by MNs was observed. Conclusions: MNs or similar structures provide a novel approach to protection of bone marrow from ionizing radiation based

Biogenic antimicrobial silver nanoparticles produced by fungi.

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Rodrigues, Alexandre G; Ping, Liu Yu; Marcato, Priscyla D; Alves, Oswaldo L; Silva, Maria C P; Ruiz, Rita C; Melo, Itamar S; Tasic, Ljubica; De Souza, Ana O

2013-01-01

Aspergillus tubingensis and Bionectria ochroleuca showed excellent extracellular ability to synthesize silver nanoparticles (Ag NP), spherical in shape and 35 ± 10 nm in size. Ag NP were characterized by transmission electron microscopy, X-ray diffraction analysis, and photon correlation spectroscopy for particle size and zeta potential. Proteins present in the fungal filtrate and in Ag NP dispersion were analyzed by electrophoresis (sodium dodecyl sulfate polyacrylamide gel electrophoresis). Ag NP showed pronounced antifungal activity against Candida sp, frequently occurring in hospital infections, with minimal inhibitory concentration in the range of 0.11-1.75 μg/mL. Regarding antibacterial activity, nanoparticles produced by A. tubingensis were more effective compared to the other fungus, inhibiting 98.0 % of Pseudomonas. aeruginosa growth at 0.28 μg/mL. A. tubingensis synthesized Ag NP with surprisingly high and positive surface potential, differing greatly from all known fungi. These data open the possibility of obtaining biogenic Ag NP with positive surface potential and new applications.

Occurrence of mycotoxin producing fungi in bee pollen.

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González, G; Hinojo, M J; Mateo, R; Medina, A; Jiménez, M

2005-11-15

The natural mycobiota occurring in bee pollen is studied in the present report with special attention to analyze the incidence of fungal species that are potential producers of mycotoxins. A total of 90 ready-to-eat bee pollen samples were analyzed. Eighty-seven samples were collected in stores placed in different Spanish areas and three were from Buenos Aires (Argentina). The statistical results (ANOVA) showed that yeasts and Penicillium spp. were the predominant fungi. With regard to the potential mycotoxin producing species, Penicillium verrucosum, Aspergillus niger aggregate, Aspergillus carbonarius, Aspergillus ochraceus, Aspergillus flavus, Aspergillus parasiticus and Alternaria spp. were found. The last genus was isolated very frequently. The potential ability for producing ochratoxin A (OTA) and aflatoxins B(1), B(2), G(1) and G(2) was studied by culturing in vitro the isolates followed by analysis of these mycotoxins in culture extracts by HPLC with fluorescent detection. It was found that 100%, 53.3%, 33.3% and 25% of the isolates of A. carbonarius, A. ochraceus, P. verrucosum and A. niger aggregate, respectively, produced OTA. Moreover, 28.6% of the isolates from the A. flavus plus A. parasiticus group were able to produce aflatoxin B(1). Aflatoxin B(2) was detected in only 10% of the cultures. Aflatoxins G(1) and G(2) were not detected in cultures under the assayed conditions. This is the first report carried out on the natural mycobiota occurring in bee pollen in general and on the toxigenic capability of these isolates in particular.

Screening and assessment of laccase producing fungi isolated from ...

African Journals Online (AJOL)

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2008-04-17

Apr 17, 2008 ... enzyme is found in many plant species and is widely distributed in fungi including wood-rotting fungi .... mat and weight of only filter paper represented biomass of fungal mat. ... substrate conversion/s) (Das et al., 1997).

The prospect of using the chitin-melanin-glukancontaining materials in measures of radiating protection

International Nuclear Information System (INIS)

Senyuk, O.F.; Myshkovskij, N.M.; Ivchenko, V.G.; Kovalev, V.A.; Gorovoj, L.F.; Kosyakov, V.N.; Kurchenko, V.P.; Sushinskaya, N.V.; Gavrilenko, N.V.

2004-01-01

An installation for testing the efficiency of Petryanov fabrics in conditions of the maximal humidity is created. It was shown in research, that chitin-melanin-glukan-containing materials (ChMGM) from higher bazidial fungi has high sorptive ability in relation to isotopes of strontium, uranium, transuranic elements, in particular to americium, and also salts of heavy metals (copper, silver, lead, chromium). Main part of metal ions are quickly absorbed by these materials. The technique of processing them by ChMGM is developed with the purpose to estimate amplification the detaining ability of these filters. High concentration of salts of alkaline and alkaline-earth metals do not essentially influence the absorption level of ChMGM heavy metals and transuranic elements

Prevention of melanin formation during aryl alcohol oxidase production under growth-limited conditions using an Aspergillus nidulans cell factory.

Science.gov (United States)

Pardo-Planas, Oscar; Prade, Rolf A; Müller, Michael; Atiyeh, Hasan K; Wilkins, Mark R

2017-11-01

An Aspergillus nidulans cell factory was genetically engineered to produce an aryl alcohol oxidase (AAO). The cell factory initiated production of melanin when growth-limited conditions were established using stationary plates and shaken flasks. This phenomenon was more pronounced when the strain was cultured in a trickle bed reactor (TBR). This study investigated different approaches to reduce melanin formation in fungal mycelia and liquid medium in order to increase the enzyme production yield. Removal of copper from the medium recipe reduced melanin formation in agar cultures and increased enzyme activities by 48% in agitated liquid cultures. Copper has been reported as a key element for tyrosinase, an enzyme responsible for melanin production. Ascorbic acid (0.44g/L) stopped melanin accumulation, did not affect growth parameters and resulted in AAO activity that was more than two-fold greater than a control treatment with no ascorbic acid. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of ultraviolet-visible irradiation in the presence of melanin isolated from human black or red hair upon Ehrlich ascites carcinoma cells

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Menon, I.A.; Persad, S.; Ranadive, N.S.; Haberman, H.F.

1983-07-01

The present study is an attempt to investigate the possibility that ultraviolet irradiation in the presence of pheomelanin may be more harmful to cells than the irradiation in the presence of eumelanin. The effects of UV-visible irradiation upon Ehrlich ascites carcinoma cells in the presence of the melanin isolated from human black hair (eumelanin) or from red hair (pheomelanin) were investigated. Irradiation of these cells was found to produce cell lysis, as observed by leakage of 51Cr from labeled cells and intracellular lactic dehydrogenase from the cells and decrease in cell viability demonstrated by the trypan blue exclusion test. The three parameters were quantitatively parallel to one another under various experimental conditions, namely different periods of irradiation and irradiation in the presence of different concentrations of melanin. The above effects were more pronounced when the irradiation was carried out in the presence of melanin from red hair than in the presence of black-hair melanin. In the absence of either melanin, the irradiation did not produce any significant effect in cell viability or cell lysis. Irradiation of the cells in the presence of red-hair melanin also decreased the transplantability of these cells. These observations clearly show that irradiation of cells in the presence of pheomelanin could produce cytotoxic effects. The present experimental design may have application in the development of in vitro models for the study of UV radiation-induced cutaneous carcinogenesis. The reactions of pheomelanin may be related to the susceptibility of ''Celtic'' skin to UV radiation-induced skin damage and carcinogenesis.

Melanin-based color of plumage: role of condition and of feathers' microstructure

Science.gov (United States)

D'Alba, Liliana; Van Hemert, Caroline R.; Spencer, Karen A.; Heidinger, Britt J.; Gill, Lisa; Evans, Neil P.; Monaghan, Pat; Handel, Colleen M.; Shawkey, Matthew D.

2014-01-01

Whether melanin-based colors honestly signal a bird's condition during the growth of feathers is controversial, and it is unclear if or how the physiological processes underlying melanogenesis or color-imparting structural feather microstructure may be adversely affected by condition. Here we report results from two experiments designed to measure the effect of condition on expression of eumelanic and pheomelanic coloration in black-capped chickadees (Poecile atricapillus) and zebra finches (Taeniopygia guttata), respectively. In chickadees, we compared feathers of birds affected and unaffected by avian keratin disorder, while in zebra finches we compared feathers of controls with feathers of those subjected to an unpredictable food supply during development. In both cases we found that control birds had brighter feathers (higher total reflectance) and more barbules, but similar densities of melanosomes. In addition, the microstructure of the feathers explained variation in color more strongly than did melanosome density. Together, these results suggest that melanin-based coloration may in part be condition-dependent, but that this may be driven by changes in keratin and feather development, rather than melanogenesis itself. Researchers should be cautious when assigning variation in melanin-based color to melanin alone and microstructure of the feather should be taken into account.

Flavonoids and Melanins: a common strategy across two kingdoms.

Science.gov (United States)

Carletti, Giorgia; Nervo, Giuseppe; Cattivelli, Luigi

2014-01-01

Ultraviolet (UV) radiations alter a number of metabolic functions in vivant. They produce damages to lipids, nucleic acids and proteins, generating reactive oxygen species such as singlet oxygen (O2), hydroxyl radical (HO) and superoxide anion (O2 (-)). Plants and animals, after their water emersion, have developed biochemical mechanisms to protect themselves from that environmental threat through a common strategy. Melanins in animals and flavonoids in plants are antioxidant pigments acting as free radical scavenging mechanisms. Both are phenol compounds constitutively synthesized and enhanced after exposure to UV rays, often conferring a red-brown-dark tissue pigmentation. Noteworthy, beside anti-oxidant scavenging activity, melanins and flavonoids have acquired secondary functions that, both in plants and animals, concern reproductions and fitness. Plants highly pigmented are more resistant to biotic and abiotic stresses. Darker wild vertebrates are generally more aggressive, sexually active and resistant to stress than lighter individuals. Flavonoids have been associated with signal attraction between flowers and insects and with plant-plant interaction. Melanin pigmentation has been proposed as trait in bird communication, acting as honest signals of quality. This review shows how the molecular mechanisms leading to tissue pigmentation have many functional analogies between plants and animals and how their origin lies in simpler organisms such as Cyanobacteria. Comparative studies between plant and animal kingdoms can reveal new insight of the antioxidant strategies in vivant.

Physico-chemical basis of radioprotection by melanin: a fungal pigment

International Nuclear Information System (INIS)

Barik, A.; Kunwar, A.; Singh, B.G.; Priyadarsini, K.I.; Raghukumar, S.

2014-01-01

Melanin is a biopolymer with wide spread biological activity like protection from UV-radiation damage, decrease of oxidative stress, binding to metals and drugs etc. Recently it has been observed that melanized fungal species grow in areas of high-radiation background in Chernobyl, and also in cooling pool water of nuclear reactors. Some of these organisms survived even after radiation exposure up to 6400 Gy. This prompted us to evaluate the radioprotecting ability of melanin. Although there are various types of melanin available, for the present radioprotection studies, melanin isolated from the culture filtrate of a fungus Gliocephalotrichum simplex was used. Chemically this particular type of melanin is the oligomeric form of dihydroxy indole and dihydroxy indole carboxylic acid and termed as eumelanin. Due to the presence of dihydroxy group in the benzene ring, they are in equilibrium with the partially oxidized (semiquinone radical form) and fully oxidized (quinone, non-radical) form. The radical nature of melanin was detected by electron paramagnetic resonance (EPR) spectrum and quantitative estimation of radical was made, in terms of spin density i. e. as 6.62 x 1017 spins/g. The protective activity of melanin was primarily due to inhibition of radiation-induced hematopoietic damages as evidenced by improvement in spleen parameters. To further understand the physico-chemical properties associated with radioprotection, reactions radiolytically generated free radicals with melanin was studied using pulse radiolysis

Gingival melanin depigmentation by Er:YAG laser: A literature review.

Science.gov (United States)

Pavlic, Verica; Brkic, Zlata; Marin, Sasa; Cicmil, Smiljka; Gojkov-Vukelic, Mirjana; Aoki, Akira

2018-04-01

Laser ablation is recently suggested as a most effective and reliable technique for depigmentation of melanin hyperpigmented gingiva. To date, different lasers have been used for gingival depigmentation (CO 2 , diode, Nd:YAG, Er:YAG and Er,Cr:YSGG lasers). The use of Er:YAG laser for depigmentation of melanin hyperpigmented gingiva has gained increasing importance in recent years. The purpose of this study was to report removal of gingival melanin pigmentation using an Er:YAG laser in a literature review. The main outcomes, such as improvement of signs (clinical parameters of bleeding, erythema, swelling and wound healing), symptoms (pain) and melanin recurrence/repigmentation were measured. The literature demonstrated that depigmentation of gingival melanin pigmentation can be performed safely and effectively by Er:YAG laser resulting in healing and an esthetically significant improvement of gingival discoloration. Thus, Er:YAG laser seems to be safe and useful in melanin depigmentation procedure. However, the main issue in giving the final conclusion of the optimal Er:YAG laser use in melanin depigmentation is that, to date, studies are offering completely discrepant Er:YAG laser procedure protocols (complex settings of laser parameters), and different criteria for the assessment of depigmentation and repigmentation (recurrence), thus hampering the comparison of the results. Therefore, further studies are necessary to give an optimal recommendation on the use of Er:YAG laser in gingival melanin hyperpigmentation.

In vivo stepwise multi-photon activation fluorescence imaging of melanin in human skin

Science.gov (United States)

Lai, Zhenhua; Gu, Zetong; Abbas, Saleh; Lowe, Jared; Sierra, Heidy; Rajadhyaksha, Milind; DiMarzio, Charles

2014-03-01

The stepwise multi-photon activated fluorescence (SMPAF) of melanin is a low cost and reliable method of detecting melanin because the activation and excitation can be a continuous-wave (CW) mode near infrared (NIR) laser. Our previous work has demonstrated the melanin SMPAF images in sepia melanin, mouse hair, and mouse skin. In this study, we show the feasibility of using SMPAF to detect melanin in vivo. in vivo melanin SMPAF images of normal skin and benign nevus are demonstrated. SMPAF images add specificity for melanin detection than MPFM images and CRM images. Melanin SMPAF is a promising technology to enable early detection of melanoma for dermatologists.

Stepwise multiphoton activation fluorescence reveals a new method of melanin detection

Science.gov (United States)

Lai, Zhenhua; Kerimo, Josef; Mega, Yair; DiMarzio, Charles A.

2013-06-01

The stepwise multiphoton activated fluorescence (SMPAF) of melanin, activated by a continuous-wave mode near infrared (NIR) laser, reveals a broad spectrum extending from the visible spectra to the NIR and has potential application for a low-cost, reliable method of detecting melanin. SMPAF images of melanin in mouse hair and skin are compared with conventional multiphoton fluorescence microscopy and confocal reflectance microscopy (CRM). By combining CRM with SMPAF, we can locate melanin reliably. However, we have the added benefit of eliminating background interference from other components inside mouse hair and skin. The melanin SMPAF signal from the mouse hair is a mixture of a two-photon process and a third-order process. The melanin SMPAF emission spectrum is activated by a 1505.9-nm laser light, and the resulting spectrum has a peak at 960 nm. The discovery of the emission peak may lead to a more energy-efficient method of background-free melanin detection with less photo-bleaching.

Indentification of huperzine A-producing endophytic fungi isolated from Huperzia serrata.

Science.gov (United States)

Dong, Li-Hui; Fan, San-Wei; Ling, Qing-Zhi; Huang, Bei-Bei; Wei, Zhao-Jun

2014-03-01

This present study was designed to investigate the production of huperzine A (HupA), an acetylcholine inhibitor, which was produced by an endophytic fungi isolated from Huperzia serrata. Screening of 94 endophytic fungal isolates obtained from plant H. serrata was carried out for the production of HupA. Their morphological characteristics were studied and rDNA sequence analysis was carried out. The cultures were grown in liquid culture medium and the extracted metabolites were analyzed by thin layer chromatography and high performance liquid chromatograph for the presence of HupA. The DPPH scavenging ratio and inhibition ratio of acetylcholinesterase (AchE) of the same were determined. 3 out of 94 strains i.e. S29, L44 and S94 showed significant AchE-inhibitory activity and antioxidant activity. Strain L44 which exhibited maximum yield of HupA (37.63 μg/g on dry weight basis) was identified as Trichoderma species by ITS sequence analysis. In conclusion, endophytic fungi from H. serrata can be used as a new resource of HupA.

Isolation of Taxol-Producing Endophytic Fungi from Iranian Yew Through Novel Molecular Approach and Their Effects on Human Breast Cancer Cell Line.

Science.gov (United States)

Kasaei, Abdollah; Mobini-Dehkordi, Mohsen; Mahjoubi, Foruzandeh; Saffar, Behnaz

2017-06-01

Taxol or paclitaxel, an approved drug by the Food and Drug Administration, is being used for the treatment of human cancers. This study aimed to isolate and determine different species of native endophytic fungi from Iranian Taxus baccata (yew) plants located in the northern forests of Iran. To do so, a novel molecular screening approach was performed for 50 isolated endophytic fungi through amplification of exon No. 1 of taxadine synthase as a key gene in taxol production pathway. We used effective colony-polymerase chain reaction technique for rapid screening of potent taxol-producing fungi instead of genomic DNA extraction. Production of taxol was performed in batch culture by selected fungi individually and produced taxol was assayed quantitatively by high-performance liquid chromatography using standard taxanes. We found that only six fungi could produce taxol and baccatin III. Interestingly, after 7 days of incubation, the highest level of taxol was found to be 129 and that of baccatin 139.2 mg/kg dw for two native isolated Cladosporium sp. named F1 and F3. The fungal taxols could decrease cell viability in MTT assay same as commercial taxol. The fungal taxols semi-quantitatively showed antimitotic effects on MCF-7 cells as human breast cancer cell line. The expression of bcl-2 anti-apoptotic gene, in contrast to bax pro-apoptotic gene, significantly decreased after treatment by standard and fungal taxols. As fungal taxol was produced simpler than other methods and could significantly affect viability and specific genes expression profile, it is recommended that using of taxol-producing fungi from Iranian yew could be a safe and confident procedure to overcome challenges of using other methods.

Topical microemulsion containing Punica granatum extract: its control over skin erythema and melanin in healthy Asian subjects.

Science.gov (United States)

Parveen, Rashida; Akhtar, Naveed; Mahmood, Tariq

2014-12-01

Punica granatum is apotent source of polyphenolic compounds with strong free radicals scavenging activity. The skin lightening effects of Punica granatum are assumed due to ellagic acid which acts by chelating copper at the active site of tyrosinase. To explore a topical microemulsion (O/W) of pomegranate (Punica granatum) extract for its control on skin erythema and melanin. Microemulsions were formulated using a polysorbate surfactant (Tween 80(®)) along with cosurfactant (propylene glycol) and were characterized regarding their stability. The placebo microemulsion (without extract) and the active microemulsion (containing Punica extract) were applied in a split face fashion by the volunteers (n = 11) for a period of 12 weeks. Skin erythema and melanin were measured at baseline and after every 15 days to determine any effect produced by these formulations. Active formulation showed a significant impact on skin erythema and melanin (p Punica granatum extract for conditions where elevated skin melanin and erythema have significantly prone skin physiology.

Melanin, a promising radioprotector: Mechanisms of actions in a mice model

Energy Technology Data Exchange (ETDEWEB)

Kunwar, A., E-mail: amitbio@rediffmail.com [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Adhikary, B. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Jayakumar, S. [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Barik, A. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Chattopadhyay, S. [Bio-Organic Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India); Raghukumar, S. [Myko Tech Private Limited, Dona Paula, Goa‐403004 (India); Priyadarsini, K.I., E-mail: kindira@barc.gov.in [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400085 (India)

2012-10-15

The radioprotective effect of extracellular melanin, a naturally occurring pigment, isolated from the fungus Gliocephalotrichum simplex was examined in BALB/C mice, and the probable mechanism of action was established. At an effective dose of 50 mg/kg body weight, melanin exhibited both prophylactic and mitigative activities, increasing the 30-day survival of mice by 100% and 60%, respectively, after exposure to radiation (7 Gy, whole body irradiation (WBI)). The protective activity of melanin was primarily due to inhibition of radiation-induced hematopoietic damages as evidenced by improvement in spleen parameters such as index, total cellularity, endogenous colony forming units, and maintenance of circulatory white blood cells and platelet counts. Melanin also reversed the radiation-induced decrease in ERK phosphorylation in splenic tissue, which may be the key feature in its radioprotective action. Additionally, our results indicated that the sustained activation of AKT, JNK and P38 proteins in splenic tissue of melanin pre-treated group may also play a secondary role. This was also supported by the fact that melanin could prevent apoptosis in splenic tissue by decreasing BAX/Bcl-XL ratio, and increasing the expressions of the proliferation markers (PCNA and Cyclin D1), compared to the radiation control group. Melanin also reduced the oxidative stress in hepatic tissue and abrogated immune imbalance by reducing the production of pro-inflammatory cytokines (IL6 and TNFα). In conclusion, our results confirmed that fungal melanin is a very effective radioprotector against WBI and the probable mechanisms of radioprotection are due to modulation in pro-survival (ERK) signaling, prevention of oxidative stress and immunomodulation. -- Highlights: ► Melanin showed promising radioprotection under pre and post irradiation condition. ► Melanin protects the hematopoietic system from radiation induced damage. ► Melanin modulates pro-survival pathways, immune system

Multimodal microscopy and the stepwise multi-photon activation fluorescence of melanin

Science.gov (United States)

Lai, Zhenhua

The author's work is divided into three aspects: multimodal microscopy, stepwise multi-photon activation fluorescence (SMPAF) of melanin, and customized-profile lenses (CPL) for on-axis laser scanners, which will be introduced respectively. A multimodal microscope provides the ability to image samples with multiple modalities on the same stage, which incorporates the benefits of all modalities. The multimodal microscopes developed in this dissertation are the Keck 3D fusion multimodal microscope 2.0 (3DFM 2.0), upgraded from the old 3DFM with improved performance and flexibility, and the multimodal microscope for targeting small particles (the "Target" system). The control systems developed for both microscopes are low-cost and easy-to-build, with all components off-the-shelf. The control system have not only significantly decreased the complexity and size of the microscope, but also increased the pixel resolution and flexibility. The SMPAF of melanin, activated by a continuous-wave (CW) mode near-infrared (NIR) laser, has potential applications for a low-cost and reliable method of detecting melanin. The photophysics of melanin SMPAF has been studied by theoretical analysis of the excitation process and investigation of the spectra, activation threshold, and photon number absorption of melanin SMPAF. SMPAF images of melanin in mouse hair and skin, mouse melanoma, and human black and white hairs are compared with images taken by conventional multi-photon fluorescence microscopy (MPFM) and confocal reflectance microscopy (CRM). SMPAF images significantly increase specificity and demonstrate the potential to increase sensitivity for melanin detection compared to MPFM images and CRM images. Employing melanin SMPAF imaging to detect melanin inside human skin in vivo has been demonstrated, which proves the effectiveness of melanin detection using SMPAF for medical purposes. Selective melanin ablation with micrometer resolution has been presented using the Target system

Aspergillus fumigatus conidial melanin modulates host cytokine response

NARCIS (Netherlands)

L.Y.A. Chai (Louis); M.G. Netea (Mihai); J. Sugui (Janyce); A.G. Vonk (Alieke); W.W.J. van de Sande (Wendy); A. Warris (Adilia); K.J. Kwon-Chung (Kyung); B. Jan Kullberg (Bart)

2010-01-01

textabstractMelanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced

Aspergillus fumigatus conidial melanin modulates host cytokine response.

NARCIS (Netherlands)

Chai, L.; Netea, M.G.; Sugui, J.; Vonk, A.G.; Sande, W.W. van de; Warris, A.; Kwon-Chung, K.J.; Kullberg, B.J.

2010-01-01

Melanin biopigments have been linked to fungal virulence. Aspergillus fumigatus conidia are melanised and are weakly immunogenic. We show that melanin pigments on the surface of resting Aspergillus fumigatus conidia may serve to mask pathogen-associated molecular patterns (PAMPs)-induced cytokine

Melanin photosensitizes ultraviolet light (UVC) DNA damage in pigmented cells

International Nuclear Information System (INIS)

Huselton, C.A.; Hill, H.Z.

1990-01-01

Melanins, pigments of photoprotection and camouflage, are very photoreactive and can both absorb and emit active oxygen species. Nevertheless, black skinned individuals rarely develop skin cancer and melanin is assumed to act as a solar screen. Since DNA is the target for solar carcinogenesis, the effect of melanin on Ultraviolet (UV)-induced thymine lesions was examined in mouse melanoma and carcinoma cells that varied in melanin content. Cells prelabeled with 14C-dThd were irradiated with UVC; DNA was isolated, purified, degraded to bases by acid hydrolysis and analyzed by HPLC. Thymine dimers were detected in all of the extracts of irradiated cells. Melanotic and hypomelanotic but not mammary carcinoma cell DNA from irradiated cells contained hydrophilic thymine derivatives. The quantity of these damaged bases was a function of both the UVC dose and the cellular melanin content. One such derivative was identified by gas chromatography-mass spectroscopy as thymine glycol. The other appears to be derived from thymine glycol by further oxidation during acid hydrolysis of the DNA. The finding of oxidative DNA damage in melanin-containing cells suggests that melanin may be implicated in the etiology of caucasian skin cancer, particularly melanoma. Furthermore, the projected decrease in stratospheric ozone could impact in an unanticipated deleterious manner on dark-skinned individuals

Melanin is Effective Radioprotector against Chronic Irradiation and Low Radiation Doses

International Nuclear Information System (INIS)

Mosse, I.; Plotnikova, S.; Kostrova, L.; Molophei, V.; Dubovic, B.

2001-01-01

Full text: Earlier we found pigment melanin ability to reduce significantly genetic consequences of acute irradiation in animals (drosophila, mice) and cultured human cells and to decrease strongly 'genetic load' accumulated in irradiated populations. The influence of melanin isolated from human hair on genetic effects of chronic irradiation in mice has been investigated. Melanin suspension or distilled water were injected every day into stomach of animals during 1-3 Gy g-irradiation with dose rate 0.007Gy/h. Levels of reciprocal translocations in germ cells were analysed cytologically. Melanin influence on genetic effect of chronic irradiation was shown to be even more effective than that of acute one. Radioadaptive response was used in order to study melanin influence on low radiation dose effect. We have demonstrated adaptive response in mice germ cells and bone marrow cells frequency of chromosomal aberrations in these cells after 0.2+1.5 Gy was about half as much as 1.7 Gy effect. Melanin injection 2 hours before the conditioning dose of 0.2 Gy resulted in the same mutation level as before 1.7 Gy adaptive response was not found. If melanin was applied between the first and second doses, both adaptive reaction and protection led to 4-fold decrease in aberration level. Thus melanin is able to remove completely low radiation dose effect. Complete toxicological tests have been conducted. The pigment melanin is not toxic and does not possess a mutagenic, teratogenic or carcinogenic activity. Melanin could be used in medicine for people protection against genetic consequences of long-term irradiation at low doses. (author)

Transcription factor VdCmr1 is required for pigment production, protection from UV irradiation, and regulates expression of melanin biosynthetic genes in Verticillium dahliae.

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Wang, Yonglin; Hu, Xiaoping; Fang, Yulin; Anchieta, Amy; Goldman, Polly H; Hernandez, Gustavo; Klosterman, Steven J

2018-04-01

Verticillium dahliae is a soilborne fungus that causes vascular wilt diseases on numerous plant species worldwide. The production of darkly melanized microsclerotia is crucial in the disease cycle of V. dahliae, as these structures allow for long-term survival in soil. Previously, transcriptomic and genomic analysis identified a cluster of genes in V. dahliae that encodes some dihydroxynaphthalene (DHN) melanin biosynthetic pathway homologues found in related fungi. In this study, we explored the roles of cluster-specific transcription factor VdCmr1, as well as two other genes within the cluster encoding a polyketide synthase (VdPKS1) and a laccase (VdLac1), enzymes at initial and endpoint steps in DHN melanin production. The results revealed that VdCmr1 and VdPKS1 are required for melanin production, but neither is required for microsclerotia production. None of the three genes were required for pathogenesis on tobacco and lettuce. Exposure of ΔVdCmr1 and wild-type strains to UV irradiation, or to high temperature (40 °C), revealed an approx. 50 % reduction of survival in the ΔVdCmr1 strain, relative to the wild-type strain, in response to either condition. Expression profiles revealed that expression of some melanin biosynthetic genes are in part dependent on VdCmr1. Combined data indicate VdCmr1 is a key regulator of melanin biosynthesis, and that via regulation of melanogenesis, VdCmr1 affects survival of V. dahliae in response to abiotic threats. We conclude with a model showing regulation of VdCmr1 by a high osmolarity glycerol response (Hog)-type MAP kinase pathway.

Odontogenic Cyst with Verrucous Proliferation Exhibiting Melanin Pigmentation

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Nidhi Manaktala

2017-01-01

Full Text Available Verrucous proliferation arising from odontogenic cysts is a rare entity. We report an unusual case of an infected odontogenic cyst with verrucous proliferation and melanin pigmentation in a 13-year-old male patient who presented with an intraoral swelling in relation to impacted teeth 26 and 27. The enucleated lesion was diagnosed as an odontogenic keratocyst and the patient died within two years of presentation due to multiple recurrences. The clinical, radiological, and microscopic features of the lesion are presented with an attempt to discuss the etiopathogenesis. The case hereby reported is uncommon with only eight cases reported in the literature.

Melanin: A scavenger in gingival inflammation

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S Nilima

2011-01-01

Full Text Available Background: One of the major direct or indirect targets of ultraviolet exposure of skin is the melanocyte or the melanin -forming cell. Epidermal melanocytes act as a trap for free radicals. Based on the protective role of melanocytes in medical literature, the role of melanin pigmentation in gingiva needs to be elucidated. Periodontal pathogens and their products demonstrate the ability to induce the generation of reactive oxygen species. Hence purpose of this study was to unravel the protective role of melanin (if any against the gingival inflammation. Materials and Methods: A total of 80 subjects; 20 in each group were selected. The selection of subjects regarding gingival pigmentation was based on Dummett′s scoring criteria 0, 3. A complete medical, dental history and an informed consent were obtained from the patients. After evaluation of clinical parameters the GCF was collected using microcapillary pipettes at the selected sites. IL-1β levels were quantitated using ELISA. Results: In non-pigmented healthy and gingivitis groups, there was a positive correlation between plaque index, gingival index and bleeding index versus IL-1β level: indicating an increase in the biochemical mediator of inflammation corresponding to an increase in the clinical parameters of inflammation. Also a positive correlation was found between the gingival index and bleeding index versus the IL-1β levels in the pigmented healthy group. The pigmented gingivitis groups showed a negative correlation between the plaque index, gingival index and bleeding index. Conclusions: The clinical markers of inflammation such as gingival index, bleeding index was of low numerical value in pigmented group than in the non-pigmented group, supposedly due to the protective action of melanin. The negative correlation of clinical markers of inflammation to the IL-1β levels in the pigmented gingivitis group could possibly be attributed to the protective role of melanins.

Melanin fluorescence spectra by step-wise three photon excitation

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Lai, Zhenhua; Kerimo, Josef; DiMarzio, Charles A.

2012-03-01

Melanin is the characteristic chromophore of human skin with various potential biological functions. Kerimo discovered enhanced melanin fluorescence by stepwise three-photon excitation in 2011. In this article, step-wise three-photon excited fluorescence (STPEF) spectrum between 450 nm -700 nm of melanin is reported. The melanin STPEF spectrum exhibited an exponential increase with wavelength. However, there was a probability of about 33% that another kind of step-wise multi-photon excited fluorescence (SMPEF) that peaks at 525 nm, shown by previous research, could also be generated using the same process. Using an excitation source at 920 nm as opposed to 830 nm increased the potential for generating SMPEF peaks at 525 nm. The SMPEF spectrum peaks at 525 nm photo-bleached faster than STPEF spectrum.

Protective role of Aspergillus fumigatus melanin against ultraviolet ...

African Journals Online (AJOL)

Melanin protects pigmented cells from physical and biological stresses which are associated with virulence in several important human pathogens, but little is known about the immune response to this ubiquitous biologic compound. Melanin content increased in Aspergillus fumigatus mycelium exposed to ultraviolet for 10 ...

Melanin determination by high performance liquid chromatography (HPLC) for K. marxianus

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Ultraviolet light (UV) mutated K. marxianus was found to turn dark brown during a growth assay. This brown color was hypothesized to be melanin overproduction influenced by the UV exposure. Cell cultures were oxidized and HPLC analyzed to determine melanin concentrations. The resulting melanin con...

Structural Color Tuning: Mixing Melanin-Like Particles with Different Diameters to Create Neutral Colors.

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Kawamura, Ayaka; Kohri, Michinari; Yoshioka, Shinya; Taniguchi, Tatsuo; Kishikawa, Keiki

2017-04-18

We present the ability to tune structural colors by mixing colloidal particles. To produce high-visibility structural colors, melanin-like core-shell particles composed of a polystyrene (PSt) core and a polydopamine (PDA) shell, were used as components. The results indicated that neutral structural colors could be successfully obtained by simply mixing two differently sized melanin-like PSt@PDA core-shell particles. In addition, the arrangements of the particles, which were important factors when forming structural colors, were investigated by mathematical processing using a 2D Fourier transform technique and Voronoi diagrams. These findings provide new insights for the development of structural color-based ink applications.

The effects of irradiated fungi to produce glucose from sago starch

International Nuclear Information System (INIS)

Andini, L.S.; Sjarief, Sri Hariani; Sumartono, Agustin; Sudradjat, Dadang; Anastasia, S.D.

1994-01-01

The effects of irradiated fungi to produce glucose from sago starch had been studied. Fungi used in this experiment were Aspergillus niger K-23, Rhizopus oryzae K-22, and Rhizopus oligosporus K-18. The experiment was carried out to find the optimum doses of irradiation for glucose production of sago starch. Irradiation dose at 0; 0.25; 0.5; and 0.75 kGy respectively from cobalt-60 gamma-cell 220 at a dose rate of 0.42 kGy/h. Concentration of sago starch is 6%. Total glucose and pH were measured on the 3rd and 6th day after incubation at 30 Celcius degrees in shaker incubator. The optimum irradiation doses obtained were 0.25 kGy for Rhizopus oryzae K-22, and 0.75 kGy for Aspergillus niger K-23, and Rhizopus oligosporus K-18. Higher dose of irradiation decreased the pH value of sago substrat, for Aspergillus niger K-23 and Rhizopus oligosporus K-18, but the opposite result was obtained for Rhizopus oryzae K-22. The glucose content at 3 days incubation was higher than at 6 days. (author). 13 refs, 5 tabs, 3 figs

Feasibility of Ionization-Mediated Pathway for Ultraviolet-Induced Melanin Damage.

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Mandal, Mukunda; Das, Tamal; Grewal, Baljinder K; Ghosh, Debashree

2015-10-22

Melanin is the pigment found in human skin that is responsible for both photoprotection and photodamage. Recently there have been reports that greater photodamage of DNA occurs when cells containing melanin are irradiated with ultraviolet (UV) radiation, thus suggesting that the photoproducts of melanin cause DNA damage. Photoionization processes have also been implicated in the photodegradation of melanin. However, not much is known about the oxidation potential of melanin and its monomers. In this work we calculate the ionization energies of monomers, dimers, and few oligomers of eumelanin to estimate the threshold energy required for the ionization of eumelanin. We find that this threshold is within the UV-B region for eumelanin. We also look at the charge and spin distributions of the various ionized states of the monomers that are formed to understand which of the ionization channels might favor monomerization from a covalent dimer.

Melanin from the nitrogen-fixing bacterium Azotobacter chroococcum: a spectroscopic characterization.

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Aulie Banerjee

Full Text Available Melanins, the ubiquitous hetero-polymer pigments found widely dispersed among various life forms, are usually dark brown/black in colour. Although melanins have variety of biological functions, including protection against ultraviolet radiation of sunlight and are used in medicine, cosmetics, extraction of melanin from the animal and plant kingdoms is not an easy task. Using complementary physicochemical techniques (i.e. MALDI-TOF, FTIR absorption and cross-polarization magic angle spinning solid-state (13C NMR, we report here the characterization of melanins extracted from the nitrogen-fixing non-virulent bacterium Azotobacter chroococcum, a safe viable source. Moreover, considering dihydroxyindole moiety as the main constituent, an effort is made to propose the putative molecular structure of the melanin hetero-polymer extracted from the bacterium. Characterization of the melanin obtained from Azotobacter chroococcum would provide an inspiration in extending research activities on these hetero-polymers and their use as protective agent against UV radiation.

Quantitative variation of melanins in alpaca (Lama pacos L.

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Marco Antonini

2011-07-01

Full Text Available The amount of melanin pigments was investigated in 95 Peruvian alpaca, representative of six different fleece colours, by means of spectrophotometric assays: SpEM (Spectrophoto­metric Eumelanin, SpPM (Spectrophotometric Pheomelanin, SpASM (Spectrophotometric Alkali Soluble Melanin, and SpTM (Spectro­photometric Total Melanin. It was found that these melanin pigments were suitable for identifying three homogeneous groups, each consisting of two closely related colours. A low, an intermediate, and a high amount of SpASM, SpTM, and SpPM characterize pinkish grey and light reddish brown, brown and reddish brown, dark reddish brown and black fleeces, respectively. SpEM and SpTM provide a further split within this latter group; higher concentrations of these pigments distinguish black fleece from dark reddish brown.

Positive Relationship between Abdominal Coloration and Dermal Melanin Density in Phrynosomatid Lizards

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Vanessa S. Quinn; Diana K. Hews

2003-01-01

Phrynosomatid lizards show considerable variation among species in the occurrence of a secondary sexual trait, blue abdominal coloration. The production of blue skin may be controlled by at least two cellular components, melanin in melanophores, and guanine in iridophores. To examine the hypothesis that a mechanism producing variation in abdominal coloration is...

Microstructure of Cell Wall-Associated Melanin in the Human Pathogenic Fungus cryptococcus neoformans

OpenAIRE

Eisenman, H.C.; Nosanchuk, J.D.; Webber, J. Beau W.; Emerson, T.A.; Casadevall, A.

2005-01-01

Melanin is a virulence factor for many pathogenic fungal species,including Cryptococcus neoformans. Melanin is deposited in the cell wall, and melanin isolated from this fungus retains the shape of the cells, resulting in hollow spheres called ``ghosts''. In this study, atomic force, scanning electron, and transmission electron microscopy revealed that melanin ghosts are covered with roughly spherical granular particles approximately 40-130 nm in diameter, and that the melanin is arranged in ...

New Poly(lactic acid Active Packaging Composite Films Incorporated with Fungal Melanin

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Łukasz Łopusiewicz

2018-04-01

Full Text Available In this work, fungal melanin was used for the first time to prepare poly(lactic acid-based composites. The films of various melanin concentrations (0.025%, 0.05% and 0.2% w/w were prepared using an extrusion method. The mechanical, antioxidant, antimicrobial, water vapor and UV-Vis barrier properties, as well as available polyphenolics on the surface, were studied. FT-IR and Raman spectroscopy studies were carried out to analyze the chemical composition of the resulting films. The hydrophobicity, color response, thermal, optical properties, and opacity values were also determined. The results of this study show that the addition of fungal melanin to poly(lactic acid (PLA as a modifier influenced mechanical and water vapor barrier properties depending on melanin concentration. In low concentration, melanin enhanced the mechanical and barrier properties of the modified films, but in larger amounts, the properties were decreased. The UV-Vis barrier properties of PLA/melanin composites were marginally improved. Differential Scanning Calorimetry (DSC analysis indicated that crystallinity of PLA increased by the addition of melanin, but this did not affect the thermal stability of the films. Modified PLA/melanin films showed good antioxidant activity and were active against Enterococcus faecalis, Pseudomonas aeruginosa and Pseudomonas putida. The addition of melanin caused changes in color values, decreasing lightness and increasing the redness and yellowness of films. Based on the results of this study, fungal melanin has good potential to be exploited as a value-added modifier that can improve the overall properties of PLA.

Genetic validation and spectroscopic detailing of DHN-melanin extracted from an environmental fungus

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Nitya Meenakshi Raman

2017-12-01

Full Text Available Accurate characterization of melanin using analytical methodologies has proved to be difficult due to its heterogeneity, insolubility in wide pH and broad range of solvents. The present study was undertaken to characterize melanin extracted from an environmental Aspergillus fumigatus AFGRD105 by studying its genes, chemical properties and spectral data. A gene based approach to confirm the type of melanin carried out indicated the extracted melanin to be of the dihydroxynaphthalene type. On comparison with synthetic melanin, UV–Vis and IR spectra of the extracted melanin revealed characteristic peaks that can be further used for confirmation of DHN-melanin extracted from any source. Solid state 13C NMR spectroscopy established the presence of the hydroxyl-naphthalene moiety and validated the results obtained by genetic analysis. The correct assignment of the observed spectral frequency characteristic of functional groups can be further adapted in future works that deal with binding capacities and biomolecule systems involving melanin.

Spiral and Rotor Patterns Produced by Fairy Ring Fungi

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Karst, N.; Dralle, D.; Thompson, S. E.

2015-12-01

Soil fungi fill many essential ecological and biogeochemical roles, e.g. decomposing litter, redistributing nutrients, and promoting biodiversity. Fairy ring fungi offer a rare glimpse into the otherwise opaque spatiotemporal dynamics of soil fungal growth, because subsurface mycelial patterns can be inferred from observations at the soil's surface. These observations can be made directly when the fungi send up fruiting bodies (e.g., mushrooms and toadstools), or indirectly via the effect the fungi have on neighboring organisms. Grasses in particular often temporarily thrive on the nutrients liberated by the fungus, creating bands of rich, dark green turf at the edge of the fungal mat. To date, only annular (the "ring" in fairy ring) and arc patterns have been described in the literature. We report observations of novel spiral and rotor pattern formation in fairy ring fungi, as seen in publically available high-resolution aerial imagery of 22 sites across the continental United States. To explain these new behaviors, we first demonstrate that a well-known model describing fairy ring formation is equivalent to the Gray-Scott reaction-diffusion model, which is known to support a wide range of dynamical behaviors, including annular traveling waves, rotors, spirals, and stable spatial patterns including spots and stripes. Bifurcation analysis and numerical simulation are then used to define the region of parameter space that supports spiral and rotor formation. We find that this region is adjacent to one within which typical fairy rings develop. Model results suggest simple experimental procedures that could potentially induce traditional ring structures to exhibit rotor or spiral dynamics. Intriguingly, the Gray-Scott model predicts that these same procedures could be used to solicit even richer patterns, including spots and stripes, which have not yet been identified in the field.

Biopretreatment of palm oil mill effluent by thermotolerant polymer-producing fungi

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Masao Ukita

2001-11-01

Full Text Available Palm oil industry is one of the three major agro-industries in Southern Thailand and generates large quantities of effluent with high organic matter (BOD and COD values of 58,000 and 110,000 mg/l, respectively, total solids and suspended solids (70,000 and 40,000 mg/l, respectively, oil & grease (25,600 mg/l, and has a low pH (4.5. Conventional anaerobic ponding system is normally employed in palm oil mills to treat the effluent. To increase its efficiency, biopretreatment to remove the organic matter and oil & grease by thermotolerant polymer-producing fungi was investigated. The palm oil mill effluent (POME was treated by the two thermotolerant polymer-producing fungi, Rhizopus sp. ST4 and Rhizopus sp. ST29, at 45ºC under aseptic and septic conditions. Rhizopus sp. ST4 gave the same oil & grease removal (84.2% under both conditions but COD removal under septic condition (62.2% was 8.8% higher than that under aseptic condition (53.4%. On the contrary, Rhizopus sp. ST 29 under aseptic condition showed 11% and 25.4% higher oil & grease removal (91.4% and COD removal (66.0% than those under septic condition. Comparison between the two isolates under aseptic condition revealed that Rhizopus sp. ST29 exhibited higher oil & grease removal (91.4% as well as COD removal (66.0% than those of Rhizopus sp. ST4 (84.2% and 53.4%, respectively. Under septic condition, Rhizopus sp. ST4 gave higher oil & grease removal (84.2% and COD removal (62.2% than did Rhizopus sp. ST 29 (80.5 and 40.6%, respectively.

Interocular agreement in melanin and macular pigment optical density.

NARCIS (Netherlands)

Kanis, M.J.; Berendschot, T.T.J.M.; van Norren, D.

2007-01-01

Macular pigment (MP) and melanin possibly protect the macular area by absorbing blue light and acting as antioxidants. Because little is known about the interocular correlation of melanin, we determined its optical density (MOD) in both eyes of healthy subjects using fundus reflectometry. The

Endophytic fungi producing of esterases: evaluation in vitro of the enzymatic activity using pH indicator

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Helen Cristina Fávero Lisboa

2013-09-01

Full Text Available A sensitive and efficient colorimetric method was optimized for detection of esterase enzymes produced by endophytic fungi for development of High-Throughput Screening (HTS. The fungi were isolated and obtained previously from plant species of Cerrado and Atlantic Forest located in areas of environmental preservation in the State of Sao Paulo / Brazil, as part of the project "Chemical and biological prospecting endophytic fungi associated to plant species of Cerrado and Atlantic Forest". The compounds ethyl butyrate, ethyl acetate and methyl propionate were used as standards esters which were hydrolyzed by extracellular enzyme from endophytic fungi (EC. 3.1.1.1 -carboxylesterases for production of carboxylic acids. Thus, the reduction of the pH increases the protonated indicator concentration (bromothymol blue, changing the color of the reaction medium (from blue to yellow, that can be observed and measured by spectrophotometry at 616 nm. The methodology with acid-base indicator was performed on 13 microorganisms, aiming Periconia atropurpurea asapotential source of esterase for biotransformation of short chain esters. The results also evidenced that this methodology showed to be efficient, fast, cheap, having low consumption of reagents and easy development, and can be applied to screen carboxylic-ester hydrolases in a large number of microorganisms.

Applying photoacoustics to quantification of melanin concentration in retinal pigment epithelium (Conference Presentation)

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Shu, Xiao; Zhang, Hao F.; Liu, Wenzhong

2016-03-01

The melanin in the retinal pigment epithelium (RPE) protects retina and other ocular tissues by photo-screening and acting as antioxidant and free radical scavenger. It helps maintain normal visual functions since human eye is subjected to lifelong high oxygen stress and photon exposure. Loss of the RPE melanin weakens the protection mechanism and jeopardizes ocular health. Local decrease in the RPE melanin concentration is believed to be both a cause and a sign of early-stage age-related macular degeneration (AMD), the leading blinding disease in developed world. Current technology cannot quantitatively measure the RPE melanin concentration which might be a promising marker in early AMD screening. Photoacoustic ophthalmoscopy (PAOM), as an emerging optical absorption-based imaging technology, can potentially be applied to measure the RPE melanin concentration if the dependence of the detectable photoacoustic (PA) signal amplitudes on the RPE melanin concentrations is verified. In this study, we tested the feasibility of using PA signal ratio from RPE melanin and the nearby retinal blood vessels as an indicator of the RPE melanin variation. A novel whole eye optical model was designed and Monte Carlo modeling of light (MCML) was employed. We examined the influences on quantification from PAOM axial resolution, the depth and diameter of the retinal blood vessel, and the RPE thickness. The results show that the scheme is robust to individual histological and illumination variations. This study suggests that PAOM is capable of quantitatively measuring the RPE melanin concentration in vivo.

The Analgesic Acetaminophen and the Antipsychotic Clozapine Can Each Redox-Cycle with Melanin.

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Temoçin, Zülfikar; Kim, Eunkyoung; Li, Jinyang; Panzella, Lucia; Alfieri, Maria Laura; Napolitano, Alessandra; Kelly, Deanna L; Bentley, William E; Payne, Gregory F

2017-12-20

Melanins are ubiquitous but their complexity and insolubility has hindered characterization of their structures and functions. We are developing electrochemical reverse engineering methodologies that focus on properties and especially on redox properties. Previous studies have shown that melanins (i) are redox-active and can rapidly and repeatedly exchange electrons with diffusible oxidants and reductants, and (ii) have redox potentials in midregion of the physiological range. These properties suggest the functional activities of melanins will depend on their redox context. The brain has a complex redox context with steep local gradients in O 2 that can promote redox-cycling between melanin and diffusible redox-active chemical species. Here, we performed in vitro reverse engineering studies and report that melanins can redox-cycle with two common redox-active drugs. Experimentally, we used two melanin models: a convenient natural melanin derived from cuttlefish (Sepia melanin) and a synthetic cysteinyldopamine-dopamine core-shell model of neuromelanin. One drug, acetaminophen (APAP), has been used clinically for over a century, and recent studies suggest that low doses of APAP can protect the brain from oxidative-stress-induced toxicity and neurodegeneration, while higher doses can have toxic effects in the brain. The second drug, clozapine (CLZ), is a second generation antipsychotic with polypharmacological activities that remain incompletely understood. These in vitro observations suggest that the redox activities of drugs may be relevant to their modes-of-action, and that melanins may interact with drugs in ways that affect their activities, metabolism, and toxicities.

Color reduction of melanin by lysosomal and peroxisomal enzymes isolated from mammalian cells.

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Park, Dong Jun; Sekhon, Simranjeet Singh; Yoon, Jihee; Kim, Yang-Hoon; Min, Jiho

2016-02-01

Lysosomes and peroxisomes are organelles with many functions in all eukaryotic cells. Lysosomes contain hydrolytic enzymes (lysozyme) that degrade molecules, whereas peroxisomes contain enzymes such as catalase that convert hydrogen peroxide (H2O2) to water and oxygen and neutralize toxicity. In contrast, melanin is known as a helpful element to protect the skin against harmful ultraviolet rays. However, a high quantity of melanin leads to hyperpigmentation or skin cancer in human. New materials have already been discovered to inhibit tyrosinase in melanogenesis; however, melanin reduction does not suggest their preparation. In this study, we report that the color intensity because of melanin decreased by the cellular activation of lysosomes and peroxisomes. An increase in the superficial intensity of lysosome and peroxisome activities of HeLa cells was observed. In addition, a decrease in the amount of melanin has also been observed in mammalian cells without using any other chemical, showing that the process can work in vivo for treating melanin. Therefore, the results of this study indicate that the amount of melanin decreases by the lysosome and peroxisome activity after entering the cells, and functional organelles are effective in color reduction. This mechanism can be used in vivo for treating melanin.

Sub-nm 3D observation of human hair melanin by high-voltage STEM.

Science.gov (United States)

Imai, Takehito; Higuchi, Kimitaka; Yamamoto, Yuta; Arai, Shigeo; Nakano, Takashi; Tanaka, Nobuo

2016-04-01

The ultrastructure of melanin granules in human hair was studied using 1,000 kV high-voltage scanning transmission electron microscopy to successfully reconstruct three-dimensional images of the whole melanin granule. It was revealed that the melanin granule was composed of a membrane-like outer structure that included many spherical vesicles, and an inner matrix containing a sheet-like structure in the elongated direction of the melanin granule and a sheet-like arrays structure in the cross direction. The outer structure of the melanin granule was maintained even after exposure to hair-bleaching agents to decompose the melanin granule, suggesting that the outer structure was a highly robust structure and composition compared with the inner matrix . © The Author 2015. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Interactions of fungi from fermented sausage with regenerated cellulose casings

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Hassan K. Sreenath; Thomas W. Jeffries

2011-01-01

This research examined cellulolytic effects of fungi and other microbes present in cured sausages on the strength and stability of regenerated cellulose casings (RCC) used in the sausage industry. Occasionally during the curing process, RCC would split or fail, thereby leading to loss of product. The fungus Penicillium sp. BT-F-1, which was isolated from fermented...

[Microscopic soil fungi - bioindicators organisms contaminated soil].

Science.gov (United States)

Donerian, L G; Vodianova, M A; Tarasova, Zh E

In the paper there are considered methodological issues for the evaluation of soil biota in terms of oil pollution. Experimental studies have shown that under the exposure of a various levels of oil pollution meeting certain gradations of the state and optimal alteration in microbocenosis in sod-podzolic soils, there is occurred a transformation of structure of the complex of micromycetes and the accumulation of toxic species, hardly typical for podzolic soils - primarily represantatives of the genus Aspergillus (A.niger and A. versicolor), Paecilomyces (P.variotii Bainer), Trichoderma (T.hamatum), the genus of phytopathogens Fusarium (F.oxysporum), dermatophytes of genus Sporothrix (S. schenckii) and dark-colored melanin containing fungi of Dematiaceae family. Besides that there are presented data on the study of microbiocenosis of the urban soil, the urban soil differed from the zone soil, but shaped in similar landscape and climatic conditions, and therefore having a tendency to a similar response from the side of microorganisms inhabiting the soil. Isolated complex of soil microscopic fungi is described by many authors as a complex, characteristic for soils of megalopolises. This allowed authors of this work to suggest that in urban soils the gain in the occurrence of pathogenic species micromycetes also increases against a background of chronic, continuously renewed inflow of petroleum hydrocarbons from various sources of pollution. Because changes in the species composition of micromycetes occurred in accordance with the increasing load of oil, so far as microscopic soil fungi can be recommended as a bioindicator organisms for oil. In the article there is also provided information about the distinctive features of modern DNA identification method of soil microscopic fungi and accepted in our country methodology of isolation of micromycetes with the use of a nutrient Czapek medium.

Uncovering of melanin fluorescence in human skin tissue

Science.gov (United States)

Scholz, Matthias; Stankovic, Goran; Seewald, Gunter; Leupold, Dieter

2007-07-01

Due to its extremely low fluorescence quantum yield, in the conventionally (one-photon) excited autofluorescence of skin tissue, melanin fluorescence is masked by several other endogenous and possibly also exogenous fluorophores (e.g. NADH, FAD, Porphyrins). A first step to enhance the melanin contribution had been realized by two-photon fs-pulse excitation in the red/near IR, based on the fact that melanin can be excited by stepwise two-photon absorption, whereas all other fluorophores in this spectral region allow only simultaneous two-photon excitation. Now, the next and decisive step has been realized: Using an extremely sensitive detection system, for the first time twophoton fluorescence of skin tissue excited with pulses in the ns-range could be measured. The motivation for this step was based on the fact that the population density of the fluorescent level resulting from a stepwise excitation has a different dependence of the pulse duration than that from a simultaneous excitation (Δt2 vs. Δt). Due to this strong discrimination between the fluorophores, practically pure melanin fluorescence can be obtained. Examples for in-vivo, ex-vivo as well as paraffin embedded skin tissue will be shown. The content of information with respect to early diagnosis of skin deseases will be discussed.

The fungus-growing termite Macrotermes natalensis harbors bacillaene-producing Bacillus sp. that inhibit potentially antagonistic fungi

DEFF Research Database (Denmark)

Um, Soohyun; Fraimout, Antoine; Sapountzis, Panagiotis

2013-01-01

colonies produce a single major antibiotic, bacillaene A (1), which selectively inhibits known and putatively antagonistic fungi of Termitomyces. Comparative analyses of the genomes of symbiotic Bacillus strains revealed that they are phylogenetically closely related to Bacillus subtilis, their genomes...... have high homology with more than 90% of ORFs being 100% identical, and the sequence identities across the biosynthetic gene cluster for bacillaene are higher between termite-associated strains than to the cluster previously reported in B. subtilis. Our findings suggest that this lineage of antibiotic......The ancient fungus-growing termite (Mactrotermitinae) symbiosis involves the obligate association between a lineage of higher termites and basidiomycete Termitomyces cultivar fungi. Our investigation of the fungus-growing termite Macrotermes natalensis shows that Bacillus strains from M. natalensis...

The role of alpha-synuclein in melanin synthesis in melanoma and dopaminergic neuronal cells.

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Tianhong Pan

Full Text Available The relatively high co-occurrence of Parkinson's disease (PD and melanoma has been established by a large number of epidemiological studies. However, a clear biological explanation for this finding is still lacking. Ultra-violet radiation (UVR-induced skin melanin synthesis is a defense mechanism against UVR-induced damage relevant to the initiation of melanoma, whereas, increased neuromelanin (NM, the melanin synthesized in dopaminergic neurons, may enhance the susceptibility to oxidative stress-induced neuronal injury relevant to PD. SNCA is a PD-causing gene coding for alpha-Synuclein (α-Syn that expresses not only in brain, but also in skin as well as in tumors, such as melanoma. The findings that α-Syn can interact with tyrosinase (TYR and inhibit tyrosine hydroxylase (TH, both of which are enzymes involved in the biosynthesis of melanin and dopamine (DA, led us to propose that α-Syn may participate in the regulation of melanin synthesis. In this study, by applying ultraviolet B (UVB light, a physiologically relevant stimulus of melanogenesis, we detected melanin synthesis in A375 and SK-MEL-28 melanoma cells and in SH-SY5Y and PC12 dopaminergic neuronal cells and determined effects of α-Syn on melanin synthesis. Our results showed that UVB light exposure increased melanin synthesis in all 4 cell lines. However, we found that α-Syn expression reduced UVB light-induced increase of melanin synthesis and that melanin content was lower when melanoma cells were expressed with α-Syn, indicating that α-Syn may have inhibitory effects on melanin synthesis in melanoma cells. Different from melanoma cells, the melanin content was higher in α-Syn-over-expressed dopaminergic neuronal SH-SY5Y and PC12 cells, cellular models of PD, than that in non-α-Syn-expressed control cells. We concluded that α-Syn could be one of the points responsible for the positive association between PD and melanoma via its differential roles in melanin synthesis in

Melanin dependent survival of Apergillus fumigatus conidia in lung epithelial cells.

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Amin, Shayista; Thywissen, Andreas; Heinekamp, Thorsten; Saluz, Hans Peter; Brakhage, Axel A

2014-07-01

Aspergillus fumigatus is the most important air-borne pathogenic fungus of humans. Upon inhalation of conidia, the fungus makes close contact with lung epithelial cells, which only possess low phagocytic activity. These cells are in particular interesting to address the question whether there is some form of persistence of conidia of A. fumigatus in the human host. Therefore, by also using uracil-auxotrophic mutant strains, we were able to investigate the interaction of A549 lung epithelial cells and A. fumigatus conidia in detail for long periods. Interestingly, unlike professional phagocytes, our study showed that the presence of conidial dihydroxynaphthalene (DHN) melanin enhanced the uptake of A. fumigatus conidia by epithelial cells when compared with non-pigmented pksP mutant conidia. Furthermore, conidia of A. fumigatus were able to survive within epithelial cells. This was due to the presence of DHN melanin in the cell wall of conidia, because melanised wild-type conidia showed a higher survival rate inside epithelial cells and led to inhibition of acidification of phagolysosomes. Both effects were not observed for white (non-melanised) conidia of the pksP mutant strain. Moreover, in contrast to pksP mutant conidia, melanised wild-type conidia were able to inhibit the extrinsic apoptotic pathway in A549 lung epithelial cells even for longer periods. The anti-apoptotic effect was not restricted to conidia, because both conidia-derived melanin ghosts (cell-free DHN melanin) and a different type of melanin, dihydroxyphenylalanine (DOPA) melanin, acted anti-apoptotically. Taken together, these data indicate the possibility of melanin-dependent persistence of conidia in lung epithelial cells. Copyright © 2014 Elsevier GmbH. All rights reserved.

Diffusible and Volatile Antifungal Compounds Produced by an Antagonistic Bacillus velezensis G341 against Various Phytopathogenic Fungi

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Seong Mi Lim

2017-10-01

Full Text Available The aim of this study was to identify volatile and agar-diffusible antifungal metabolites produced by Bacillus sp. G341 with strong antifungal activity against various phytopathogenic fungi. Strain G341 isolated from four-year-old roots of Korean ginseng with rot symptoms was identified as Bacillus velezensis based on 16S rDNA and gyrA sequences. Strain G341 inhibited mycelial growth of all phytopathogenic fungi tested. In vivo experiment results revealed that n-butanol extract of fermentation broth effectively controlled the development of rice sheath blight, tomato gray mold, tomato late blight, wheat leaf rust, barley powdery mildew, and red pepper anthracnose. Two antifungal compounds were isolated from strain G341 and identified as bacillomycin L and fengycin A by MS/MS analysis. Moreover, volatile compounds emitted from strain G341 were found to be able to inhibit mycelial growth of various phytopathogenic fungi. Based on volatile compound profiles of strain G341 obtained through headspace collection and analysis on GC-MS, dimethylsulfoxide, 1-butanol, and 3-hydroxy-2-butanone (acetoin were identified. Taken together, these results suggest that B. valezensis G341 can be used as a biocontrol agent for various plant diseases caused by phytopathogenic fungi.

Diffusible and Volatile Antifungal Compounds Produced by an Antagonistic Bacillus velezensis G341 against Various Phytopathogenic Fungi.

Science.gov (United States)

Lim, Seong Mi; Yoon, Mi-Young; Choi, Gyung Ja; Choi, Yong Ho; Jang, Kyoung Soo; Shin, Teak Soo; Park, Hae Woong; Yu, Nan Hee; Kim, Young Ho; Kim, Jin-Cheol

2017-10-01

The aim of this study was to identify volatile and agar-diffusible antifungal metabolites produced by Bacillus sp. G341 with strong antifungal activity against various phytopathogenic fungi. Strain G341 isolated from four-year-old roots of Korean ginseng with rot symptoms was identified as Bacillus velezensis based on 16S rDNA and gyrA sequences. Strain G341 inhibited mycelial growth of all phytopathogenic fungi tested. In vivo experiment results revealed that n -butanol extract of fermentation broth effectively controlled the development of rice sheath blight, tomato gray mold, tomato late blight, wheat leaf rust, barley powdery mildew, and red pepper anthracnose. Two antifungal compounds were isolated from strain G341 and identified as bacillomycin L and fengycin A by MS/MS analysis. Moreover, volatile compounds emitted from strain G341 were found to be able to inhibit mycelial growth of various phytopathogenic fungi. Based on volatile compound profiles of strain G341 obtained through headspace collection and analysis on GC-MS, dimethylsulfoxide, 1-butanol, and 3-hydroxy-2-butanone (acetoin) were identified. Taken together, these results suggest that B. valezensis G341 can be used as a biocontrol agent for various plant diseases caused by phytopathogenic fungi.

Bioproduction and characterization of extracellular melanin-like pigment from industrially polluted metagenomic library equipped Escherichia coli.

Science.gov (United States)

Amin, Shivani; Rastogi, Rajesh P; Sonani, Ravi R; Ray, Arabinda; Sharma, Rakesh; Madamwar, Datta

2018-04-15

To explore the potential genes from the industrially polluted Amlakhadi canal, located in Ankleshwar, Gujarat, India, its community genome was extracted and cloned into E. coli EPI300™-T1 R using a fosmid vector (pCC2 FOS™) generating a library of 3,92,000 clones with average size of 40kb of DNA-insert. From this library, the clone DM1 producing brown colored melanin-like pigment was isolated and characterized. For over expression of the pigment, further sub-cloning of the clone DM1 was done. Sub-clone containing 10kb of the insert was sequenced for gene identification. The amino acids sequence of a protein 4-Hydroxyphenylpyruvate dioxygenase (HPPD), which is know to be involved in melanin biosynthesis was obtained from the gene sequence. The sequence-homology based 3D structure model of HPPD was constructed and analyzed. The physico-chemical nature of pigment was further analysed using 1 H and 13 C NMR, LC-MS, FTIR and UV-visible spectroscopy. The pigment was readily soluble in DMSO with an absorption maximum around 290nm. Based on the genetic and chemical characterization, the compound was confirmed as melanin-like pigment. The present results indicate that the metagenomic library from industrially polluted environment generated a microbial tool for the production of melanin-like pigment. Copyright © 2018 Elsevier B.V. All rights reserved.

Melanin-targeting antibody as a potential agent for radioimmunotherapy of melanoma

International Nuclear Information System (INIS)

Dadachova, E.; Nosanchuk, J.D.; Shi, L.; Casadevall, A.

2002-01-01

Aim: Melanoma is a cancer of increasing incidence for which new methods of treatment and imaging are urgently needed. Currently there is no effective therapy for metastatic melanoma as this tumor is resistant to radiation and chemotherapy. The majority of human melanomas are pigmented with melanin. Here we investigated the possibility of using a melanin-binding antibody (mAb 6D2) which was originally developed against fungal melanin as a delivery vehicle for RIT of pigmented melanoma. Materials and Methods: MAb 6D2 (IgM type) was generated from hybridomas obtained from mice immunized with melanin isolated from Cryptococcus neoformans. The mAb was radiolabeled with 213 Bi or 111 In via bifunctional chelator CHXA'' and with 188 Re - via 'direct labeling'. The immunoreactivity of radiolabeled 6D2 mAb towards fungal melanin was tested by immunofluorescence. Cell binding of 213 Bi-6D2, 188 Re-6D2 and irrelevant IgM 12A1 was evaluated by incubating 2 μg/mL mAb with 0.23-2 x 10 6 human slightly pigmented melanoma cells SK-28-MEL (whole or lysed) which were grown with or without 110 μM L-tyrosine to promote melanin formation. In vivo binding of 111 In-6D2 was studied by scintigraphic imaging in nude mice injected IP with 2.8 x 10 6 SK-28-MEL cells 24 h before 111 In-6D2; biodistribution of 188 Re-6D2 was performed in nude mice bearing SK-28-MEL xenografted tumors. Results: The immunoreactivity of radiolabeled 6D2 mAb to melanin was demonstrated by immunofluorescence. Cell binding of 213 Bi-6D2 and 188 Re-6D2 was higher for the melanoma cells grown with 110 μM L-tyrosine suggesting melanin-specific binding. There was no significant difference (P>0.05) in binding to the whole or lysed cells which may be due to reactivity with melanin or precursors found on the cell surface. In mice injected IP with SK-28-MEL cells there was more retention of 111 In-6D2 in intraperitoneal cavity compared to irrelevant 111 In-IgM and control animals with no tumor cells. The biodistribution

Cytochalasin produced by Xylaria sp., a endophytic fungi of Piper aduncum (Piperaceae)

International Nuclear Information System (INIS)

Silva, Geraldo H.; Oliveira, Camila M. de; Teles, Helder L.; Bolzani, Vanderlan da S.; Araujo, Angela R.; Pfenning, Ludwig H.; Young, Maria Claudia M.; Costa-Neto, Claudio M.; Haddad, Renato; Eberlin, Marcos N.

2010-01-01

A chemical study on the EtOAc extract produced by Xylaria sp., an endophytic fungus from Piper aduncum, resulted in the isolation of a new cytochalasin 1, along with five known 19,20-epoxycytochalasin D (2), C (3), N (4), Q (5), and R (6). The 1-6 were evaluated against the fungi C. cladosporioides and C. sphaerospermum and only 5 showed weak activity. The cytotoxicity in vitro against HeLA and CHO cells lines were investigated and the cytochalasins 2-4, and 6 showed a strong activity against HeLA. The DNA damaging activity of 1-6 were also investigated against mutant strains of S. cerevisiae. (author)

Antimicrobial activity of saponins produced by two novel endophytic fungi from Panax notoginseng.

Science.gov (United States)

Jin, Zhaoxia; Gao, Lin; Zhang, Lin; Liu, Tianyi; Yu, Fang; Zhang, Zongshen; Guo, Qiong; Wang, Biying

2017-11-01

Endophytes in plants may be co-producer of the bioactive compounds of their hosts. We conducted a study to bioprospect for saponin-producing endophytic fungi from Panax notoginseng and evaluate the antimicrobial activity of saponins. Two novel fungal endophytes, Fusarium sp. PN8 and Aspergillus sp. PN17, were isolated from traditional Chinese medicinal herb P. notoginseng. After eight days of fermentation, the total saponins produced in the culture broth of PN8 and PN17 were 1.061 and 0.583 mg mL -1 , respectively. The saponin extracts exhibited moderate to high (inhibition zone diameter 15.7-28.4 mm, MIC 1.6-12.5 mg mL -1 ) antimicrobial activity against pathogens tested. Further analysis showed that triterpenoid saponins produced by Fusarium PN8 were Rb 1 , Rd and 20(S)-Rg 3 , while Aspergillus PN17 had the ability to synthesise ginsenoside Re, Rd and 20(S)-Rg 3 . The isolated endophytes may be used as potential sources for microbial production of plant secondary metabolites and for antimicrobial agents.

Duration of reappearance of gingival melanin pigmentation after surgical removal - A clinical study

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Kaur Harjit

2010-01-01

Full Text Available Background: In dentistry, esthetics has a special place. Although gingival melanin pigmentation does not present a medical problem, clinicians are often faced with a challenge of achieving gingival esthetics. Materials and Methods: A method of de-epithelialization of the pigmented gingiva using Kirkland′s gingivectomy knife is described. Twenty patients who were conscious about their gingival melanin pigmentation were selected. The gingiva of the whole of the arch was abraded until the entire visible pigmentation was removed. Clinical observations for intensity of pigmentation were recorded at baseline and then after surgery at monthly intervals over a period of 9 months according to Dummett-Gupta Oral Pigmentation Index scoring criteria proposed by Dummett C. O. in 1964. Results: The mean gingival melanin pigmentation score came down to 0.407 after 9 months as compared to preoperative score, which was 2.24. No repigmentation occurred in fair-complexioned persons. In persons with wheatish complexion, repigmentation was seen in 85.71% of the cases, but scores came down to 0.38 postoperatively as compared to 2.27 preoperatively. In dark complexioned persons, repigmentation occurred in all cases, but the mean scores were 0.93 as compared to 2.40 preoperatively. The difference between preoperative and postoperative mean scores for each segment was put to statistical analysis by applying paired t test and was found to be significant. Conclusion: As this method has shown statistically significant results, it can be used in patients who are conscious of pigmented gingiva and want an esthetically satisfactory color.

Increased melanin concentrating hormone receptor type I in the human hypothalamic infundibular nucleus in cachexia

NARCIS (Netherlands)

Unmehopa, Unga A.; van Heerikhuize, Joop J.; Spijkstra, Wenda; Woods, John W.; Howard, Andrew D.; Zycband, Emanuel; Feighner, Scott D.; Hreniuk, Donna L.; Palyha, Oksana C.; Guan, Xiao-Ming; Macneil, Douglas J.; van der Ploeg, Lex H. T.; Swaab, Dick F.

2005-01-01

Melanin-concentrating hormone (MCH) exerts a positive regulation on appetite and binds to the G protein-coupled receptors, MCH1R and MCH2R. In rodents, MCH is produced by neurons in the lateral hypothalamus with projections to various hypothalamic and other brain sites. In the present study, MCH1R

Increased melanin concentrating hormone receptor type I in the human hypothalamic infundibular nucleus in cachexia.

NARCIS (Netherlands)

Unmehopa, U.A.; Heerikhuize, J.J. van; Spijkstra, W.; Woods, J.W.; Howard, A.D.; Zycband, E.; Feighner, S.D.; Hreniuk, D.L.; Palyha, O.C.; Guan, X.-M.; MacNeil, D.J.; Ploeg, L.H.T.; Swaab, D.F.

2005-01-01

Melanin-concentrating hormone (MCH) exerts a positive regulation on appetite and binds to the G protein-coupled receptors, MCH1R and MCH2R. In rodents, MCH is produced by neurons in the lateral hypothalamus with projections to various hypothalamic and other brain sites. In the present study, MCH1R

MMS 1001 inhibits melanin synthesis via ERK activation.

Science.gov (United States)

Lee, Hyun-E; Song, Jiho; Kim, Su Yeon; Park, Kyoung-Chan; Min, Kyung Hoon; Kim, Dong-Seok

2013-03-01

Melanin plays major a role in pigmentation of hair, eyes, and skin in mammals. In this study, the inhibitory effects of MMS 1001 on alpha-MSH-stimulated melanogenesis were investigated in B16F10 melanoma cells. MMS 1001 did not show cytotoxic effects up to 10 microM. Melanin content and intracellular tyrosinase activity were inhibited by MMS 1001 treatment in a dose-dependent manner. In Western blot analysis, MITF expression was decreased by MMS 1001. In addition, tyrosinase expressions were also reduced after MMS 1001 treatment. Further results showed that the phosphorylation of ERK was induced by MMS 1001. Moreover, a specific MEK inhibitor, PD98059, abrogated the inhibitory effects of MMS 1001 on melanin production and tyrosinase expression. These results indicate that the hypopigmentary effects of MMS 1001 resulted from the inhibition of MITF and tyrosinase expression via phosphorylation of ERK. Thus, MMS 1001 could be developed as a new effective skin-whitening agent.

Phylogeny of Alternaria fungi known to produce host-specific toxins on the basis of variation in internal transcribed spacers of ribosomal DNA.

Science.gov (United States)

Kusaba, M; Tsuge, T

1995-10-01

The internal transcribed spacer regions (ITS1 and ITS2) of ribosomal DNA from Alternaria species, including seven fungi known to produce host-specific toxins, were analyzed by polymerase chain reaction-amplification and direct sequencing. Phylogenetic analysis of the sequence data by the Neighbor-joining method showed that the seven toxin-producing fungi belong to a monophyletic group together with A. alternata. In contract, A. dianthi, A. panax, A. dauci, A. bataticola, A. porri, A. sesami and A. solani, species that can be morphologically distinguished from A. alternata, could be clearly separated from A. alternata by phylogenetic of the ITS variation. These results suggest that Alternaria pathogens which produce host-specific toxins are pathogenic variants within a single variable species, A. alternata.

Syndecan-2 regulates melanin synthesis via protein kinase C βII-mediated tyrosinase activation.

Science.gov (United States)

Jung, Hyejung; Chung, Heesung; Chang, Sung Eun; Choi, Sora; Han, Inn-Oc; Kang, Duk-Hee; Oh, Eok-Soo

2014-05-01

Syndecan-2, a transmembrane heparan sulfate proteoglycan that is highly expressed in melanoma cells, regulates melanoma cell functions (e.g. migration). Since melanoma is a malignant tumor of melanocytes, which largely function to synthesize melanin, we investigated the possible involvement of syndecan-2 in melanogenesis. Syndecan-2 expression was increased in human skin melanoma tissues compared with normal skin. In both mouse and human melanoma cells, siRNA-mediated knockdown of syndecan-2 was associated with reduced melanin synthesis, whereas overexpression of syndecan-2 increased melanin synthesis. Similar effects were also detected in human primary epidermal melanocytes. Syndecan-2 expression did not affect the expression of tyrosinase, a key enzyme in melanin synthesis, but instead enhanced the enzymatic activity of tyrosinase by increasing the membrane and melanosome localization of its regulator, protein kinase CβII. Furthermore, UVB caused increased syndecan-2 expression, and this up-regulation of syndecan-2 was required for UVB-induced melanin synthesis. Taken together, these data suggest that syndecan-2 regulates melanin synthesis and could be a potential therapeutic target for treating melanin-associated diseases. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Melanin binding study of clinical drugs with cassette dosing and rapid equilibrium dialysis inserts

OpenAIRE

Pelkonen L; Tengvall-Unadike U; Ruponen M; Kidron H; del Amo EM; Reinisalo M; Urtti A

2017-01-01

Melanin pigment is a negatively charged polymer found in pigmented human tissues. In the eye, iris, ciliary body, choroid and retinal pigment epithelium (RPE) are heavily pigmented. Several drug molecules are known to bind to melanin, but larger sets of drugs have not been compared often in similar test conditions. In this study, we introduce a powerful tool for screening of melanin binding. The binding of a set of 34 compounds to isolated porcine RPE melanin was determined by cassette (n-in-...

Clinical study on the removal of gingival melanin pigmentation: comparison between Nd:YAG laser ablation and mechanical abrasion

International Nuclear Information System (INIS)

Lopes, Luis Mario de Melo

2002-01-01

Melanin pigmentation occurs as a result of excessive deposition of melanin, produced by the melanocytes present in the basal layer of the epithelium. This study compares clinical parameters such as inflammation and/or hemorrhage, healing process and re-pigmentation, caused by the Nd:YAG laser ablation and the mechanical abrasion of the melanin, by means of photographic images, taken during the first 30 days after the treatment. The patients comfort was monitored during the first ten days after the treatment using the method of the Visual Analog Scale to measure the pain. Six patients with gingival melanin pigmentation were selected. The left upper gingival quadrant was treated with the Nd:YAG laser using 125 mJ per pulse and 20 Hz, the right upper gingival quadrant received mechanical abrasion and the lower quadrants served for control. Both techniques did not result in inflammation and/or hemorrhage. The healing process was slower with the laser. Using mechanical abrasion, ali patients showed remaining pigmentation or re-pigmentation of varying intensity after a period of 30 days. With the laser 50 % of the patients did not show any re-pigmentation after this period. The pain analysis showed that the pain sensed 24 hours after the treatment with the laser is higher than using mechanical abrasion. (author)

Temperature and pH optima of enzyme activities produced by cellulolytic thermophilic fungi in batch and solid-state cultures

Energy Technology Data Exchange (ETDEWEB)

Grajek, W

1986-01-01

The temperature and pH optima of cellulolytic activities produced by thermophilic fungi in liquid and solid-state cultures were established. Some differences in optimal conditions for enzyme activities, which depended on culture methods, were confirmed. 10 references.

Thermophilic Fungi: Their Physiology and Enzymes†

Science.gov (United States)

Maheshwari, Ramesh; Bharadwaj, Girish; Bhat, Mahalingeshwara K.

2000-01-01

Thermophilic fungi are a small assemblage in mycota that have a minimum temperature of growth at or above 20°C and a maximum temperature of growth extending up to 60 to 62°C. As the only representatives of eukaryotic organisms that can grow at temperatures above 45°C, the thermophilic fungi are valuable experimental systems for investigations of mechanisms that allow growth at moderately high temperature yet limit their growth beyond 60 to 62°C. Although widespread in terrestrial habitats, they have remained underexplored compared to thermophilic species of eubacteria and archaea. However, thermophilic fungi are potential sources of enzymes with scientific and commercial interests. This review, for the first time, compiles information on the physiology and enzymes of thermophilic fungi. Thermophilic fungi can be grown in minimal media with metabolic rates and growth yields comparable to those of mesophilic fungi. Studies of their growth kinetics, respiration, mixed-substrate utilization, nutrient uptake, and protein breakdown rate have provided some basic information not only on thermophilic fungi but also on filamentous fungi in general. Some species have the ability to grow at ambient temperatures if cultures are initiated with germinated spores or mycelial inoculum or if a nutritionally rich medium is used. Thermophilic fungi have a powerful ability to degrade polysaccharide constituents of biomass. The properties of their enzymes show differences not only among species but also among strains of the same species. Their extracellular enzymes display temperature optima for activity that are close to or above the optimum temperature for the growth of organism and, in general, are more heat stable than those of the mesophilic fungi. Some extracellular enzymes from thermophilic fungi are being produced commercially, and a few others have commercial prospects. Genes of thermophilic fungi encoding lipase, protease, xylanase, and cellulase have been cloned and

Efektivitas kurkumin sebagai antioksidan dan inhibitor melanin pada kultur sel B16F1

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Sugiharto Sugiharto

2013-03-01

Full Text Available Melanin inhibitors have become increasingly important ingredients in medication and cosmetics for the prevention ofhyperpigmentation. In the last few years, a huge number of natural herbal extracts have been tested as inhibitors of melanin synthesisand some of these effects are related to the antioxidant properties. The objectives of this study were to determine of curcumin propertiesas antioxidant activity and melanin inhibitors. In this study, our data indicated that antioxidant assay with DPPH showed IC50 was16,05 μg/ml. In the absence of α-MSH (α-Melanocyte Stimulating Hormone, melanin content assay in cell B16-F1 indicated thatthe highest activity of curcumin to reduce melanin content of 45,67% at 25 μg/ml. Meanwhile, in the presence of α-MSH at the sameconcentration indicated that the highest activity was 53,87%. Based on the data, curcumin has potential properties as antioxidantactivity and melanin inhibitor.

Evaluation of five essential oils from aromatic plants of Cameroon for controlling food spoilage and mycotoxin producing fungi.

Science.gov (United States)

Nguefack, J; Leth, V; Amvam Zollo, P H; Mathur, S B

2004-08-01

Five essential oils (EO) extracted from Cymbopogon citratus, Monodora myristica, Ocimum gratissimum, Thymus vulgaris and Zingiber officinale were investigated for their inhibitory effect against three food spoilage and mycotoxin producing fungi, Fusarium moniliforme, Aspergillus flavus and Aspergillus fumigatus. Five strains of each fungus were tested. The agar dilution technique was used to determine the inhibitory effect of each EO on the radial growth of the fungus, and a dose response was recorded. The EO from O. gratissimum, T. vulgaris and C. citratus were the most effective and prevented conidial germination and the growth of all three fungi on corn meal agar at 800, 1000 and 1200 ppm, respectively. Moderate activity was observed for the EO from Z. officinale between 800 and 2500 ppm, while the EO from M. myristica was less inhibitory. These effects against food spoilage and mycotoxin producing fungi indicated the possible ability of each essential oil as a food preservative. A comparative test on the preservative ability of the EO from O. gratissimum and potassium sorbate against A. flavus at pH 3.0 and 4.5 showed that the EO remained stable at both pH, whereas the efficacy of potassium sorbate was reduced at higher pH. We concluded that the EO from O. gratissimum is a potential food preservative with a pH dependent superiority against potassium sorbate, and these are novel scientific information.

Plant Bioactive Metabolites and Drugs Produced by Endophytic Fungi of Spermatophyta

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Rosario Nicoletti

2015-09-01

Full Text Available It is known that plant-based ethnomedicine represented the foundation of modern pharmacology and that many pharmaceuticals are derived from compounds occurring in plant extracts. This track still stimulates a worldwide investigational activity aimed at identifying novel bioactive products of plant origin. However, the discovery that endophytic fungi are able to produce many plant-derived drugs has disclosed new horizons for their availability and production on a large scale by the pharmaceutical industry. In fact, following the path traced by the blockbuster drug taxol, an increasing number of valuable compounds originally characterized as secondary metabolites of plant species belonging to the Spermatophyta have been reported as fermentation products of endophytic fungal strains. Aspects concerning sources and bioactive properties of these compounds are reviewed in this paper.

UV causation of melanoma in Xiphophorus is dominated by melanin photosensitized oxidant production

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Wood, Simon R.; Berwick, Marianne; Ley, Ronald D.; Walter, Ronald B.; Setlow, Richard B.; Timmins, Graham S.

2006-01-01

Controversy continues both as to which wavelengths of sunlight cause melanoma and the mechanisms by which these different wavelengths act. Direct absorption of UVB by DNA is central in albino animal models, but melanin-pigmented models have shown major contributions by wavelengths longer than UVB that are thought to be mediated by photosensitized oxidant production. The only model for which the action spectrum of melanoma causation is known is a genetically melanoma-susceptible specific cross of Xiphophorus fish. We used electron paramagnetic resonance to quantitatively detect the UV induction of reactive melanin radicals in situ in the melanin-containing cells in the skin of this model and derived the action spectrum for melanin-photosensitized oxidant production (Φox). This action spectrum was identical to that for melanoma induction (Φmel). These results confirm the hypothesis that melanin-photosensitized radical production is the major causative step of melanoma in this model and demonstrate that the wavelengths and mechanisms of melanoma causation in different models are dependent on the presence of melanin. This approach should be applicable to humans, thus providing an accurate surrogate for Φmel for prevention studies. PMID:16537493

Interactions between Melanin Enzymes and Their Atypical Recruitment to the Secretory Pathway by Palmitoylation

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Srijana Upadhyay

2016-11-01

Full Text Available Melanins are biopolymers that confer coloration and protection to the host organism against biotic or abiotic insults. The level of protection offered by melanin depends on its biosynthesis and its subcellular localization. Previously, we discovered that Aspergillus fumigatus compartmentalizes melanization in endosomes by recruiting all melanin enzymes to the secretory pathway. Surprisingly, although two laccases involved in the late steps of melanization are conventional secretory proteins, the four enzymes involved in the early steps of melanization lack a signal peptide or a transmembrane domain and are thus considered “atypical” secretory proteins. In this work, we found interactions among melanin enzymes and all melanin enzymes formed protein complexes. Surprisingly, the formation of protein complexes by melanin enzymes was not critical for their trafficking to the endosomal system. By palmitoylation profiling and biochemical analyses, we discovered that all four early melanin enzymes were strongly palmitoylated during conidiation. However, only the polyketide synthase (PKS Alb1 was strongly palmitoylated during both vegetative hyphal growth and conidiation when constitutively expressed alone. This posttranslational lipid modification correlates the endosomal localization of all early melanin enzymes. Intriguingly, bioinformatic analyses predict that palmitoylation is a common mechanism for potential membrane association of polyketide synthases (PKSs and nonribosomal peptide synthetases (NRPSs in A. fumigatus. Our findings indicate that protein-protein interactions facilitate melanization by metabolic channeling, while posttranslational lipid modifications help recruit the atypical enzymes to the secretory pathway, which is critical for compartmentalization of secondary metabolism.

Pharmacological Properties of Melanin and its Function in Health.

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ElObeid, Adila Salih; Kamal-Eldin, Afaf; Abdelhalim, Mohamed Anwar K; Haseeb, Adil M

2017-06-01

The biological pigment melanin is present in most of the biological systems. It manifests a host of biological and pharmacological properties. Its role as a molecule with special properties and functions affecting general health, including photoprotective and immunological action, are well recognized. Its antioxidant, anti-inflammatory, immunomodulatory, radioprotective, hepatic, gastrointestinal and hypoglycaemic benefits have only recently been recognized and studied. It is also associated with certain disorders of the nervous system. In this MiniReview, we consider the steadily increasing literature on the bioavailability and functional activity of melanin. Published literature shows that melanin may play a number of possible pharmacological effects such as protective, stimulatory, diagnostic and curative roles in human health. In this MiniReview, possible health roles and pharmacological effects are considered. © 2016 Nordic Association for the Publication of BCPT (former Nordic Pharmacological Society).

Genetically Engineering Entomopathogenic Fungi.

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Zhao, H; Lovett, B; Fang, W

2016-01-01

Entomopathogenic fungi have been developed as environmentally friendly alternatives to chemical insecticides in biocontrol programs for agricultural pests and vectors of disease. However, mycoinsecticides currently have a small market share due to low virulence and inconsistencies in their performance. Genetic engineering has made it possible to significantly improve the virulence of fungi and their tolerance to adverse conditions. Virulence enhancement has been achieved by engineering fungi to express insect proteins and insecticidal proteins/peptides from insect predators and other insect pathogens, or by overexpressing the pathogen's own genes. Importantly, protein engineering can be used to mix and match functional domains from diverse genes sourced from entomopathogenic fungi and other organisms, producing insecticidal proteins with novel characteristics. Fungal tolerance to abiotic stresses, especially UV radiation, has been greatly improved by introducing into entomopathogens a photoreactivation system from an archaean and pigment synthesis pathways from nonentomopathogenic fungi. Conversely, gene knockout strategies have produced strains with reduced ecological fitness as recipients for genetic engineering to improve virulence; the resulting strains are hypervirulent, but will not persist in the environment. Coupled with their natural insect specificity, safety concerns can also be mitigated by using safe effector proteins with selection marker genes removed after transformation. With the increasing public concern over the continued use of synthetic chemical insecticides and growing public acceptance of genetically modified organisms, new types of biological insecticides produced by genetic engineering offer a range of environmentally friendly options for cost-effective control of insect pests. Copyright © 2016 Elsevier Inc. All rights reserved.

An objective assessment of melanin in vitiligo skin treated with Balneo PUVA therapy.

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Hegyi, V; Petrovajová, M; Novotný, M

2014-02-01

Visual clinical methods of skin color evaluation for diagnostic purposes are so far mostly subjective and thus inaccurate. We present a modified method of melanin amount measurement based on diffuse reflectance spectroscopy (DRS). This method is non-invasive and objective, and allows easy quantification and comparison of melanin levels. Skin pigmentation was measured by DRS method in 0-18 year old patients at the Department of Pediatric Dermatovenerology, School of Medicine Comenius University Bratislava. Patients were treated for their vitiligo by Balneo PUVA treatment twice weekly. Each patient had measured his remittance spectra from the treated vitiliginous skin before the treatment was started, after 10 irradiations of Balneo PUVA and at the end of the treatment after 25 irradiations of Balneo PUVA. In our study as a reference skin for spectroscopic assessment of melanin in vivo was used the averaged remittance spectra (measured on the inner arm) from the sample of 10 albino patients. The remittance spectra obtained from the vitiligo patients were ratioed against the newly described remittance reference albino skin. We exploited the linear behavior of the spectral curve in the 620-720 nm interval (significant for melanin absorption) and used the slope of the regression line to compute the quantification index α. By clinical examination before the Balneo PUVA therapy, after the 10th dose of Balneo PUVA therapy as well as at the end of the complete course of Balneo PUVA therapy (after 25 irradiations) we recorded a marked increase of pigmentation in all treated patients for their vitiligo. In each patient the values of melanin quantification angle α were calculated. Statistically we found a significant difference between the melanin quantification angle α in vitiliginous skin before, during the 10th dose of treatment and after the treatment. Similar significant difference was also observed between treated and non-involved skin. We could confirm a clear

Melanin fate in the human epidermis: a reassessment of how best to detect and analyse histologically.

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Joly-Tonetti, Nicolas; Wibawa, Judata I D; Bell, Mike; Tobin, Desmond

2016-07-01

Melanin is the predominant pigment responsible for skin colour and is synthesized by the melanocyte in the basal layer of the epidermis and then transferred to surrounding keratinocytes. Despite its optical properties, melanin is barely detectable in unstained sections of human epidermis. However, identification and localization of melanin is of importance for the study of skin pigmentation in health and disease. Current methods for the histologic quantification of melanin are suboptimal and are associated with significant risk of misinterpretation. The aim of this study was to reassess the existing literature and to develop a more effective histological method of melanin quantification in human skin. Moreover, we confirm that Warthin-Starry (WS) stain provides a much more sensitive and more specific melanin detection method than the commonplace Fontana-Masson (FM) stain. For example, WS staining sensitivity allowed the visualization of melanin even in very pale Caucasian skin that was missed by FM or Von Kossa (VK) stains. From our reassessment of the histology-related literature, we conclude that so-called melanin dust is most likely an artifact of discoloration due to non-specific silver deposition in the stratum corneum. Unlike FM and VK, WS was not associated with this non-specific stratum corneum darkening, misinterpreted previously as 'degraded' melanin. Finally, WS melanin particle counts were largely similar to previously reported manual counts by transmission electron microscopy, in contrast to both FM and VK. Together these findings allow us to propose a new histology/Image J-informed method for the accurate and precise quantification of epidermal melanin in skin. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Comparative genomics provides insights into the lifestyle and reveals functional heterogeneity of dark septate endophytic fungi.

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Knapp, Dániel G; Németh, Julianna B; Barry, Kerrie; Hainaut, Matthieu; Henrissat, Bernard; Johnson, Jenifer; Kuo, Alan; Lim, Joanne Hui Ping; Lipzen, Anna; Nolan, Matt; Ohm, Robin A; Tamás, László; Grigoriev, Igor V; Spatafora, Joseph W; Nagy, László G; Kovács, Gábor M

2018-04-20

Dark septate endophytes (DSE) are a form-group of root endophytic fungi with elusive functions. Here, the genomes of two common DSE of semiarid areas, Cadophora sp. and Periconia macrospinosa were sequenced and analyzed with another 32 ascomycetes of different lifestyles. Cadophora sp. (Helotiales) and P. macrospinosa (Pleosporales) have genomes of 70.46 Mb and 54.99 Mb with 22,766 and 18,750 gene models, respectively. The majority of DSE-specific protein clusters lack functional annotation with no similarity to characterized proteins, implying that they have evolved unique genetic innovations. Both DSE possess an expanded number of carbohydrate active enzymes (CAZymes), including plant cell wall degrading enzymes (PCWDEs). Those were similar in three other DSE, and contributed a signal for the separation of root endophytes in principal component analyses of CAZymes, indicating shared genomic traits of DSE fungi. Number of secreted proteases and lipases, aquaporins, and genes linked to melanin synthesis were also relatively high in our fungi. In spite of certain similarities between our two DSE, we observed low levels of convergence in their gene family evolution. This suggests that, despite originating from the same habitat, these two fungi evolved along different evolutionary trajectories and display considerable functional differences within the endophytic lifestyle.

Mechanistic insights into the bleaching of melanin by alkaline hydrogen peroxide.

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Smith, R A W; Garrett, B; Naqvi, K R; Fülöp, A; Godfrey, S P; Marsh, J M; Chechik, V

2017-07-01

This work aims to determine the roles of reactive oxygen species HO∙ and HO 2 - in the bleaching of melanins by alkaline hydrogen peroxide. Experiments using melanosomes isolated from human hair indicated that the HO∙ radical generated in the outside solution does not contribute significantly to bleaching. However, studies using soluble Sepia melanin demonstrated that both HO 2 - and HO∙ will individually bleach melanin. Additionally, when both oxidants are present, bleaching is increased dramatically in both rate and extent. Careful experimental design enabled the separation of the roles and effects of these key reactive species, HO∙ and HO 2 - . Rationalisation of the results presented, and review of previous literature, allowed the postulation of a simplified general scheme whereby the strong oxidant HO∙ is able to pre-oxidise melanin units to o-quinones enabling more facile ring opening by the more nucleophilic HO 2 - . In this manner the efficiency of the roles of both species is maximised. Copyright © 2017 Elsevier Inc. All rights reserved.

Effect of microscopic fungi on the 137Cs accumulation by some plants growing on radionuclides contaminated soil

International Nuclear Information System (INIS)

Zhdanova, N.; Vasilevskaya, A.; Lashko, T.; Gerzabek, H.

2003-01-01

The influence of soil micromycetes (melanin-containing, dark-pigmented Cladosporium cladosporioides and light-pigmented Paecilomyces lilacinus) on 137C s accumulation by aboveground phytomass of some higher plants (sugar beet, cabbage and clover) was studied in field experiments in radionuclides contaminated soil of the Chernobyl zone with total radioactivity 37-50 kBq/kg. Abundance of these fungi was determined 1, 3 and 5 months after their introduction into the soil. P. lilacinus colonies were isolated in the beginning of the experiment in contrast to C. cladosporioides colonies that were isolated at the end of plants vegetation. The coefficients of 137C s accumulation by aboveground phytomass were higher after the introduction of light-pigmented than of dark-pigmented fungus. These coefficients were higher after the simultaneous introduction of the two fungi than after each fungus introduced separately. (author)

Lipase-producing fungi for potential wastewater treatment and ...

African Journals Online (AJOL)

The use of fungal biomass as a lipase biocatalyst represents an attractive approach for the treatments of oil wastewater as well as for the production of biodiesel from oil and residual grease, due to its greater stability, possibility of reuse, and lower cost. In this work, 20 filamentous fungi were isolated from the grease trap ...

Microbiological Control of Flour-Manufacture: Dissemination of Mycotoxins Producing Fungi in Cereal Products

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T.D. Doolotkeldieva

2010-01-01

Full Text Available Wheat grain and its products are widely consumed as fodder and basic daily food stuffs in Kyrgyzstan. Mycobiota is known to produce hazardous effects to a consumer since it produces mycotoxins. Henceforth, mycobiota starting from the field stage to flour, grain and flour samples were selected for mycological analysis from eight sites of flour manufacture: grain stored in storehouses before milling, mechanically cleaned grain, washed grain, grain dried and prepared for mill, roughly-milled flour, first grade flour and high grade flour. The samples were analyzed using classical mycological and immunoassay methods in order to detect mycotoxins producing fungi species. We isolated overall 27 species belonging to 7 genera. Mycotoxins producing species like Aspergillus flavus, Aspergillus ochraceus and Penicillium cyclopium were detected in the stored grains and in mechanically-cleaned grains. The species of Penicillium, Alternaria and Fusarium genera dominated in roughly-milled flour samples, so this site of flour manufacture still has a risk and danger of contamination with mycotoxins producing fungus. Only the final product i.e. the high grade flour lacked any fungal contamination. We recommend to scrutinize flour samples at the last stages of processing, particularly in the mills like B1, C1 and C4.

Borelli's lactritmel agar induces conidiation in rare-macroconidia producing dermatophytic fungi.

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Ilkit, Macit; Gümral, Ramazan; Döğen, Aylin

2012-10-01

Macroconidia are among the most important indicators used to identify dermatophytic fungi, but several do not usually sporulate and/or produce macroconidia on Sabouraud glucose agar. Specifically, Microsporum audouinii, M. ferrugineum, Trichophyton concentricum, T. schoenleinii, T. verrucosum, and T. violaceum (including T. soudanense and T. yaoundei) rarely form macroconidia and, therefore, cannot be easily identified. In this study, we investigated the production of macroconidia on nine common laboratory media, including Borelli's lactritmel agar (BLA), modified Borelli's lactritmel agar (MBLA), brain heart infusion agar (BHIA), Christensen's urease agar in Petri dishes (UPA), cornmeal dextrose agar (CMDA), Lowenstein-Jensen agar (LJA), malt extract agar (MEA), oatmeal agar (OA), and potato dextrose agar (PDA). The performance of these media was evaluated using 18 rare-macroconidia producing isolates, including representative of the six species mentioned above. All cultures in this study were incubated at 26°C on the bench, and conidia formation on each was investigated at 5, 10, 15, 20, 25, and 30 days of incubation. BLA apparently improved macroconidia production after 15 days and was the most useful nutrient agar medium to induce these phenotypic characters in daily practice, closely followed by OA, PDA, and MBLA.

Melanin targets LC3-associated phagocytosis (LAP): A novel pathogenetic mechanism in fungal disease.

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Chamilos, Georgios; Akoumianaki, Tonia; Kyrmizi, Irene; Brakhage, Axel; Beauvais, Anne; Latge, Jean-Paul

2016-05-03

Intracellular swelling of conidia of the major human airborne fungal pathogen Aspergillus fumigatus results in surface exposure of immunostimulatory pathogen-associated molecular patterns (PAMPs) and triggers activation of a specialized autophagy pathway called LC3-associated phagocytosis (LAP) to promote fungal killing. We have recently discovered that, apart from PAMPs exposure, cell wall melanin removal during germination of A. fumigatus is a prerequisite for activation of LAP. Importantly, melanin promotes fungal pathogenicity via targeting LAP, as a melanin-deficient A. fumigatus mutant restores its virulence upon conditional inactivation of Atg5 in hematopoietic cells of mice. Mechanistically, fungal cell wall melanin selectively excludes the CYBA/p22phox subunit of NADPH oxidase from the phagosome to inhibit LAP, without interfering with signaling regulating cytokine responses. Notably, inhibition of LAP is a general property of melanin pigments, a finding with broad physiological implications.

Antidepressant effects of exercise are produced via suppression of hypocretin/orexin and melanin-concentrating hormone in the basolateral amygdala.

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Kim, Tae-Kyung; Kim, Ji-Eun; Park, Jin-Young; Lee, Jung-Eun; Choi, Juli; Kim, Hannah; Lee, Eun-Hwa; Kim, Seung-Woo; Lee, Ja-Kyeong; Kang, Hyun-Sik; Han, Pyung-Lim

2015-07-01

Physical exercise is considered beneficial in the treatment of depression, but the underlying mechanism is not clearly understood. In the present study, we investigated the mechanism regulating antidepressant effects of exercise by focusing on the role of the amygdala using a well-defined animal model of depression. C57BL/6 mice treated with repeated restraint showed depression-like behaviors, which was counteracted by post-stress treatment with physical exercise. The two neuropeptides hypocretin/orexin (Hcrt/Orx) and melanin-concentrating hormone (MCH) were transcriptionally upregulated in the BLA after repeated stress, and their enhanced expression was downregulated by treatment with exercise, mirroring stress-induced depression-like behaviors and their reversal by exercise. Stereotaxic injection of either Hcrt/Orx peptide or MCH peptide within the BLA commonly increased phospho-CaMKIIα level and produced depression-like behaviors, mimicking the neural states in the BLA of mice subjected to repeated stress. In contrast, siRNA-mediated suppression of Hcrt/Orx or MCH in the BLA blocked stress-induced depression-like behaviors. Furthermore, siRNA-mediated inhibition of CaMKIIα in the BLA also counteracted stress-induced depression-like behaviors. Local injection of Hcrt/Orx peptide or MCH peptide within the BLA in exercise-treated animals blocked antidepressant-like effects of exercise. Together these results suggest that exercise produces antidepressant effects via suppression of Hcrt/Orx and MCH neural systems in the BLA. Copyright © 2015 Elsevier Inc. All rights reserved.

Rab11b mediates melanin transfer between donor melanocytes and acceptor keratinocytes via coupled exo/endocytosis.

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Tarafder, Abul K; Bolasco, Giulia; Correia, Maria S; Pereira, Francisco J C; Iannone, Lucio; Hume, Alistair N; Kirkpatrick, Niall; Picardo, Mauro; Torrisi, Maria R; Rodrigues, Inês P; Ramalho, José S; Futter, Clare E; Barral, Duarte C; Seabra, Miguel C

2014-04-01

The transfer of melanin from melanocytes to keratinocytes is a crucial process underlying maintenance of skin pigmentation and photoprotection against UV damage. Here, we present evidence supporting coupled exocytosis of the melanin core, or melanocore, by melanocytes and subsequent endocytosis by keratinocytes as a predominant mechanism of melanin transfer. Electron microscopy analysis of human skin samples revealed three lines of evidence supporting this: (1) the presence of melanocores in the extracellular space; (2) within keratinocytes, melanin was surrounded by a single membrane; and (3) this membrane lacked the melanosomal membrane protein tyrosinase-related protein 1 (TYRP1). Moreover, co-culture of melanocytes and keratinocytes suggests that melanin exocytosis is specifically induced by keratinocytes. Furthermore, depletion of Rab11b, but not Rab27a, caused a marked decrease in both keratinocyte-stimulated melanin exocytosis and transfer to keratinocytes. Thus, we propose that the predominant mechanism of melanin transfer is keratinocyte-induced exocytosis, mediated by Rab11b through remodeling of the melanosome membrane, followed by subsequent endocytosis by keratinocytes.

Optimization of physico-chemical and nutritional parameters for a novel pullulan-producing fungus, Eurotium chevalieri.

Science.gov (United States)

Gaur, R; Singh, R; Tiwari, S; Yadav, S K; Daramwal, N S

2010-09-01

To isolate the novel nonmelanin pullulan-producing fungi from soil and to optimize the physico-chemical and nutritional parameters for pullulan production. A selective enrichment method was followed for the isolation, along with development of a suitable medium for pullulan production, using shake flask experiments. Pullulan content was confirmed using pure pullulan and pullulanase hydrolysate. Eurotium chevalieri was able to produce maximum pullulan (38 ± 1·0 g l(-1) ) at 35°C, pH 5·5, 2·5% sucrose, 0·3% ammonium sulfate and 0·2% yeast extract in a shake flash culture medium with an agitation rate of 30 rev min(-1) for 65 h. The novel pullulan-producing fungus was identified as E. chevalieri (MTCC no. 9614), which was able to produce nonmelanin pullulan at from poorer carbon and nitrogen sources than Aureobasidium pullulans and may therefore be useful for the commercial production of pullulan. Eurotium chevalieri could produce pullulan in similar amounts to A. pullulans. Therefore, in future, this fungus could also be used for commercial pullulan production, because it is neither polymorphic nor melanin producing, hence its handling during pullulan fermentation will be easier and more economical. © 2010 The Authors. Journal compilation © 2010 The Society for Applied Microbiology.

Andrographolide suppresses melanin synthesis through Akt/GSK3β/β-catenin signal pathway.

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Zhu, Ping-Ya; Yin, Wei-Han; Wang, Meng-Ran; Dang, Yong-Yan; Ye, Xi-Yun

2015-07-01

Tyrosinase (TYR) is the key enzyme controlling the production of melanin. Very few papers have reported that andrographolide can inhibit melanin content. To investigate the effects of andrographolide on melanin synthesis. Cell viability, melanin content, TYR activity, transcriptional and protein expression levels of TYR family and other kinds of proteins involved in melanogenesis were measured after the treatments of andrographolide. It was found that andrographolide decreased melanin content, TYR activity and transcriptional and protein expression of TYR family and microphthalmia-associated transcription factor (MITF) in B16F10 melanoma cells. Data showed andrographolide also decreased melanin content and TYR content in ultraviolet B (UVB) irradiation induced brown guinea pigs. Moreover, we found that melanin content and TYR activity were effectively inhibited in Human Epidermis Melanocyte (HEM) treated with andrographolide at the medium concentrations without apparent effect on cell viability. Results in experiments treated with MG-132 or cycloheximide (CHX) showed that andrographolide lowered the content of β-catenin in cell nucleus resulting from accelerating the degradation of β-catenin. Phosphorylation of glycogen synthase kinase 3β (GSK3β) and Akt decreased simultaneously. 6-Bromoindirubin-3'-oxime (BIO, inhibitor of GSK3β) and insulin-like growth factors-1 (IGF-1, activator of Akt) could reverse the decline of β-catenin in B16F10 cells induced by andrographolide. These results demonstrate that andrographolide can effectively suppress melanin content and TYR activity in B16F10 cells, HEM cells and UVB-induced brown guinea pig skin by decreasing phosphorylation of GSK3β dependent on Akt, promoting the degradation of β-catenin, inhibiting β-catenin into the nucleus and decreasing the expression of MITF and TYR family. Data indicate that andrographolide may be a potential whiting agent which can have great market in cosmetics and in clinical such as

Control of In Vivo Transport and Toxicity of Nanoparticles by Tea Melanin

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Yu-Shiun Chen

2012-01-01

Full Text Available Nanoparticles are unfamiliar to researchers in toxicology. Toxicity may be generated simply due to the reduction in size. Compounds that prevent or cure toxic materials may not work on nanoparticles. Furthermore, as there are more and more applications of nanoparticles in drug delivery and in vivo imaging, controlling the transport and toxicity will be primary concerns for medical application of nanoparticles. Gold nanoparticles (GNPs if injected intraperitoneally into mice can enter hippocampus and induce cognitive impairment. GNPs caused a global imbalance of monoamine levels, specifically affecting the dopaminergic and serotonergic neurons. Pretreatment of tea melanin significantly prevented the deposition of GNPs in mouse brains, especially in the hippocampus. Pretreatment of melanin completely alleviated GNP-induced impairment of cognition. Pre-administration of melanin stably maintained monoamines at normal profiles. Melanin completely prevented the invasion of GNPs into the Cornu Ammonis region of the hippocampus shown by coherent anti-Stoke Raman scattering microscopy. Here we show that the administration of tea melanin prevented the accumulation of Au in brain, the imbalance of monoamines, and the impairment of cognition in mice. The current study provides a therapeutic approach to toxicity of nanoparticles and a novel strategy to control the transport of GNP in mouse brain.

Caryolan-1-ol, an antifungal volatile produced by Streptomyces spp., inhibits the endomembrane system of fungi.

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Cho, Gyeongjun; Kim, Junheon; Park, Chung Gyoo; Nislow, Corey; Weller, David M; Kwak, Youn-Sig

2017-07-01

Streptomyces spp. have the ability to produce a wide variety of secondary metabolites that interact with the environment. This study aimed to discover antifungal volatiles from the genus Streptomyces and to determine the mechanisms of inhibition. Volatiles identified from Streptomyces spp. included three major terpenes, geosmin, caryolan-1-ol and an unknown sesquiterpene. antiSMASH and KEGG predicted that the volatile terpene synthase gene clusters occur in the Streptomyces genome. Growth inhibition was observed when fungi were exposed to the volatiles. Biological activity of caryolan-1-ol has previously not been investigated. Fungal growth was inhibited in a dose-dependent manner by a mixture of the main volatiles, caryolan-1-ol and the unknown sesquiterpene, from Streptomyces sp. S4-7. Furthermore, synthesized caryolan-1-ol showed similar antifungal activity. Results of chemical-genomics profiling assays showed that caryolan-1-ol affected the endomembrane system by disrupting sphingolipid synthesis and normal vesicle trafficking in the fungi. © 2017 The Authors.

Autophagy participates in isoliquiritigenin-induced melanin degradation in human epidermal keratinocytes through PI3K/AKT/mTOR signaling.

Science.gov (United States)

Yang, Zhibo; Zeng, Biyun; Pan, Yi; Huang, Pan; Wang, Chang

2018-01-01

Melanin is the pigment responsible for the color of human skin and hair. Melanin serves as a double-edge sword which can exert both protective and spot-causing effects on skin. Although melanin has an important role in protecting the skin against UV damage, an excessive or uneven melanin production can lead to the formation of freckles and age spots. Isoliquiritigenin (ISL) has been reported to inhibit melanin synthesis; however, its role in melanin degradation remains unclear. In the present study, we evaluated the detailed function of ISL in melanin degradation in human epidermal keratinocytes. Since autophagy has been reported to be related to melanin degradation, we also examined the activation of autophagy by ISL treatment in keratinocytes by measurement of autophagy-related proteins, ATG7, LC3 and p62. Moreover, si-ATG7-induced ATG7 knockdown and autophagy inhibitor 3-MA decreased LC3 II protein levels and increased PMEL17, p62 and melanin levels in HaCaT cells, which could be partially reversed by ISL treatment, indicating that autophagy participated in melanin degradation. The decreased p-AKT and p-mTOR proteins upon ISL treatment indicated the involvement of PI3K/AKT/mTOR signaling in ISL-induced melanin degradation. Taken together, we demonstrated that autophagy participates in ISL-induced melanin degradation in human epidermal keratinocytes through PI3K/AKT/mTOR signaling. Copyright © 2017. Published by Elsevier Masson SAS.

Chemical and biological characterization of phytotoxins produced by Diplodia species, fungi involved in forest plants diseases

OpenAIRE

Masi, Marco

2013-01-01

In recent years, numerous studies have been initiated in order to understand what are the microorganisms involved in forest plants diseases and the role played by phytotoxins produced in the pathogenesis processes. The aim of the present thesis was to study the fungi and the phytotoxins associated with canker disease of the Italian cypress (Cupressus sempervirens L.) and the branch dieback of juniper (Juniperus phoenicea L.) which are plant diseases with noteworthy social and economical impli...

Effects of disrupting the polyketide synthase gene WdPKS1 in Wangiella [Exophiala] dermatitidis on melanin production and resistance to killing by antifungal compounds, enzymatic degradation, and extremes in temperature

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Mandal Piyali

2006-06-01

Full Text Available Abstract Background Wangiella dermatitidis is a human pathogenic fungus that is an etiologic agent of phaeohyphomycosis. W. dermatitidis produces a black pigment that has been identified as a dihydroxynaphthalene melanin and the production of this pigment is associated with its virulence. Cell wall pigmentation in W. dermatitidis depends on the WdPKS1 gene, which encodes a polyketide synthase required for generating the key precursor for dihydroxynaphthalene melanin biosynthesis. Results We analyzed the effects of disrupting WdPKS1 on dihydroxynaphthalene melanin production and resistance to antifungal compounds. Transmission electron microscopy revealed that wdpks1Δ-1 yeast had thinner cell walls that lacked an electron-opaque layer compared to wild-type cells. However, digestion of the wdpks1Δ-1 yeast revealed small black particles that were consistent with a melanin-like compound, because they were acid-resistant, reacted with melanin-binding antibody, and demonstrated a free radical signature by electron spin resonance analysis. Despite lacking the WdPKS1 gene, the mutant yeast were capable of catalyzing the formation of melanin from L-3,4-dihyroxyphenylalanine. The wdpks1Δ-1 cells were significantly more susceptible to killing by voriconazole, amphotericin B, NP-1 [a microbicidal peptide], heat and cold, and lysing enzymes than the heavily melanized parental or complemented strains. Conclusion In summary, W. dermatitidis makes WdPKS-dependent and -independent melanins, and the WdPKS1-dependent deposition of melanin in the cell wall confers protection against antifungal agents and environmental stresses. The biological role of the WdPKS-independent melanin remains unclear.

Melanised endophytic fungi may increase stores of organic carbon in soil

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McGee, Peter; Mukasa Mugerwa, Tendo

2013-04-01

The processes underlying the carbon cycle in soil, especially sequestration of organic carbon (OC), are poorly understood. Hydrolysis and oxidation reduce organic matter. Hydrolysis degrades linear organic molecules in aerobic and anaerobic conditions, though it is slower in anaerobic conditions. Aromatic compounds are only degraded by oxidation. Oxygen is by far the most common electron acceptor in soil. Anaerobic conditions preclude oxidation in soil and will result in the preservation of aromatic compounds so long as the conditions remain anaerobic. We experimentally tested this model using melanised endophytic fungi. Melanin is a polyaromatic compound that can be readily visualised, though is difficult to quantify. An endophytic association provides the fungus with an ongoing source of energy. Fungal hyphae elongate considerable distances in soil where they may colonise aggregates, the core of which may be anaerobic. The hypothesis we tested is that melanised endophytic fungi increase OC in soil. Seedlings of subterranean clover inoculated with single isolates were grown in split pots where the impact of the fungus could be quantified in the hyphal chamber, separated from the roots by a steel mesh. We found that melanised endophytic fungi significantly increased OC and aromatic carbon in a well-aggregated carbon-rich soil. OC increased by up to 17% within 14 weeks. Twenty out of 24 isolates statistically significantly increased and none decreased OC. Increases differed between fungal isolates. Increases in the hyphal chamber were independent of any change in OC associated with the roots of the host plant. The storage of OC in field soils is being explored. Inoculation of plant roots with melanised endophytic fungi offers one means whereby OC may be increased in field soils.

EFFECTS OF THE APPLICATION OF A MINERAL-AND-ORGANIC FERTILISER PRODUCED FROM BROWN COAL ON THE OCCURRENCE AND INFECTIOUS POTENTIAL OF ENTOMOPATHOGENIC FUNGI IN SOIL

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Anna Majchrowska-Safaryan

2017-05-01

Full Text Available This study compared the species composition and rate of entomopathogenic fungi occurrence in cultivable soil following the application of a mineral-and-organic fertiliser produced from brown coal. The material for testing consisted of soil samples collected in the second year of the experiment on two dates in 2015 (spring and autumn. The experiment was carried out on the following plots: control plot (no fertilisation; a plot fertilised with mineral fertilisers NPK presowing + N60 for top dressing; a plot fertilised with NPK presowing + manure; a plot fertilised with a fertiliser produced from brown coal at a dose of 1 t/ha NPK presowing + N20 for top dressing; and a plot fertilised with a fertiliser produced from brown coal at a dose of 5 t/ha NPK presowing + N40 for top dressing. Entomopathogenic fungi were isolated from soil of particular fertilisation experiment plots using insect traps (Galleria mellonella larvae as well as a selective medium. Three species of entomopathogenic fungi, i.e. Beauveria bassiana, Metarhizium anisopliae s.l. and Isaria fumosorosea, were isolated using two methods, from the soil samples collected from particular fertilisation experiment plots on two dates, i.e. spring and autumn. Fungus M. anisopliae s.l. proved to be the predominant species in the tested soil samples. The addition of the mineral-and-organic fertiliser, produced based on brown coal, to the soil at both applied doses contributed to an increase in the number of infectious units (CFUs of entomopathogenic fungi formed in relation to the control plot.

Low temperature specific heat anomalies in melanins and tumor melanosomes

Energy Technology Data Exchange (ETDEWEB)

Mizutani, U [Carnegie--Mellon Univ., Pittsburgh; Massalski, T B; McGinness, J E; Corry, P M

1976-02-12

Human malignant melanoma cells obtained at autopsy were used. Data indicate that melanins exhibit a large linear term (50-200 erg g/sup -1/K/sup -2/) and that they seem to undergo a phase transition as indicated by the heat capacity near 1.9/sup 0/K. A table is presented to show low temperature specific heat data for melanin samples. The measurements include two anomalies, a transition and an unusually high linear contribution. (HLW)

Melanin: spin behaviour and implications for bioelectronic devices (Presentation Recording)

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Meredith, Paul; Sheliakina, Margarita; Mostert, Bernard

2015-10-01

The melanins are a broad class of pigmentary macromolecules found through nature that perform a wide range of functions including photo-protection [1]. The most common melanin - the brown, black pigment eumelanin, has been much studied because of its role in melanoma and also for its functional material properties [2]. Synthetic eumelanin has been shown to be photoconductive in the solid state and also possess a water content dependent dark conductivity [3]. It is now well established that these electrical properties arise from hybrid ionic-electronic behaviour, leading to the proposition that melanins could be model biocompatible systems for ion-to-electron transduction in bioelectronics. In my talk, I will discuss the basic science behind these bioelectronics properties - electrical and optical. In this context I will also describe recent electron paramagnetic spin studies which isolate the role of the various chemical moieties responsible for the hybrid ionic-electronic behaviour. I will also highlight preliminary results on prototype melanin-based bioelectronics devices and discuss possible architectures to realise elements such as solid-state switches and transducers. [1] "The physical and chemical properties of eumelanin", P. Meredith and T. Sarna, Pigment Cell Research, 19(6), pp572-594 (2006). [2] "Electronic and optoelectronic materials and devices inspired by nature", P Meredith, C.J. Bettinger, M. Irimia-Vladu, A.B. Mostert and P.E. Schwenn, Reports on Progress in Physics, 76, 034501 (2013). [3] "Is melanin a semiconductor: humidity induced self doping and the electrical conductivity of a biopolymer", A.B. Mostert, B.J. Powell, F.L. Pratt, G.R. Hanson, T. Sarna, I.R. Gentle and P. Meredith, Proceedings of the National Academy of Sciences of the USA, 109(23), 8943-8947 (2012).

Investigation of Inonotus obliquus (Pers. Pil. Extracts and Melanins after RF-plasma Treatment of Raw Material

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O.Yu. Kuznetsova

2016-03-01

Full Text Available High-frequency capacitive discharge (RF plasma at low pressure was used as preliminary stage for the intensification of extraction from natural medicinal raw material. RF-plasma treatment was carried out in two modes differed by the nature of plasma-forming gas. Chaga (Inonotus obliquus (Pers. Pil. known as the birch mushroom was selected as a perspective source of raw material. Extraction was carried out in two ways – remaceration and maceration. The analy-sis of chaga extracts and melanins was performed using traditional techniques including determination of physical and chemical, antioxidant and spectral characteristics. The obtained extracts and melanins were compared to the control samples and literature data. RF-plasma treatment of medicinal raw material increased the yield of extractive substances, in particular of the main active component of chaga – melanin. The antioxidant activity of chaga extracts grew, while for melanins it remained at the level similar to that of control samples. The IR spectral characteristics of the studied chaga melanins are similar and agree well with the literature data. Insignificant deviations in the position and intensity of absorption strips were observed for the samples after RF treatment. IR spectra of the studied chaga melanins are similar to those for mushroom melanins, thereby confirming the similarity in their nature. RF-plasma treatment of chaga medicinal raw materials allows to modify them partially. The structural and mechanical properties of melanins modified by RF plasma remain the same.

Hesperetin induces melanin production in adult human epidermal melanocytes.

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Usach, Iris; Taléns-Visconti, Raquel; Magraner-Pardo, Lorena; Peris, José-Esteban

2015-06-01

One of the major sources of flavonoids for humans are citrus fruits, hesperidin being the predominant flavonoid. Hesperetin (HSP), the aglycon of hesperidin, has been reported to provide health benefits such as antioxidant, anti-inflammatory and anticarcinogenic effects. However, the effect of HSP on skin pigmentation is not clear. Some authors have found that HSP induces melanogenesis in murine B16-F10 melanoma cells, which, if extrapolated to in vivo conditions, might protect skin against photodamage. Since the effect of HSP on normal melanocytes could be different to that observed on melanoma cells, the described effect of HSP on murine melanoma cells has been compared to the effect obtained using normal human melanocytes. HSP concentrations of 25 and 50 µM induced melanin synthesis and tyrosinase activity in human melanocytes in a concentration-dependent manner. Compared to control melanocytes, 25 µM HSP increased melanin production and tyrosinase activity 1.4-fold (p melanin production in human melanocyte cultures could be reproduced on human skin. Copyright © 2015 Elsevier Ltd. All rights reserved.

Influence of variation in melanin content on absorbance spectra of liquid skin phantoms

CSIR Research Space (South Africa)

Smit, Jacoba E

2010-09-01

Full Text Available content on absorbance spectra of liquid skin phantoms JE Smit, AE Karsten, AF Grobler, RW Sparrow Presented by JE Smit Date: 25 September 2010 circle6 Background circle6 Why study melanin? circle6 Skin pigments, melanocytes, melanosomes, melanin...

Nitroxides as redox probes of melanins: dark-induced and photoinduced changes in redox equilibria

International Nuclear Information System (INIS)

Sarna, T.; Korytowski, W.; Sealy, R.C.

1985-01-01

The interaction of nitroxide free radicals and their reduced products (hydroxylamines) with synthetic and natural melanins has been studied. Electron spin resonance spectroscopy was used to measure changes in radical concentration in the dark and during irradiation with visible or uv light. Some reduction of nitroxide occurs in the dark, and is reversible: the nitroxide can be completely regenerated by the one-electron oxidant ferricyanide. The kinetics of the process depend strongly on radical charge and pH. For positively charged nitroxides the rate is much faster than for either neutral or anionic radicals. At pH 10 the rate is about 20 times faster than at pH 5. Oxidation of hydroxylamine also can occur so that a redox equilibrium is established. The equilibrium constant has been estimated for the reaction between a nitroxide and melanin from autoxidation of 3,4-dihydroxyphenylalanine. Results are also dependent upon the type of melanin used and chemical modification (oxidation or reduction) of the melanin. Redox equilibria are altered during irradiation with either visible or uv light. Rapid oxidation of hydroxylamine to nitroxide is apparent, together with a slower reduction of nitroxide. Action spectra for these processes are related to those for melanin radical production and oxygen consumption in nitroxide-free melanin systems. Reduction of nitroxide is inhibited by oxygen, suggesting a competition between nitroxide and oxygen for photoinduced reducing equivalents

Regulation of melanin biosynthesis via the dihydroxynaphthalene pathway is dependent on sexual development in the ascomycete Sordaria macrospora.

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Engh, Ines; Nowrousian, Minou; Kück, Ulrich

2007-10-01

The filamentous ascomycete Sordaria macrospora accumulates melanin during sexual development. The four melanin biosynthesis genes pks, teh, sdh and tih were isolated and their homology to genes involved in 1,8 dihydroxynaphthalene (DHN) melanin biosynthesis was shown. The presence of DHN melanin in S. macrospora was further confirmed by disrupting the pks gene encoding a putative polyketide synthase and by RNA interference-mediated silencing of the sdh gene encoding a putative scytalone dehydratase. Because melanin occurs in fruiting bodies that develop through several intermediate stages within 7 days of growth, a Northern analysis of a developmental time-course was conducted. These data revealed a time-dependent regulation of teh and sdh transcript levels. Comparing the transcriptional expression by real-time PCR of melanin biosynthesis genes in the wild type under conditions allowing or repressing sexual development, a significant downregulation during vegetative growth was detected. Quantitative real-time PCR and Northern blot analysis of melanin biosynthesis gene expression in different developmental mutants confirmed that melanin biosynthesis is linked to fruiting body development and is under the control of specific regulatory genes that participate in sexual differentiation.

The role of melanin as protector against free radicals in skin and its role as free radical indicator in hair

Science.gov (United States)

Herrling, Thomas; Jung, Katinka; Fuchs, Jürgen

2008-05-01

Throughout the body, melanin is a homogenous biological polymer containing a population of intrinsic, semiquinone-like radicals. Additional extrinsic free radicals are reversibly photo-generated by UV and visible light. Melanin photochemistry, particularly the formation and decay of extrinsic radicals, has been the subject of numerous electron spin resonance (ESR) spectroscopy studies. Several melanin monomers exist, and the predominant monomer in a melanin polymer depends on its location within an organism. In skin and hair, melanin differs in content of eumelanin or pheomelanin. Its bioradical character and its susceptibility to UV irradiation makes melanin an excellent indicator for UV-related processes in both skin and hair. The existence of melanin in skin is strongly correlated with the prevention against free radicals/ROS generated by UV radiation. Especially in the skin melanin (mainly eumelanin) ensures the only natural UV protection by eliminating the generated free radicals/ROS. Melanin in hair can be used as a free radical detector for evaluating the efficacy of hair care products. The aim of this study was to investigate the suitability of melanin as protector of skin against UV generated free radicals and as free radical indicator in hair.

Screening for Endophytic Fungi from Turmeric Plant (Curcuma longa L.) of Sukabumi and Cibinong with Potency as Antioxidant Compounds Producer.

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Bustanussalam; Rachman, Fauzy; Septiana, Eris; Lekatompessy, Sylvia J R; Widowati, Tiwit; Sukiman, Harmastini I; Simanjuntak, Partomuan

2015-01-01

Potency of medicinal plant is related to microorganisms lived in the plant tissue. Those microorganisms are known as endophytic microbes that live and form colonies in the plant tissue without harming its host. Each plant may contains several endophytic microbes that produce biological compounds or secondary metabolites due to co-evolution or genetic transfer from the host plant to endophytic microbes. Endophytic fungi research done for turmeric plant (Curcuma longa L.) gave 44 isolated fungi as results. Those 44 fungi isolated were fermented in Potato Dextrose Broth (PDB) media, filtered, extracted with ethylacetate and then were analyzed by Thin Layer Chromatography (TLC) method and tested for their antioxidant activity by radical scavenging method. The antioxidant activity of the ethylacetate filtrate extracts either from Sukabumi or Cibinong were higher than the biomass extracts. There were 6 fungi that showed antioxidant activities over 65%, i.e., with code name K.Cl.Sb.R9 (93.58%), K.Cl.Sb.A11 (81.49%), KCl.Sb.B1 (78.81%), KCl.Sb.R11 (71.67%) and K.Cl.Sb.A12 (67.76%) from Sukabumi and K.Cl.Cb.U1 (69.27%) from Cibinong. These results showed that bioproduction by endophytic microbes can gave potential antioxidant compounds.

Genetic Basis of Melanin Pigmentation in Butterfly Wings.

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Zhang, Linlin; Martin, Arnaud; Perry, Michael W; van der Burg, Karin R L; Matsuoka, Yuji; Monteiro, Antónia; Reed, Robert D

2017-04-01

Despite the variety, prominence, and adaptive significance of butterfly wing patterns, surprisingly little is known about the genetic basis of wing color diversity. Even though there is intense interest in wing pattern evolution and development, the technical challenge of genetically manipulating butterflies has slowed efforts to functionally characterize color pattern development genes. To identify candidate wing pigmentation genes, we used RNA sequencing to characterize transcription across multiple stages of butterfly wing development, and between different color pattern elements, in the painted lady butterfly Vanessa cardui This allowed us to pinpoint genes specifically associated with red and black pigment patterns. To test the functions of a subset of genes associated with presumptive melanin pigmentation, we used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 genome editing in four different butterfly genera. pale , Ddc , and yellow knockouts displayed reduction of melanin pigmentation, consistent with previous findings in other insects. Interestingly, however, yellow-d , ebony , and black knockouts revealed that these genes have localized effects on tuning the color of red, brown, and ochre pattern elements. These results point to previously undescribed mechanisms for modulating the color of specific wing pattern elements in butterflies, and provide an expanded portrait of the insect melanin pathway. Copyright © 2017 by the Genetics Society of America.

Melanin deposition ruled out as cause of color changes in the red-eared sliders (Trachemys scripta elegans).

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Cao, Dainan; Gong, Shiping; Yang, Jiangbo; Li, Weiye; Ge, Yan; Wei, Yufeng

2018-03-01

Animal coloration primarily depends on the presence of pigments and the mixing ratio of eumelanin and pheomelanin. The color of red-eared slider's carapace varies with age, from an olive green to a yellow green, and then to a yellow brown in juveniles, generally. The purpose of the present study was to investigate whether this color change is related to the difference in melanin expression. Melanin deposition levels were examined in the carapace, skin, eye and muscle of the three color-types using hematoxylin and eosin staining. Moreover, the full-length coding sequence (CDS) of red-eared slider turtle melanin biosynthesis regulatory genes TYR, TYRP1, MITF and SLC24A5 were cloned, sequenced and quantitatively analyzed. Both histological view of melanin deposition and quantitative real-time PCR test of melanin-regulated gene expressions showed that there are significant differences among different tissues of red-eared slider, but no significant difference among different color-types, indicating that melanin deposition is not associated with ontogenetic color change in the carapace of red-eared slider. This study initially explore the melanin deposition and the mRNA expression of melanin biosynthesis regulatory genes in red-eared slider, which serve as a foundation for further insight into the pigmentation patterns and the mechanism of body color change in turtles. Copyright © 2017 Elsevier Inc. All rights reserved.

Management of arbuscular mycorrhizal fungi by growing petunia hybrida (l.) mill. as an ornamental plant in saudi arabia - a case study

International Nuclear Information System (INIS)

Qarawi, A.A.; Mridha, M.A.U.; Alghamdi, O.M.

2014-01-01

Arbuscular mycorrhizal fungi (AMF) regarded as ubiquitous soil fungi which help in improving plant growth under harsh conditions. Petunia hybrida is one of the most favorite ornamental plants growing all over the Riyadh city of Saudi Arabia. In the present study, we would like to highlight the Petunia as a mycotrophic plant for the management of mycorrhizal fungi under field conditions. Roots along with rhizosphere soils of P. hybrida were collected from various sites in Riyadh, Saudi Arabia to study AM colonization and biodiversity of AMF. The data obtained in this study indicated that P. hybrida is a very highly mycotrophic plants, and all the samples produced very high colonization with mycelium, vesicles, coiled hyphae and arbuscules. The significant variation was found with the occurrence of mycelium and vesicles among the locations but in case of arbuscules more or less same range of occurrence was found. Only different species of Glomus were observed in all the locations. Glomus showed diversity in all the locations as indicated by the Shanon Diversity Index. As the P. hybrida is a highly mycotrophic plant, so this plant may be grown under harsh condition of Saudi Arabia to manage the plant growth under different stresses viz., water stress, saline soils and heavy metal toxicity conditions. (author)

Bioactive alkaloids produced by fungi. I. Updates on alkaloids from the species of the genera Boletus, Fusarium and psilocybe.

Science.gov (United States)

Mahmood, Zafar Alam; Ahmed, Syed Waseemuddin; Azhar, Iqbal; Sualeh, Mohammad; Baig, Mirza Tasawer; Zoha, Sms

2010-07-01

Fungi, in particular, are able in common with the higher plants and bacteria, to produce metabolites, including alkaloids. Alkaloids, along with other metabolites are the most important fungal metabolites from pharmaceutical and industrial point of view. Based on this observation, the authors of this review article have tried to provide an information on the alkaloids produced by the species of genera: Boletus, Fusarium and Psilocybef from 1981-2009. Thus the review would be helpful and provides valuable information for the researchers of the same field.

Discovering the role of the apolipoprotein gene and the genes in the putative pullulan biosynthesis pathway on the synthesis of pullulan, heavy oil and melanin in Aureobasidium pullulans.

Science.gov (United States)

Guo, Jian; Huang, Siyao; Chen, Yefu; Guo, Xuewu; Xiao, Dongguang

2017-12-18

Pullulan produced by Aureobasidium pullulans presents various applications in food manufacturing and pharmaceutical industry. However, the pullulan biosynthesis mechanism remains unclear. This work proposed a pathway suggesting that heavy oil and melanin may correlate with pullulan production. The effects of overexpression or deletion of genes encoding apolipoprotein, UDPG-pyrophosphorylase, glucosyltransferase, and α-phosphoglucose mutase on the production of pullulan, heavy oil, and melanin were examined. Pullulan production increased by 16.93 and 8.52% with the overexpression of UDPG-pyrophosphorylase and apolipoprotein genes, respectively. Nevertheless, the overexpression or deletion of other genes exerted little effect on pullulan biosynthesis. Heavy oil production increased by 146.30, 64.81, and 33.33% with the overexpression of UDPG-pyrophosphorylase, α-phosphoglucose mutase, and apolipoprotein genes, respectively. Furthermore, the syntheses of pullulan, heavy oil, and melanin can compete with one another. This work may provide new guidance to improve the production of pullulan, heavy oil, and melanin through genetic approach.

Fungi and mycotoxins: Food contaminants

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Kocić-Tanackov Sunčica D.

2013-01-01

Full Text Available The growth of fungi on food causes physical and chemical changes which, further affect negatively the sensory and nutritive quality of food. Species from genera: Aspergillus, Penicillium, Fusarium, Alternariа, Cladosporium, Mucor, Rhizopus, Eurotium and Emericella are usually found. Some of them are potentially dangerous for humans and animals, due to possible synthesis and excretion of toxic secondary metabolites - mycotoxins into the food. Their toxic syndroms in animals and humans are known as mycotoxicoses. The pathologic changes can be observed in parenhimatic organs, and in bones and central nervous system also. Specific conditions are necessary for mycotoxin producing fungi to synthetize sufficient quantities of these compounds for demonstration of biologic effects. The main biochemical paths in the formation of mycotoxins include the polyketide (aflatoxins, sterigmatocystin, zearalenone, citrinine, patulin, terpenic (trichothecenes, aminoacid (glicotoxins, ergotamines, sporidesmin, malformin C, and carbonic acids path (rubratoxins. Aflatoxins are the most toxigenic metabolites of fungi, produced mostly by Aspergillus flavus and A. parasiticus species. Aflatoxins appear more frequently in food in the tropic and subtropic regions, while the food in Europe is more exposed to also very toxic ochratoxin A producing fungi (A. ochraceus and some Penicillium species. The agricultural products can be contaminated by fungi both before and after the harvest. The primary mycotoxicoses in humans are the result of direct intake of vegetable products contaminated by mycotoxins, while the secondary mycotoxicoses are caused by products of animal origin. The risk of the presence of fungi and mycotoxin in food is increasing, having in mind that some of them are highly thermoresistent, and the temperatures of usual food sterilization is not sufficient for their termination. The paper presents the review of most important mycotoxins, their biologic effects

Testing in mice the hypothesis that melanin is protective in malaria infections.

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Michael Waisberg

Full Text Available Malaria has had the largest impact of any infectious disease on shaping the human genome, exerting enormous selective pressure on genes that improve survival in severe malaria infections. Modern humans originated in Africa and lost skin melanization as they migrated to temperate regions of the globe. Although it is well documented that loss of melanization improved cutaneous Vitamin D synthesis, melanin plays an evolutionary ancient role in insect immunity to malaria and in some instances melanin has been implicated to play an immunoregulatory role in vertebrates. Thus, we tested the hypothesis that melanization may be protective in malaria infections using mouse models. Congenic C57BL/6 mice that differed only in the gene encoding tyrosinase, a key enzyme in the synthesis of melanin, showed no difference in the clinical course of infection by Plasmodium yoelii 17XL, that causes severe anemia, Plasmodium berghei ANKA, that causes severe cerebral malaria or Plasmodium chabaudi AS that causes uncomplicated chronic disease. Moreover, neither genetic deficiencies in vitamin D synthesis nor vitamin D supplementation had an effect on survival in cerebral malaria. Taken together, these results indicate that neither melanin nor vitamin D production improve survival in severe malaria.

Complexation in two-component chlortetracycline-melanin solutions

Science.gov (United States)

Lapina, V. A.; Pershukevich, P. P.; Dontsov, A. E.; Bel'Kov, M. V.

2008-01-01

The spectra and kinetics of fluorescence of two-component solutions of the chlortetracycline (CHTC)-DOPA-melanin (melanin or ME) system in water have been investigated. The data obtained have been compared to similar data for solutions of CHTC-melanosome from bull eye (MB), which contains natural melanin, in K-phosphate buffer at pH 7.4. The overall results indicate the occurrence of complexation between molecules of CHTC and ME as they are being excited. The studies of complexation in the solution of CHTC-MB in the buffer are complicated by the formation of a CHTC-buffer complex. The effect of optical radiation in the range 330-750 nm on the CHTC-ME complex shows selectivity: the greatest change in the spectrum occurs when the wavelength of the exciting radiation coincides with the long-wavelength band maximum of the fluorescence excitation spectrum of the CHTC-ME complex in aqueous solution. In this range, CHTC and especially ME show high photochemical stability. The nature of the radiation effect on the studied compounds in the hard UV range (λ < 330 nm) differs greatly from that in the range 330-750 nm. It is apparently accompanied by significant photochemical transmutations of all system components. By comparing the characteristics of the CHTC-ME systems with those of the related drug doxycycline (DC-ME), the conclusion has been made that the chlorine atom plays a vital role in formation of the short-wavelength band in the fluorescence spectrum of the CHTC-ME complex.

Effects of melanin-induced free radicals on the isolated rat peritoneal mast cells

International Nuclear Information System (INIS)

Ranadive, N.S.; Shirwadkar, S.; Persad, S.; Menon, I.A.

1986-01-01

Pheomelanin from human red hair (RHM) produces considerably more cellular damage in Ehrlich ascites carcinoma cells when subjected to radiations of wavelength 320-700 nm than eumelanin from black hair (BHM). Irradiation of RHM generated large amounts of superoxide while BHM did not produce detectable amounts of superoxide. The present investigations describe the effects of irradiation of mast cells in the presence of various natural and synthetic melanins. Irradiation of mast cells in the presence of RHM and red hair melanoprotein released large amounts of histamine while BHM and synthetic melanins prepared from dopa, cysteinyldopa, or a mixture of dopa and cysteinyldopa did not release histamine. The release of histamine at lower concentrations of RHM was not accompanied by the release of 51 Cr from chromium-loaded cells, suggesting that this release was of noncytotoxic nature. On the other hand, the release of histamine at higher concentrations of RHM was due to cell lysis since both histamine and cytoplasmic marker 51 Cr were released to the same extent. The release evoked by large concentration RHM was not inhibited by superoxide dismutase or catalase. This suggests that the cell lysis under these conditions was not due to H 2 O 2 or O-2. The finding that mast cells release histamine when irradiated in the presence of RHM suggests that the immediate and late-phase reactions seen in sunburn may in part be due to the release of mediators from these cells

Effects of melanin-induced free radicals on the isolated rat peritoneal mast cells

Energy Technology Data Exchange (ETDEWEB)

Ranadive, N.S.; Shirwadkar, S.; Persad, S.; Menon, I.A.

1986-03-01

Pheomelanin from human red hair (RHM) produces considerably more cellular damage in Ehrlich ascites carcinoma cells when subjected to radiations of wavelength 320-700 nm than eumelanin from black hair (BHM). Irradiation of RHM generated large amounts of superoxide while BHM did not produce detectable amounts of superoxide. The present investigations describe the effects of irradiation of mast cells in the presence of various natural and synthetic melanins. Irradiation of mast cells in the presence of RHM and red hair melanoprotein released large amounts of histamine while BHM and synthetic melanins prepared from dopa, cysteinyldopa, or a mixture of dopa and cysteinyldopa did not release histamine. The release of histamine at lower concentrations of RHM was not accompanied by the release of /sup 51/Cr from chromium-loaded cells, suggesting that this release was of noncytotoxic nature. On the other hand, the release of histamine at higher concentrations of RHM was due to cell lysis since both histamine and cytoplasmic marker /sup 51/Cr were released to the same extent. The release evoked by large concentration RHM was not inhibited by superoxide dismutase or catalase. This suggests that the cell lysis under these conditions was not due to H/sub 2/O/sub 2/ or O-2. The finding that mast cells release histamine when irradiated in the presence of RHM suggests that the immediate and late-phase reactions seen in sunburn may in part be due to the release of mediators from these cells.

Ebselen is a new skin depigmenting agent that inhibits melanin biosynthesis and melanosomal transfer.

Science.gov (United States)

Kasraee, Behrooz; Nikolic, Damjan S; Salomon, Denis; Carraux, Pierre; Fontao, Lionel; Piguet, Vincent; Omrani, Gholamhossein R; Sorg, Olivier; Saurat, Jean-Hilaire

2012-01-01

We assessed the ability of ebselen, a glutathione peroxidase mimic, to reduce pigmentation in various models. In murine B16 melanocytes, 25 μm ebselen inhibited melanogenesis and induced a depolymerisation of actin filaments. In co-cultures of B16 melanocytes with BDVII keratinocytes, a pretreatment of melanocytes with ebselen resulted in a strong inhibition of melanosome transfer to keratinocytes, as shown under optical and electron microscopy. In reconstructed epidermis, topical 0.5% ebselen led to a twofold decrease of melanin without affecting the density of active melanocytes. A similar result was obtained with topical 0.5% ebselen in black guinea pig ears. Ebselen induced a decrease of epidermal melanin parallel to a localisation of melanin and melanosomes in the basal layer. Ebselen appears as a new depigmenting compound that inhibits melanin synthesis and melanosome transfer to keratinocytes. © 2011 John Wiley & Sons A/S.

Melanins and melanogenesis: from pigment cells to human health and technological applications.

Science.gov (United States)

d'Ischia, Marco; Wakamatsu, Kazumasa; Cicoira, Fabio; Di Mauro, Eduardo; Garcia-Borron, Josè Carlos; Commo, Stephane; Galván, Ismael; Ghanem, Ghanem; Kenzo, Koike; Meredith, Paul; Pezzella, Alessandro; Santato, Clara; Sarna, Tadeusz; Simon, John D; Zecca, Luigi; Zucca, Fabio A; Napolitano, Alessandra; Ito, Shosuke

2015-09-01

During the past decade, melanins and melanogenesis have attracted growing interest for a broad range of biomedical and technological applications. The burst of polydopamine-based multifunctional coatings in materials science is just one example, and the list may be expanded to include melanin thin films for organic electronics and bioelectronics, drug delivery systems, functional nanoparticles and biointerfaces, sunscreens, environmental remediation devices. Despite considerable advances, applied research on melanins and melanogenesis is still far from being mature. A closer intersectoral interaction between research centers is essential to raise the interests and increase the awareness of the biomedical, biomaterials science and hi-tech sectors of the manifold opportunities offered by pigment cells and related metabolic pathways. Starting from a survey of biological roles and functions, the present review aims at providing an interdisciplinary perspective of melanin pigments and related pathway with a view to showing how it is possible to translate current knowledge about physical and chemical properties and control mechanisms into new bioinspired solutions for biomedical, dermocosmetic, and technological applications. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Photobiological implications of melanin photoprotection after UVB-induced tanning of human skin but not UVA-induced tanning.

Science.gov (United States)

Coelho, Sergio G; Yin, Lanlan; Smuda, Christoph; Mahns, Andre; Kolbe, Ludger; Hearing, Vincent J

2015-03-01

Repetitive suberythemal UVA and/or UVB exposures were used to generate comparable UV-induced tans in human skin over the course of 2 weeks. To evaluate the potential photoprotective values of those UVA- and/or UVB- induced tans and to avoid the confounding issue of residual UV-induced DNA damage, we waited 1 week before challenging those areas with a 1.5 MED of UVA+UVB after which we measure DNA damage. The results show that the type of UV used to induce skin pigmentation affects the redistribution of melanin in the skin and/or de novo melanin synthesis. The UVA-induced tans failed to even provide a minimal SPF of 1.5, which suggests that producing a tan with UVA-rich sunlamps prior to a holiday or vacation is completely counterproductive. Published 2014. This article is a US Government work and is in the public domain in the USA.

Distribution of sterigmatocystin in filamentous fungi

DEFF Research Database (Denmark)

Rank, Christian; Nielsen, Kristian Fog; Larsen, Thomas Ostenfeld

2011-01-01

. Six new ST producing fungi were discovered: Aspergillus asperescens, Aspergillus aureolatus, Aspergillus eburneocremeus, Aspergillus protuberus, Aspergillus tardus, and Penicillium inflatum and one new aflatoxin producer: Aspergillus togoensis (=Stilbothamnium togoense). ST was confirmed in 23...

Photoreactivity of biologically active compounds. VII. Interaction of antimalarial drugs with melanin in vitro as part of phototoxicity screening.

Science.gov (United States)

Kristensen, S; Orsteen, A L; Sande, S A; Tønnesen, H H

1994-10-01

The drugs commonly used in the treatment of malaria are photochemically unstable. Several of these compounds accumulate in melanin-rich tissues and cause toxic reactions which may be light induced. As part of the screening of the photochemical properties and phototoxic capabilities of antimalarials, the in vitro interaction of eight antimalarials with melanin was studied. The dissociation constant for the drug-melanin complex and the relative number of binding sites on melanin were estimated for six of the drugs using a curve-fitting program. The reaction rate for the formation of the melanin-drug complex was determined, and the complexes were further characterized by zeta potential measurements.

Promising carbons for supercapacitors derived from fungi

Energy Technology Data Exchange (ETDEWEB)

Zhu, Hui; Wang, Xiaolei; Yang, Fan; Yang, Xiurong [State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022 (China)

2011-06-24

Activated carbons with promising performance in capacitors are produced from fungi via a hydrothermal assistant pyrolysis approach. This study introduces a facile strategy to discover carbonaceous materials and triggers interest in exploring fungi for material science applications. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Aflatoxigenic Fungi and Aflatoxins in Portuguese Almonds

Science.gov (United States)

Rodrigues, P.; Venâncio, A.; Lima, N.

2012-01-01

Aflatoxin contamination of nuts is an increasing concern to the consumer's health. Portugal is a big producer of almonds, but there is no scientific knowledge on the safety of those nuts, in terms of mycotoxins. The aim of this paper was to study the incidence of aflatoxigenic fungi and aflatoxin contamination of 21 samples of Portuguese almonds, and its evolution throughout the various stages of production. All fungi belonging to Aspergillus section Flavi were identified and tested for their aflatoxigenic ability. Almond samples were tested for aflatoxin contamination by HPLC-fluorescence. In total, 352 fungi belonging to Aspergillus section Flavi were isolated from Portuguese almonds: 127 were identified as A. flavus (of which 28% produced aflatoxins B), 196 as typical or atypical A. parasiticus (all producing aflatoxins B and G), and 29 as A. tamarii (all nonaflatoxigenic). Aflatoxins were detected in only one sample at 4.97 μg/kg. PMID:22666128

Aflatoxigenic Fungi and Aflatoxins in Portuguese Almonds

Directory of Open Access Journals (Sweden)

P. Rodrigues

2012-01-01

Full Text Available Aflatoxin contamination of nuts is an increasing concern to the consumer’s health. Portugal is a big producer of almonds, but there is no scientific knowledge on the safety of those nuts, in terms of mycotoxins. The aim of this paper was to study the incidence of aflatoxigenic fungi and aflatoxin contamination of 21 samples of Portuguese almonds, and its evolution throughout the various stages of production. All fungi belonging to Aspergillus section Flavi were identified and tested for their aflatoxigenic ability. Almond samples were tested for aflatoxin contamination by HPLC-fluorescence. In total, 352 fungi belonging to Aspergillus section Flavi were isolated from Portuguese almonds: 127 were identified as A. flavus (of which 28% produced aflatoxins B, 196 as typical or atypical A. parasiticus (all producing aflatoxins B and G, and 29 as A. tamarii (all nonaflatoxigenic. Aflatoxins were detected in only one sample at 4.97 μg/kg.

Methionine supplementation influences melanin-based plumage colouration in Eurasian kestrel, Falco tinnunculus, nestlings.

Science.gov (United States)

Parejo, Deseada; Silva, Nadia

2009-11-01

The extent to which the expression of melanin-based plumage colouration in birds is genetically or environmentally determined is controversial. Here, we performed a between-nest design supplementation with either the sulphur amino acid dl-methionine or with water to investigate the importance of the non-genetic component of melanin-based plumage colouration in the Eurasian kestrel, Falco tinnunculus. Methionine affects growth and immunity, thus we aimed to modify nestling growth and immunity before feather development. Then, we measured the effect of the experiment on colouration of two melanin-based plumage patches of nestling kestrels. We found that methionine slowed down nestling growth through treatment administration and that nestlings compensated by speeding up their growth later. We did not find any effects of methionine on nestling immunity (i.e. lymphocyte counts, natural antibody levels or complement-mediated immunity). Effects on growth seemed to be mirrored by changes in nestling colouration in the two sexes: methionine-nestlings showed less intense brown plumage on their backs compared with control nestlings. These results provide support for a non-genetic determination of a melanin-based plumage patch in the two sexes of nestling kestrels.

Sexual dimorphism in melanin pigmentation, feather coloration and its heritability in the barn swallow (Hirundo rustica.

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Nicola Saino

Full Text Available Melanin is the main pigment in animal coloration and considerable variation in the concentrations of the two melanin forms (pheo- and eumlanin in pigmented tissues exists among populations and individuals. Melanin-based coloration is receiving increasing attention particularly in socio-sexual communication contexts because the melanocortin system has been hypothesized to provide a mechanistic basis for covariation between coloration and fitness traits. However, with few notable exceptions, little detailed information is available on inter-individual and inter-population variation in melanin pigmentation and on its environmental, genetic and ontogenetic components. Here, we investigate melanin-based coloration in an Italian population of a passerine bird, the barn swallow (Hirundo rustica rustica, its sex- and age-related variation, and heritability. The concentrations of eu- and pheomelanin in the throat (brown and belly (white-to-brownish feathers differed between sexes but not according to age. The relative concentration of either melanin (Pheo:Eu differed between sexes in throat but not in belly feathers, and the concentrations in males compared to females were larger in belly than in throat feathers. There were weak correlations between the concentrations of melanins within as well as among plumage regions. Coloration of belly feathers was predicted by the concentration of both melanins whereas coloration of throat feathers was only predicted by pheomelanin in females. In addition, Pheo:Eu predicted coloration of throat feathers in females and that of belly feathers in males. Finally, we found high heritability of color of throat feathers. Melanization was found to differ from that recorded in Hirundo rustica rustica from Scotland or from H. r. erythrogaster from North America. Hence, present results show that pigmentation strategies vary in a complex manner according to sex and plumage region, and also among geographical populations

Aflatoxins associated with storage fungi in fish feed | Samuel | Ife ...

African Journals Online (AJOL)

Cereals and legumes are a very important part of feed used in culturing fishes. Feed, when not properly stored, enhances the growth of storage fungi which is a source of mycotoxins, secondary metabolites produced by storage fungi. This study investigates storage fungi and aflatoxin in fish feed stored under three different ...

Neural stem cells inhibit melanin production by activation of Wnt inhibitors.

Science.gov (United States)

Hwang, Insik; Park, Ju-Hwang; Park, Hang-Soo; Choi, Kyung-Ah; Seol, Ki-Cheon; Oh, Seung-Ick; Kang, Seongman; Hong, Sunghoi

2013-12-01

Melanin for skin pigmentation is synthesized from tyrosine via an enzymatic cascade that is controlled by tyrosinase (TYR), tyrosinase-related protein 1 (TRP1), and dopachrome tautomerase/tyrosinase related protein 2 (Dct/TRP2), which are the targets of microphthalmia-associated transcription factor (MITF). MITF is a master regulator of pigmentation and a target of β-catenin in Wnt/β-catenin signaling during melanocyte differentiation. Stem cells have been used in skin pigmentation studies, but the mechanisms were not determined for the conditioned medium (CM)-mediated effects. In this study, the inhibition and mechanisms of melanin synthesis were elucidated in B16 melanoma cells and UV-B irradiated C57/BL-6 mice that were treated with human neural stem cell-conditioned medium (NSC-CM). B16-F10 melanoma cells (1.5×10(4)cells/well) and the shaved dorsal skin of mice were pretreated with various amount (5, 10, 20, 50, and 100%) of NSC-CM. Melanin contents and TYR activity were measured by a Spectramax spectrophotometer. The expression of TYR, TRP1, Dct/TRP2, MITF, β-catenin and Wnt inhibitors were evaluated by RT-PCR and western blot. The dorsal skin samples were analyzed by immunofluorescence with various antibodies and compared with that control of tissues. Marked decreases were evident in melanin content and TYR, TRP1, DCT/TRP2, MITF, and β-catenin expression in B16 cells and C57/BL-6 mice. NSC-CM negatively regulated Wnt/β-catenin signaling by decreasing the expression of β-catenin protein, which resulted from robust expression of Wnt inhibitors Dickkopf-1 (DKK1) and secreted frizzled-related protein 2 (sFRP2). These results demonstrate that NSC-CM suppresses melanin production in vitro and in vivo, suggesting that factors in NSC-CM may play an important role in deregulation of epidermal melanogenesis. Copyright © 2013 Japanese Society for Investigative Dermatology. All rights reserved.

Screening of Auricularia auricula strains for strong production ability of melanin pigments

OpenAIRE

ZOU, Yu; MA, Kun

2017-01-01

Abstract Melanin pigments have great application value and development potential in food industry to use as nature functional food colorants. In initial study, twenty-two Auricularia auricula strains were screened for stronger production ability of melanin pigments by solid culture. Three A. auricula strains (RF201, QD2 and QD6) with higher pigment production capacity were selected for further study through submerged culture supplementing 1 g/L l-tyrosine. The maximal pigment yields of A. aur...

Methyl gallate from Acer barbinerve decreases melanin synthesis in Mel-Ab cells.

Science.gov (United States)

Kim, In Wook; jeong, Hyo-Soon; Kim, Jin Kyu; Lee, Jin-Koo; Kim, Hak Rim; Yun, Hye-Young; Baek, Kwang Jin; Kwon, Nyoun Soo; Park, Kyoung-Chan; Kim, Dong-Seok

2015-01-01

Methyl gallate (MG) was isolated from the bark of Acer barbinerve, which has traditionally been used in Oriental medicine. In the present study, we examined the effects of MG on melanin synthesis in Mel-Ab melanocyte cells. MG decreased melanin pigmentation in a concentration-dependent manner, but did not directly inhibit tyrosinase activity. Further analysis showed that MG had no effect on extracellular signal-regulated kinase (ERK) activation, but induced phosphorylation of glycogen synthase kinase (GSK)3β, which is known to increase β-catenin accumulation. Accordingly, the β-catenin level was increased by MG. However, a specific GSK3β inhibitor did not rescue the MG-induced inhibition of melanogenesis. Additionally, MG decreased the protein expression of microphthalmia-associated transcription factor (MITF) and tyrosinase, which regulate melanin synthesis. Based on these results, we conclude that MG inhibits melanogenesis by decreasing the expression of MITF and tyrosinase.

Menadione (Vitamin K3) decreases melanin synthesis through ERK activation in Mel-Ab cells.

Science.gov (United States)

Kim, Eun-Hyun; Kim, Myo-Kyoung; Yun, Hye-Young; Baek, Kwang Jin; Kwon, Nyoun Soo; Park, Kyoung-Chan; Kim, Dong-Seok

2013-10-15

Menadione is a synthetic vitamin K3 derivative. Here, we examined the effects of menadione on melanogenesis and its related signaling pathways. Our results showed that melanin content was significantly reduced after menadione treatment in a dose-dependent manner. However, menadione treatment did not reduce tyrosinase activity directly. Wnt signaling is known to play a major role in the control of melanin synthesis. Thus, we tested the effects of menadione treatment on GSK3β and β-catenin signaling, but found that menadione did not influence either of these signaling pathways. We also investigated changes in the phosphorylation of ERK, which is related to melanin regulation. These results indicated that menadione treatment led to the phosphorylation of ERK. Additionally, menadione treatment reduced both MITF and tyrosinase protein levels. Treatment with PD98059, a specific ERK pathway inhibitor, restored menadione-induced melanin reduction and also prevented MITF and tyrosinase downregulation by menadione. These results suggest that the hypopigmentary action of menadione is due to MITF and tyrosinase downregulation by ERK activation. © 2013 Elsevier B.V. All rights reserved.

Studies of separation and purification of fungi for uranium-leaching

International Nuclear Information System (INIS)

Wang Yongdong; Li Guangyue; Shi Wenge; Hu Nan; Pan Wenjun; Zhou Zhixiang; Deng Qinwen; Ding Dexin

2010-01-01

To obtain purified fungi for uranium-leaching, fungi in uranium ores were separated using Dox(-), SDA, PDA and Dox(+) medium, then spores were picked from the plates for fungi purification. Four strains of fungi were acquired and one of them is aspergillus niger,others are Penicillium. The results demonstrate that a large number of fungi species exist in uranium ores, and some of them have the ability of producing organic acid, in addition,they have high growing velocity with the potential of being applied to uranium leaching. (authors)

Pharmacokinetics study of Zr-89-labeled melanin nanoparticle in iron-overload mice

International Nuclear Information System (INIS)

Zhang, Pengjun; Yue, Yuanyuan; Pan, Donghui; Yang, Runlin; Xu, Yuping; Wang, Lizhen; Yan, Junjie; Li, Xiaotian; Yang, Min

2016-01-01

Melanin, a natural biological pigment present in many organisms, has been found to exhibit multiple functions. An important property of melanin is its ability to chelate metal ions strongly, which might be developed as an iron chelator for iron overload therapy. Herein, we prepared the ultrasmall water-soluble melanin nanoparticle (MP) and firstly evaluate the pharmacokinetics of MP in iron-overload mice to provide scientific basis for treating iron-overload. To study the circulation time and biodistribution, MP was labeled with 89 Zr, a long half-life (78.4 h) positron-emitting metal which is suited for the labeling of nanoparticles and large bioactive molecule. MP was chelated with 89 Zr directly at pH 5, resulting in non-decay-corrected yield of 89.6% and a radiochemical purity of more than 98%. The specific activity was at least190 MBq/μmol. The 89 Zr-MP was stable in human plasma and PBS for at least 48 h. The half-life of 89 Zr-MP was about 15.70 ± 1.74 h in iron-overload mice. Biodistribution studies and MicroPET imaging showed that 89 Zr-MP mainly accumulated in liver and spleen, which are the target organ of iron-overload. The results indicate that the melanin nanoparticle is promising for further iron overload therapy.

A Multifunctional and Possible Skin UV Protectant, (3R-5-Hydroxymellein, Produced by an Endolichenic Fungus Isolated from Parmotrema austrosinense

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Lu Zhao

2016-12-01

Full Text Available Lichens are considered a great bio-resource because they produce large numbers of secondary metabolites with many biological activities; however, they have not been cultivated under artificial conditions to date. As a result, lichen substances from natural sources are limited and have not been widely utilized in commercial applications. Accordingly, interest in lichen-associated fungi, especially endogenic fungi, has increased. Ultraviolet (UV radiation in sunlight is harmful to human health, resulting in demand for effective UV filtering agents for use in sunscreen. In this study, we purified (3R-5-hydroxymellein, which has UVA absorption activity, from the secondary metabolites of an endolichenic fungus (ELF000039. The antioxidant properties were then assessed by in vitro tests. The antioxidant activity of (3R-5-hydroxymellein was high when compared to the recognized antioxidants ascorbic acid (ASA and butyl hydroxyl anisole (BHA. Moreover, the compound exhibited no cytotoxicity toward mouse melanoma cell lines, B16F1 and B16F10, or the normal cell line, HaCaT. Furthermore, (3R-5-hydroxymellein recovered the damage caused by UVB irradiation and inhibited melanin synthesis. Taken together, these results suggest that (3R-5-hydroxymellein could have an interesting and vital profile to go further development as a multifunctional skin UV protectant.

Population-related genetic aspects of the low doses radiological risk and melanin influence on genetic radiosensitivity

International Nuclear Information System (INIS)

Mosse, I.B.; Plotnikova, S.I.; Kostrova, L.N.; Subbot, S.T.; Maksymenia, I.P.; Dubovic, B.V.

1997-01-01

From the genetic point of view, radiation sensitivity is a quantitative character, and the distribution of individuals in the population with different radiation sensitivities is characterized by a binomial curve. Thus rise in irradiation dose first results in a very slow increase in the number of sensitive genotypes, and then in a sharp rise. Since quantitative characters are dependent on several polymeric genes, and their manifestation is strongly affected by external conditions, radiation sensitivity of the organism depends on many hereditary and environmental factors. One of them is the presence of melanin pigment in cells. In particular, we have shown that the introduction of exogenous melanin into the organisms of mice reduces (2-4 times) the frequency of mutations, induced not only by acute, but also by chronic irradiation. It was also established, that mutational load, accumulated in drosophila populations, irradiated within 125 generations, has been decreased under melanin influence almost to the control level. Antimutagenic action of melanin is also manifested on cultured human cells. So, it was shown by the example of melanin, that it is possible to increase the radiation resistance of individuals, and in the first place of the population highly sensitive fraction. (author)

New Poly(lactic acid) Active Packaging Composite Films Incorporated with Fungal Melanin

OpenAIRE

Łukasz Łopusiewicz; Filip Jędra; Małgorzata Mizielińska

2018-01-01

In this work, fungal melanin was used for the first time to prepare poly(lactic acid)-based composites. The films of various melanin concentrations (0.025%, 0.05% and 0.2% w/w) were prepared using an extrusion method. The mechanical, antioxidant, antimicrobial, water vapor and UV-Vis barrier properties, as well as available polyphenolics on the surface, were studied. FT-IR and Raman spectroscopy studies were carried out to analyze the chemical composition of the resulting films. The hydrophob...

Objective evaluation of choroidal melanin contents with polarization-sensitive optical coherence tomography

Science.gov (United States)

Miura, Masahiro; Makita, Shuichi; Yasuno, Yoshiaki; Ikuno, Yasushi; Uematsu, Sato; Iwasaki, Takuya; Goto, Hiroshi

2018-02-01

We non-invasively evaluated choroidal melanin contents in human eyes with PS-OCT. We calculated the percentage area of low DOPU in the choroidal interstitial stroma for Vogt-Koyanagi- Harada disease with sunset glow fundus, without sunset glow fundus, control group and tessellated fundus with high myopia. The mean percentage area of low DOPU in the sunset group was significantly lower than the other groups. PS-OCT provides an in vivo objective evaluation of choroidal melanin loss in vivo human eyes.

Inhibitory effect of isoprenoid-substituted flavonoids isolated from Artocarpus heterophyllus on melanin biosynthesis.

Science.gov (United States)

Arung, Enos Tangke; Shimizu, Kuniyoshi; Kondo, Ryuichiro

2006-07-01

Isoprenoid-substituted flavonoids were isolated from the wood of Artocarpus heterophyllus by means of activity-guided fractionation. Artocarpin (1), cudraflavone C (2), 6-prenylapigenin (3), kuwanon C (4), norartocarpin (5) and albanin A (6) inhibited melanin biosynthesis in B16 melanoma cells without inhibiting tyrosinase. A structure-activity investigation indicated that the presence of the isoprenoid-substituted moiety enhanced the inhibitory activity on melanin production in B16 melanoma cells.

Endophytic Fungi from Frankincense Tree Improves Host Growth and Produces Extracellular Enzymes and Indole Acetic Acid.

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Abdul Latif Khan

Full Text Available Boswellia sacra, an economically important frankincense-producing tree found in the desert woodlands of Oman, is least known for its endophytic fungal diversity and the potential of these fungi to produce extracellular enzymes and auxins. We isolated various fungal endophytes belonging to Eurotiales (11.8%, Chaetomiaceae (17.6%, Incertae sadis (29.5%, Aureobasidiaceae (17.6%, Nectriaceae (5.9% and Sporomiaceae (17.6% from the phylloplane (leaf and caulosphere (stem of the tree. Endophytes were identified using genomic DNA extraction, PCR amplification and sequencing the internal transcribed spacer regions, whereas a detailed phylogenetic analysis of the same gene fragment was made with homologous sequences. The endophytic colonization rate was significantly higher in the leaf (5.33% than the stem (0.262%. The Shannon-Weiner diversity index was H' 0.8729, while Simpson index was higher in the leaf (0.583 than in the stem (0.416. Regarding the endophytic fungi's potential for extracellular enzyme production, fluorogenic 4-methylumbelliferone standards and substrates were used to determine the presence of cellulases, phosphatases and glucosidases in the pure culture. Among fungal strains, Penicillum citrinum BSL17 showed significantly higher amounts of glucosidases (62.15±1.8 μM-1min-1mL and cellulases (62.11±1.6 μM-1min-1mL, whereas Preussia sp. BSL10 showed significantly higher secretion of glucosidases (69.4±0.79 μM-1min-1mL and phosphatases (3.46±0.31μM-1min-1mL compared to other strains. Aureobasidium sp. BSS6 and Preussia sp. BSL10 showed significantly higher potential for indole acetic acid production (tryptophan-dependent and independent pathways. Preussia sp. BSL10 was applied to the host B. sacra tree saplings, which exhibited significant improvements in plant growth parameters and accumulation of photosynthetic pigments. The current study concluded that endophytic microbial resources producing extracellular enzymes and auxin

Endophytic Fungi from Frankincense Tree Improves Host Growth and Produces Extracellular Enzymes and Indole Acetic Acid.

Science.gov (United States)

Khan, Abdul Latif; Al-Harrasi, Ahmed; Al-Rawahi, Ahmed; Al-Farsi, Zainab; Al-Mamari, Aza; Waqas, Muhammad; Asaf, Sajjad; Elyassi, Ali; Mabood, Fazal; Shin, Jae-Ho; Lee, In-Jung

2016-01-01

Boswellia sacra, an economically important frankincense-producing tree found in the desert woodlands of Oman, is least known for its endophytic fungal diversity and the potential of these fungi to produce extracellular enzymes and auxins. We isolated various fungal endophytes belonging to Eurotiales (11.8%), Chaetomiaceae (17.6%), Incertae sadis (29.5%), Aureobasidiaceae (17.6%), Nectriaceae (5.9%) and Sporomiaceae (17.6%) from the phylloplane (leaf) and caulosphere (stem) of the tree. Endophytes were identified using genomic DNA extraction, PCR amplification and sequencing the internal transcribed spacer regions, whereas a detailed phylogenetic analysis of the same gene fragment was made with homologous sequences. The endophytic colonization rate was significantly higher in the leaf (5.33%) than the stem (0.262%). The Shannon-Weiner diversity index was H' 0.8729, while Simpson index was higher in the leaf (0.583) than in the stem (0.416). Regarding the endophytic fungi's potential for extracellular enzyme production, fluorogenic 4-methylumbelliferone standards and substrates were used to determine the presence of cellulases, phosphatases and glucosidases in the pure culture. Among fungal strains, Penicillum citrinum BSL17 showed significantly higher amounts of glucosidases (62.15±1.8 μM-1min-1mL) and cellulases (62.11±1.6 μM-1min-1mL), whereas Preussia sp. BSL10 showed significantly higher secretion of glucosidases (69.4±0.79 μM-1min-1mL) and phosphatases (3.46±0.31μM-1min-1mL) compared to other strains. Aureobasidium sp. BSS6 and Preussia sp. BSL10 showed significantly higher potential for indole acetic acid production (tryptophan-dependent and independent pathways). Preussia sp. BSL10 was applied to the host B. sacra tree saplings, which exhibited significant improvements in plant growth parameters and accumulation of photosynthetic pigments. The current study concluded that endophytic microbial resources producing extracellular enzymes and auxin could

Compositional changes of human hair melanin resulting from bleach treatment investigated by nanoscale secondary ion mass spectrometry.

Science.gov (United States)

Kojima, Toru; Yamada, Hiromi; Isobe, Mitsuru; Yamamoto, Toshihiko; Takeuchi, Miyuki; Aoki, Dan; Matsushita, Yasuyuki; Fukushima, Kazuhiko

2014-11-01

It is important to understand the influence of bleach treatment on human hair because it is one of the most important chemical treatments in hair cosmetic processes. A comparison of the elemental composition of melanin between virgin hair and bleached hair would provide important information about the structural changes of melanin. To investigate the elemental composition of melanin granules in virgin black hair and bleached hair, these hair cross-sections are analyzed by using a nanoscale secondary ion mass spectrometry (NanoSIMS). The virgin black hair and bleached hair samples were embedded in resin and smooth hair cross-sections were obtained using an ultramicrotome. NanoSIMS measurements were performed using a Cs(+) primary ion beam to detect negative secondary ions. More intensive (16) O(-) ions were detected from the melanin granules of bleached hair than from those of virgin black hair in NanoSIMS (16) O(-) ion image. In addition, it was indicated that (16) O(-) ion intensity and (16) O(-) /(12) C(14) N(-) ion intensity ratio of melanin granules in bleached hair were higher than those in virgin black hair. Nanoscale secondary ion mass spectrometry analysis of the cross-sections of virgin black hair and bleached hair indicated that the oxygen content in melanin granules was increased by bleach treatment. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Loss of Melanin by Eye Retinal Pigment Epithelium Cells Is Associated with Its Oxidative Destruction in Melanolipofuscin Granules.

Science.gov (United States)

Dontsov, A E; Sakina, N L; Ostrovsky, M A

2017-08-01

The effect of superoxide radicals on melanin destruction and degradation of melanosomes isolated from cells of retinal pigment epithelium (RPE) of the human eye was studied. We found that potassium superoxide causes destruction of melanin in melanosomes of human and bovine RPE, as well as destruction of melanin from the ink bag of squid, with the formation of fluorescent decay products having an emission maximum at 520-525 nm. The initial kinetics of the accumulation of the fluorescent decay products is linear. Superoxide radicals lead simultaneously to a decrease in the number of melanosomes and to a decrease in concentration of paramagnetic centers in them. Complete degradation of melanosomes leads to the formation of a transparent solution containing dissolved proteins and melanin degradation products that do not exhibit paramagnetic properties. To completely degrade one melanosome of human RPE, 650 ± 100 fmol of superoxide are sufficient. The concentration of paramagnetic centers in a melanolipofuscin granule of human RPE is on average 32.5 ± 10.4% (p melanin undergoing a destruction process in these granules. RPE cells also contain intermediate granules that have an EPR signal with a lower intensity than that of melanolipofuscin granules, but higher than that of lipofuscin granules. This signal is due to the presence of residual melanin in these granules. Irradiation of a mixture of melanosomes with lipofuscin granules with blue light (450 nm), in contrast to irradiation of only melanosomes, results in the appearance of fluorescent melanin degradation products. We suggest that one of the main mechanisms of age-related decrease in melanin concentration in human RPE cells is its destruction in melanolipofuscin granules under the action of superoxide radicals formed during photoinduced oxygen reduction by lipofuscin fluorophores.

Physiological and Molecular Characterization of Biosurfactant Producing Endophytic Fungi Xylaria regalis from the Cones of Thuja plicata as a Potent Plant Growth Promoter with Its Potential Application

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Mohd Adnan

2018-01-01

Full Text Available Currently, there is an absolute concern for all nations in agricultural productivity to meet growing demands of human population. In recent time, biosurfactants produced by diverse group of microorganisms are used to achieve such demands as it is known for its ecofriendly use in elimination of plant pathogens and for increasing the bioavailability of nutrients for plants. Endophytic fungi are the important source of secondary metabolites and novel bioactive compounds for different biological applications. In the present study, endophytic fungi Xylaria regalis (X. regalis recovered from the cones of Thuja plicata was evaluated for its biosurfactant producing ability and plant growth-promoting abilities through various screening methods and also via its antagonistic activity against phytopathogens like Fusarium oxysporum and Aspergillus niger. In addition, X. regalis was also tested in vivo for a various range of growth parameters in chilli under greenhouse conditions. Significant increase in shoot and root length, dry matter production of shoot and root, chlorophyll, nitrogen, and phosphorus contents of chilli seedlings was found, which reveals its ability to improve the growth of crop plants. Hence, this study suggests the possibility of biosurfactant producing endophytic fungi X. regalis as a source of novel green biosurfactant for sustainable agriculture to achieve growing demands.

antibacterial activity of endophytic fungi isolated from conifers needles

African Journals Online (AJOL)

Ravnikar, Matjaž

2015-03-11

Mar 11, 2015 ... taxonomically place fungi producing ones to determined active metabolites. Seventy three strains of endophytic fungi were isolated ... great number of diverse bioactive compounds (Devaraju and Satish, 2010), which have been ... closed with a glass stopper. The extraction solvents utilized were methanol ...

Diversion of the melanin synthetic pathway by dopamine product

African Journals Online (AJOL)

acetylcysteine adducts of dopamine studied using quantum chemical ... cyclization reaction of dopaminoquinone which leads to the synthesis of melanin. ..... a hydrogen bond with the carbonyl oxygen (−O−H---O=C− and the second one points ...

Endophytic Fungi Isolated from Coleus amboinicus Lour Exhibited Antimicrobial Activity

OpenAIRE

Puji Astuti; Sudarsono Sudarsono; Khoirun Nisak; Giri Wisnu Nugroho

2014-01-01

Purpose: Coleus amboinicus is a medicinal plant traditionally used to treat various diseases such as throat infection, cough and fever, diarrhea, nasal congestion and digestive problems. The plant was explored for endophytic fungi producing antimicrobial agents. Methods: Screening for endophytic fungi producing antimicrobial agents was conducted using agar plug method and antimicrobial activity of promising ethyl acetate extracts was determined by disc diffusion assay. Thin layer chromatograp...

Predicting human epidermal melanin concentrations for different skin tones

CSIR Research Space (South Africa)

Smit, Jacoba E

2011-07-01

Full Text Available epidermal melanin concentrations for different skin tones JE Smit 1 , AE Karsten 2 , RW Sparrow 1 1 CSIR Biosciences, Pretoria, South Africa 2 CSIR National Laser Centre, Pretoria, South Africa Author e-mail address: KSmit...

Bioactive Metabolites from Pathogenic and Endophytic Fungi of Forest Trees.

Science.gov (United States)

Masi, Marco; Maddau, Lucia; Linaldeddu, Benedetto Teodoro; Scanu, Bruno; Evidente, Antonio; Cimmino, Alessio

2018-01-01

Fungi play an important role in terrestrial ecosystems interacting positively or negatively with plants. These interactions are complex and the outcomes are different depending on the fungal lifestyles, saprotrophic, mutualistic or pathogenic. Furthermore, fungi are well known for producing secondary metabolites, originating from different biosynthetic pathways, which possess biological properties of considerable biotechnological interest. Among the terrestrial ecosystems, temperate forests represent an enormous reservoir of fungal diversity. This review will highlight the goldmine of secondary metabolites produced by pathogenic and endophytic fungi of forest trees with focus on their biological activities. A structured search of bibliographic databases for peer-reviewed research literature was undertaken using a research discovery application providing access to a large and authoritative source of references. The papers selected were examined and the main results were reported and discussed. Two hundred forthy-one papers were included in the review, outlined a large number of secondary metabolites produced by pathogenic and endophiltic fungi and their biological activities, including phytotoxic, antifungal, antioomycetes, antibacterial, brine shrimp lethality, mosquito biting deterrence and larvicidal, cytotoxic, antiproliferative and many other bioactivities. The findings of this review confirm the importance of secondary metabolites produced by pathogenic and endophytic fungi from forest plants growing in temperate regions as an excellent prospects to discover compounds with new bioactivities and mode of actions. In addition, the potential of some metabolites as a source of new drugs and biopesticides is underlined. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Xerophiles and other fungi associated with cereal baby foods locally produced in Uganda

Directory of Open Access Journals (Sweden)

Mady A. Ismail

2013-12-01

Full Text Available Fifty samples from five baby food products mainly made of cereal flour(s were analyzed. The moisture contents of these products were between 11.14% and 11.9%, a level below 14.0%, the recommended level for safe storage of cereal grains and their products. The mycological analysis was carried out using the dilution plate method and two isolation media (DG18 for isolation of xerophilic fungi and DRBC for fungi in general. A total of 80 species related to 37 genera in addition to some unidentified fungal and yeast species were recorded on both media from the five products. The products were contaminated abundantly by xerophilic fungi which were occurring in 88% of food samples and accounting for 18.1% of the total CFU as recorded on DG18. The highest contamination level by xerophiles was registered in Mwebaza rice porridge (a component of rice flour and the lowest in Mukuza (a product of maize, soyabean and sorghum flours. 11 xerophilic species were recorded of which Aspergillus and Eurotium (4 species each were the predominant giving rise to 9.1% and 8.9% of the total CFU, with A. wentii, A. candidus, E. cristatum and E. repens were the most contaminating species. Of the fungi recorded other than xerophiles, species of Aspergillus (particularly A. flavus followed by A. niger, Penicillium (P. citrinum, P. oxalicum, Fusarium (F. solani, F. tricinctum, Cladosporium (C. sphaerospermum and yeasts were the most predominant. Contamination of such foods is a matter of health hazard as these foods are for babies. So, the use of fresh, well-dried and uncontaminated flours for production of such foods is recommended.

Utilization of fungi for biotreatment of raw wastewaters | Coulibaly ...

African Journals Online (AJOL)

However, the detoxification rates seem to be dependent on media and culture conditions. The postreatement by anaerobic bioprocesses of effluents that have been pretreated with fungi can lead to higher biogas than the original effluents. In addition to the degradation of organic pollutants, fungi produce added-value ...

The effects of Sophora angustifolia and other natural plant extracts on melanogenesis and melanin transfer in human skin cells.

Science.gov (United States)

Singh, Suman K; Baker, Richard; Wibawa, Judata I D; Bell, Mike; Tobin, Desmond J

2013-01-01

Skin pigmentation is a multistep process of melanin synthesis by melanocytes, its transfer to recipient keratinocytes and its degradation. As dyspigmentation is a prominent marker of skin ageing, novel effective agents that modulate pigmentation safely are being sought for both clinical and cosmetic use. Here, a number of plant extracts were examined for their effect on melanogenesis (by melanin assay and Western blotting) and melanin transfer (by confocal immunomicroscopy of gp100-positive melanin granules in cocultures and by SEM analysis of filopodia), in human melanocytes and in cocultures with phototype-matched normal adult epidermal keratinocytes. Mulberry, Kiwi and Sophora extracts were assessed against isobutylmethylxanthine, hydroquinone, vitamin C and niacinamide. Compared with unstimulated control, all extracts significantly reduced melanogenesis in human melanoma cells and normal adult epidermal melanocytes. These extracts also reduced melanin transfer and reduced filopodia expression on melanocytes, similar to hydroquinone and niacinamide, indicating their effectiveness as multimode pigmentation actives. © 2013 John Wiley & Sons A/S.

Mites and fungi in heavily infested stores in the Czech Republic.

Science.gov (United States)

Hubert, J; Stejskal, V; Munzbergová, Z; Kubátová, A; Vánová, M; Zd'árková, E

2004-12-01

Toxigenic and allergen-producing fungi represent a serious hazard to human food and animal feed safety. Ninety-four fungal species were isolated from mite-infested samples of seeds taken from Czech seed stores. Fungi were isolated from the surface of four kinds of seeds (wheat, poppy, lettuce, and mustard) and from the gut and external surface of five species of mites (i.e., Acarus siro L., 1758, Caloglyphus rhizoglyphoides (Zachvatkin, 1973), Lepidoglyphus destructor (Schrank, 1781), Tyrophagus putrescentnae (Schrank, 1781) and Cheyletus malaccensis Oudemans 1903) separately. Multivariate analysis of fungi complex composition showed that the frequency of fungal was species significantly influenced by the kind of seed. Fungal frequencies differed between mites gut and exoskeleton surface and between the surfaces of mites and seeds. Three groups of fungal species were recognized: 1) mite surface-associated fungi: Penicillium brevicompactum, Alternaria alternata, and Aspergillus versicolor; 2) mite surface- and seed-associated fungi: Aspergillus niger, Penicillium crustosum, Penicillium aurantiogriseum, Penicillium chrysogenum, and Aspergillus flavus; and 3) seed-associated fungi: Cladosporium herbarum, Mucor dimorphosporus f. dimorphosporus, Botrytis cinerea, Penicillium griseofulvum, and Eurotium repens. Mite-carried species of microfungi are known to produce serious mycotoxins (e.g., aflatoxin B1, cyclopiazonic acid, sterigmatocystin, ochratoxin A, and nephrotoxic glycopeptides) as well as allergen producers (e.g., A. alternata and P. brevicompactum). Storage mites may play an important role in the spread of some medically hazardous micromycetes. In addition, these mite-fungi associations may heighten the risk of occurrence of mycotoxins in food and feed stuffs and cause mixed contamination by fungal and mite allergens.

Transferring Biomarker into Molecular Probe: Melanin Nanoparticle as a Naturally Active Platform for Multimodality Imaging

OpenAIRE

Fan, Quli; Cheng, Kai; Hu, Xiang; Ma, Xiaowei; Zhang, Ruiping; Yang, Min; Lu, Xiaomei; Xing, Lei; Huang, Wei; Gambhir, Sanjiv Sam; Cheng, Zhen

2014-01-01

Developing multifunctional and easily prepared nanoplatforms with integrated different modalities is highly challenging for molecular imaging. Here, we report the successful transfer of an important molecular target, melanin, into a novel multimodality imaging nanoplatform. Melanin is abundantly expressed in melanotic melanomas and thus has been actively studied as a target for melanoma imaging. In our work, the multifunctional biopolymer nanoplatform based on ultrasmall (

Sexual selection and the function of a melanin-based plumage ornament in polygamous penduline tits Remiz pendulinus

NARCIS (Netherlands)

Kingma, Sjouke A.; Szentirmai, Istvan; Szekely, Tamas; Bokony, Veronika; Bleeker, Maarten; Liker, Andras; Komdeur, Jan; McGraw, K.

Melanin-based ornaments are often involved in signaling aggression and dominance, and their role in sexual selection is increasingly recognized. We investigated the functions of a melanin-based plumage ornament (facial 'mask') in male Eurasian penduline tits Remiz pendulinus in the contexts of

DNA Integrity and Shock Wave Transformation Efficiency of Bacteria and Fungi

Science.gov (United States)

Loske, Achim M.; Campos-Guillén, Juan; Fernández, Francisco; Pastrana, Xóchitl; Magaña-Ortíz, Denis; Coconi-Linares, Nancy; Ortíz-Vázquez, Elizabeth; Gómez-Lim, Miguel

Delivery of DNA into bacteria and fungi is essential in medicine and biotechnology to produce metabolites, enzymes, antibiotics and proteins. So far, protocols to genetically transform bacteria and fungi are inefficient and have low reproducibility.

Isolation and partial characterization of a mutant of Bacillus thuringiensis producing melanin Isolamento e caracterização parcial de um mutante de Bacillus thuringiensis produtor de melanina

Directory of Open Access Journals (Sweden)

Gislayne T. Vilas-Bôas

2005-09-01

Full Text Available A mutant (407-P of Bacillus thuringiensis subsp. thuringiensis strain 407 producing a melanin was obtained after treatment with the mutagenic agent ethyl-methane-sulfonate. Several microbiological and biochemical properties of the two strains were analyzed and the results were similar. The mutant 407-P was also incorporated into non-sterilized soil samples, recovered, easily identified, and quantified, what enables its use in ecology of B. thuringiensis.Um mutante (407-P da linhagem Bacillus thuringiensis subsp. thuringiensis 407 produtor de melanina foi obtido após tratamento com o agente mutagênico etil-metano-sulfonato. Diversas propriedades microbiológicas e bioquímicas das duas linhagens foram analisadas e os resultados foram similares. O mutante 407-P foi incorporado em amostras de solo não esterilizado, recuperado, facilmente identificado e quantificado, possibilitando seu uso em estudos de ecologia de B. thuringiensis.

Human eccrine sweat gland cells turn into melanin-uptaking keratinocytes in dermo-epidermal skin substitutes.

Science.gov (United States)

Böttcher-Haberzeth, Sophie; Biedermann, Thomas; Pontiggia, Luca; Braziulis, Erik; Schiestl, Clemens; Hendriks, Bart; Eichhoff, Ossia M; Widmer, Daniel S; Meuli-Simmen, Claudia; Meuli, Martin; Reichmann, Ernst

2013-02-01

Recently, Biedermann et al. (2010) have demonstrated that human eccrine sweat gland cells can develop a multilayered epidermis. The question still remains whether these cells can fulfill exclusive and very specific functional properties of epidermal keratinocytes, such as the incorporation of melanin, a feature absent in sweat gland cells. We added human melanocytes to eccrine sweat gland cells to let them develop into an epidermal analog in vivo. The interaction between melanocytes and sweat gland-derived keratinocytes was investigated. The following results were gained: (1) macroscopically, a pigmentation of the substitutes was seen 2-3 weeks after transplantation; (2) we confirmed the development of a multilayered, stratified epidermis with melanocytes distributed evenly throughout the basal layer; (3) melanocytic dendrites projected to suprabasal layers; and (4) melanin was observed to be integrated into former eccrine sweat gland cells. These skin substitutes were similar or equal to skin substitutes cultured from human epidermal keratinocytes. The only differences observed were a delay in pigmentation and less melanin uptake. These data suggest that eccrine sweat gland cells can form a functional epidermal melanin unit, thereby providing striking evidence that they can assume one of the most characteristic keratinocyte properties.

Morphological and chemical composition characterization of commercial sepia melanin

CSIR Research Space (South Africa)

Mbonyiryivuze, A

2015-06-01

Full Text Available granules with different size distributions that have been determined using image-J software. The small granule diameter obtained from different TEM and SEM micrographs were 100-200nm. EDS reveals that C and O were the most abundant in sepia melanin...

Corticosterone mediates the condition-dependent component of melanin-based coloration

Czech Academy of Sciences Publication Activity Database

Roulin, A.; Almasi, B.; Rossi-Pedruzzi, A.; Ducrest, A.-L.; Wakamatsu, K.; Mikšík, Ivan; Blount, J.D.; Jenni-Eiermann, S.; Jenni, L.

2008-01-01

Roč. 75, č. 4 (2008), s. 1351-1358 ISSN 0003-3472 Institutional research plan: CEZ:AV0Z50110509 Keywords : coricosterone * barn owl * melanin Subject RIV: CE - Biochemistry Impact factor: 2.828, year: 2008

Toxins of filamentous fungi.

Science.gov (United States)

Bhatnagar, Deepak; Yu, Jiujiang; Ehrlich, Kenneth C

2002-01-01

Mycotoxins are low-molecular-weight secondary metabolites of fungi. The most significant mycotoxins are contaminants of agricultural commodities, foods and feeds. Fungi that produce these toxins do so both prior to harvest and during storage. Although contamination of commodities by toxigenic fungi occurs frequently in areas with a hot and humid climate (i.e. conditions favorable for fungal growth), they can also be found in temperate conditions. Production of mycotoxins is dependent upon the type of producing fungus and environmental conditions such as the substrate, water activity (moisture and relative humidity), duration of exposure to stress conditions and microbial, insect or other animal interactions. Although outbreaks of mycotoxicoses in humans have been documented, several of these have not been well characterized, neither has a direct correlation between the mycotoxin and resulting toxic effect been well established in vivo. Even though the specific modes of action of most of the toxins are not well established, acute and chronic effects in prokaryotic and eukaryotic systems, including humans have been reported. The toxicity of the mycotoxins varies considerably with the toxin, the animal species exposed to it, and the extent of exposure, age and nutritional status. Most of the toxic effects of mycotoxins are limited to specific organs, but several mycotoxins affect many organs. Induction of cancer by some mycotoxins is a major concern as a chronic effect of these toxins. It is nearly impossible to eliminate mycotoxins from the foods and feed in spite of the regulatory efforts at the national and international levels to remove the contaminated commodities. This is because mycotoxins are highly stable compounds, the producing fungi are ubiquitous, and food contamination can occur both before and after harvest. Nevertheless, good farm management practices and adequate storage facilities minimize the toxin contamination problems. Current research is

Human hypocretin and melanin-concentrating hormone levels are linked to emotion and social interaction.

Science.gov (United States)

Blouin, Ashley M; Fried, Itzhak; Wilson, Charles L; Staba, Richard J; Behnke, Eric J; Lam, Hoa A; Maidment, Nigel T; Karlsson, Karl Æ; Lapierre, Jennifer L; Siegel, Jerome M

2013-01-01

The neurochemical changes underlying human emotions and social behaviour are largely unknown. Here we report on the changes in the levels of two hypothalamic neuropeptides, hypocretin-1 and melanin-concentrating hormone, measured in the human amygdala. We show that hypocretin-1 levels are maximal during positive emotion, social interaction and anger, behaviours that induce cataplexy in human narcoleptics. In contrast, melanin-concentrating hormone levels are minimal during social interaction, but are increased after eating. Both peptides are at minimal levels during periods of postoperative pain despite high levels of arousal. Melanin-concentrating hormone levels increase at sleep onset, consistent with a role in sleep induction, whereas hypocretin-1 levels increase at wake onset, consistent with a role in wake induction. Levels of these two peptides in humans are not simply linked to arousal, but rather to specific emotions and state transitions. Other arousal systems may be similarly emotionally specialized.

A role of melanin-concentrating hormone producing neurons in the central regulation of paradoxical sleep

Directory of Open Access Journals (Sweden)

Salin Paul

2003-09-01

Full Text Available Abstract Background Peptidergic neurons containing the melanin-concentrating hormone (MCH and the hypocretins (or orexins are intermingled in the zona incerta, perifornical nucleus and lateral hypothalamic area. Both types of neurons have been implicated in the integrated regulation of energy homeostasis and body weight. Hypocretin neurons have also been involved in sleep-wake regulation and narcolepsy. We therefore sought to determine whether hypocretin and MCH neurons express Fos in association with enhanced paradoxical sleep (PS or REM sleep during the rebound following PS deprivation. Next, we compared the effect of MCH and NaCl intracerebroventricular (ICV administrations on sleep stage quantities to further determine whether MCH neurons play an active role in PS regulation. Results Here we show that the MCH but not the hypocretin neurons are strongly active during PS, evidenced through combined hypocretin, MCH, and Fos immunostainings in three groups of rats (PS Control, PS Deprived and PS Recovery rats. Further, we show that ICV administration of MCH induces a dose-dependant increase in PS (up to 200% and slow wave sleep (up to 70% quantities. Conclusion These results indicate that MCH is a powerful hypnogenic factor. MCH neurons might play a key role in the state of PS via their widespread projections in the central nervous system.

Targeting allergenic fungi in agricultural environments aids the identification of major sources and potential risks for human health.

Science.gov (United States)

Weikl, F; Radl, V; Munch, J C; Pritsch, K

2015-10-01

Fungi are, after pollen, the second most important producers of outdoor airborne allergens. To identify sources of airborne fungal allergens, a workflow for qPCR quantification from environmental samples was developed, thoroughly tested, and finally applied. We concentrated on determining the levels of allergenic fungi belonging to Alternaria, Cladosporium, Fusarium, and Trichoderma in plant and soil samples from agricultural fields in which cereals were grown. Our aims were to identify the major sources of allergenic fungi and factors potentially influencing their occurrence. Plant materials were the main source of the tested fungi at and after harvest. Amounts of A. alternata and C. cladosporioides varied significantly in fields under different management conditions, but absolute levels were very high in all cases. This finding suggests that high numbers of allergenic fungi may be an inevitable side effect of farming in several crops. Applied in large-scale studies, the concept described here may help to explain the high number of sensitization to airborne fungal allergens. Copyright © 2015 Elsevier B.V. All rights reserved.

Madecassoside Inhibits Melanin Synthesis by Blocking Ultraviolet-Induced Inflammation

Directory of Open Access Journals (Sweden)

Eunsun Jung

2013-12-01

Full Text Available Madecassoside (MA, a pentacyclic triterpene isolated from Centella asitica (L., is used as a therapeutic agent in wound healing and also as an anti-inflammatory and anti-aging agent. However, the involvement of MA in skin-pigmentation has not been reported. This study was conducted to investigate the effects of MA on ultraviolet (UV-induced melanogenesis and mechanisms in a co-culture system of keratinocytes and melanocytes. MA significantly inhibited UVR-induced melanin synthesis and melanosome transfer in the co-culture system. These effects were further demonstrated by the MA-induced inhibition of protease-activated receptor-2 expression and its signaling pathway, cyclooxygenase-2, prostaglandin E2 and prostaglandin F2 alpha in keratinocytes. The clinical efficacy of MA was confirmed on artificially tanned human skin. MA significantly reduced UV-induced melanin index at 8 weeks after topical application. Overall, the study demonstrated significant benefits of MA use in the inhibition of hyperpigmentation caused by UV irradiation.

Aflatoxigenic Fungi and Aflatoxins in Portuguese Almonds

OpenAIRE

Rodrigues, P.; Venâncio, A.; Lima, N.

2012-01-01

Aflatoxin contamination of nuts is an increasing concern to the consumer’s health. Portugal is a big producer of almonds, but there is no scientific knowledge on the safety of those nuts, in terms of mycotoxins. The aim of this paper was to study the incidence of aflatoxigenic fungi and aflatoxin contamination of 21 samples of Portuguese almonds, and its evolution throughout the various stages of production. All fungi belonging to Aspergillus section Flavi were identified and tested ...

In vivo interactions of entomopathogenic fungi, Beauveria spp. and Metarhizium anisopliae with selected opportunistic soil fungi of sugarcane ecosystem.

Science.gov (United States)

Geetha, N; Preseetha, M; Hari, K; Santhalakshmi, G; Bai, K Subadra

2012-07-01

In the present study, the interactions of entomopathogenic fungi viz., Beauveria bassiana, Beauveria brongniartii and Metarhizium anisopliae among themselves and three other opportunistic soil fungi from the sugarcane ecosystem namely, Fusarium saachari, Aspergillus sp. and Penecillium sp. were assayed in vivo against Galleria mellonella larvae. The tested fungi were co-applied on IV instar G. mellonella @ 1 x 10(7) ml(-1), in combinations of two, at the interval of 24 hrs either preceding or succeeding each otherto assess their efficacy and sporulation rates. Results showed that often mortality rates did not correspond to the spore harvest of the mortality agent and presence of other fungus may be antagonistic. The efficacy of B. bassiana (90%) and B. brongniartii (100%) was not enhanced further but was negatively affected in most combinations with other fungi. In case of M. anisopliae compatibility was higher, resulting in higher mortality by application of B. bassiana before (100%) or after (83.3%) M. anisopliae than when it was applied alone (70%). During sporulation, B. bassiana faced the most intense competition from M. anisopliae (2.75 x 10(6) larva(-1)) and enhancement due to F sacchari irrespective of sequence of application. In case of B. brongniartii, sporulation was lowest in the combination of B. brongniartiipreceding M. anisopliae (1.83 x10(6) larva(-1)) and B. brongniartii succeeding B. bassiana (1.58 x 10(6) larva(-1)). Of all fungi tested, except F sacchari (65.33 x 10(6) larva(-1)) all the other species affected sporulation of M. ansiopliae with the least in treatment of B. bassiana application following M. anisopliae. Similar kind of interaction was observed during sporulation of soil fungi when combined with entomopathogenic fungi, though individually they could not cause mortality of larvae.

Melanin production by a yeast strain XJ5-1 of Aureobasidium melanogenum isolated from the Taklimakan desert and its role in the yeast survival in stress environments.

Science.gov (United States)

Jiang, Hong; Liu, Nan-Nan; Liu, Guang-Lei; Chi, Zhe; Wang, Jian-Ming; Zhang, Ly-Ly; Chi, Zhen-Ming

2016-07-01

The yeast strain XJ5-1 isolated from the Taklimakan desert soil was identified to be a strain of Aureobasdium melanogenum and could produce a large amount of melanin when it was grown in the PDA medium, but its melanin biosynthesis and expression of the PKS gene responsible for the melanin biosynthesis was significantly repressed in the presence of (NH4)2SO4. However, A. melanogenum P5 strain isolated from a mangrove ecosystem grown in both the presence and the absence of (NH4)2SO4 did not produce any melanin. The cell size of A. melanogenum XJ5-1 strain was much higher than that of A. melanogenum P5 strain. The melanized cells of the yeast strain XJ5-1 had higher tolerance to UV radiation, oxidation (200.0 mM H2O2), heat treatment (40 °C), salt shock (200.0 g/L NaCl), desiccation and strong acid hydrolysis (6.0 M HCl) at high temperature (80 °C) than the non-melanized cells of the same yeast strain XJ5-1. At the same time, the melanized cells of the yeast strain XJ5-1 also had higher tolerance to UV radiation, oxidation (200.0 mM H2O2), desiccation and strong acid hydrolysis (6.0 M HCl) at high temperature (80 °C) than A. melanogenum P5 strain, but had similar resistance to heat treatment (40 °C) and salt shock (200.0 g/L NaCl) compared to those of A. melanogenum P5 strain. All the results revealed that many characteristics of A. melanogenum XJ5-1 isolated from the Taklimakan desert soil was different from those of A. melanogenum P5 strain isolated from the mangrove ecosystem.

LIGHT REGULATION OF GROWTH AND MELANIN FORMATION IN Inonotus оbliquus (Pers. Pilat

Directory of Open Access Journals (Sweden)

N. L. Poyedinok

2013-04-01

Full Text Available The study aims to investigate possibilities of using different sources of low-intensity light for the regulation of mycelium growth and melanin synthesis by medicinal mushroom Inonotus obliquus (Pers. Pilat. Studies of the light’s influence on the linear growth, biomass accumulation and melanin synthesis I. obliquus were performed using experimental installations that provide both lasing (coherent light with specified parameters, as well as sources of incoherent light. It has been demonstrated that the greatest stimulating effect took place during the irradiation of mycelium with blue light. It has been found that further realization of photobiological effect is largely dependent on the method of cultivation. Irradiation with laser light within all studied wavelength ranges was more conducive to growth, biomass and melanin accumulation in the mushroom mycelium than incoherent light irradiation within the same wavelength range. Light treatment made it possible to significantly reduce the duration of fermentation. The results of studies allow considering lowintensity light in the visible part of the spectrum as a perspective growth and biosynthetic activity regulator of I. obliquus in the biotechnology of its cultivation.

Real-time visualization of melanin granules in normal human skin using combined multiphoton and reflectance confocal microscopy.

Science.gov (United States)

Majdzadeh, Ali; Lee, Anthony M D; Wang, Hequn; Lui, Harvey; McLean, David I; Crawford, Richard I; Zloty, David; Zeng, Haishan

2015-05-01

Recent advances in biomedical optics have enabled dermal and epidermal components to be visualized at subcellular resolution and assessed noninvasively. Multiphoton microscopy (MPM) and reflectance confocal microscopy (RCM) are noninvasive imaging modalities that have demonstrated promising results in imaging skin micromorphology, and which provide complementary information regarding skin components. This study assesses whether combined MPM/RCM can visualize intracellular and extracellular melanin granules in the epidermis and dermis of normal human skin. We perform MPM and RCM imaging of in vivo and ex vivo skin in the infrared domain. The inherent three-dimensional optical sectioning capability of MPM/RCM is used to image high-contrast granular features across skin depths ranging from 50 to 90 μm. The optical images thus obtained were correlated with conventional histologic examination including melanin-specific staining of ex vivo specimens. MPM revealed highly fluorescent granular structures below the dermal-epidermal junction (DEJ) region. Histochemical staining also demonstrated melanin-containing granules that correlate well in size and location with the granular fluorescent structures observed in MPM. Furthermore, the MPM fluorescence excitation wavelength and RCM reflectance of cell culture-derived melanin were equivalent to those of the granules. This study suggests that MPM can noninvasively visualize and quantify subepidermal melanin in situ. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Parkinson's disease-associated melanin steal.

Science.gov (United States)

Hinz, Marty; Stein, Alvin; Cole, Ted

2014-01-01

Urinary dopamine fluctuations in the competitive inhibition state were first documented in 2009. At that time, it was noted that progressively higher daily dosing values of L-tyrosine decreased the magnitude of these fluctuations. While extensive statistical analysis has been performed by the authors since 2004, it was not until 2012 that a plausible explanation was formulated. In the process, correlations with L-tyrosine administration and the on/off effect of Parkinson's disease were defined. This paper documents the current knowledge with regard to the management of retrograde phase 1 dopamine fluctuations and investigates the hypothesis that they are caused by a melanin steal phenomenon.

Effect of cellulase producing fungi on plant residues degradation used as organic fertilizer

International Nuclear Information System (INIS)

Ibrahim, R.M.M

2009-01-01

Series of laboratory and field experiments were conducted at Soil microbiology Unit and Farm of soil and Water research department, Nuclear Research Center, Atomic Energy Authority, Egypt. Laboratory experiments revealed that between nine fungal strain, A. niger was the most potent cellulolytic fungus able to degrade many cellulosic sources (CP, CMC, and FP). Study the effect of cellulolytic fungi on degradation of plant residues used as organic fertilizer in addition to nitrogen fixing bacteria (symbiotically) on lupine growth, yield and nutrients uptake (Field experiment) had been carried out. This objective aims to recycling different plant residues in soil which is consistent with (sustainable development) and utilization of these organic residues as a single carbon source for cellulolytic fungi.Application of 15 N- tracer technique gave us the chance and opportunity to quantify the exact amounts of N derived from the different sources of nitrogen available to lupine plant under the effect of cellulolytic fungi on different plant residues.The obtained results could be summarized as following:I.Laboratory Technique Selection of the most potent cellulolytic fungi 1-Nine fungal strains of Aspergillus niger; Penicillium oxalicum; Trichoderma longibranchiatum; Aspergillus terreus; Aspergillus flavus; Alterrnaria sp.; Trichderma harzianum ; Rhizopus sp. and Syncephalastrum sp. obtained from different sources and tested for their cellulolytic activity. 2-Aspergillus niger and Pencillium oxalicum exhibited the highest cellulase productivity followed by Trichoderma longibranchiatum and Aspergillus terreus.3- fungal mixtures of the most potent four genera Aspergillus niger; Penicillium oxalicum; Trichoderma longibranchiatum and Aspergillus terreus found to have a lower cellulolytic activities for all substrates compared with single inoculation with A. niger.4-Highest FPase activities were exhibited by A. niger when filter paper (FP) used as a carbon source.5-A. niger is

Hypocretin and melanin-concentrating hormone in patients with Huntington disease.

NARCIS (Netherlands)

Aziz, A.; Fronczek, R.; Maat-Schieman, M.L.; Unmehopa, U.A.; Roelandse, F.W.; Overeem, S.; Duinen, S.G. van; Lammers, G.J.; Swaab, D.F.; Roos, R.A.C.

2008-01-01

To evaluate whether hypocretin-1 (orexin-A) and melanin-concentrating hormone (MCH) neurotransmission are affected in patients with Huntington disease (HD), we immunohistochemically stained hypocretin and MCH neurons and estimated their total numbers in the lateral hypothalamus of both HD patients

Simultaneous estimation of transcutaneous bilirubin, hemoglobin, and melanin based on diffuse reflectance spectroscopy

Science.gov (United States)

Nishidate, Izumi; Abdul, Wares MD.; Ohtsu, Mizuki; Nakano, Kazuya; Haneishi, Hideaki

2018-02-01

We propose a method to estimate transcutaneous bilirubin, hemoglobin, and melanin based on the diffuse reflectance spectroscopy. In the proposed method, the Monte Carlo simulation-based multiple regression analysis for an absorbance spectrum in the visible wavelength region (460-590 nm) is used to specify the concentrations of bilirubin (Cbil), oxygenated hemoglobin (Coh), deoxygenated hemoglobin (Cdh), and melanin (Cm). Using the absorbance spectrum calculated from the measured diffuse reflectance spectrum as a response variable and the extinction coefficients of bilirubin, oxygenated hemoglobin, deoxygenated hemoglobin, and melanin, as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of bilirubin, oxygenated hemoglobin, deoxygenated hemoglobin, and melanin, are then determined from the regression coefficients using conversion vectors that are numerically deduced in advance by the Monte Carlo simulations for light transport in skin. Total hemoglobin concentration (Cth) and tissue oxygen saturation (StO2) are simply calculated from the oxygenated hemoglobin and deoxygenated hemoglobin. In vivo animal experiments with bile duct ligation in rats demonstrated that the estimated Cbil is increased after ligation of bile duct and reaches to around 20 mg/dl at 72 h after the onset of the ligation, which corresponds to the reference value of Cbil measured by a commercially available transcutaneous bilirubin meter. We also performed in vivo experiments with rats while varying the fraction of inspired oxygen (FiO2). Coh and Cdh decreased and increased, respectively, as FiO2 decreased. Consequently, StO2 was dramatically decreased. The results in this study indicate potential of the method for simultaneous evaluation of multiple chromophores in skin tissue.

Thermophilic fungi in the new age of fungal taxonomy.

Science.gov (United States)

de Oliveira, Tássio Brito; Gomes, Eleni; Rodrigues, Andre

2015-01-01

Thermophilic fungi are of wide interest due to their potential to produce heat-tolerant enzymes for biotechnological processes. However, the taxonomy of such organisms remains obscure, especially given new developments in the nomenclature of fungi. Here, we examine the taxonomy of the thermophilic fungi most commonly used in industry in light of the recent taxonomic changes following the adoption of the International Code of Nomenclature for Algae, Fungi and Plants and also based on the movement One Fungus = One Name. Despite the widespread use of these fungi in applied research, several thermotolerant fungi still remain classified as thermophiles. Furthermore, we found that while some thermophilic fungi have had their genomes sequenced, many taxa still do not have barcode sequences of reference strains available in public databases. This lack of basic information is a limiting factor for the species identification of thermophilic fungi and for metagenomic studies in this field. Based on next-generation sequencing, such studies generate large amounts of data, which may reveal new species of thermophilic fungi in different substrates (composting systems, geothermal areas, piles of plant material). As discussed in this study, there are intrinsic problems associated with this method, considering the actual state of the taxonomy of thermophilic fungi. To overcome such difficulties, the taxonomic classification of this group should move towards standardizing the commonly used species names in industry and to assess the possibility of including new systems for describing species based on environmental sequences.

Bioinspired Multifunctional Melanin-Based Nanoliposome for Photoacoustic/Magnetic Resonance Imaging-Guided Efficient Photothermal Ablation of Cancer

Science.gov (United States)

Zhang, Liang; Sheng, Danli; Wang, Dong; Yao, Yuanzhi; Yang, Ke; Wang, Zhigang; Deng, Liming; Chen, Yu

2018-01-01

Background: The construction of theranostic nanosystems with concurrently high biosafety and therapeutic performance is a challenge but has great significance for the clinical translation of nanomedicine for combating cancer. Methods: Bio-inspired melanin-based nanoliposomes (Lip-Mel) as theranostic agents were constructed for simultaneous photoacoustic (PA) imaging- and T1-weighted magnetic resonance (MR) imaging-guided photothermal ablation of tumors, which was demonstrated both in vitro and in vivo. The high biosafety of Lip-Mel was also systematically evaluated. Results: The achieved Lip-Mel nanoliposomes demonstrated their imaging capability for both PA and T1-weighted MR imaging (r1 = 0.25 mM-1·s-1) both in vitro and in vivo, providing the potential for therapeutic guidance and monitoring. Importantly, the desirable photothermal-conversion efficiency of the as-prepared Lip-Mel achieved complete eradication of tumors in breast cancer-bearing mice, exhibiting remarkable photothermal-based therapeutic performance. In particular, the efficient encapsulation of melanin into the PEGylated liposome mitigated the potential toxicity of melanin and improved the photothermal performance of the loaded melanin. Systematic in vivo biosafety evaluations demonstrated the high biocompatibility of Lip-Mel at a high dose of 100 mg/kg. Conclusion: In this work, we reported a bioinspired strategy where melanin, a natural product in the human body, is encapsulated into PEGylated nanoliposomes for efficient theranostics with high biocompatibility. This work provides a new strategy for creating desirable theranostic agents with concurrent high biocompatibility and satisfactory theranostic performance through the use of materials that totally originate from biosystems. PMID:29556343

Increased sporulation of vesicular-arbuscular mycorrhizal fungi by manipulation of nutrient regimens.

Science.gov (United States)

Douds, D D; Schenck, N C

1990-02-01

Adjustment of pot culture nutrient solutions increased root colonization and sporulation of vesicular-arbuscular mycorrhizal (VAM) fungi. Paspalum notatum Flugge and VAM fungi were grown in a sandy soil low in N and available P. Hoagland nutrient solution without P enhanced sporulation in soil and root colonization of Acaulospora longula, Scutellospora heterogama, Gigaspora margarita, and a wide range of other VAM fungi over levels produced by a tap water control or nutrient solutions containing P. However, Glomus intraradices produced significantly more spores in plant roots in the tap water control treatment. The effect of the nutrient solutions was not due solely to N nutrition, because the addition of NH(4)NO(3) decreased both colonization and sporulation by G. margarita relative to levels produced by Hoagland solution without P.

Genetic monitoring of irradiated Drosophila populations treated with antimutagen melanine

International Nuclear Information System (INIS)

Mosseh, I.B.; Savchenko, V.K.; Lyakh, I.P.

1986-01-01

It was shown that viability of irradiated Drosophila is, on an average, lower than in intact populations. The fertility first decreases then increases exceeding the control level. Melanine added to the diet increases fertility and viability of both exposed and intact Drosophila populations

Identification Sponges-Associated Fungi From Karimunjawa National Park

Science.gov (United States)

Trianto, Agus; Sabdono, Agus; Rochaddi, Baskoro; Wulan Triningsih, Desy; Seswita Zilda, Dewi

2018-02-01

Marine sponges are rich sources of bioactive substances with various pharmacological activities. Previous studies have shown that most bioactive compounds were originally produced by associated-microorganisms. Fungi associated with the marine sponges collected off Karimunjawa National Park were isolated and identified by morphological characteristics and molecular level analyses based on internal transcribed spacer (ITS) regions. A total of 2 isolates which were characterized, the fungi Penicillium spinulosum and Trichoderma virens have been revealed.

Endophytic Fungi Isolated from Coleus amboinicus Lour Exhibited Antimicrobial Activity.

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Astuti, Puji; Sudarsono, Sudarsono; Nisak, Khoirun; Nugroho, Giri Wisnu

2014-12-01

Coleus amboinicus is a medicinal plant traditionally used to treat various diseases such as throat infection, cough and fever, diarrhea, nasal congestion and digestive problems. The plant was explored for endophytic fungi producing antimicrobial agents. Screening for endophytic fungi producing antimicrobial agents was conducted using agar plug method and antimicrobial activity of promising ethyl acetate extracts was determined by disc diffusion assay. Thin layer chromatography (TLC) - bioautography was performed to localize the bioactive components within the extract. TLC visualization detection reagents were used to preliminary analyze phytochemical groups of the bioactive compounds. Three endophytic fungi were obtained, two of them showed promising potential. Agar diffusion method showed that endophytic fungi CAL-2 exhibited antimicrobial activity against P. aeruginosa, B. subtilis, S. aureus and S. thypi, whilst CAS-1 inhibited the growth of B. subtilis. TLC bioautography of ethyl acetate extract of CAL-2 revealed at least three bands exhibited antimicrobial activity and at least two bands showed inhibition of B. subtilis growth. Preliminary analysis of the crude extracts suggests that bioactive compounds within CAL-2 extract are terpenoids, phenolics and phenyl propanoid compounds whilst the antimicrobial agents within CAS-1 extract are terpenoids, propylpropanoids, alkaloids or heterocyclic nitrogen compounds. These data suggest the potential of endophytic fungi of C. amboinicus as source for antimicrobial agents.

A regulator of ubiquitin-proteasome activity, 2-hexyldecanol, suppresses melanin synthesis and the appearance of facial hyperpigmented spots.

Science.gov (United States)

Hakozaki, T; Laughlin, T; Zhao, S; Wang, J; Deng, D; Jewell-Motz, E; Elstun, L

2013-07-01

2-Hexyldecanol has long been used in skin-care products, but has not previously been reported as an active ingredient for skin benefits. To evaluate 2-hexyldecanol in in vitro and ex vivo systems and, if found to be active, progress it to topical clinical testing to determine effects on pigmentation in skin. 2-Hexyldecanol was tested in melanocyte cell culture systems (B16 mouse melanoma cells and normal human melanocytes) for its effect on proteolytic activity and melanin production, in the absence and presence of the proteasome-specific inhibitor, MG132. It was further tested in a human skin explant model for its effect on melanin production. Lastly, topically applied 2-hexyldecanol was evaluated for its effect on the appearance of facial pigmentation in an 8-week, randomized, double-blind, vehicle-controlled, split-face incomplete block design study in Chinese women. In submerged cell culture, 2-hexyldecanol upregulated proteolytic activity and decreased melanin synthesis. These effects were antagonized by the proteasome-specific inhibitor MG132. MG132, tested in the absence of 2-hexyldecanol, increased melanin production. In a human skin explant model, topical 2-hexyldecanol suppressed the production of melanin vs. a vehicle control. In a human clinical study in Chinese women (n = 110 observations per test material), a 2-hexyldecanol-containing formulation significantly reduced the appearance of facial hyperpigmented spots vs. its control. These data indicate that regulation of proteasome activity is a viable target for control of melanin production, that 2-hexyldecanol upregulates proteasomal activity in melanocytes, and that topical 2-hexyldecanol reduces the appearance of hyperpigmentation. © 2013 The Authors BJD © 2013 British Association of Dermatologists.

From tyrosine to melanin: Signaling pathways and factors regulating melanogenesis

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Zuzanna Rzepka

2016-06-01

Full Text Available Melanins are natural pigments of skin, hair and eyes and can be classified into two main types: brown to black eumelanin and yellow to reddish-brown pheomelanin. Biosynthesis of melanins takes place in melanosomes, which are specialized cytoplasmic organelles of melanocytes - dendritic cells located in the basal layer of the epidermis, uveal tract of the eye, hair follicles, as well as in the inner ear, central nervous system and heart. Melanogenesis is a multistep process and begins with the conversion of amino acid L-tyrosine to DOPAquinone. The addition of cysteine or glutathione to DOPAquinone leads to the intermediates formation, followed by subsequent transformations and polymerization to the final product, pheomelanin. In the absence of thiol compounds DOPAquinone undergoes an intramolecular cyclization and oxidation to form DOPAchrome, which is then converted to 5,6-dihydroksyindole (DHI or 5,6-dihydroxyindole-2-carboxylic acid (DHICA. Eumelanin is formed by polymerization of DHI and DHICA and their quinones. Regulation of melanogenesis is achieved by physical and biochemical factors. The article presents the intracellular signaling pathways: cAMP/PKA/CREB/MITF cascade, MAP kinases cascade, PLC/DAG/PKCβ cascade and NO/cGMP/PKG cascade, which are involved in the regulation of expression and activity of the melanogenesis-related proteins by ultraviolet radiation and endogenous agents (cytokines, hormones. Activity of the key melanogenic enzyme, tyrosinase, is also affected by pH and temperature. Many pharmacologically active substances are able to inhibit or stimulate melanin biosynthesis, as evidenced by in vitro studies on cultured pigment cells.

Oral melanin pigmentation in 467 Thai and Malaysian people with special emphasis on smoker's melanosis.

Science.gov (United States)

Hedin, C A; Axéll, T

1991-01-01

At the faculties of dentistry in Chiang Mai, Thailand (CM), and Kuala Lumpur, Malaysia (KL), 234 and 233 consecutive out-patients were interviewed concerning tobacco and chewing habits and examined for the presence of oral melanin pigmentation. Tobacco was regularly used by 32% and 28% of the studied populations in CM and KL. Cigarette smoking was the predominant habit, but the chewing of betel and tea leaves (miang) and the smoking of banana leaf cigars (khi yo) was also registered. The genetically acquired pigmentation dominated. Although nearly all non-tobacco users in the Malay and Indian populations had oral melanin pigmentation, it was found that tobacco smokers had significantly more oral surfaces pigmented than non-tobacco users. Among Thais, the percentage of pigmented individuals was significantly higher among tobacco smokers. It was concluded that tobacco smoking stimulates oral melanocytes to a higher melanin production also in dark-skinned ethnic groups.

Extracellular oxidases and the transformation of solubilised low-rank coal by wood-rot fungi

Energy Technology Data Exchange (ETDEWEB)

Ralph, J.P. [Flinders Univ. of South Australia, Bedford Park (Australia). School of Biological Sciences; Graham, L.A. [Flinders Univ. of South Australia, Bedford Park (Australia). School of Biological Sciences; Catcheside, D.E.A. [Flinders Univ. of South Australia, Bedford Park (Australia). School of Biological Sciences

1996-12-31

The involvement of extracellular oxidases in biotransformation of low-rank coal was assessed by correlating the ability of nine white-rot and brown-rot fungi to alter macromolecular material in alkali-solubilised brown coal with the spectrum of oxidases they produce when grown on low-nitrogen medium. The coal fraction used was that soluble at 3.0{<=}pH{<=}6.0 (SWC6 coal). In 15-ml cultures, Gloeophyllum trabeum, Lentinus lepideus and Trametes versicolor produced little or no lignin peroxidase, manganese (Mn) peroxidase or laccase activity and caused no change to SWC6 coal. Ganoderma applanatum and Pycnoporus cinnabarinus also produced no detectable lignin or Mn peroxidases or laccase yet increased the absorbance at 400 nm of SWC6 coal. G. applanatum, which produced veratryl alcohol oxidase, also increased the modal apparent molecular mass. SWC6 coal exposed to Merulius tremellosus and Perenniporia tephropora, which secreted Mn peroxidases and laccase and Phanerochaete chrysosporium, which produced Mn and lignin peroxidases was polymerised but had unchanged or decreased absorbance. In the case of both P. chrysosporium and M. tremellosus, polymerisation of SWC6 coal was most extensive, leading to the formation of a complex insoluble in 100 mM NaOH. Rigidoporus ulmarius, which produced only laccase, both polymerised and reduced the A{sub 400} of SWC6 coal. P. chrysosporium, M. tremellosus and P. tephropora grown in 10-ml cultures produced a spectrum of oxidases similar to that in 15-ml cultures but, in each case, caused more extensive loss of A{sub 400}, and P. chrysosporium depolymerised SWC6 coal. It is concluded that the extracellular oxidases of white-rot fungi can transform low-rank coal macromolecules and that increased oxygen availability in the shallower 10-ml cultures favours catabolism over polymerisation. (orig.)

Melanin offers protection against induction of cyclobutane pyrimidine dimers and 6-4 photoproducts by UVB in cultured human melanocytes

NARCIS (Netherlands)

Smit, N.P.M.; Vink, A.A.; Kolb, R.M.; Steenwinkel, M.J.S.T.; Berg, P.T.M. van den; Nieuwpoort, F. van; Roza, L.; Pavel, S.

2001-01-01

The goal of this investigation was to correlate the melanin content in human pigmentary cells with the generation of UVB-induced photoproducts and to examine the relationship between the melanin content and the removal of the photoproducts. Cultured melanocytes from light-skinned individuals

MICROSCOPIC FUNGI ISOLATED FROM POLISH HONEY

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Soňa Felšöciová

2012-12-01

Full Text Available The characterization of some honey samples from Poland was carried out on the basis of their microbiological (fungi and yeasts analysis. Most of the samples contained less than 20 % water. The amount of fungi found in the honey samples was less than 1 x 102 CFU.g-1 but 19 % of the samples had more yeasts than 1 x 102 CFU.g-1 – up to 5.7 x 102 CFU.g-1. The isolated fungi were Alternaria spp., Aspergillus spp., Cladosporium spp., Fusarium spp., Mycelia sterilia, Rhizopus spp. and Penicillium spp. The last genus was isolated very frequently. A total number of eight fungal Penicillium species were identified namely, Penicillium brevicompactum, P. commune, P. corylophilum, P. crustosum, P. expansum, P. griseofulvum, P. chrysogenum and P. polonicum. They were isolated using dilution plate method. The results showed that honeys produced in this region are of good microbiological quality.

Fungi colonizing dead leaves of herbs

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Maria Kowalik

2013-04-01

Full Text Available The material was collected from the Botanical Garden and the Collegium Medicum Medicinal Plant Garden of the Jagiellonian University in Krakow. The investigated species were: lemon balm (Mellisa officinalis L., common lavender (Lavendula angustifolia Mill., horsemint (Mentha longifolia L., sage (Salvia officinalis L., sweet basil (Ocimum basilicum L., and wild marjoram (Origanum vulgare L.. The aim of the investigation was to identify fungi causing the death of leaf tissues of herbs from the mint family Lamiaceae. In mycological investigations, 180 fragments of each plant leaves (1,080 dead leaf fragments in total were placed in a 2% PDA medium. Over 970 colonies of fungi belonging to 48 species were isolated from the dead leaf tissues of the six herb species. Alternaria alternata (toxin-producing, Epicoccum nigrum and Sordaria fimicola were the most frequently isolated. The largest numbers of colonies and species of fungi were isolated from horsemint, while the lowest numbers were from wild marjoram leaves. It was shown that the death of leaves of selected herb species from the Lamiaceae family was caused by various fungi. The results of the mycological analysis confirmed the diversity of species colonizing the leaves of the herbs.

Induced mutation and somatic recombination as tools for genetic analysis and breeding of imperfect fungi

NARCIS (Netherlands)

Bos, C.J.

1986-01-01

Many fungi which are important in Agriculture as plant pathogens or in Biotechnology as producers of organic acids, antibiotics or enzymes, are imperfect fungi. These fungi do not have a sexual stage, which implies that they lack a meiotic recombination mechanism.

However, many

Minor and trace elements in melanins determined by neutron activation analysis

International Nuclear Information System (INIS)

Kochanska-Dziurowicz, A.A.; Wilczok, T.; Mosulishvili, L.; Kharabadze, N.

1986-01-01

The presence of Au, Br, Sb, Ag, Fe, Zn, Co, Cr, Ni, Hg and Sn determined by neutron activation analysis was demonstrated in melanins isolated from human dark hair, banana peels or prepared synthetically from tyrosine. (author)

Inhibitory Effect of Arctigenin from Fructus Arctii Extract on Melanin Synthesis via Repression of Tyrosinase Expression

Science.gov (United States)

Park, Hwayong; Song, Kwang Hoon; Jung, Pil Mun; Kim, Ji-Eun; Kim, Mi Yoon; Ma, Jin Yeul

2013-01-01

To identify the active compound arctigenin in Fructus Arctii (dried seed of medicinal plant Arctium lappa) and to elucidate the inhibitory mechanism in melanogenesis, we analyzed melanin content and tyrosinase activity on B16BL6 murine melanoma and melan-A cell cultures. Water extracts of Fructus Arctii were shown to inhibit tyrosinase activity in vitro and melanin content in α-melanocyte stimulating hormone-stimulated cells to similar levels as the well-known kojic acid and arbutin, respectively. The active compound arctigenin of Fructus Arctii displayed little or no cytotoxicity at all concentrations examined and decreased the relative melanin content and tyrosinase activity in a dose-dependent manner. Melanogenic inhibitory activity was also identified in vivo with zebrafish embryo. To determine the mechanism of inhibition, the effects of arctigenin on tyrosinase gene expression and tyrosinase promoter activity were examined. Also in addition, in the signaling cascade, arctigenin dose dependently decreased the cAMP level and promoted the phosphorylation of extracellular signal-regulated kinase. This result suggests that arctigenin downregulates cAMP and the tyrosinase enzyme through its gene promoter and subsequently upregulates extracellular signal-regulated kinase activity by increasing phosphorylation in the melanogenesis signaling pathway, which leads to a lower melanin content. PMID:23781272

Inhibitory Effect of Arctigenin from Fructus Arctii Extract on Melanin Synthesis via Repression of Tyrosinase Expression

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Hwayong Park

2013-01-01

Full Text Available To identify the active compound arctigenin in Fructus Arctii (dried seed of medicinal plant Arctium lappa and to elucidate the inhibitory mechanism in melanogenesis, we analyzed melanin content and tyrosinase activity on B16BL6 murine melanoma and melan-A cell cultures. Water extracts of Fructus Arctii were shown to inhibit tyrosinase activity in vitro and melanin content in α-melanocyte stimulating hormone-stimulated cells to similar levels as the well-known kojic acid and arbutin, respectively. The active compound arctigenin of Fructus Arctii displayed little or no cytotoxicity at all concentrations examined and decreased the relative melanin content and tyrosinase activity in a dose-dependent manner. Melanogenic inhibitory activity was also identified in vivo with zebrafish embryo. To determine the mechanism of inhibition, the effects of arctigenin on tyrosinase gene expression and tyrosinase promoter activity were examined. Also in addition, in the signaling cascade, arctigenin dose dependently decreased the cAMP level and promoted the phosphorylation of extracellular signal-regulated kinase. This result suggests that arctigenin downregulates cAMP and the tyrosinase enzyme through its gene promoter and subsequently upregulates extracellular signal-regulated kinase activity by increasing phosphorylation in the melanogenesis signaling pathway, which leads to a lower melanin content.

An experimental and theoretical approach to the study of the photoacoustic signal produced by cancer cells

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Rafael Pérez Solano

2012-03-01

Full Text Available The distinctive spectral absorption characteristics of cancer cells make photoacoustic techniques useful for detection in vitro and in vivo. Here we report on our evaluation of the photoacoustic signal produced by a series of monolayers of different cell lines in vitro. Only the melanoma cell line HS936 produced a detectable photoacoustic signal in which amplitude was dependent on the number of cells. This finding appears to be related to the amount of melanin available in these cells. Other cell lines (i.e. HL60, SK-Mel-1, T47D, Hela, HT29 and PC12 exhibited values similar to a precursor of melanin (tyrosinase, but failed to produce sufficient melanin to generate a photoacoustic signal that could be distinguished from background noise. To better understand this phenomenon, we determined a formula for the time-domain photoacoustic wave equation for a monolayer of cells in a non-viscous fluid on the thermoelastic regime. The theoretical results showed that the amplitude and profile of the photoacoustic signal generated by a cell monolayer depended upon the number and distribution of the cells and the location of the point of detection. These findings help to provide a better understanding of the factors involved in the generation of a photoacoustic signal produced by different cells in vitro and in vivo.

Biology of flower-infecting fungi.

Science.gov (United States)

Ngugi, Henry K; Scherm, Harald

2006-01-01

The ability to infect host flowers offers important ecological benefits to plant-parasitic fungi; not surprisingly, therefore, numerous fungal species from a wide range of taxonomic groups have adopted a life style that involves flower infection. Although flower-infecting fungi are very diverse, they can be classified readily into three major groups: opportunistic, unspecialized pathogens causing necrotic symptoms such as blossom blights (group 1), and specialist flower pathogens which infect inflorescences either through the gynoecium (group 2) or systemically through the apical meristem (group 3). This three-tier system is supported by life history attributes such as host range, mode of spore transmission, degree of host sterilization as a result of infection, and whether or not the fungus undergoes an obligate sexual cycle, produces resting spores in affected inflorescences, and is r- or K-selected. Across the three groups, the flower as an infection court poses important challenges for disease management. Ecologically and evolutionarily, terms and concepts borrowed from the study of venereal (sexually transmitted) diseases of animals do not adequately capture the range of strategies employed by fungi that infect flowers.

Analysis of the melanin distribution in different ethnic groups by in vivo laser scanning microscopy

International Nuclear Information System (INIS)

Antoniou, C; Lademann, J; Richter, H; Patzelt, A; Sterry, W; Astner, S; Zastrow, L; Koch, S

2009-01-01

The aim of this study was to determine whether Laser scanning confocal microscopy (LSM) is able to visualize differences in melanin content and distribution in different Skin Phototypes. The investigations were carried out on six healthy volunteers with Skin Phototypes II, IV, and VI. Representative skin samples of Skin Phototypes II, V, and VI were obtained for histological analysis from remaining tissue of skin grafts and were used for LSM-pathologic correlation. LSM evaluation showed significant differences in melanin distribution in Skin Phototypes II, IV, and VI, respectively. Based on the differences in overall reflectivity and image brightness, a visual evaluation scheme showed increasing brightness of the basal and suprabasal layers with increasing Skin Phototypes. The findings correlated well with histological analysis. The results demonstrate that LSM may serve as a promising adjunctive tool for real time assessment of melanin content and distribution in human skin, with numerous clinical applications and therapeutic and preventive implications

Transferring biomarker into molecular probe: melanin nanoparticle as a naturally active platform for multimodality imaging.

Science.gov (United States)

Fan, Quli; Cheng, Kai; Hu, Xiang; Ma, Xiaowei; Zhang, Ruiping; Yang, Min; Lu, Xiaomei; Xing, Lei; Huang, Wei; Gambhir, Sanjiv Sam; Cheng, Zhen

2014-10-29

Developing multifunctional and easily prepared nanoplatforms with integrated different modalities is highly challenging for molecular imaging. Here, we report the successful transfer of an important molecular target, melanin, into a novel multimodality imaging nanoplatform. Melanin is abundantly expressed in melanotic melanomas and thus has been actively studied as a target for melanoma imaging. In our work, the multifunctional biopolymer nanoplatform based on ultrasmall (passive nanoplatforms require complicated and time-consuming processes for prebuilding reporting moieties or chemical modifications using active groups to integrate different contrast properties into one entity. In comparison, utilizing functional biomarker melanin can greatly simplify the building process. We further conjugated αvβ3 integrins, cyclic c(RGDfC) peptide, to MNPs to allow for U87MG tumor accumulation due to its targeting property combined with the enhanced permeability and retention (EPR) effect. The multimodal properties of MNPs demonstrate the high potential of endogenous materials with multifunctions as nanoplatforms for molecular theranostics and clinical translation.

Preparation of a Sepia Melanin and Poly(ethylene-alt-maleic Anhydride Hybrid Material as an Adsorbent for Water Purification

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Guido Panzarasa

2018-01-01

Full Text Available Meeting the increasing demand of clean water requires the development of novel efficient adsorbent materials for the removal of organic pollutants. In this context the use of natural, renewable sources is of special relevance and sepia melanin, thanks to its ability to bind a variety of organic and inorganic species, has already attracted interest for water purification. Here we describe the synthesis of a material obtained by the combination of sepia melanin and poly(ethylene-alt-maleic anhydride (P(E-alt-MA. Compared to sepia melanin, the resulting hybrid displays a high and fast adsorption efficiency towards methylene blue (a common industrial dye for a wide pH range (from pH 2 to 12 and under high ionic strength conditions. It is easily recovered after use and can be reused up to three times. Given the wide availability of sepia melanin and P(E-alt-MA, the synthesis of our hybrid is simple and affordable, making it suitable for industrial water purification purposes.

Melanins as biomarkers of ovarian follicular atresia in the catfish Heteropneustes fossilis: biochemical and histochemical characterization, seasonal variation and hormone effects.

Science.gov (United States)

Kumar, Ravi; Joy, Keerikkattil P

2015-06-01

Follicular atresia is a common feature of the vertebrate ovary that occurs at different stages of folliculogenesis and ovarian regression. It has physiological significance to maintain homeostasis and control fecundity, and ensure removal of post-ovulatory follicular remnants for preparing the ovary for the next cycle. Pigments appear late in the atretic process as indigestible waste formed out of the degradation of the oocytes, follicle wall and granulocytes. In the present study, pigment accumulation was demonstrated by Schmorl's and Perls' staining methods in the atretic ovarian follicles of Heteropneustes fossilis during follicular development and regression. Melanins were characterized spectrophotometrically for the first time in fish ovary. The predominant form is eumelanin, followed by pheomelanin and alkali-soluble melanin. Melanins showed significant seasonal variations with levels low in gonad resting phase, increasing to the peak in the post-spawning phase. The concentration of melanins increased time-dependently in post-ovulated ovary after human chorionic gonadotropin treatment. In the spawning phase, in vitro incubation of ovary slices with estradiol-17β or dexamethasone for 8 or 16 h decreased both eumelanin and pheomelanin levels time-dependently. The alkali-soluble melanin showed a significant decrease only in the dexamethasone group at 16 h. The results show that melanin assay can be used as a biomarker of follicular atresia in fish ovary, natural or induced by environmental toxicants.

Melanin targeting for intracellular drug delivery: Quantification of bound and free drug in retinal pigment epithelial cells.

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Rimpelä, Anna-Kaisa; Hagström, Marja; Kidron, Heidi; Urtti, Arto

2018-05-31

Melanin binding affects drug distribution and retention in pigmented ocular tissues, thereby affecting drug response, duration of activity and toxicity. Therefore, it is a promising possibility for drug targeting and controlled release in the pigmented cells and tissues. Intracellular unbound drug concentrations determine pharmacological and toxicological actions, but analyses of unbound vs. total drug concentrations in pigmented cells are lacking. We studied intracellular binding and cellular drug uptake in pigmented retinal pigment epithelial cells and in non-pigmented ARPE-19 cells with five model drugs (chloroquine, propranolol, timolol, diclofenac, methotrexate). The unbound drug fractions in pigmented cells were 0.00016-0.73 and in non-pigmented cells 0.017-1.0. Cellular uptake (i.e. distribution ratio Kp), ranged from 1.3 to 6300 in pigmented cells and from 1.0 to 25 in non-pigmented cells. Values for intracellular bioavailability, F ic , were similar in both cells types (although larger variation in pigmented cells). In vitro melanin binding parameters were used to predict intracellular unbound drug fraction and cell uptake. Comparison of predictions with experimental data indicates that other factors (e.g. ion-trapping, lipophilicity-related binding to other cell components) also play a role. Melanin binding is a major factor that leads to cellular uptake and unbound drug fractions of a range of 3-4 orders of magnitude indicating that large reservoirs of melanin bound drug can be generated in the cells. Understanding melanin binding has important implications on retinal drug targeting, efficacy and toxicity. Copyright © 2017. Published by Elsevier B.V.

REGULATION OF COAL POLYMER DEGRADATION BY FUNGI

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John A. Bumpus

1998-11-30

A variety of lignin degrading fungi mediate solubilization and subsequent biodegradation of coal macromolecules (a.k.a. coal polymer) from highly oxidized low rank coals such as leonardites. It appears that oxalate or possibly other metal chelators (i.e., certain Krebs Cycle intermediates) mediate solubilization of low rank coals while extracellular oxidases have a role in subsequent oxidation of solubilized coal macromolecule. These processes are under nutritional control. For example, in the case of P. chrysosporium, solubilization of leonardite occurred when the fungi were cultured on most but not all nutrient agars tested and subsequent biodegradation occurred only in nutrient nitrogen limited cultures. Lignin peroxidases mediate oxidation of coal macromolecule in a reaction that is dependent on the presence of veratryl alcohol and hydrogen peroxide. Kinetic evidence suggests that veratryl alcohol is oxidized to the veratryl alcohol cation radical which then mediates oxidation of the coal macromolecule. Results by others suggest that Mn peroxidases mediate formation of reactive Mn{sup 3+} complexes which also mediate oxidation of coal macromolecule. A biomimetic approach was used to study solubilization of a North Dakota leonardite. It was found that a concentration {approximately}75 mM sodium oxalate was optimal for solubilization of this low rank coal. This is important because this is well above the concentration of oxalate produced by fungi in liquid culture. Higher local concentrations probably occur in solid agar cultures and thus may account for the observation that greater solubilization occurs in agar media relative to liquid media. The characteristics of biomimetically solubilized leonardite were similar to those of biologically solubilized leonardite. Perhaps our most interesting observation was that in addition to oxalate, other common Lewis bases (phosphate/hydrogen phosphate/dihydrogen phosphate and bicarbonate/carbonate ions) are able to mediate

Endophytic Fungi Isolated from Coleus amboinicus Lour Exhibited Antimicrobial Activity

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Puji Astuti

2014-12-01

Full Text Available Purpose: Coleus amboinicus is a medicinal plant traditionally used to treat various diseases such as throat infection, cough and fever, diarrhea, nasal congestion and digestive problems. The plant was explored for endophytic fungi producing antimicrobial agents. Methods: Screening for endophytic fungi producing antimicrobial agents was conducted using agar plug method and antimicrobial activity of promising ethyl acetate extracts was determined by disc diffusion assay. Thin layer chromatography (TLC - bioautography was performed to localize the bioactive components within the extract. TLC visualization detection reagents were used to preliminary analyze phytochemical groups of the bioactive compounds. Results: Three endophytic fungi were obtained, two of them showed promising potential. Agar diffusion method showed that endophytic fungi CAL-2 exhibited antimicrobial activity against P. aeruginosa, B. subtilis, S. aureus and S. thypi, whilst CAS-1 inhibited the growth of B. subtilis. TLC bioautography of ethyl acetate extract of CAL-2 revealed at least three bands exhibited antimicrobial activity and at least two bands showed inhibition of B. subtilis growth. Preliminary analysis of the crude extracts suggests that bioactive compounds within CAL-2 extract are terpenoids, phenolics and phenyl propanoid compounds whilst the antimicrobial agents within CAS-1 extract are terpenoids, propylpropanoids, alkaloids or heterocyclic nitrogen compounds. Conclusion: These data suggest the potential of endophytic fungi of C. amboinicus as source for antimicrobial agents.

A new class of IMP dehydrogenase with a role in self-resistance of mycophenolic acid producing fungi

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Mortensen Uffe H

2011-09-01

Full Text Available Abstract Background Many secondary metabolites produced by filamentous fungi have potent biological activities, to which the producer organism must be resistant. An example of pharmaceutical interest is mycophenolic acid (MPA, an immunosuppressant molecule produced by several Penicillium species. The target of MPA is inosine-5'-monophosphate dehydrogenase (IMPDH, which catalyses the rate limiting step in the synthesis of guanine nucleotides. The recent discovery of the MPA biosynthetic gene cluster from Penicillium brevicompactum revealed an extra copy of the IMPDH-encoding gene (mpaF embedded within the cluster. This finding suggests that the key component of MPA self resistance is likely based on the IMPDH encoded by mpaF. Results In accordance with our hypothesis, heterologous expression of mpaF dramatically increased MPA resistance in a model fungus, Aspergillus nidulans, which does not produce MPA. The growth of an A. nidulans strain expressing mpaF was only marginally affected by MPA at concentrations as high as 200 μg/ml. To further substantiate the role of mpaF in MPA resistance, we searched for mpaF orthologs in six MPA producer/non-producer strains from Penicillium subgenus Penicillium. All six strains were found to hold two copies of IMPDH. A cladistic analysis based on the corresponding cDNA sequences revealed a novel group constituting mpaF homologs. Interestingly, a conserved tyrosine residue in the original class of IMPDHs is replaced by a phenylalanine residue in the new IMPDH class. Conclusions We identified a novel variant of the IMPDH-encoding gene in six different strains from Penicillium subgenus Penicillium. The novel IMPDH variant from MPA producer P. brevicompactum was shown to confer a high degree of MPA resistance when expressed in a non-producer fungus. Our study provides a basis for understanding the molecular mechanism of MPA resistance and has relevance for biotechnological and pharmaceutical applications.

Exploration of unique relation among industrial fungi by statistical analysis

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Asma Siddique

2012-12-01

Full Text Available This work was carried out to explore the relation among thermophilic cellulolytic fungi, which are of industrialimportance. There was no report found about the genetic relationship of fungi, which are used to produce industrial enzymes.So the aim of the study was to observe the similarity among different cellulolytic fungi on genetic level, which will providethe background to understand the correlation among cellulase producing systems of these fungi. Eleven (11 fungi werestudied for genetic diversity using the Random Amplified Polymorphic DNA (RAPD a PCR based molecular marker system.In this regard twenty universal decamers used for RAPD resulted in 1527 numbers of bands observed during comparison ofall wild strains. Maximum polymorphism was generated with GLA-07. Average numbers of bands per 20 primers were 65-72.An Interesting feature of the study was the similarity of Humicola insolens with Torula thermophile, more than with theother members of the Humicola family. This genetic pattern affects the physical structure of the fungi. Spores of Torulathermophila are more related to Humicola insolens than to its own family. Similarity between the two was found to be 57.8%,whereas between Humicola lanuginosa (Thermomysis lanuginosus and Humicola grisea it was 57.3%. Apart from this,similarity between Talaromyces dupontii and Rhizomucor pusillus was 51.5%. Least similarity was found in Rhizomucorpusillus and Humicola grisea, which was 18.7% and Chaetomium thermophile and Sporotrichum thermophile, which was18.3%. Genetic similarity matrix was constructed on the basis of Nei and Li’s index.

Melanocytes and melanin represent a first line of innate immunity against Candida albicans.

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Tapia, Cecilia V; Falconer, Maryanne; Tempio, Fabián; Falcón, Felipe; López, Mercedes; Fuentes, Marisol; Alburquenque, Claudio; Amaro, José; Bucarey, Sergio A; Di Nardo, Anna

2014-07-01

Melanocytes are dendritic cells located in the skin and mucosae that synthesize melanin. Some infections induce hypo- or hyperpigmentation, which is associated with the activation of Toll-like receptors (TLRs), especially TLR4. Candida albicans is an opportunist pathogen that can switch between blastoconidia and hyphae forms; the latter is associated with invasion. Our objectives in this study were to ascertain whether C. albicans induces pigmentation in melanocytes and whether this process is dependent on TLR activation, as well as relating this with the antifungal activity of melanin as a first line of innate immunity against fungal infections. Normal human melanocytes were stimulated with C. albicans supernatants or with crude extracts of the blastoconidia or hyphae forms, and pigmentation and TLR2/TLR4 expression were measured. Expression of the melanosomal antigens Melan-A and gp100 was examined for any correlation with increased melanin levels or antifungal activity in melanocyte lysates. Melanosomal antigens were induced earlier than cell pigmentation, and hyphae induced stronger melanization than blastoconidia. Notably, when melanocytes were stimulated with crude extracts of C. albicans, the cell surface expression of TLR2/TLR4 began at 48 h post-stimulation and peaked at 72 h. At this time, blastoconidia induced both TLR2 and TLR4 expression, whereas hyphae only induced TLR4 expression. Taken together, these results suggest that melanocytes play a key role in innate immune responses against C. albicans infections by recognizing pathogenic forms of C. albicans via TLR4, resulting in increased melanin content and inhibition of infection. © The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Endophytic Fungi Associated With Turmeric (Curcuma longa L. Can Inhibit Histamine-Forming Bacteria in Fish

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Eris Septiana

2017-01-01

Full Text Available Turmeric (Curcuma longa L. is a medicinal plant that is commonly used as spice and preservative. Many types of endophytic fungi have been reported as being associated with medicinal plants and able to synthesize secondary metabolites. In this study, endophytic fungi were isolated from all plant parts of turmeric plants. Identification of the endophytic fungi was done using morphological characteristics and sequencing of the internal transcribed spacer (ITS region of ribosomal DNA. The dual culture method was used for screening antibacterial activity of the endophytic fungi against Morganella morganii, a common histamine-producing bacteria. The disc diffusion method was used to test the ability of water fractions of selected endophytic fungi to inhibit M. morganii growth. Two-dimensional thin layer chromatography was used to determine the fungal extract inhibition activity on histamine formation. In total, 11 endophytic fungi were successfully isolated and identified as Arthrobotrys foliicola, Cochliobolus kusanoi, Daldinia eschscholzii, Fusarium oxysporum, Fusarium proliferatum, Fusarium solani, Fusarium verticillioides, Phanerochaete chrysosporium, and Phaeosphaeria ammophilae. Five isolates showed inhibition activity against M. morganii in the dual culture tests. Based on the disc diffusion assay, A. foliicola and F. verticillioides inhibited the growth of M. morganii as a histamine-producing bacteria, and inhibiting histamine formation in fish. The best effects in inhibiting growth of the histamine-producing bacteria and histamine formation inhibition in fish were produced with F. verticillioides water fraction at 0°C incubation.

Inhibitory Effect of Arctigenin from Fructus Arctii Extract on Melanin Synthesis via Repression of Tyrosinase Expression

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Park, Hwayong; Song, Kwang Hoon; Jung, Pil Mun; Kim, Ji-Eun; Ro, Hyunju; Kim, Mi Yoon; Ma, Jin Yeul

2013-01-01

To identify the active compound arctigenin in Fructus Arctii (dried seed of medicinal plant Arctium lappa) and to elucidate the inhibitory mechanism in melanogenesis, we analyzed melanin content and tyrosinase activity on B16BL6 murine melanoma and melan-A cell cultures. Water extracts of Fructus Arctii were shown to inhibit tyrosinase activity in vitro and melanin content in ? -melanocyte stimulating hormone-stimulated cells to similar levels as the well-known kojic acid and arbutin, respect...

Mycolytic enzymes produced by Streptomyces violaceusniger and their role in antagonism towards wood-rotting fungi.

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Nagpure, Anand; Choudhary, Bharti; Gupta, Rajinder K

2014-05-01

Extracellular mycolytic enzymes produced under submerged fermentation by the fungal antagonist Streptomyces violaceusniger MTCC 3959 were characterized. This streptomycete produced higher amounts of extracellular chitinase and protease during late exponential phase, whereas β-1,3-glucanase production was at peak in mid-stationary phase. Cell-free culture filtrate (CCF) exhibited a broad range of antifungal activity against both white rot and brown rot fungi. The inhibitory activity was completely lost after treatment with proteinase K and heat, indicating that extracellular antifungal metabolites are heat labile and proteinaceous in nature. Optimum pH and temperature for enzyme activity were: 9.0 and 60 °C for chitinase; 6.0 and 60 °C for β-1,3-glucanase; and 9.0 and 70 °C for protease. Mycolytic enzymes were moderately thermostable, and had a wide pH stability range extending from pH 5.0 to 10.0. The zymogram analysis of CCF revealed five chitinase isoenzymes with an apparent molecular weight of 20.8, 33.3, 45.6, 67.4, and 114.8 kDa, one β-1,3-glucanase appeared as a single band of ∼131.8 kDa and four protease isoenzymes with approximate molecular weights of 22.8, 62.52, 74.64, and 120.5 kDa. S. violaceusniger MTCC 3959 produced mycolytic enzymes that can be effectively used for suppression of phytopathogenic basidiomycetes. It has the potential to be an effective biofungicide. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Inhibitory Effects of Adlay Extract on Melanin Production and Cellular Oxygen Stress in B16F10 Melanoma Cells

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Huey-Chun Huang

2014-09-01

Full Text Available The aim of this study was to determine the effects of adlay extract on melanin production and the antioxidant characteristics of the extract. The seeds were extracted by the supercritical fluid CO2 extraction (SFE method. The effect of adlay extract on melanin production was evaluated using mushroom tyrosinase activity assay, intracellular tyrosinase activity, antioxidant properties and melanin content. Those assays were performed spectrophotometrically. In addition, the expression of melanogenesis-related proteins was determined by western blotting. The results revealed that the adlay extract suppressed intracellular tyrosinase activity and decreased the amount of melanin in B16F10 cells. The adlay extract decreased the expression of microphthalmia-associated transcription factor (MITF, tyrosinase, tyrosinase related protein-1 (TRP-1 and tyrosinase related protein-2 (TRP-2. The extract also exhibited antioxidant characteristics such as free radical scavenging capacity and reducing power. It effectively decreased intracellular reactive oxygen species (ROS levels in B16F10 cells. We concluded that the adlay extract inhibits melanin production by down-regulation of MITF, tyrosinase, TRP-1 and TRP-2. The antioxidant properties of the extract may also contribute to the inhibition of melanogenesis. The adlay extract can therefore be applied as an inhibitor of melanogenesis and could also act as a natural antioxidant in skin care products.

Melanin distribution in human epidermis affords localized protection against DNA photodamage and concurs with skin cancer incidence difference in extreme phototypes.

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Fajuyigbe, Damilola; Lwin, Su M; Diffey, Brian L; Baker, Richard; Tobin, Desmond J; Sarkany, Robert P E; Young, Antony R

2018-02-02

Epidermal DNA damage, especially to the basal layer, is an established cause of keratinocyte cancers (KCs). Large differences in KC incidence (20- to 60-fold) between white and black populations are largely attributable to epidermal melanin photoprotection in the latter. The cyclobutane pyrimidine dimer (CPD) is the most mutagenic DNA photolesion; however, most studies suggest that melanin photoprotection against CPD is modest and cannot explain the considerable skin color-based differences in KC incidence. Along with melanin quantity, solar-simulated radiation-induced CPD assessed immediately postexposure in the overall epidermis and within 3 epidermal zones was compared in black West Africans and fair Europeans. Melanin in black skin protected against CPD by 8.0-fold in the overall epidermis and by 59.0-, 16.5-, and 5.0-fold in the basal, middle, and upper epidermis, respectively. Protection was related to the distribution of melanin, which was most concentrated in the basal layer of black skin. These results may explain, at least in part, the considerable skin color differences in KC incidence. These data suggest that a DNA protection factor of at least 60 is necessary in sunscreens to reduce white skin KC incidence to a level that is comparable with that of black skin.-Fajuyigbe, D., Lwin, S. M., Diffey, B. L., Baker, R., Tobin, D. J., Sarkany, R. P. E., Young, A. R. Melanin distribution in human epidermis affords localized protection against DNA photodamage and concurs with skin cancer incidence difference in extreme phototypes.

Fungi and fungi-like Oomycetes isolated from affected leaves of rhododendron

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Maria Kowalik

2013-12-01

Full Text Available The aim of the work is to identify fungi and fungi-like Oomycetes occurring on affected leaves of rhododendron Rhododendron L. Mycological analyses were carried out on 200 leaves collected from green areas of Kraków from May till September 2005. Isolated fungi-like Oomycetes belonged to 67 taxa. The most frequently found fungi included: Alternaria alternata, Aspergillus niger, Botrytis cinerea, Coelophoma empetri, Nigrospora sphaerica, Pestalotia sydowiana, Phialophora cyclaminis, Phomopsis archeri, Septoria azalea and Sordaria fimicola. Among fungi-like organisms Phytophthora cinnamomi and P. citricola were isolated.

Genetic monitoring of irradiated Drosophila populations treated with antimutagen melanine

International Nuclear Information System (INIS)

Mosseh, I.B.; Savchenko, V.K.; Lyakh, I.P.

1986-01-01

A nonspecific increase was noted in the resistance of Drosophila populations to toxic and mutagenic effects of ionizing radiation and the chemical mutagen ethylmethansulphonate during long-term exposure. It was established that under the effect of melanine, less resistant genotypes retained, and the resistance of the populations to damaging factors did not increase

Compost biodegradation of recalcitrant hoof keratin by bacteria and fungi.

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Reuter, T; Gilroyed, B H; Xu, W; McAllister, T A; Stanford, K

2015-08-01

Compost activities efficiently break down a wide range of organic substances over time. In this study, bovine hoof was used as recalcitrant protein model to gain so far cryptic information on biodegradation during livestock mortalities composting. Bovine hooves (black and white), containing different amounts of melanin, placed into nylon bags were monitored during composting of cattle mortalities for up to 230 days. Besides physiochemical analysis, bacterial 16S and fungal 18S DNA fragments were amplified by PCR and profiles were separated by DGGE. Sequence analysis of separated fragments revealed various bacterial and fungal identities during composting. The microbial diversity was affected by a time-temperature interaction and by the hoof colour. Our molecular data, supported by electron microscopy, suggest hoof colonization by shifting bacteria and fungi communities. During composting, microbial communities work collaboratively in the degradation of recalcitrant organic matter such as keratin over time. A number of biomolecules including recalcitrant proteins may persist in environmental reservoirs, but breakdown can occur during composting. A combination of bioactivity and physiochemical conditions appear to be decisive for the fate of persistent biomolecules. © 2015 The Society for Applied Microbiology.

Interpretation of Ocular Melanin Drug Binding Assays. Alternatives to the Model of Multiple Classes of Independent Sites.

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Manzanares, José A; Rimpelä, Anna-Kaisa; Urtti, Arto

2016-04-04

Melanin has a high binding affinity for a wide range of drugs. The determination of the melanin binding capacity and its binding affinity are important, e.g., in the determination of the ocular drug distribution, the prediction of drug effects in the eye, and the trans-scleral drug delivery. The binding parameters estimated from a given data set vary significantly when using different isotherms or different nonlinear fitting methods. In this work, the commonly used bi-Langmuir isotherm, which assumes two classes of independent sites, is confronted with the Sips isotherm. Direct, log-log, and Scatchard plots are used, and the interpretation of the binding curves in the latter is critically analyzed. In addition to the goodness of fit, the emphasis is placed on the physical meaning of the binding parameters. The bi-Langmuir model imposes a bimodal distribution of binding energies for the sites on the melanin granules, but the actual distribution is most likely continuous and unimodal, as assumed by the Sips isotherm. Hence, the latter describes more accurately the distribution of binding energies and also the experimental results of melanin binding to drugs and metal ions. Simulations are used to show that the existence of two classes of sites cannot be confirmed on the sole basis of the shape of the binding curve in the Scatchard plot, and that serious doubts may appear on the meaning of the binding parameters of the bi-Langmuir model. Experimental results of melanin binding to chloroquine and metoprolol are used to illustrate the importance of the choice of the binding isotherm and of the method used to evaluate the binding parameters.

FungiDB: An Integrated Bioinformatic Resource for Fungi and Oomycetes

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Evelina Y. Basenko

2018-03-01

Full Text Available FungiDB (fungidb.org is a free online resource for data mining and functional genomics analysis for fungal and oomycete species. FungiDB is part of the Eukaryotic Pathogen Genomics Database Resource (EuPathDB, eupathdb.org platform that integrates genomic, transcriptomic, proteomic, and phenotypic datasets, and other types of data for pathogenic and nonpathogenic, free-living and parasitic organisms. FungiDB is one of the largest EuPathDB databases containing nearly 100 genomes obtained from GenBank, Aspergillus Genome Database (AspGD, The Broad Institute, Joint Genome Institute (JGI, Ensembl, and other sources. FungiDB offers a user-friendly web interface with embedded bioinformatics tools that support custom in silico experiments that leverage FungiDB-integrated data. In addition, a Galaxy-based workspace enables users to generate custom pipelines for large-scale data analysis (e.g., RNA-Seq, variant calling, etc.. This review provides an introduction to the FungiDB resources and focuses on available features, tools, and queries and how they can be used to mine data across a diverse range of integrated FungiDB datasets and records.

Uptake and transformation of arsenic during the vegetative life stage of terrestrial fungi

International Nuclear Information System (INIS)

Nearing, Michelle M.; Koch, Iris; Reimer, Kenneth J.

2015-01-01

Many species of terrestrial fungi produce fruiting bodies that contain high proportions of arsenobetaine (AB), an arsenic compound of no known toxicity. It is unknown whether fungi produce or accumulate AB from the surrounding environment. The present study targets the vegetative life stage (mycelium) of fungi, to examine the role of this stage in arsenic transformations and potential formation of AB. The mycelia of three different fungi species were cultured axenically and exposed to AB, arsenate (As(V)) and dimethylarsinoyl acetic acid for 60 days. Agaricus bisporus was additionally exposed to hypothesized precursors for AB and the exposure time to As(V) and dimethlyarsinic acid was also extended to 120 days. The mycelia of all fungi species accumulated all arsenic compounds with two species accumulating significantly more AB than other compounds. Few biotransformations were observed in these experiments indicating that it is unlikely that the mycelium of the fungus is responsible for biosynthesizing AB. - Highlights: • Mycelia of terrestrial fungi were exposed to arsenobetaine (AB) and potential precursors. • Mycelium may be selectively accumulating AB and transporting it to fruiting bodies. • Mycelium did not biosynthesize AB. - Mycelia of edible mushrooms preferentially accumulate arsenobetaine but do not biosynthesize this non-toxic arsenical

Clinical study on the removal of gingival melanin pigmentation: comparison between Nd:YAG laser ablation and mechanical abrasion; Estudo clinico comparativo entre as tecnicas de despigmentacao melanica gengival: laser neodimio (1064 nm) e gengivoabrasao

Energy Technology Data Exchange (ETDEWEB)

Lopes, Luis Mario de Melo

2002-07-01

Melanin pigmentation occurs as a result of excessive deposition of melanin, produced by the melanocytes present in the basal layer of the epithelium. This study compares clinical parameters such as inflammation and/or hemorrhage, healing process and re-pigmentation, caused by the Nd:YAG laser ablation and the mechanical abrasion of the melanin, by means of photographic images, taken during the first 30 days after the treatment. The patients comfort was monitored during the first ten days after the treatment using the method of the Visual Analog Scale to measure the pain. Six patients with gingival melanin pigmentation were selected. The left upper gingival quadrant was treated with the Nd:YAG laser using 125 mJ per pulse and 20 Hz, the right upper gingival quadrant received mechanical abrasion and the lower quadrants served for control. Both techniques did not result in inflammation and/or hemorrhage. The healing process was slower with the laser. Using mechanical abrasion, ali patients showed remaining pigmentation or re-pigmentation of varying intensity after a period of 30 days. With the laser 50 % of the patients did not show any re-pigmentation after this period. The pain analysis showed that the pain sensed 24 hours after the treatment with the laser is higher than using mechanical abrasion. (author)

Treatment of gingival pigmentation : A case series

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Prasad Deepak

2005-01-01

Full Text Available A smile expresses a feeling of joy, success, sensuality, affection and courtesy, and reveals self confidence and kindness. The harmony of the smile is determined not only by the shape, the position and the color of the teeth but also by the gingival tissues. Gingival health and appearance are essential components of an attractive smile. Gingival pigmentation results from melanin granules, which are produced by melanoblasts. The degree of pigmentation depends on melanoblastic activity. Although melanin pigmentation of the gingiva is completely benign and does not present a medical problem, complaints of ′black gums′ are common particularly in patients having a very high smile line (gummy smile. For depigmentation of gingiva different treatment modalities have been reported like- Bur abrasion, scraping, partial thickness flap, cryotherapy, electrosurgery and laser. In the present case series bur abrasion, scraping, partial thickness flap (epithelial excision cryotherapy and electrosurgery have been tried for depigmentation, which are simple, effective and yield good results, along with good patient satisfaction. The problems encountered with some of these techniques have also been discussed.

Increased Sporulation of Vesicular-Arbuscular Mycorrhizal Fungi by Manipulation of Nutrient Regimens †

OpenAIRE

Douds, David D.; Schenck, N. C.

1990-01-01

Adjustment of pot culture nutrient solutions increased root colonization and sporulation of vesicular-arbuscular mycorrhizal (VAM) fungi. Paspalum notatum Flugge and VAM fungi were grown in a sandy soil low in N and available P. Hoagland nutrient solution without P enhanced sporulation in soil and root colonization of Acaulospora longula, Scutellospora heterogama, Gigaspora margarita, and a wide range of other VAM fungi over levels produced by a tap water control or nutrient solutions contain...

EXTRACELLULAR CELLULOLYTIC COMPLEXES PRODUCTION BY MICROSCOPIC FUNGI

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S. O. Syrchin

2015-10-01

Full Text Available The aim of this work was to screen and to study the effect of inducers on the synthesis of the cellulolytic enzyme complexes by microscopic fungi. Cellulolytic and xylanolytic activities were determined by reducing sugar with DNS reagent, and β-glucosidase activity by pNPG hydrolysis. The enzyme preparations were obtained by ammonium sulphate precipitation. Among 32 studied strains of microscopic fungi 14 produced cellulo- and xylanolytic enzyme complexes. Fusarium sp. 5 and Fennellia sp. 2806 demonstrated the highest levels of all studied enzyme activities. Enzyme preparations with high endo-, exoglucanase, xylanase and β-glucosidase activities were obtained from these strains. Fusarium sp. 5 and Fennellia sp. 2806 were active producers of cellulase enzyme complexes during growth on natural substrates. It was shown that inductors of cellulolytic enzymes in Fusarium sp. 5 and Fennellia sp. 2806 differed from the ones in Trichoderma reesei.

Role of Fungi in the Biomineralization of Calcite

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Saskia Bindschedler

2016-05-01

Full Text Available In the field of microbial biomineralization, much of the scientific attention is focused on processes carried out by prokaryotes, in particular bacteria, even though fungi are also known to be involved in biogeochemical cycles in numerous ways. They are traditionally recognized as key players in organic matter recycling, as nutrient suppliers via mineral weathering, as well as large producers of organic acids such as oxalic acid for instance, an activity leading to the genesis of various metal complexes such as metal-oxalate. Their implications in the transformation of various mineral and metallic compounds has been widely acknowledged during the last decade, however, currently, their contribution to the genesis of a common biomineral, calcite, needs to be more thoroughly documented. Calcite is observed in many ecosystems and plays an essential role in the biogeochemical cycles of both carbon (C and calcium (Ca. It may be physicochemical or biogenic in origin and numerous organisms have been recognized to control or induce its biomineralization. While fungi have often been suspected of being involved in this process in terrestrial environments, only scarce information supports this hypothesis in natural settings. As a result, calcite biomineralization by microbes is still largely attributed to bacteria at present. However, in some terrestrial environments there are particular calcitic habits that have been described as being fungal in origin. In addition to this, several studies dealing with axenic cultures of fungi have demonstrated the ability of fungi to produce calcite. Examples of fungal biomineralization range from induced to organomineralization processes. More examples of calcite biomineralization related to direct fungal activity, or at least to their presence, have been described within the last decade. However, the peculiar mechanisms leading to calcite biomineralization by fungi remain incompletely understood and more research is

Melanin-concentrating hormone and its receptor are expressed and functional in human skin.

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Hoogduijn, Martin J; Ancans, Janis; Suzuki, Itaru; Estdale, Siân; Thody, Anthony J

2002-08-23

In this study, we have demonstrated the presence of melanin-concentrating hormone (MCH) and melanin-concentrating hormone receptor (MCHR1) transcripts in human skin. Sequence analysis confirmed that the transcripts of both genes were identical to those previously found in human brain. In culture, endothelial cells showed pro-MCH expression whereas no signal was found in keratinocytes, melanocytes, and fibroblasts. MCHR1 expression was restricted to melanocytes and melanoma cells. Stimulation of cultured human melanocytes with MCH reduced the alpha-MSH-induced increase in cAMP production. Furthermore, the melanogenic actions of alpha-MSH were inhibited by MCH. We propose that the MCH/MCHR1 signalling system is present in human skin and may have a role with the melanocortins in regulating the melanocyte.

Antioxidative role of ocular melanin pigment in the model of lens induced uveitis.

Science.gov (United States)

Bilgihan, A; Bilgihan, M K; Akata, R F; Aricioğlu, A; Hasanreisoğlu, B

1995-12-01

Ocular melanin pigment has antioxidant effect against excess of dispersed light. To investigate whether it has a similar effect in ocular inflammations, we used albino and pigmented guinea pigs and measured retinal glutathione peroxidase activities and lipid peroxide levels (expressed as thiobarbituric acid reactive substances) in a model of lens induced uveitis. Although the increase in the levels of the retinal lipid peroxides were higher in the albino group (204%, p < 0.05), the decrease in the activities of glutathione peroxidase were higher in pigmented guinea pigs (26%, p < 0.005). The results of the study suggest that pigmentless animals are more sensitive to the ocular inflammations, and ocular melanin pigment may act as an endojen antioxidant in lens induced uveitis.

Melanin photosensitization and the effect of visible light on epithelial cells.

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Orlando Chiarelli-Neto

Full Text Available Protecting human skin from sun exposure is a complex issue that involves unclear aspects of the interaction between light and tissue. A persistent misconception is that visible light is safe for the skin, although several lines of evidence suggest otherwise. Here, we show that visible light can damage melanocytes through melanin photosensitization and singlet oxygen (1O2 generation, thus decreasing cell viability, increasing membrane permeability, and causing both DNA photo-oxidation and necro-apoptotic cell death. UVA (355 nm and visible (532 nm light photosensitize 1O2 with similar yields, and pheomelanin is more efficient than eumelanin at generating 1O2 and resisting photobleaching. Although melanin can protect against the cellular damage induced by UVB, exposure to visible light leads to pre-mutagenic DNA lesions (i.e., Fpg- and Endo III-sensitive modifications; these DNA lesions may be mutagenic and may cause photoaging, as well as other health problems, such as skin cancer.

Comparison of the thermostability of cellulases from various thermophilic fungi

Energy Technology Data Exchange (ETDEWEB)

Wojtczak, G; Breuil, C; Yamada, J; Saddler, J N

1987-10-01

The cellulase activities of six thermophilic fungi were compared. Although the thermophilic fungi grew at relatively high temperatures (> 45/sup 0/C) the optimum temperatures for assaying the various cellulase activities were only slightly higher than the optimum temperatures for the mesophilic fungi, Trichoderma harzianum. Over prolonged incubation (> 24 h) the thermophilic strains demonstrated a higher hydrolytic potential as a result of the greater thermostability of the cellulase components. Although the extracellular cellulase activities had similar pH and temperature optima, in some cases the thermostability of the extracellular components were considerably lower.

Simultaneous in vivo imaging of melanin and lipofuscin in the retina with multimodal photoacoustic ophthalmoscopy

Science.gov (United States)

Zhang, Xiangyang; Zhang, Hao F.; Zhou, Lixiang; Jiao, Shuliang

2012-02-01

We combined photoacoustic ophthalmoscopy (PAOM) with autofluorescence imaging for simultaneous in vivo imaging of dual molecular contrasts in the retina using a single light source. The dual molecular contrasts come from melanin and lipofuscin in the retinal pigment epithelium (RPE). Melanin and lipofuscin are two types of pigments and are believed to play opposite roles (protective vs. exacerbate) in the RPE in the aging process. We successfully imaged the retina of pigmented and albino rats at different ages. The experimental results showed that multimodal PAOM system can be a potentially powerful tool in the study of age-related degenerative retinal diseases.

Fungi with multifunctional lifestyles: endophytic insect pathogenic fungi.

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Barelli, Larissa; Moonjely, Soumya; Behie, Scott W; Bidochka, Michael J

2016-04-01

This review examines the symbiotic, evolutionary, proteomic and genetic basis for a group of fungi that occupy a specialized niche as insect pathogens as well as endophytes. We focus primarily on species in the genera Metarhizium and Beauveria, traditionally recognized as insect pathogenic fungi but are also found as plant symbionts. Phylogenetic evidence suggests that these fungi are more closely related to grass endophytes and diverged from that lineage ca. 100 MYA. We explore how the dual life cycles of these fungi as insect pathogens and endophytes are coupled. We discuss the evolution of insect pathogenesis while maintaining an endophytic lifestyle and provide examples of genes that may be involved in the transition toward insect pathogenicity. That is, some genes for insect pathogenesis may have been co-opted from genes involved in endophytic colonization. Other genes may be multifunctional and serve in both lifestyle capacities. We suggest that their evolution as insect pathogens allowed them to effectively barter a specialized nitrogen source (i.e. insects) with host plants for photosynthate. These ubiquitous fungi may play an important role as plant growth promoters and have a potential reservoir of secondary metabolites.

Coloration principles of nymphaline butterflies - thin films, melanin, ommochromes and wing scale stacking.

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Stavenga, Doekele G; Leertouwer, Hein L; Wilts, Bodo D

2014-06-15

The coloration of the common butterflies Aglais urticae (small tortoiseshell), Aglais io (peacock) and Vanessa atalanta (red admiral), belonging to the butterfly subfamily Nymphalinae, is due to the species-specific patterning of differently coloured scales on their wings. We investigated the scales' structural and pigmentary properties by applying scanning electron microscopy, (micro)spectrophotometry and imaging scatterometry. The anatomy of the wing scales appears to be basically identical, with an approximately flat lower lamina connected by trabeculae to a highly structured upper lamina, which consists of an array of longitudinal, parallel ridges and transversal crossribs. Isolated scales observed at the abwing (upper) side are blue, yellow, orange, red, brown or black, depending on their pigmentation. The yellow, orange and red scales contain various amounts of 3-OH-kynurenine and ommochrome pigment, black scales contain a high density of melanin, and blue scales have a minor amount of melanin pigment. Observing the scales from their adwing (lower) side always revealed a structural colour, which is blue in the case of blue, red and black scales, but orange for orange scales. The structural colours are created by the lower lamina, which acts as an optical thin film. Its reflectance spectrum, crucially determined by the lamina thickness, appears to be well tuned to the scales' pigmentary spectrum. The colours observed locally on the wing are also due to the degree of scale stacking. Thin films, tuned pigments and combinations of stacked scales together determine the wing coloration of nymphaline butterflies. © 2014. Published by The Company of Biologists Ltd.

Maintaining heterokaryosis in pseudo-homothallic fungi.

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Grognet, Pierre; Silar, Philippe

2015-01-01

Among all the strategies displayed by fungi to reproduce and propagate, some species have adopted a peculiar behavior called pseudo-homothallism. Pseudo-homothallic fungi are true heterothallics, i.e., they need 2 genetically-compatible partners to mate, but they produce self-fertile mycelium in which the 2 different nuclei carrying the compatible mating types are present. This lifestyle not only enables the fungus to reproduce without finding a compatible partner, but also to cross with any mate it may encounter. However, to be fully functional, pseudo-homothallism requires maintaining heterokaryosis at every stage of the life cycle. We recently showed that neither the structure of the mating-type locus nor hybrid-enhancing effect due to the presence of the 2 mating types accounts for the maintenance of heterokaryosis in the pseudo-homothallic fungus P. anserina. In this addendum, we summarize the mechanisms creating heterokaryosis in P. anserina and 2 other well-known pseudo-homothallic fungi, Neurospora tetrasperma and Agaricus bisporus. We also discuss mechanisms potentially involved in maintaining heterokaryosis in these 3 species.

Methods to preserve potentially toxigenic fungi

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Lucas Costa Guimarães

2014-01-01

Full Text Available Microorganisms are a source of many high-value compounds which are useful to every living being, such as humans, plants and animals. Since the process of isolating and improving a microorganism can be lengthy and expensive, preserving the obtained characteristic is of paramount importance, so the process does not need to be repeated. Fungi are eukaryotic, achlorophyllous, heterotrophic organisms, usually filamentous, absorb their food, can be either macro or microscopic, propagate themselves by means of spores and store glycogen as a source of storage. Fungi, while infesting food, may produce toxic substances such as mycotoxins. The great genetic diversity of the Kingdom Fungi renders the preservation of fungal cultures for many years relevant. Several international reference mycological culture collections are maintained in many countries. The methodologies that are most fit for preserving microorganisms for extended periods are based on lowering the metabolism until it reaches a stage of artificial dormancy . The goal of this study was to analyze three methods for potentially toxigenic fungal conservation (Castellani's, continuous subculture and lyophilization and to identify the best among them.

Differences in the melanosome distribution within the epidermal melanin units and its association with the impairing background of leukoderma in vitiligo and halo nevi: a retrospective study.

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Xiong, Xi-Xi; Ding, Gao-Zhong; Zhao, Wen-E; Li, Xue; Ling, Yu-Ting; Sun, Li; Gong, Qing-Li; Lu, Yan

2017-07-01

Skin color is determined by the number of melanin granules produced by melanocytes that are transferred to keratinocytes. Melanin synthesis and the distribution of melanosomes to keratinocytes within the epidermal melanin unit (EMU) within the skin of vitiligo patients have been poorly studied. The ultrastructure and distribution of melanosomes in melanocytes and surrounding keratinocytes in perilesional vitiligo and normal skin were investigated using transmission electron microscopy (TEM). Furthermore, we performed a quantitative analysis of melanosome distribution within the EMUs with scatter plot. Melanosome count within keratinocytes increased significantly compared with melanocytes in perilesional stable vitiligo (P vitiligo. Furthermore, melanosome counts within melanocytes and their surrounding keratinocytes in perilesional active vitiligo skin decreased significantly compared with the other groups. In addition, taking the means-standard error of melanosome count within melanocytes and keratinocytes in healthy controls as a normal lower limit, EMUs were graded into 3 stages (I-III). Perilesional active vitiligo presented a significantly different constitution in stages compared to other groups (P vitiligo. Active vitiligo varies in stages and in stage II, EMUs are slightly impaired, but can be resuscitated, providing a golden opportunity with the potential to achieve desired repigmentation with an appropriate therapeutic choice. Adverse milieu may also contribute to the low melanosome count in keratinocytes.

Two-photon excited fluorescence spectroscopy and imaging of melanin in vitro and in vivo

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Krasieva, Tatiana B.; Liu, Feng; Sun, Chung-Ho; Kong, Yu; Balu, Mihaela; Meyskens, Frank L.; Tromberg, Bruce J.

2012-03-01

The ability to detect early melanoma non-invasively would improve clinical outcome and reduce mortality. Recent advances in two-photon excited fluorescence (TPEF) in vivo microscopy offer a powerful tool in early malignant melanoma diagnostics. The goal of this work was to develop a TPEF optical index for measuring relative concentrations of eumelanin and pheomelanin since ex vivo studies show that changes in this ratio have been associated with malignant transformation. We acquired TPEF emission spectra (λex=1000 nm) of melanin from several specimens, including human hair, malignant melanoma cell lines, and normal melanocytes and keratinocytes in different skin layers (epidermis, papillary dermis) in five healthy volunteers in vivo. We found that the pheomelanin emission peaks at around 620 nm and is blue-shifted from the eumelanin with broad maximum at 640-680nm. We defined "optical melanin index" (OMI) as a ratio of fluorescence signal intensities measured at 645 nm and 615nm. The measured OMI for a melanoma cell line MNT-1 was 1.6+/-0.2. The MNT-46 and MNT-62 lines (Mc1R gene knockdown) showed an anticipated change in melanins production ratio and had OMI of 0.55+/-0.05 and 0.17+/-0.02, respectively, which strongly correlated with HPLC data obtained for these lines. Average OMI measured for basal cells layers (melanocytes and keratinocytes) in normal human skin type I, II-III (not tanned and tanned) in vivo was 0.5, 1.05 and 1.16 respectively. We could not dependably detect the presence of pheomelanin in highly pigmented skin type V-VI. These data suggest that a non-invasive TPEF index could potentially be used for rapid melanin ratio characterization both in vitro and in vivo, including pigmented lesions.

Constitutive melanin density is associated with higher 25-hydroxyvitamin D and potentially total body BMD in older Caucasian adults via increased sun tolerance and exposure.

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Thompson, M J W; Jones, G; Aitken, D A

2018-06-01

Greater skin pigmentation reduces dose equivalent cutaneous vitamin D3 production, potentially impacting lifetime vitamin D status and fracture risk. We show that melanin density was positively associated with 25-hydroxyvitamin D and total body bone mineral density. These relationships were partially explained by greater sun exposure due to more permissive skin phenotype. Higher cutaneous melanin reduces vitamin D3 production. This may impact lifetime vitamin D status and increase fracture risk. This study aimed to describe the relationship between spectrophotometrically determined constitutive melanin density, osteoporotic risk factors and potential intermediaries in a cohort of exclusively older Caucasian adults. One thousand seventy-two community-dwelling adults aged 50-80 years had constitutive melanin density quantified using spectrophotometry. Sun exposure, skin phenotype, non-melanoma skin cancer (NMSC) prevalence and smoking status were assessed by questionnaire. Bone mineral density (BMD), falls risk, physical activity and 25-hydroxyvitamin D were measured using DXA, the short form Physiological Profile Assessment, pedometer and radioimmunoassay, respectively. Higher melanin density was independently associated with greater ability to tan (RR = 1.27, p density and sun exposure (RR = 1.05-1.11, p density (β = 1.71-2.05, p = 0.001). The association between melanin density and total body BMD (β = 0.007, p = 0.04) became non-significant after adjustment for 25-hydroxyvitamin D. There was no association between melanin density and physical activity, falls risk or BMD at other sites. Our data support a model of higher constitutive melanin density underpinning a less photosensitive skin phenotype, permitting greater sun exposure with fewer sequelae and yielding higher 25-hydroxyvitamin D and, potentially, total body BMD.

Chemical ecology of fungi.

Science.gov (United States)

Spiteller, Peter

2015-07-01

Fungi are widespread in nature and have conquered nearly every ecological niche. Fungi occur not only in terrestrial but also in freshwater and marine environments. Moreover, fungi are known as a rich source of secondary metabolites. Despite these facts, the ecological role of many of these metabolites is still unknown and the chemical ecology of fungi has not been investigated systematically so far. This review intends to present examples of the various chemical interactions of fungi with other fungi, plants, bacteria and animals and to give an overview of the current knowledge of fungal chemical ecology.

Pneumocystis carinii and specific fungi have a common epitope, identified by a monoclonal antibody

DEFF Research Database (Denmark)

Lundgren, B; Kovacs, J A; Nelson, N N

1992-01-01

Because Pneumocystis carinii may be related to fungi, we evaluated the reactivities of monoclonal antibodies raised against P. carinii with a variety of fungi. Fifty-two fungi and six protozoa were evaluated by immunofluorescence. One of three monoclonal antibodies (MAbs) tested (MAb 7D7) reacted...... with 15 fungi but no protozoa. Saccharomyces cerevisiae showed the strongest reactivity by immunofluorescence. The reactive antigen was characterized for four fungi by the immunoblot technique. In all cases the antigen that was reactive with MAb 7D7 was larger than the P. carinii antigens that reacted...

Analysis of cellulase and polyphenol oxidase production by southern pine beetle associated fungi

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Abduvali Valiev; Zumrut B. Ogel; Dier D. Klepzig

2009-01-01

In this study, the production of extracellular enzymes by fungi associated with southern pine beetle was investigated for the first time. Cellulase and polyphenol oxidase production were analyzed for three beetle associated fungi. Only the mutualistic symbiont Entomocorticium sp. A was found to produce cellulases and polyphenol oxidase....

Production of D-xylanases by thermophilic fungi using different methods of culture

Energy Technology Data Exchange (ETDEWEB)

Grajek, W

1986-01-01

Seven thermophilic strains of fungi were examined for their ability to produce D-xylanase in liquid and solid-state fermentations. It was confirmed that the best producers of xylanase, among microorganisms used, were H. lanuginosa and S. thermophile in liquid fermentation, and T. aurantiacus and H. lanuginosa in solid-state fermentations. The higher productivity of xylanase, namely 18,72 IU/ml, was obtained in liquid culture of H. lanuginosa. The pH and temperature optima of enzymes from liquid and solid-state cultures of fungi used were also presented.

Diversity and Biological Activities of Endophytic Fungi Associated with Micropropagated Medicinal Plant Echinacea purpurea (L.) Moench

Science.gov (United States)

2012-08-01

1105 Diversity and Biological Activities of Endophytic Fungi Associated with Micropropagated Medicinal Plant Echinacea purpurea (L.) Moench Luiz H...fungal community and micropropagated clones of E. purpurea was re-established after acclimatization to soil and the endophytic fungi produced compounds...Diversity and Biological Activities of Endophytic Fungi Associated with Micropropagated Medicinal Plant Echinacea purpurea (L.) Moench 5a. CONTRACT

Identification of mycotoxigenic fungi using an oligonucleotide microarray

CSIR Research Space (South Africa)

Barros, E

2013-01-01

Full Text Available Mycotoxins are secondary metabolites produced by fungi; they can play a role as food contaminants and have the ability to negatively influence human and animal health. To improve food safety and to protect consumers from harmful contaminants...

Techno-Economic Analysis of Integrating First and Second-Generation Ethanol Production Using Filamentous Fungi: An Industrial Case Study

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Karthik Rajendran

2016-05-01

Full Text Available The 2nd generation plants producing ethanol from lignocelluloses demand risky and high investment costs. This paper presents the energy- and economical evaluations for integrating lignocellulose in current 1st generation dry mill ethanol processes, using filamentous fungi. Dry mills use grains and have mills, liquefactions, saccharifications, fermentation, and distillation to produce ethanol, while their stillage passes centrifugation, and evaporation to recycle the water and dry the cake and evaporated syrup into animal feed. In this work, a bioreactor was considered to cultivate fungi on the stillage either before or after the centrifugation step together with pretreated lignocellulosic wheat bran. The results showed that the integrated 1st and 2nd generation ethanol process requires a capital investment of 77 million USD, which could yield NPV of 162 million USD after 20 years. Compared to the fungal cultivation on thin stillage modified 1st generation process, the integrated process resulted in 53 million USD higher NPV. The energy analysis showed that the thin stillage modified 1st generation process could reduce the overall energy consumption by 2.5% and increase the ethanol production by 4%. Such modifications in the 1st generation processes and integration concepts could be interesting for the ethanol industries, as integrating lignocelluloses to their existing setup requires less capital investment.

Waste biorefineries using filamentous ascomycetes fungi: Present status and future prospects.

Science.gov (United States)

Ferreira, Jorge A; Mahboubi, Amir; Lennartsson, Patrik R; Taherzadeh, Mohammad J

2016-09-01

Filamentous ascomycetes fungi have had important roles in natural cycles, and are already used industrially for e.g. supplying of citric, gluconic and itaconic acids as well as many enzymes. Faster human activities result in higher consumption of our resources and producing more wastes. Therefore, these fungi can be explored to use their capabilities to convert back wastes to resources. The present paper reviews the capabilities of these fungi in growing on various residuals, producing lignocellulose-degrading enzymes and production of organic acids, ethanol, pigments, etc. Particular attention has been on Aspergillus, Fusarium, Neurospora and Monascus genera. Since various species are used for production of human food, their biomass can be considered for feed applications and so biomass compositional characteristics as well as aspects related to culture in bioreactor are also provided. The review has been further complemented with future research avenues. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Melanin-gamma rays assistants for bismuth oxide nanoparticles synthesis at room temperature for enhancing antimicrobial, and photocatalytic activity.

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El-Batal, Ahmed I; El-Sayyad, Gharieb S; El-Ghamry, Abbas; Agaypi, Kerolos M; Elsayed, Mohamed A; Gobara, Mohamed

2017-08-01

Melanin pigment has been deemed as a natural photoprotector with strong hydrophobicity. It allured considerable compatibility with many applications in medicine, food, and nanotechnology. Penicillium chrysogenium has been devoted to the green synthesis of melanin whereby optimizing its culture and environmental conditions. The impacts of alternative economic L-tyrosine natural sources (unprecedented alternate origins) and gamma radiation were pledged for the potential growing of the pigment. Herein, notable increases in melanin yield (6.4mg/ml; much higher than nonoptimized one by 40 folds) was obtained by optimizing the culture, and environmental requirements [potato starch (3.0%), yeast extract (5.0%), copper sulfate (0.2mM), 0.25% L-tyrosine, 0.1% L-glycine, and 0.1% Tween 20 at pH5.0, and 30°C for 7.0days using 180.0rpm shaking speed]. The addition of banana's peel (2.0%) has been led to increase the melanin production up to (8.3mg/ml; much higher than optimized one by 1.29 folds). It stimulated the induced enzymes, (i.e., tyrosinase) because it contained significant amounts of L-tyrosine, dopamine, and L-DOPA as resources for melanin biosynthesis. Then irradiated P. chrysogenium (2.5kGy) induced the pigment yield to 10.3mg/ml; much higher than optimized one by (1.61 folds). On the other hand, we tailored a methodology involved the product of melanin and gamma rays (25.0kGy) to an eco-friendly synthesis of Bismuth oxide nanoparticles (BiONPs) at the room temperature. Melanin under such alkaline condition functioning as simultaneously hydrolyzes, photoprotection of the Bi seeds, and stabilizer against the uncontrolled growth and the free radicals attack. Whereas the gamma irradiation induced the room temperature condensation reaction to occur, a novel mechanism proposal was discussed. BiONPs were characterized by UV-Vis., DLS, XRD, SEM, EDX, and FTIR. DLS and XRD calculations with TEM analysis exhibited the mean diameter of BiONPs was 29.82nm. Moreover, the as

Blood Supply--Susceptible Formation of Melanin Pigment in Hair Bulb Melanocytes of Mice

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Shogo Maeda, MD

2015-03-01

Conclusions: Melanin pigment formation in the hair bulb melanocytes appeared to be susceptible to the blood supply, and melanocytosis was promoted in the follicles and in the epidermis of Kitl-Tg C57BL/6 mice.

Exploring the potential of fungi isolated from PAH-polluted soil as a source of xenobiotics-degrading fungi.

Science.gov (United States)

Godoy, Patricia; Reina, Rocío; Calderón, Andrea; Wittich, Regina-Michaela; García-Romera, Inmaculada; Aranda, Elisabet

2016-10-01

The aim of this study was to find polycyclic aromatic hydrocarbon (PAH)-degrading fungi adapted to polluted environments for further application in bioremediation processes. In this study, a total of 23 fungal species were isolated from a historically pyrogenic PAH-polluted soil in Spain and taxonomically identified. The dominant groups in these samples were the ones associated with fungi belonging to the Ascomycota phylum and two isolates belonging to the Mucoromycotina subphylum and Basiodiomycota phylum. We tested their ability to convert the three-ring PAH anthracene in a 42-day time course and analysed their ability to secrete extracellular oxidoreductase enzymes. Among the 23 fungal species screened, 12 were able to oxidize anthracene, leading to the formation of 9,10-anthraquinone as the main metabolite, a less toxic one than the parent compound. The complete removal of anthracene was achieved by three fungal species. In the case of Scopulariopsis brevicaulis, extracellular enzyme independent degradation of the initial 100 μM anthracene occurred, whilst in the case of the ligninolytic fungus Fomes (Basidiomycota), the same result was obtained with extracellular enzyme-dependent transformation. The yield of accumulated 9,10-anthraquinone was 80 and 91 %, respectively, and Fomes sp. could slowly deplete it from the growth medium when offered alone. These results are indicative for the effectiveness of these fungi for pollutant removal. Graphical abstract ᅟ.

An efficient method for DNA extraction from Cladosporioid fungi.

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Moslem, M A; Bahkali, A H; Abd-Elsalam, K A; Wit, P J G M

2010-11-23

We developed an efficient method for DNA extraction from Cladosporioid fungi, which are important fungal plant pathogens. The cell wall of Cladosporioid fungi is often melanized, which makes it difficult to extract DNA from their cells. In order to overcome this we grew these fungi for three days on agar plates and extracted DNA from mycelium mats after manual or electric homogenization. High-quality DNA was isolated, with an A(260)/A(280) ratio ranging between 1.6 and 2.0. Isolated genomic DNA was efficiently digested with restriction enzymes and produced distinct banding patterns on agarose gels for the different Cladosporium species. Clear DNA fragments from the isolated DNA were amplified by PCR using small and large subunit rDNA primers, demonstrating that this method provides DNA of sufficiently high quality for molecular analyses.

Role of Melanin in Melanocyte Dysregulation of Reactive Oxygen Species

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Noah C. Jenkins

2013-01-01

Full Text Available We have recently reported a potential alternative tumor suppressor function for p16 relating to its capacity to regulate oxidative stress and observed that oxidative dysregulation in p16-depleted cells was most profound in melanocytes, compared to keratinocytes or fibroblasts. Moreover, in the absence of p16 depletion or exogenous oxidative insult, melanocytes exhibited significantly higher basal levels of reactive oxygen species (ROS than these other epidermal cell types. Given the role of oxidative stress in melanoma development, we speculated that this increased susceptibility of melanocytes to oxidative stress (and greater reliance on p16 for suppression of ROS may explain why genetic compromise of p16 is more commonly associated with predisposition to melanoma rather than other cancers. Here we show that the presence of melanin accounts for this differential oxidative stress in normal and p16-depleted melanocytes. Thus the presence of melanin in the skin appears to be a double-edged sword: it protects melanocytes as well as neighboring keratinocytes in the skin through its capacity to absorb UV radiation, but its synthesis in melanocytes results in higher levels of intracellular ROS that may increase melanoma susceptibility.

The Use of Rock Phosphate and Phosphate Solubilising Fungi ...

African Journals Online (AJOL)

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produces citric and oxalic acids to solubilize calcium ... acid). Available phosphorus was determined using the method of Bray & Kurtz (1945). ..... Oxalate production by fungi: its role in pathogenicity and ecology in the soil environment.

The rhizobacterium Arthrobacter agilis produces dimethylhexadecylamine, a compound that inhibits growth of phytopathogenic fungi in vitro.

Science.gov (United States)

Velázquez-Becerra, Crisanto; Macías-Rodríguez, Lourdes I; López-Bucio, José; Flores-Cortez, Idolina; Santoyo, Gustavo; Hernández-Soberano, Christian; Valencia-Cantero, Eduardo

2013-12-01

Plant diseases caused by fungal pathogens such as Botrytis cinerea and the oomycete Phytophthora cinnamomi affect agricultural production worldwide. Control of these pests can be done by the use of fungicides such as captan, which may have deleterious effects on human health. This study demonstrates that the rhizobacterium Arthrobacter agilis UMCV2 produces volatile organic compounds that inhibit the growth of B. cinerea in vitro. A single compound from the volatile blends, namely dimethylhexadecylamine (DMHDA), could inhibit the growth of both B. cinerea and P. cinnamomi when supplied to the growth medium in low concentrations. DMHDA also inhibited the growth of beneficial fungi Trichoderma virens and Trichoderma atroviride but at much higher concentrations. DMHDA-related aminolipids containing 4, 8, 10, 12, and 14 carbons in the alkyl chain were tested for their inhibitory effect on the growth of the pathogens. The results show that the most active compound from those tested was dimethyldodecylamine. This effect correlates with a decrease in the number of membrane lipids present in the mycelium of the pathogen including eicosanoic acid, (Z)-9-hexadecenoic acid, methyl ester, and (Z)-9-octadecenoic acid, methyl ester. Strawberry leaflets treated with DMHDA were not injured by the compound. These data indicate that DMHDA and related compounds, which can be produced by microorganisms may effectively inhibit the proliferation of certain plant pathogens.

Control of grapevine wood fungi in commercial nurseries

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C. Rego

2009-05-01

Full Text Available Previous surveys conducted in commercial nurseries found that different wood fungi, namely Cylindrocarpon spp., Botryosphaeriaceae, Phomopsis viticola and Phaeomoniella chlamydospora infect grapevine cuttings. Two field trials were carried out to evaluate the effectiveness of cyprodinil + fludioxonil, pyraclostrobin + metiram, fludioxonil and cyprodinil to prevent or reduce natural infections caused by such fungi. Rootstock and scion cuttings were soaked in fungicidal suspensions for 50 min prior to grafting. After callusing, the grafted cuttings were planted in two commercial field nurseries with and without a previous history of grapevine cultivation. After nine months in the nursery, the plants were uprooted and analysed for the incidence and severity of the wood fungi. Plants uprooted from the field without a previous history of grapevine cultivation were generally less strongly infected by wood fungi. Under this condition, only the mixture cyprodinil + fludioxonil simultaneously reduced the incidence of Cylindrocarpon and Botryosphaeriaceae fungi, as well as the severity of Cylindrocarpon infections. Treatments did not produce significant differences in the incidence and severity of P. viticola, and Pa. chlamydospora. For plants grown in the field with a grapevine history, all fungicides except cyprodinil significantly reduced the incidence and severity of Cylindrocarpon fungi. Also, the incidence and severity of Botryosphaeriaceae pathogens were significantly decreased both by cyprodinil + fludioxonil and by cyprodinil. No significant differences were noticed for P. viticola incidence and severity, and Pa. chlamydospora was not detected again. These results suggest that the practice of soaking grapevine cuttings in selected fungicides prior to grafting significantly reduces Cylindrocarpon spp. and Botryosphaeriaceae infections, thus improving the quality of planting material.

Antimicrobial activity of filamentous fungi isolated from highly antibiotic-contaminated river sediment

Science.gov (United States)

Svahn, K. Stefan; Göransson, Ulf; El-Seedi, Hesham; Bohlin, Lars; Larsson, D.G. Joakim; Olsen, Björn; Chryssanthou, Erja

2012-01-01

Background Filamentous fungi are well known for their production of substances with antimicrobial activities, several of which have formed the basis for the development of new clinically important antimicrobial agents. Recently, environments polluted with extraordinarily high levels of antibiotics have been documented, leading to strong selection pressure on local sentinel bacterial communities. In such microbial ecosystems, where multidrug-resistant bacteria are likely to thrive, it is possible that certain fungal antibiotics have become less efficient, thus encouraging alternative strategies for fungi to compete with bacteria. Methods In this study, sediment of a highly antibiotic-contaminated Indian river was sampled in order to investigate the presence of cultivable filamentous fungi and their ability to produce substances with antimicrobial activity. Results Sixty one strains of filamentous fungi, predominantly various Aspergillus spp. were identified. The majority of the Aspergillus strains displayed antimicrobial activity against methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing Escherichia coli, vancomycin-resistant Enterococcus faecalis and Candida albicans. Bioassay-guided isolation of the secondary metabolites of A. fumigatus led to the identification of gliotoxin. Conclusion This study demonstrated proof of principle of using bioassay-guided isolation for finding bioactive molecules. PMID:22957125

Antimicrobial activity of filamentous fungi isolated from highly antibiotic-contaminated river sediment

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K. Stefan Svahn

2012-05-01

Full Text Available Background: Filamentous fungi are well known for their production of substances with antimicrobial activities, several of which have formed the basis for the development of new clinically important antimicrobial agents. Recently, environments polluted with extraordinarily high levels of antibiotics have been documented, leading to strong selection pressure on local sentinel bacterial communities. In such microbial ecosystems, where multidrug-resistant bacteria are likely to thrive, it is possible that certain fungal antibiotics have become less efficient, thus encouraging alternative strategies for fungi to compete with bacteria. Methods: In this study, sediment of a highly antibiotic-contaminated Indian river was sampled in order to investigate the presence of cultivable filamentous fungi and their ability to produce substances with antimicrobial activity. Results: Sixty one strains of filamentous fungi, predominantly various Aspergillus spp. were identified. The majority of the Aspergillus strains displayed antimicrobial activity against methicillin-resistant Staphylococcus aureus, extended-spectrum beta-lactamase-producing Escherichia coli, vancomycin-resistant Enterococcus faecalis and Candida albicans. Bioassay-guided isolation of the secondary metabolites of A. fumigatus led to the identification of gliotoxin. Conclusion: This study demonstrated proof of principle of using bioassay-guided isolation for finding bioactive molecules.

Solid-state NMR Reveals the Carbon-based Molecular Architecture of Cryptococcus neoformans Fungal Eumelanins in the Cell Wall*

Science.gov (United States)

Chatterjee, Subhasish; Prados-Rosales, Rafael; Itin, Boris; Casadevall, Arturo; Stark, Ruth E.

2015-01-01

Melanin pigments protect against both ionizing radiation and free radicals and have potential soil remediation capabilities. Eumelanins produced by pathogenic Cryptococcus neoformans fungi are virulence factors that render the fungal cells resistant to host defenses and certain antifungal drugs. Because of their insoluble and amorphous characteristics, neither the pigment bonding framework nor the cellular interactions underlying melanization of C. neoformans have yielded to comprehensive molecular-scale investigation. This study used the C. neoformans requirement of exogenous obligatory catecholamine precursors for melanization to produce isotopically enriched pigment “ghosts” and applied 2D 13C-13C correlation solid-state NMR to reveal the carbon-based architecture of intact natural eumelanin assemblies in fungal cells. We demonstrated that the aliphatic moieties of solid C. neoformans melanin ghosts include cell-wall components derived from polysaccharides and/or chitin that are associated proximally with lipid membrane constituents. Prior to development of the mature aromatic fungal pigment, these aliphatic moieties form a chemically resistant framework that could serve as the scaffold for melanin synthesis. The indole-based core aromatic moieties show interconnections that are consistent with proposed melanin structures consisting of stacked planar assemblies, which are associated spatially with the aliphatic scaffold. The pyrrole aromatic carbons of the pigments bind covalently to the aliphatic framework via glycoside or glyceride functional groups. These findings establish that the structure of the pigment assembly changes with time and provide the first biophysical information on the mechanism by which melanin is assembled in the fungal cell wall, offering vital insights that can advance the design of bioinspired conductive nanomaterials and novel therapeutics. PMID:25825492

Solid-state NMR Reveals the Carbon-based Molecular Architecture of Cryptococcus neoformans Fungal Eumelanins in the Cell Wall.

Science.gov (United States)

Chatterjee, Subhasish; Prados-Rosales, Rafael; Itin, Boris; Casadevall, Arturo; Stark, Ruth E

2015-05-29

Melanin pigments protect against both ionizing radiation and free radicals and have potential soil remediation capabilities. Eumelanins produced by pathogenic Cryptococcus neoformans fungi are virulence factors that render the fungal cells resistant to host defenses and certain antifungal drugs. Because of their insoluble and amorphous characteristics, neither the pigment bonding framework nor the cellular interactions underlying melanization of C. neoformans have yielded to comprehensive molecular-scale investigation. This study used the C. neoformans requirement of exogenous obligatory catecholamine precursors for melanization to produce isotopically enriched pigment "ghosts" and applied 2D (13)C-(13)C correlation solid-state NMR to reveal the carbon-based architecture of intact natural eumelanin assemblies in fungal cells. We demonstrated that the aliphatic moieties of solid C. neoformans melanin ghosts include cell-wall components derived from polysaccharides and/or chitin that are associated proximally with lipid membrane constituents. Prior to development of the mature aromatic fungal pigment, these aliphatic moieties form a chemically resistant framework that could serve as the scaffold for melanin synthesis. The indole-based core aromatic moieties show interconnections that are consistent with proposed melanin structures consisting of stacked planar assemblies, which are associated spatially with the aliphatic scaffold. The pyrrole aromatic carbons of the pigments bind covalently to the aliphatic framework via glycoside or glyceride functional groups. These findings establish that the structure of the pigment assembly changes with time and provide the first biophysical information on the mechanism by which melanin is assembled in the fungal cell wall, offering vital insights that can advance the design of bioinspired conductive nanomaterials and novel therapeutics. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Antibacterial Activity of Melanin from Cuttlefish and Squid Ink

OpenAIRE

Yuspihana Fitrial; Iin Khusnul Khotimah

2017-01-01

Marine environment comprises of many organism which are known to posses bioactive compound as a common means of self-defense or for the protection of eggs and embryos. Class Cephalopods (such as squidand cuttlefish) are notable for their defences, such as jetting escape movements, changes in colouration, toxic venom and inking.This study aims to compare the antibacterial activity of melanin from cuttlefish ink (Sepia sp.) with squid ink (Loligo sp.) against E. coli. Extraction and purificatio...

Chitosan produced from Mucorales fungi using agroindustrial by-products and its efficacy to inhibit Colletotrichum species.

Science.gov (United States)

Ramos Berger, Lúcia Raquel; Montenegro Stamford, Thayza Christina; de Oliveira, Kataryne Árabe Rimá; de Miranda Pereira Pessoa, Adjane; de Lima, Marcos Antonio Barbosa; Estevez Pintado, Maria Manuela; Saraiva Câmara, Marcos Paz; de Oliveira Franco, Luciana; Magnani, Marciane; de Souza, Evandro Leite

2018-03-01

This study evaluated corn steep liquor (CSL) and papaya peel juice (PPJ) in mixture as substrates for the cultivation (96h, 28°C, pH 5.6, 150rpm) of Mucorales fungi for chitosan production, and determined the growth-inhibitory effect of the fungal chitosan (FuCS) obtained under optimized conditions against phytopathogenic Colletotrichum species. All Mucorales fungi tested were capable of growing in CSL-PPJ medium, showing FuCS production in the range of 5.02 (Fennelomyces heterothalicus SIS 28) - 15.63mg/g (Cunninghamella elegans SIS 41). Highest FuCS production (37.25mg/g) was achieved when C. elegans was cultivated in medium containing 9.43% CSL and 42.5% PPJ. FuCS obtained under these conditions showed a deacetylation degree of 86%, viscosity of 120cP and molecular weight of 4.08×10 4 g/mol. FuCS at 5000, 7500 and 10,000ppm inhibited the growth of all Colletotrichum species tested. FuCS also induced alterations in the morphology of C. fructicola hyphae. CSL-PPJ mixtures are suitable substrates for the cultivation of Mucorales fungi for FuCS production. Chitosan from C. elegans cultivated in CSL-PPJ medium is effective in inhibiting phytopathogenic Colletotrichum species. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of Melanogenesis in A-375 Cells in the Presence of DMSO and Analysis of Pyrolytic Profile of Isolated Melanin

Science.gov (United States)

Chodurek, Ewa; Orchel, Arkadiusz; Orchel, Joanna; Kurkiewicz, Sławomir; Gawlik, Natalia; Dzierżewicz, Zofia; Stępień, Krystyna

2012-01-01

The increase of a skin malignant melanoma (melanoma malignum) incidence in the world has been observed in recent years. The tumour, especially in advanced stadium with metastases, is highly resistant to conventional treatment. One of the strategies is to modulate melanogenesis using chemical compounds. In this study, the processes of differentiation and melanogenesis induced by dimethylsulfoxide (DMSO) in human melanoma cells (A-375) were investigated. Natural melanin isolated from A-375 melanoma cell line treated with 0.3% DMSO was analyzed by pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) method. The products derived from pheomelanin have not been stated in the pyrolytic profile of analyzed melanin. Within all products derived from eumelanins, 1,2-benzenediol has been predominated. It has been shown that in the melanoma cells stimulated with 0.3% and 1% DMSO, the increase of transcriptional activity of the tyrosinase gene took place. It was accompanied by the rise of tyrosinase activity and an accumulation of melanin in the cells. The better knowledge about the structure of melanins can contribute to establish the uniform criteria of malignant melanoma morbidity risk. PMID:22654640

Massive gene swamping among cheese-making Penicillium fungi

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Jeanne Ropars

2015-03-01

Full Text Available Horizontal gene transfers (HGT, i.e., the transmission of genetic material between species not directly attributable to meiotic gene exchange, have long been acknowledged as a major driver of prokaryotic evolution and is increasingly recognized as an important source of adaptation in eukaryotes. In fungi in particular, many convincing examples of HGT have been reported to confer selective advantages on the recipient fungal host, either promoting fungal pathogenicity on plants or increasing their toxicity by the acquisition of secondary metabolic clusters, resulting in adaptation to new niches and in some cases eventually even in speciation. These horizontal gene transfers involve single genes, complete metabolic pathways or even entire chromosomes. A recent study has uncovered multiple recent horizontal transfers of a 575 kb genomic island in cheese Penicillium fungi, representing ca. 2% of the Penicillium roqueforti’s genome, that may confer selective advantage in the competing cheese environment where bacteria and fungi occur. Novel phylogenomic methods are being developed, revealing massive HGT among fungi. Altogether, these recent studies indicate that HGT is a crucial mechanism of rapid adaptation, even among eukaryotes.

Diversion of the melanin synthetic pathway by dopamine product scavengers: A quantum chemical modeling of the reaction mechanisms

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T. B. Demissie

2017-01-01

Full Text Available We report the stability and reactivity of the oxidation products as well as L-cysteine and N-acetylcysteine adducts of dopamine studied using quantum chemical calculations. The overall reactions studied were subdivided into four reaction channels. The first reaction channel is the oxidation of dopamine to form dopaminoquinone. The second reaction channel leads to melanin formation through subsequent reactions. The third and fourth reaction channels are reactions leading to the formation of dopaminoquinone adducts which are aimed to divert the synthesis of melanin. The results indicate that L-cysteine and N-acetylcysteine undergo chemical reactions mainly at C5 position of dopaminoquinone. The analyses of the thermodynamic energies indicate that L-cysteine and N-acetylcysteine covalently bind to dopaminoquinone by competing with the internal cyclization reaction of dopaminoquinone which leads to the synthesis of melanin. The analysis of the results, based on the reaction free energies, is also supported by the investigation of the natural bond orbitals of the reactants and products.

Autoradiography of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP): Uptake in the monoaminergic pathways and in melanin containing tissues

Energy Technology Data Exchange (ETDEWEB)

Lyden, A; Lindquist, N G; Bondesson, U; Larsson, B S; Olsson, L -I

1985-01-01

A recently discovered neurotoxic compound, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, has been found to cause a parkinsonian-like syndrome in man and monkey, but not in laboratory animals such as rat, mouse and guinea pig. MPTP seems to selectively destroy the melanin containing dopaminergic cells in pars compacta of substantia nigra. Lower mammalian species do not have melanin in these cells, which indicates that the presence of neuromelanin may be of importance for the development of MPTP-induced lesions. By means of whole-body autoradiography of TH-MPTP in mice, accumulation and retention was observed in the dopaminergic pathways, in locus ceruleus and in structures in the medulla oblongata and spinal cord. A high uptake was also seen in melanin-containing tissues such as in the eyes of pigmented mice. MPTP has earlier been found to have high affinity in vitro for dopamine melanin, which is similar to the pigment in substantia nigra. The typical features of the MPTP-induced neurotoxicity with destruction of pigmented nerve cells and development of parkinsonism may be due to accumulation adn retention of MPTP and its metabolites in these cells. In species with pigmented nerve cells, such as man and monkey, the accumulation may be much more pronounced because of the melanin affinity of MPTP and its metabolites. (author).

Bleaching of melanin in the epidermis of South American fur seal and its application on enzyme immunohistochemistry

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A.P. Silva

2011-03-01

Full Text Available The South American fur seal (Arctocephalus australis is an amphibious marine mammal distributed along the Atlantic and Pacific coasts of South America. The species is well adjusted to different habitats due to the morphology of its fin-like members and due to some adaptations in their integumentary system. Immunohistochemical studies are very important to evaluate the mechanisms of skin adaptation due the differential expression of the antigens present in the tissue depending of the region of the body surface. However, its strongly pigmented (melanin epidermis prevents the visualization of the immuno-histochemical chromogens markers. In this study a melanin bleaching method was developed aimed to allow the visualization of the chromogens without interfering in the antigen-antibody affinity for immunohistochemistry. The analysis of PCNA (proliferating cell nuclear antigen index in the epidermis of A. australis by immunohistochemistry with diaminobenzidine (DAB as chromogen was used to test the method. The bleaching of the melanin allowed to obtain the cell proliferation index in epidermis and to avoid false positive results without affecting the immunohistochemical results.

A reappraisal of fungi producing aflatoxins

DEFF Research Database (Denmark)

Varga, János; Frisvad, Jens Christian; Samson, Robert A.

2009-01-01

Aflatoxins are decaketide-derived secondary metabolites which are produced by a complex biosynthetic pathway. Aflatoxins are among the economically most important mycotoxins. Aflatoxin B1 exhibits hepatocarcinogenic and hepatotoxic properties, and is frequently referred to as the most potent natu...

Physiological Studies on Phytate-Degrading Enzymes Produced by Some Fungi with Special Reference to the Effect of Gamma Radiation

International Nuclear Information System (INIS)

Shalaby, Kh.E.M.

2013-01-01

Fungi isolated from soil and compost samples collected from different localities in Sharkia and Dakahlia governorates were screened for phytase production. Fifty isolates showed varying phytase activities depending on strain type. Three isolates identified as Aspergillus niger, Aspergillus oryzae and Trichoderma viride proved to be the most potent regarding phytase production. Factors affecting phytase production aiming to optimize submerged fermentation conditions to achieve maximum phytase production by the three selected fungi were studied. Maximum phytase production was reached after 6 days incubation of fermentation medium having initial ph 6.0 inoculated with 1 ml inocula of spore suspensions (104/ml) of selected fungi and incubated at 30 degree C. Sucrose proved to be the best carbon source enhancing phytase production by the three selected fungi. Sucrose concentration 1.5% (w/v) recorded highest phytase activities (11.72, 11.21 and 11.12 u/ml) in case of A. niger, A. oryzae and T. viride, respectively. Regarding nitrogen source, yeast extract yielded maximum phytase production by A. niger and A.oryzae and NH_4NO_3 was the best for T.viride. Upon studying the effect of different phosphate sources and concentrations, maximum phytase production by A.niger and A.oryzae was observed in fermentation medium supplemented by NH_4H_2PO_4 while Na_2HPO_4 was the best for T.viride. Subjecting the three tested fungi to increase doses of gamma irradiation revealed activation of phytase production by all tested fungi at 0.5 kGy followed by slight decrease at 0.75 and 1.0 kGy but still above the control. Meanwhile dose levels 3 and 3.5 kGy completely inhibited phytase production by A. niger and (A. oryzae and T. virde), respectively. The recorded D10 values for A. niger, A. oryzae and T. viride were 0.639, 0.886 and 0.947 confirming higher radioresistance of T. viride. Phytase production during solid state fermentation (SSF) of mean feed stuffs (corn meal cotton seed meal

A without-prejudice list of generic names of fungi for protection under the International Code of Nomenclature for algae, fungi, and plants.

Science.gov (United States)

Kirk, Paul M; Stalpers, Joost A; Braun, Uwe; Crous, Pedro W; Hansen, Karen; Hawksworth, David L; Hyde, Kevin D; Lücking, Robert; Lumbsch, Thorsten H; Rossman, Amy Y; Seifert, Keith A; Stadler, Mark

2013-12-01

As a first step towards the production of a List of Protected Generic Names for Fungi, a without-prejudice list is presented here as a basis for future discussion and the production of a List for formal adoption. We include 6995 generic names out of the 17072 validly published names proposed for fungi and invite comments from all interested mycologists by 31 March 2014. The selection of names for inclusion takes note of recent major publications on different groups of fungi, and further the decisions reached so far by international working groups concerned with particular families or genera. Changes will be sought in the Code to provide for this and lists at other ranks to be protected against any competing unlisted names, and to permit the inclusion of names of lichen-forming fungi. A revised draft will be made available for further discussion at the 10(th) International Mycological Congress in Bangkok in August 2014. A schedule is suggested for the steps needed to produce a list for adoption by the International Botanical Congress in August 2017. This initiative provides mycologists with an opportunity to place nomenclature at the generic level on a more secure and stable base.

AP-1/KIF13A Blocking Peptides Impair Melanosome Maturation and Melanin Synthesis

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Cécile Campagne

2018-02-01

Full Text Available Melanocytes are specialized cells that generate unique organelles called melanosomes in which melanin is synthesized and stored. Melanosome biogenesis and melanocyte pigmentation require the transport and delivery of melanin synthesizing enzymes, such as tyrosinase and related proteins (e.g., TYRP1, from endosomes to maturing melanosomes. Among the proteins controlling endosome-melanosome transport, AP-1 together with KIF13A coordinates the endosomal sorting and trafficking of TYRP1 to melanosomes. We identify here β1-adaptin AP-1 subunit-derived peptides of 5 amino acids that block the interaction of KIF13A with AP-1 in cells. Incubating these peptides with human MNT-1 cells or 3D-reconstructed pigmented epidermis decreases pigmentation by impacting the maturation of melanosomes in fully pigmented organelles. This study highlights that peptides targeting the intracellular trafficking of melanocytes are candidate molecules to tune pigmentation in health and disease.

Diagnosis of filamentous fungi on tissue sections by immunohistochemistry using anti-aspergillus antibody.

Science.gov (United States)

Challa, Sundaram; Uppin, Shantveer G; Uppin, Megha S; Pamidimukkala, Umabala; Vemu, Lakshmi

2015-06-01

Identification based on histology alone has limitations as Aspergillus species share morphology with other filamentous fungi. Differentiation of Aspergillus species from hyalohyphomycetes and dematiaceous fungi is important as the antifungal susceptibility varies among different species and genera. Given these problems, ancillary techniques are needed to increase specificity. Our aim was to study the utility of immunohistochemistry (IHC) with anti-Aspergillus antibody in the identification of Aspergillus species and to differentiate them from other filamentous fungi. Fifty formalin fixed, paraffin embedded tissue sections including 47 from cases of culture proven filamentous fungi, 3 from colonies of cultures of hyalohyphomycetes, and 11 smears from cultures were subjected to IHC studies using polyclonal rabbit anti-Aspergillus antibody (Abcam, UK) after antigen retrieval. The IHC on tissue sections was positive in 88% cases involving culture proven Aspergillus species. There was no cross reactivity with Mucorales species, Candida species, dematiaceous fungi and hyalohyphomycetes. Hence immunohistochemistry can be used as an ancillary technique for the diagnosis of Aspergillus species. © The Author 2015. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Simultaneous in vivo imaging of melanin and lipofuscin in the retina with photoacoustic ophthalmoscopy and autofluorescence imaging

Science.gov (United States)

Zhang, Xiangyang; Zhang, Hao F.; Puliafito, Carmen A.; Jiao, Shuliang

2011-08-01

We combined photoacoustic ophthalmoscopy (PAOM) with autofluorescence imaging for simultaneous in vivo imaging of dual molecular contrasts in the retina using a single light source. The dual molecular contrasts come from melanin and lipofuscin in the retinal pigment epithelium (RPE). Melanin and lipofuscin are two types of pigments and are believed to play opposite roles (protective versus exacerbate) in the RPE in the aging process. We have successfully imaged the retina of pigmented and albino rats at different ages. The experimental results showed that multimodal PAOM system can be a potentially powerful tool in the study of age-related degenerative retinal diseases.

Phosphorous availability influences the dissolution of apatite by soil fungi

Science.gov (United States)

Rosling, A.; Suttle, K. B.; Johansson, E.; van Hees, P. W.; Banfield, J. F.

2007-12-01

We conducted mineral dissolution experiments using fungi isolated from a grassland soil in northern California to determine the response of fungi to different levels of phosphorus availability and to identify pathways of apatite dissolution by fungal exudates. Fluorapatite dissolution experiments were performed either with fungi present or under abiotic conditions using cell-free liquid media conditioned by fungal growth at different phosphorus and calcium availabilities. Among biogeochemically active soil fungal isolates apatite dissolution was either active in response to phosphorus limiting growth conditions or passive as a result of mycelial growth. Zygomycete isolates in the order of Mucorales acidify their growth media substrate in the presence of phosphorus, mainly through production of oxalic acid. Cell-free exudates induced fluorapatite dissolution at a rate of 10 -0.9 ± 0.14 and 10 -1.2 ± 0.22 mmol P/m2/s. The Ascomycete isolate, in the family Trichocomaceae, induced fluorapatite dissolution at a rate of 10 - 1.1 ± 0.05 mmol P/m2/s by lowering the pH of the media under phosphorus-limited conditions, without producing significant amounts of low molecular weight organic acids (LMWOAs). Oxalate strongly etches fluorapatite along channels parallel to [001], forming needle like features, while exudates from Trichocomaceae induced surface rounding. We conclude that while LMWOAs are well-studied weathering agents these does not appear to be produced by fungi in response to phosphorus limiting growth conditions.

An assessment of natural product discovery from marine (sensu strictu) and marine-derived fungi

Science.gov (United States)

Overy, David P.; Bayman, Paul; Kerr, Russell G.; Bills, Gerald F.

2014-01-01

The natural products community has been investigating secondary metabolites from marine fungi for several decades, but when one attempts to search for validated reports of new natural products from marine fungi, one encounters a literature saturated with reports from ‘marine-derived’ fungi. Of the 1000+ metabolites that have been characterized to date, only approximately 80 of these have been isolated from species from exclusively marine lineages. These metabolites are summarized here along with the lifestyle and habitats of their producing organisms. Furthermore, we address some of the reasons for the apparent disconnect between the stated objectives of discovering new chemistry from marine organisms and the apparent neglect of the truly exceptional obligate marine fungi. We also offer suggestions on how to reinvigorate enthusiasm for marine natural products discovery from fungi from exclusive marine lineages and highlight the need for critically assessing the role of apparently terrestrial fungi in the marine environment. PMID:25379338

Towards the development of a novel bioinspired functional material: synthesis and characterization of hybrid TiO2/DHICA-melanin nanoparticles.

Science.gov (United States)

Pezzella, Alessandro; Capelli, Luigia; Costantini, Aniello; Luciani, Giuseppina; Tescione, Fabiana; Silvestri, Brigida; Vitiello, Giuseppe; Branda, Francesco

2013-01-01

A large number of recent literature data focus on modification/modulation of surface chemistry of inorganic materials in order to improve their functional properties. Melanins, a wide class of natural pigments, are recently emerging as a powerful organic component for developing bioinspired active material for a large number of applications from organoelectronics to bioactive compounds. Here we report the use of the approach referred as "chimie douce", involving in situ formation of the hybrids through reactions of precursors under mild conditions, to prepare novel hybrid functional architectures based on eumelanin like 5,6 dihydroxyindole-2-carboxylic acid (DHICA) polymer and TiO2. Two synthesis procedures were carried out to get DHICA-melanin coated TiO2 nanoparticles as well as mixed DHICA/TiO2 hybrid nanostructures. Such systems were characterized through EPR, FT-IR and fluorescence spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and TEM microscopy in order to assess the effect of synthesis path as well as of DHICA content on structural, morphological and optical properties of TiO2 nanostructures. In particular, EPR, FT-IR spectra and TGA analysis confirmed the presence of DHICA-melanin in these samples. TEM measurements indicated the formation of the nanoparticles having relatively narrow size distribution with average particle size of about 10nm. DHICA-melanin does act as a morphological agent affecting morphology of hybrid nanostructures. XRD analysis proved that TiO2 hybrid nanoparticles kept anatase structures for DHICA-melanin contents within the range of investigated compositions, i.e. up to 50% wt/wt. Copyright © 2012 Elsevier B.V. All rights reserved.

Predominant mycotoxins, mycotoxigenic fungi and climate change related to wine.

Science.gov (United States)

Paterson, R Russell M; Venâncio, Armando; Lima, Nelson; Guilloux-Bénatier, Michèle; Rousseaux, Sandrine

2018-01-01

Wine is a significant contributor to the economies of many countries. However, the commodity can become contaminated with mycotoxins produced by certain fungi. Most information on mycotoxins in wine is from Spain, Italy and France. Grapes can be infected by mycotoxigenic fungi, of which Aspergillus carbonarius producing ochratoxin A (OTA) is of highest concern. Climate is the most important factor in determining contamination once the fungi are established, with high temperatures being a major factor for OTA contamination: OTA in wine is at higher concentrations in warmer southern Europe than northern. Contamination by fumonisins is a particular concern, related to Aspergillus niger producing these compounds and the fungus being isolated frequently from grapes. Aflatoxins can be present in wine, but patulin is seldom detected. Alternaria mycotoxins (e.g. alternariol) have been frequently observed. There are indications that T-2 toxin may be common. Also, the combined effects of mycotoxins in wine require consideration. No other mycotoxins are currently of concern. Accurate fungal identifications and mycotoxin detection from the fungi are important and a consideration of practical methods are required. There is a diversity of wines that can be contaminated (e.g. red, white, sweet, dry and fortified). The occurrence of OTA is higher in red and sweet than white wines. Steps to control mycotoxins in wine involve good agriculture practices. The effect of climate change on vines and mycotoxins in wine needs urgent consideration by well-constructed modelling studies and expert interpretation of existing data. Reliable models of the effect of climate change on vines is a priority: the health of vines affects mycotoxin contamination. A modelling study of OTA in grapes at higher temperatures over 100years is required. Progress has been made in reducing OTA in wine. The other mycotoxins require consideration and the effects of climate change will become crucial. Copyright �

Dung-inhabiting fungi: a potential reservoir of novel secondary metabolites for the control of plant pathogens.

Science.gov (United States)

Sarrocco, Sabrina

2016-04-01

Coprophilous fungi are a large group of saprotrophic fungi mostly found in herbivore dung. The number of these fungi undergoing investigation is continually increasing, and new species and genera continue to be described. Dung-inhabiting fungi play an important ecological role in decomposing and recycling nutrients from animal dung. They produce a large array of bioactive secondary metabolites and have a potent enzymatic arsenal able to utilise even complex molecules. Bioactive secondary metabolites are actively involved in interaction with and defence against other organisms whose growth can be inhibited, resulting in an enhanced ecological fitness of producer strains. Currently, these antibiotics and bioactive secondary metabolites are of interest in medicine in particular, while very little information is available concerning their potential use in agriculture. This review introduces the ecology of dung-inhabiting fungi, with particular emphasis on the production of antibiotic compounds as a means to compete with other microorganisms. Owing to the fast pace of technological progress, new approaches to predicting the biosynthesis of bioactive metabolites are proposed. Coprophilous fungi should be considered as elite candidate organisms for the discovery of novel antifungal compounds, above all in view of their exploitation for crop protection. © 2015 Society of Chemical Industry.

Nematode-Trapping Fungi.

Science.gov (United States)

Jiang, Xiangzhi; Xiang, Meichun; Liu, Xingzhong

2017-01-01

Nematode-trapping fungi are a unique and intriguing group of carnivorous microorganisms that can trap and digest nematodes by means of specialized trapping structures. They can develop diverse trapping devices, such as adhesive hyphae, adhesive knobs, adhesive networks, constricting rings, and nonconstricting rings. Nematode-trapping fungi have been found in all regions of the world, from the tropics to Antarctica, from terrestrial to aquatic ecosystems. They play an important ecological role in regulating nematode dynamics in soil. Molecular phylogenetic studies have shown that the majority of nematode-trapping fungi belong to a monophyletic group in the order Orbiliales (Ascomycota). Nematode-trapping fungi serve as an excellent model system for understanding fungal evolution and interaction between fungi and nematodes. With the development of molecular techniques and genome sequencing, their evolutionary origins and divergence, and the mechanisms underlying fungus-nematode interactions have been well studied. In recent decades, an increasing concern about the environmental hazards of using chemical nematicides has led to the application of these biological control agents as a rapidly developing component of crop protection.

Production and New Extraction Method of Polyketide Red Pigments Produced by Ascomycetous Fungi from Terrestrial and Marine Habitats.

Science.gov (United States)

Lebeau, Juliana; Venkatachalam, Mekala; Fouillaud, Mireille; Petit, Thomas; Vinale, Francesco; Dufossé, Laurent; Caro, Yanis

2017-06-28

The use of ascomycetous fungi as pigment producers opens the way to an alternative to synthetic dyes, especially in the red-dye industries, which have very few natural pigment alternatives. The present paper aimed to bio-prospect and screen out 15 selected ascomycetous fungal strains, originating from terrestrial and marine habitats belonging to seven different genera ( Penicillium , Talaromyces , Fusarium , Aspergillus , Trichoderma , Dreschlera , and Paecilomyces ). We identified four strains, Penicillium purpurogenum rubisclerotium , Fusarium oxysporum , marine strains identified as Talaromyces spp., and Trichoderma atroviride , as potential red pigment producers. The extraction of the pigments is a crucial step, whereby the qualitative and quantitative compositions of each fungal extract need to be respected for reliable identification, as well as preserving bioactivity. Furthermore, there is a growing demand for more sustainable and cost-effective extraction methods. Therefore, a pressurized liquid extraction technique was carried out in this study, allowing a greener and faster extraction step of the pigments, while preserving their chemical structures and bioactivities in comparison to conventional extraction processes. The protocol was illustrated with the production of pigment extracts from P. purpurogenum rubisclerotium and Talaromyces spp. Extracts were analyzed by high-performance liquid-chromatography combined with photodiode array-detection (HPLC-DAD) and high-resolution mass spectrometry (UHPLC-HRMS). The more promising strain was the isolate Talaromyces spp. of marine origin. The main polyketide pigment produced by this strain has been characterized as N -threoninerubropunctamine, a non-toxic red Monascus -like azaphilone pigment.

Fusarium and other opportunistic hyaline fungi

Science.gov (United States)

This chapter focuses on those fungi that grow in tissue in the form of hyaline or lightly colored septate hyphae. These fungi include Fusarium and other hyaline fungi. Disease caused by hyaline fungi is referred to as hyalohyphomycosis. Hyaline fungi described in this chapter include the anamorphic,...

Mucoralean fungi for sustainable production of bioethanol and biologically active molecules.

Science.gov (United States)

Satari, Behzad; Karimi, Keikhosro

2018-02-01

Mucoralean fungi are suitable microorganisms for the sustainable production of food, fodder, and fuels from inexpensive natural resources. Ethanol-producing Mucorales are particularly advantageous for second-generation ethanol production in comparison to the conventional ethanolic yeasts and bacteria. They are able to ferment a wide range of sugars to a range of valuable products, while they are typically resistance against the inhibitors available in different substrates, including untreated lignocellulosic hydrolysates. In addition to a high ethanol yield, the fungi produce several commercially valuable by-products, including chitosan, microbial oil (mainly polyunsaturated fatty acids), and protein. Moreover, the fungal extracts can replace the expensive nutrients required in fermentation. Besides, their morphologies can be altered from filamentous to yeast like and are adjustable based on the process requirement. The focus of this review is on applying Mucorales in producing ethanol and the biomass by-products thereof.

Substantial Effect of Melanin Influencing Factors on Melanogenesis in Muzzle Melanocytes of Differently Colored Hanwoo

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Touseef Amna

2012-07-01

Full Text Available The present study was designed to investigate the effect of α-melanocyte-stimulating hormone (α-MSH, nitric oxide (NO and L-cysteine on melanin production and expression of related genes MC1R, Tyr, Tyrp-1 and Tyrp-2 in muzzle melanocytes of differently colored three native Hanwoo cattle. Muzzle samples were taken from black, brindle and brown Hanwoo and purified melanocytes were cultured with α-MSH, nitric oxide and L-cysteine at 100 nM, 50 µM and 0.07 mg/ml of media respectively. The amounts of total melanin, eumelanin and mRNA expression at Tyr, Tyrp-1, Tyrp-2 and MC1R levels were quantified. α-MSH and nitric oxide significantly increased (p<0.05 the amount of total melanin in black and brindle whereas eumelanin production in brown Hanwoo muzzle melanocytes. On the contrary, L-cysteine greatly (p<0.05 depressed the eumelanin production in black color but increased in brown. Simultaneously, up regulation of Tyr by nitric oxide and α-MSH and down regulation of Tyr, Tyrp-2 and MC1R genes by L-cysteine were observed in muzzle melanocytes of all three phenotypes. The results of this study revealed nitric oxide and α-MSH contribute hyper-pigmentation by enhancing eumelanogenesis whereas L-cysteine contributes to pheomelanin production in different colored Hanwoo muzzle melanocytes.

Vegan-mycoprotein concentrate from pea-processing industry byproduct using edible filamentous fungi.

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Souza Filho, Pedro F; Nair, Ramkumar B; Andersson, Dan; Lennartsson, Patrik R; Taherzadeh, Mohammad J

2018-01-01

Currently around one billion people in the world do not have access to a diet which provides enough protein and energy. However, the production of one of the main sources of protein, animal meat, causes severe impacts on the environment. The present study investigates the production of a vegan-mycoprotein concentrate from pea-industry byproduct (PpB), using edible filamentous fungi, with potential application in human nutrition. Edible fungal strains of Ascomycota ( Aspergillus oryzae , Fusarium venenatum , Monascus purpureus , Neurospora intermedia ) and Zygomycota ( Rhizopus oryzae ) phyla were screened and selected for their protein production yield. A. oryzae had the best performance among the tested fungi, with a protein yield of 0.26 g per g of pea-processing byproduct from the bench scale airlift bioreactor cultivation. It is estimated that by integrating the novel fungal process at an existing pea-processing industry, about 680 kg of fungal biomass attributing to about 38% of extra protein could be produced for each 1 metric ton of pea-processing byproduct. This study is the first of its kind to demonstrate the potential of the pea-processing byproduct to be used by filamentous fungi to produce vegan-mycoprotein for human food applications. The pea-processing byproduct (PpB) was proved to be an efficient medium for the growth of filamentous fungi to produce a vegan-protein concentrate. Moreover, an industrial scenario for the production of vegan-mycoprotein concentrate for human nutrition is proposed as an integrated process to the existing PPI production facilities.

Responses of mycorrhizal fungi and other rootassociated fungi to climate change

DEFF Research Database (Denmark)

Merrild, Marie Porret

Climate change is expected to affect many terrestrial ecosystem processes. Mycorrhizal fungi are important to soil carbon (C) and nutrient cycling thus changes in abundance of mycorrhizal fungi could alter ecosystem functioning. The aim of the present thesis was therefore to investigate responses...... of mycorrhizal fungi to climate change in a seasonal and long-term perspective. Effects of elevated CO2 (510 ppm), night-time warming and extended summer drought were investigated in the long-term field experiment CLIMAITE located in a Danish semi-natural heathland. Mycorrhizal colonization was investigated...... levels. Colonization by arbuscular mycorrhizal (AM) fungi increased under elevated CO2 and warming in spring while ericoid mycorrhiza (ErM) colonisation decreased in response to drought and warming. Increased AM colonization correlated with higher phosphorus and nitrogen root pools. Dark septate...

DIVERSITY OF ARBUSCULAR MYCORRHIZAL FUNGI ALONG A SAND DUNE STABILIZATION GRADIENT: A CASE STUDY AT PRAIA DE JOAQUINA, ILHA DE SANTA CATARINA, SOUTH BRAZIL

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Species diversity of abuscular mycorrhizal fungi (AMF) was assessed along a dunes stabilization gradient (embyonic dune, foredune and fixed dune) at Praia da Joaquina (Joaquina Beach), Ilha de Santa Catarina. These dunes served as a case study to assess whether diversity and myc...

Assessing the potential of fatty acids produced by filamentous fungi as feedstock for biodiesel production.

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Rivaldi, Juan Daniel; Carvalho, Ana Karine F; da Conceição, Leyvison Rafael V; de Castro, Heizir F

2017-11-26

Increased costs and limited availability of traditional lipid sources for biodiesel production encourage researchers to find more sustainable feedstock at low prices. Microbial lipid stands out as feedstock replacement for vegetable oil to convert fatty acid esters. In this study, the potential of three isolates of filamentous fungi (Mucor circinelloides URM 4140, M. hiemalis URM 4144, and Penicillium citrinum URM 4126) has been assessed as single-cell oil (SCO) producers. M. circinelloides 4140 had the highest biomass concentration with lipid accumulation of up to 28 wt% at 120 hr of cultivation. The profile of fatty acids revealed a high content of saturated (SFA) and monounsaturated fatty acids (MUFA), including palmitic (C16:0, 33.2-44.1 wt%) and oleic (C18:1, 20.7-31.2 wt%) acids, with the absence of polyunsaturated fatty acids (PUFA) having more than four double bonds. Furthermore, the predicted properties of biodiesel generated from synthesized SCOs have been estimated by using empirical models which were in accordance with the limits imposed by the USA (ASTM D6715), European Union (EN 14214), and Brazilian (ANP 45/2014) standards. These results suggest that the assessed filamentous fungus strains can be considered as alternative feedstock sources for high-quality biofuel production.

Inhibitory effect of artocarpanone from Artocarpus heterophyllus on melanin biosynthesis.

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Arung, Enos Tangke; Shimizu, Kuniyoshi; Kondo, Ryuichiro

2006-09-01

In our previous efforts to find new tyrosinase inhibitory materials, we investigated 44 Indonesian medicinal plants belonging to 24 families. Among those plants, the extract of Artocarpus heterophyllus was one of the strongest inhibitors of tyrosinase activity. By activity-guided fractionation of A. heterophyllus wood extract, we isolated artocarpanone, which inhibited both mushroom tyrosinase activity and melanin production in B16 melanoma cells. This compound is a strong candidate as a remedy for hyperpigmentation in human skin.

Identification of a phenoloxidase- and melanin-dependent defence mechanism in Achatina fulica infected with Angiostrongylus vasorum.

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Coaglio, Aytube Lucas; Ferreira, Mônica Alves Neves Diniz; Dos Santos Lima, Walter; de Jesus Pereira, Cíntia Aparecida

2018-02-27

Angiostrongylus vasorum has different freshwater aquatic and terrestrial gastropod molluscs as an intermediate host, e.g. Arion spp. The mollusc Achatina fulica is a danger to public health, given the large diversity of nematodes utilizing it as an intermediate host, such as the parasites of the genus Angiostrongylus, of importance in human and veterinary medicine. Achatina fulica has been shown to have an excellent capacity for maintaining outbreaks and natural infections with A. cantonensis in Asia. Within the mollusc, the nematode parasites activate haemocytes and/or haemolymph factors and in some invertebrates, phenoloxidase (PO), that induces the release of toxic elements and eliminates the parasites. Despite the importance of A. fulica in the life-cycle of nematodes, little is known regarding the defence mechanisms involving PO in molluscs infected with nematodes. Here, the presence of PO and nitric oxide (NO) in the haemolymph and haemocytes of A. fulica infected with first-stage (L1) larvae of Angiostrongylus vasorum was evaluated, together with the presence of melanin in the cephalopod mollusc tissue. An increase in PO at one day post infection (dpi), in comparison with the control using the substrates L-tyrosine (F (4,90)  = 6.73, P = 0.00006), L-DOPA (F (4,90)  = 22.67, P = 0.02) and p-phenylenediamine (PPD) (F (4,90)  = 27.58, P = 0.0019), was observed. PO increase coincided with the presence of melanin in the cephalopodal tissue. At 8 dpi, PO activity, compared to L-DOPA (F (4,90)  = 22.67, P = 0.00002) and PPD (F (4,90)  = 27.58, P = 0.079) decreased, while melanin increased. At 13 dpi, PO decreased with PPD (F (4,90)  = 27.58, P = 0.000015) and also the amount of melanin observed in histology. At 30 dpi, PO increased along with the substrates L-DOPA and PPD, while melanin decreased. NO levels increased until 8 dpi, and decreased after 13 dpi. To our knowledge, this is the first study that

Free amino acids production by ectomycorrhizal fungi of pine (Pinus sylvestris L.).

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Rózycki, H; Strzelczyk, E

1985-01-01

Studies on free amino acids production by five species of ectomycorrhizal fungi (Amanita muscaria, Suillus granulatus, Suillus luteus, Suillus bovinus and Rhizopogon luteolus) show that all the fungi produced mainly: glutamic acid, leucine, lysine, ornithine, arginine and an unidentified ninhydrin-positive compound X3. Both the quality and quantity of amino acids released was different in the fungal species studied. The predominant amino acids in post-culture liquids in general did not exceed 1.5 micrograms/mg dry mass.

Enzymatic activity of fungi isolated from crops

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Wioletta A. Żukiewicz-Sobczak

2016-12-01

Full Text Available Aim: To detect and assess the activity of extracellular hydrolytic enzymes and to find differences in enzymograms between fungi isolated from wheat and rye samples and grown on Czapek-Dox Broth and Sabouraud Dextrose Broth enriched with cereal (wheat or rye. Isolated strains were also classified in the scale of biosafety levels (BSL. Material and methods: The study used 23 strains of fungi cultured from samples of wheat and rye (grain, grain dust obtained during threshing and soil collected in the Lublin region (eastern Poland. API ZYM test (bioMérieux was carried out according to the manufacturer’s instructions. Classification of BSL (Biosafety levels was based on the current literature. Results : High enzymatic activity was found in strains cultured in media containing 1% of wheat grain ( Bipolaris holmi, Penicillium decumbens and with an addition of 1% of rye grain ( Cladosporium herbarum, Aspergillus versicolor, Alternaria alternata . The total number of enzymes varied depending on the type of media, and in most cases it was higher in the culture where an addition of cereal grains was used. Conclusions : Isolated strains of fungi reveal differences in the profiles of the enzyme assay. It can be assumed that the substrate enriched in grains stimulate the higher activity of mold enzymes. Key words: enzymatic activity, mold fungi, zymogram, biohazards.

Fungi, aflatoxins, and cyclopiazonic acid associated with peanut retailing in Botswana.

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Mphande, Fingani A; Siame, Bupe A; Taylor, Joanne E

2004-01-01

Peanuts are important food commodities, but they are susceptible to fungal infestation and mycotoxin contamination. Raw peanuts were purchased from retail outlets in Botswana and examined for fungi and mycotoxin (aflatoxins and cyclopiazonic acid) contamination. Zygomycetes were the most common fungi isolated; they accounted for 41% of all the isolates and were found on 98% of the peanut samples. Among the Zygomycetes, Absidia corymbifera and Rhizopus stolonifer were the most common. Aspergillus spp. accounted for 35% of all the isolates, with Aspergillus niger being the most prevalent (20.4%). Aspergillus flavus/parasiticus were also present and accounted for 8.5% of all the isolates, with A. flavus accounting for the majority of the A. flavus/parasiticus identified. Of the 32 isolates of A. flavus screened for mycotoxin production, 11 did not produce detectable aflatoxins, 8 produced only aflatoxins B1 and B2, and 13 produced all four aflatoxins (B1, B2, G1, and G2) in varying amounts. Only 6 of the A. flavus isolates produced cyclopiazonic acid at concentrations ranging from 1 to 55 microg/kg. The one A. parasiticus isolate screened also produced all the four aflatoxins (1,200 microg/kg) but did not produce cyclopiazonic acid. When the raw peanut samples (n = 120) were analyzed for total aflatoxins, 78% contained aflatoxins at concentrations ranging from 12 to 329 microg/kg. Many of the samples (49%) contained total aflatoxins at concentrations above the 20 microg/kg limit set by the World Health Organization. Only 21% (n = 83) of the samples contained cyclopiazonic acid with concentrations ranging from 1 to 10 microg/kg. The results show that mycotoxins and toxigenic fungi are common contaminants of peanuts sold at retail in Botswana.

Plant-microbe interactions: Plant hormone production by phylloplane fungi. Research report

Energy Technology Data Exchange (ETDEWEB)

Tuomi, T.; Ilvesoksa, J.; Rosenqvist, H.

1993-06-23

The molds Botrytis cinerea, Cladosporium cladosporioides and the yeast Aureobasidium pullulans, isolated from the leaves of three short-rotation Salix clones, were found to produce indole-3-acetic acid (a growth promoter of plants). Abscisic acid (a growth inhibitor of plants) production was detected in B. cinerea. The contents of indole-3-acetic acid and abscisic acid in the leaves of the Salix clones and the amounts of fungal propagules in these leaves were also measured, in order to evaluate whether the amounts of plant growth regulators produced by the fungi would make a significant contribution to the hormonal quantities of the leaves. The content of abscisic acid, and to a lesser degree that of indole-3-acetic acid, showed a positive correlation with the frequency of infection by the hormone producing organisms. The amounts of hormone producing fungi on leaves that bore visible colonies were, however, not sufficiently high to support the argument that neither the fungal production of abscisic nor indole-3-acetic acid would to a significant degree contribute to the hormonal contents of the leaves of the Salix clones.

N2O production, a widespread trait in fungi

Science.gov (United States)

Maeda, Koki; Spor, Aymé; Edel-Hermann, Véronique; Heraud, Cécile; Breuil, Marie-Christine; Bizouard, Florian; Toyoda, Sakae; Yoshida, Naohiro; Steinberg, Christian; Philippot, Laurent

2015-04-01

N2O is a powerful greenhouse gas contributing both to global warming and ozone depletion. While fungi have been identified as a putative source of N2O, little is known about their production of this greenhouse gas. Here we investigated the N2O-producing ability of a collection of 207 fungal isolates. Seventy strains producing N2O in pure culture were identified. They were mostly species from the order Hypocreales order--particularly Fusarium oxysporum and Trichoderma spp.--and to a lesser extent species from the orders Eurotiales, Sordariales, and Chaetosphaeriales. The N2O 15N site preference (SP) values of the fungal strains ranged from 15.8‰ to 36.7‰, and we observed a significant taxa effect, with Penicillium strains displaying lower SP values than the other fungal genera. Inoculation of 15 N2O-producing strains into pre-sterilized arable, forest and grassland soils confirmed the ability of the strains to produce N2O in soil with a significant strain-by-soil effect. The copper-containing nitrite reductase gene (nirK) was amplified from 45 N2O-producing strains, and its genetic variability showed a strong congruence with the ITS phylogeny, indicating vertical inheritance of this trait. Taken together, this comprehensive set of findings should enhance our knowledge of fungi as a source of N2O in the environment.

Tomographic reconstruction of melanin structures of optical coherence tomography via the finite-difference time-domain simulation

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Huang, Shi-Hao; Wang, Shiang-Jiu; Tseng, Snow H.

2015-03-01

Optical coherence tomography (OCT) provides high resolution, cross-sectional image of internal microstructure of biological tissue. We use the Finite-Difference Time-Domain method (FDTD) to analyze the data acquired by OCT, which can help us reconstruct the refractive index of the biological tissue. We calculate the refractive index tomography and try to match the simulation with the data acquired by OCT. Specifically, we try to reconstruct the structure of melanin, which has complex refractive indices and is the key component of human pigment system. The results indicate that better reconstruction can be achieved for homogenous sample, whereas the reconstruction is degraded for samples with fine structure or with complex interface. Simulation reconstruction shows structures of the Melanin that may be useful for biomedical optics applications.

Estimation of Melanin and Hemoglobin Using Spectral Reflectance Images Reconstructed from a Digital RGB Image by the Wiener Estimation Method

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Yoshihisa Aizu

2013-06-01

Full Text Available A multi-spectral diffuse reflectance imaging method based on a single snap shot of Red-Green-Blue images acquired with the exposure time of 65 ms (15 fps was investigated for estimating melanin concentration, blood concentration, and oxygen saturation in human skin tissue. The technique utilizes the Wiener estimation method to deduce spectral reflectance images instantaneously from an RGB image. Using the resultant absorbance spectrum as a response variable and the extinction coefficients of melanin, oxygenated hemoglobin and deoxygenated hemoglobin as predictor variables, multiple regression analysis provides regression coefficients. Concentrations of melanin and total blood are then determined from the regression coefficients using conversion vectors that are numerically deduced in advance by the Monte Carlo simulations for light transport in skin. Oxygen saturation is obtained directly from the regression coefficients. Experiments with a tissue-like agar gel phantom validated the method. In vivo experiments on fingers during upper limb occlusion demonstrated the ability of the method to evaluate physiological reactions of human skin.

Manakins can produce iridescent and bright feather colours without melanosomes.

Science.gov (United States)

Igic, Branislav; D'Alba, Liliana; Shawkey, Matthew D

2016-06-15

Males of many species often use colourful and conspicuous ornaments to attract females. Among these, male manakins (family: Pipridae) provide classic examples of sexual selection favouring the evolution of bright and colourful plumage coloration. The highly iridescent feather colours of birds are most commonly produced by the periodic arrangement of melanin-containing organelles (melanosomes) within barbules. Melanin increases the saturation of iridescent colours seen from optimal viewing angles by absorbing back-scattered light; however, this may reduce the wide-angle brightness of these signals, contributing to a dark background appearance. We examined the nanostructure of four manakin species (Lepidothrix isidorei, L. iris, L. nattereri and L. coeruleocapilla) to identify how they produce their bright plumage colours. Feather barbs of all four species were characterized by dense and fibrous internal spongy matrices that likely increase scattering of light within the barb. The iridescent, yet pale or whitish colours of L. iris and L. nattereri feathers were produced not by periodically arranged melanosomes within barbules, but by periodic matrices of air and β-keratin within barbs. Lepidothrix iris crown feathers were able to produce a dazzling display of colours with small shifts in viewing geometry, likely because of a periodic nanostructure, a flattened barb morphology and disorder at a microstructural level. We hypothesize that iridescent plumage ornaments of male L. iris and L. nattereri are under selection to increase brightness or luminance across wide viewing angles, which may potentially increase their detectability by females during dynamic and fast-paced courtship displays in dim light environments. © 2016. Published by The Company of Biologists Ltd.

Short CommuniCationS, noteS and reportS

African Journals Online (AJOL)

wrongly, applied is the name Albino or. Partial Albino. This name is widely used for all sorts of different colour aberrations, but in only a few percent of the cases it is used correctly. Due to the mutation, an Albino is unable to produce melanin pigments at all. A mostly white bird which nevertheless shows some form of melanin.

Assessment of endophytic fungi cultural filtrate on soybean seed ...

African Journals Online (AJOL)

Soybean seeds have high amount of isoflavones but its germination is often confronted with a variety of environmental problems resulting in low germination rate and growth. To overcome this in eco-friendly manner, we investigated the influence of cultural filtrate (CF) of gibberellins-producing endophytic fungi on soybean ...

Fungi in space--literature survey on fungi used for space research.

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Kern, V D; Hock, B

1993-09-01

A complete review of the scientific literature on experiments involving fungi in space is presented. This review begins with balloon experiments around 1935 which carried fungal spores, rocket experiments in the 1950's and 60's, satellite and moon expeditions, long-time orbit experiments and Spacelab missions in the 1980's and 90's. All these missions were aimed at examining the influence of cosmic radiation and weightlessness on genetic, physiological, and morphogenetic processes. During the 2nd German Spacelab mission (D-2, April/May 1993), the experiment FUNGI provided the facilities to cultivate higher basidiomycetes over a period of 10 d in orbit, document gravimorphogenesis and chemically fix fruiting bodies under weightlessness for subsequent ultrastructural analysis. This review shows the necessity of space travel for research on the graviperception of higher fungi and demonstrates the novelty of the experiment FUNGI performed within the framework of the D-2 mission.

Antimycobacterial and antimalarial activities of endophytic fungi associated with the ancient and narrowly endemic neotropical plant Vellozia gigantea from Brazil.

Science.gov (United States)

Ferreira, Mariana C; Cantrell, Charles L; Wedge, David E; Gonçalves, Vívian N; Jacob, Melissa R; Khan, Shabana; Rosa, Carlos A; Rosa, Luiz H

2017-10-01

Endophytic fungi, present mainly in the Ascomycota and Basidiomycota phyla, are associated with different plants and represent important producers of bioactive natural products. Brazil has a rich biodiversity of plant species, including those reported as being endemic. Among the endemic Brazilian plant species, Vellozia gigantea (Velloziaceae) is threatened by extinction and is a promising target to recover endophytic fungi. The present study focused on bioprospecting of bioactive compounds of the endophytic fungi associated with V. gigantea, an endemic, ancient, and endangered plant species that occurs only in the rupestrian grasslands of Brazil. The capability of 285 fungal isolates to produce antimicrobial and antimalarial activities was examined. Fungi were grown at solid-state fermentation to recover their crude extracts in dichloromethane. Bioactive extracts were analysed by chromatographic fractionation and NMR and displayed compounds with antimicrobial, antimycobacterial, and antimalarial activities. Five fungi produced antimicrobial and antimalarial compounds. Extracts of Diaporthe miriciae showed antifungal, antibacterial, and antimalarial activities; Trichoderma effusum displayed selective antibacterial activity against methicillin-resistant Staphylococcus aureus and Mycobacterium intracellulare; and three Penicillium species showed antibacterial activity. D. miriciae extract contained highly functionalised secondary metabolites, yielding the compound epoxycytochalasin H with high antimalarial activity against the chloroquine-resistant strain of Plasmodium falciparum, with an IC50 approximately 3.5-fold lower than that with chloroquine. Our results indicate that V. gigantea may represent a microhabitat repository hotspot of potential fungi producers of bioactive compounds and suggest that endophytic fungal communities might be an important biological component contributing to the fitness of the plants living in the rupestrian grassland.

Effects of Growth Media on the Diversity of Culturable Fungi from Lichens

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Lucia Muggia

2017-05-01

Full Text Available Microscopic and molecular studies suggest that lichen symbioses contain a plethora of associated fungi. These are potential producers of novel bioactive compounds, but strains isolated on standard media usually represent only a minor subset of these fungi. By using various in vitro growth conditions we are able to modulate and extend the fraction of culturable lichen-associated fungi. We observed that the presence of iron, glucose, magnesium and potassium in growth media is essential for the successful isolation of members from different taxonomic groups. According to sequence data, most isolates besides the lichen mycobionts belong to the classes Dothideomycetes and Eurotiomycetes. With our approach we can further explore the hidden fungal diversity in lichens to assist in the search of novel compounds.

Effects of Growth Media on the Diversity of Culturable Fungi from Lichens.

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Muggia, Lucia; Kopun, Theodora; Grube, Martin

2017-05-17

Microscopic and molecular studies suggest that lichen symbioses contain a plethora of associated fungi. These are potential producers of novel bioactive compounds, but strains isolated on standard media usually represent only a minor subset of these fungi. By using various in vitro growth conditions we are able to modulate and extend the fraction of culturable lichen-associated fungi. We observed that the presence of iron, glucose, magnesium and potassium in growth media is essential for the successful isolation of members from different taxonomic groups. According to sequence data, most isolates besides the lichen mycobionts belong to the classes Dothideomycetes and Eurotiomycetes. With our approach we can further explore the hidden fungal diversity in lichens to assist in the search of novel compounds.

Radioanalytical methods for the measurement of melanin concentrating hormone (MCH) and detection its receptor in rat tissues

International Nuclear Information System (INIS)

Lelesz, B.; Szilvassy, Z.; Varga, A.; Juhasz, B.; Nemeth, J.; Toth, G.K.; Toth, A.; Enyedi, A.; Felszeghy, E.

2016-01-01

In the present paper the development and application of a novel melanin concentrating hormone radioimmunoassay and receptor-binding assay are described. 125 I-labeling of melanin concentrating hormone (MCH) was performed by iodogen and the mono-iodinated peptide was separated by reversed-phase high performance liquid chromatography. Detection limit of the MCH specific assay was 0.2 fmol/ml. As a practical application of the novel radioimmunoassay, we measured the MCH concentration in different rat organs. High MCH concentrations were detected in the small intestine, pancreas, kidney, liver, trachea, hypothalamus and spinal cord. 125 I-MCH was also suitable for RBA to demonstrate the presence of MCH receptors in the rat brain. (author)

Determination of the optical properties of melanin-pigmented human skin equivalents using terahertz time-domain spectroscopy

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Lipscomb, Dawn; Echchgadda, Ibtissam; Peralta, Xomalin G.; Wilmink, Gerald J.

2013-02-01

Terahertz time-domain spectroscopy (THz-TDS) methods have been utilized in previous studies in order to characterize the optical properties of skin and its primary constituents (i.e., water, collagen, and keratin). However, similar experiments have not yet been performed to investigate whether melanocytes and the melanin pigment that they synthesize contribute to skin's optical properties. In this study, we used THz-TDS methods operating in transmission geometry to measure the optical properties of in vitro human skin equivalents with or without normal human melanocytes. Skin equivalents were cultured for three weeks to promote gradual melanogenesis, and THz time domain data were collected at various time intervals. Frequency-domain analysis techniques were performed to determine the index of refraction (n) and absorption coefficient (μa) for each skin sample over the frequency range of 0.1-2.0 THz. We found that for all samples as frequency increased, n decreased exponentially and the μa increased linearly. Additionally, we observed that skin samples with higher levels of melanin exhibited greater n and μa values than the non-pigmented samples. Our results indicate that melanocytes and the degree of melanin pigmentation contribute in an appreciable manner to the skin's optical properties. Future studies will be performed to examine whether these contributions are observed in human skin in vivo.

Haste makes waste: accelerated molt adversely affects the expression of melanin-based and depigmented plumage ornaments in house sparrows.

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Csongor I Vágási

2010-12-01

Full Text Available Many animals display colorful signals in their integument which convey information about the quality of their bearer. Theoretically, these ornaments incur differential production and/or maintenance costs that enforce their honesty. However, the proximate mechanisms of production costs are poorly understood and contentious in cases of non-carotenoid-based plumage ornaments like the melanin-based badge and depigmented white wing-bar in house sparrows Passer domesticus. Costly life-history events are adaptively separated in time, thus, when reproduction is extended, the time available for molt is curtailed and, in turn, molt rate is accelerated.We experimentally accelerated the molt rate by shortening the photoperiod in order to test whether this environmental constraint is mirrored in the expression of plumage ornaments. Sparrows which had undergone an accelerated molt developed smaller badges and less bright wing-bars compared to conspecifics that molted at a natural rate being held at natural-like photoperiod. There was no difference in the brightness of the badge or the size of the wing-bar.These results indicate that the time available for molt and thus the rate at which molt occurs may constrain the expression of melanin-based and depigmented plumage advertisements. This mechanism may lead to the evolution of honest signaling if the onset of molt is condition-dependent through the timing of and/or trade-off between breeding and molt.

Isolation of peat swamp forest foliar endophyte fungi as biofertilizer

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Safinah Surya Hakim

2017-01-01

Full Text Available Peatland restoration activity is facing many obstacles, particularly in planting techniques and poor nutrient in peat soil. Naturally, endophytic fungi are abundant and have great potential as biofertilizer. This research investigates the potential endophytic fungi isolated from leaves of peat swamp tree species for biofertilizer. Research activities include: exploration, in vitro test to examine the phosphate solubilization and identification. Result showed that there were 360 leave segments collected from 4 sampling locations. The colonization percentage of 222 isolates ranged from 52.17% - 60.17%. Fifty seven morphospecies were selected from 222 isolates. Twelve isolates demonstrated ability to produce clear zones and ten isolates were selected for identification. It is concluded that twelve isolated demonstrated potential ability to produce clear zone and Penicillum citrinum isolate P3.10 was identified as an isolate that show the highest potential ability as a biofertilizer

The Protective Role of Melanin Against UV Damage in Human Skin

OpenAIRE

Brenner, Michaela; Hearing, Vincent J.

2008-01-01

Human skin is repeatedly exposed to ultraviolet radiation (UVR) that influences the function and survival of many cell types and is regarded as the main causative factor in the induction of skin cancer. It has been traditionally believed that skin pigmentation is the most important photoprotective factor, since melanin, besides functioning as a broadband UV absorbent, has antioxidant and radical scavenging properties. Besides, many epidemiological studies have shown a lower incidence for skin...

Microneedling dilates the follicular infundibulum and increases transfollicular absorption of liposomal sepia melanin

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Serrano G

2015-06-01

Full Text Available Gabriel Serrano,1 Patricia Almudéver,2 Juan M Serrano,3 Julio Cortijo,2 Carmen Faus,1 Magda Reyes,1 Inmaculada Expósito,3 Ana Torrens,3 Fernando Millán1 1Clínica Dermatológica Serrano, 2Department of Pharmacology, University of Valencia, 3Research and Development Department, Sesderma Laboratories, Valencia, Spain Abstract: Encapsulation of chemicals in liposomes and microneedling are currently used techniques to enhance the penetration of several substances through skin and hair. In this study, we apply a liposomal melanin–fluorescein compound to an ex vivo model of human skin, using a new electrical microneedling device (Nanopore turbo roller. The product was applied by hand massage (A or with the assistance of the electrical roller for 2 minutes (B. An additional test was performed free of product and with only the E-roller (C. Histological changes and product absorption were evaluated by optical and fluorescent microscopy 60 and 90 minutes after the treatment. Site B showed larger deposits of melanin–fluorescein at superficial and deep levels of hair structures in comparison to site A. Light, epidermal deposits of the melanin–fluorescein complex were also observed. Sites B and C showed a significant widening (47% of the follicular infundibulum which could explain the increased penetration of the formulation. Microneedling also removed the scales and sebum residues in the neighborhood of the infundibulum. Targeting hair follicles with melanin may be useful to dye poorly pigmented hairs, improving laser hair removal. The procedure accelerates the delivery of melanin into hair structures allowing an even absorption, larger pigment deposits, and deeper penetration of the formulation into the hair. Keywords: liposomes, melanin, microneedling, follicular infundibulum, hair removal

ESTIMATION OF MELANIN CONTENT IN IRIS OF HUMAN EYE

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E. A. Genina

2008-12-01

Full Text Available Based on the experimental data obtained in vivo from digital analysis of color images of human irises, the mean melanin content in human eye irises has been estimated. For registration of color images the digital camera Olympus C-5060 has been used. The images have been obtained from irises of healthy volunteers as well as from irises of patients with open-angle glaucoma. The computer program has been developed for digital analysis of the images. The result has been useful for development of novel methods and optimization of already existing ones for non-invasive glaucoma diagnostics.

Kinetic and thermodynamic studies on the adsorption of heavy metals from aqueous solution by melanin nanopigment obtained from marine source: Pseudomonas stutzeri.

Science.gov (United States)

Manirethan, Vishnu; Raval, Keyur; Rajan, Reju; Thaira, Harsha; Balakrishnan, Raj Mohan

2018-05-15

The difficulty in removal of heavy metals at concentrations below 10 mg/L has led to the exploration of efficient adsorbents for removal of heavy metals. The adsorption capacity of biosynthesized melanin for Mercury (Hg(II)), Chromium (Cr(VI)), Lead (Pb(II)) and Copper (Cu(II)) was investigated at different operating conditions like pH, time, initial concentration and temperature. The heavy metals adsorption process was well illustrated by the Lagergren's pseudo-second-order kinetic model and the equilibrium data fitted excellently to Langmuir isotherm. Maximum adsorption capacity obtained from Langmuir isotherm for Hg(II) was 82.4 mg/g, Cr(VI) was 126.9 mg/g, Pb(II) was 147.5 mg/g and Cu(II) was 167.8 mg/g. The thermodynamic parameters revealed that the adsorption of heavy metals on melanin is favorable, spontaneous and endothermic in nature. Binding of heavy metals on melanin surface was proved by Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray Photoelectron Spectroscopy (XPS). Contemplating the results, biosynthesized melanin can be a potential adsorbent for efficient removal of Hg(II), Cr(VI), Pb(II) and Cu(II) ions from aqueous solution. Copyright © 2018 Elsevier Ltd. All rights reserved.

Melanin concentrating hormone receptor 1 (MCHR1) antagonists - Still a viable approach for obesity treatment?

DEFF Research Database (Denmark)

Högberg, T.; Frimurer, T.M.; Sasmal, P.K.

2012-01-01

Obesity is a global epidemic associated with multiple severe diseases. Several pharmacotherapies have been investigated including the melanin concentrating hormone (MCH) and its receptor 1. The development of MCHR1 antagonists are described with a specific perspective on different chemotypes...

Philatelic Mycology: Families of Fungi

NARCIS (Netherlands)

Marasas, W.F.O.; Marasas, H.M.; Wingfield, M.J.; Crous, P.W.

2014-01-01

Philately, the study of postage stamps, and mycology, the study of fungi, are seldom connected by those that practice these very different activities. When associated, philatelic mycology would be considered as the study of fungi on stamps. The Fungi touch every aspect of our daily lives, most

Application of ATR-FTIR Spectroscopy to Compare the Cell Materials of Wood Decay Fungi with Wood Mould Fungi

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Barun Shankar Gupta

2015-01-01

Full Text Available Wood fungi create vast damage among standing trees and all types of wood materials. The objectives of this study are to (a characterize the cell materials of two major wood decay fungi (Basidiomycota, namely, Trametes versicolor and Postia placenta, and (b compare the cell materials of decay fungi with four wood mould fungi (Ascomycota, namely, Aureobasidium pullulans, Alternaria alternata, Cladosporium cladosporioides, and Ulocladium atrum. Fourier transform infrared (FTIR spectroscopy is used to characterize the microbial cellular materials. The results showed that the IR bands for the fatty acid at ∼2900 cm−1 were different for the two-decay-fungi genre. Postia placenta shows more absorbance peaks at the fatty acid region. Band ratio indices for amide I and amide II from protein amino acids were higher for the mould fungi (Ascomycota than the decay fungi (Basidiomycota. Similarly, the band ratio index calculated for the protein end methyl group was found to be higher for the mould fungi than the decay fungi. Mould fungi along with the decay fungi demonstrated a positive correlation (R2=0.75 between amide I and amide II indices. The three-component multivariate, principal component analysis showed a strong correlation of amide and protein band indices.

Simultaneous exposure of nematophagous fungi, entomopathogenic nematodes and entomopathogenic fungi can modulate belowground insect pest control.

Science.gov (United States)

Bueno-Pallero, Francisco Ángel; Blanco-Pérez, Rubén; Dionísio, Lídia; Campos-Herrera, Raquel

2018-05-01

Entomopathogenic nematodes (EPNs) and fungi (EPF) are well known biological control agents (BCAs) against insect pests. Similarly, the nematophagous fungi (NF) are considered good BCA candidates for controlling plant parasitic nematodes. Because NF can employ EPNs as food and interact with EPF, we speculate that the simultaneous application of EPNs and EPF might result in higher insect mortality, whereas the triple species combination with NF will reduce the EPN and EPF activity by predation or inhibition. Here we evaluated single, dual (EPN + EPF, EPF + NF, EPN + NF) and triple (EPN + EPF + NF) combinations of one EPN, Steinernema feltiae (Rhabditida: Steinernematidae), one EPF, Beauveria bassiana (Hypocreales: Clavicipitaceae), and two NF, Arthrobotrys musiformis (Orbiliales: Orbiliaceae) and Purpureocillium lilacinum (Hypocreales: Ophiocordycipitaceae) under laboratory conditions. First, we showed that EPF reduced the growth rate of NF and vice versa when combined in both rich and limiting media, suggesting a negative interaction when combining both fungi. Three different fungal applications (contact with mycelia-conidia, immersion in conidial suspension, and injection of conidial suspension) were tested in single, dual and triple species combinations, evaluating Galleria mellonella (Lepidoptera: Pyralidae) larval mortality and time to kill. When mycelia was presented, the EPF appeared to be the dominant in combined treatments, whereas in immersion exposure was the EPN. In both types of exposure, NF alone did not produce any effect on larvae. However, when A. musiformis was injected, it produced larval mortalities >70% in the same time span as EPN. Overall, additive effects dominated the dual and triple combinations, with the exception of injection method, where synergisms occurred for both NF species combined with EPN + EPF. This study illustrates how differences in species combination and timing of fungal arrival can modulate the action

Ecological plasticity of Trichoderma fungi in leached chernozem

Science.gov (United States)

Svistova, I. D.; Senchakova, T. Yu.

2010-03-01

The autecological properties of Trichoderma fungi ecotypes isolated from the leached chernozem of the forest-steppe zone of the European part of Russia have been studied. We were the first who carried out the complex study of the synecological relations of micromycetes of such kinds in a system including the soil, microbial community, and plants, i.e., their relations with soil saprotrophic fungi, bacteria, actinomycetes, plants, and pathogenic fungi. It was shown that the ecological plasticity of the Trichoderma genus in the soil of this zone is determined by its growth rate, the optimum pH and temperature, the biosynthesis of extracellular hydrolytic enzymes, the biological action of mycotoxins, and the ability for parasitism. The efficiency of the introduction of Trichoderma species typical and atypical for the leached chernozem into this soil and their influence on the structure of the microbial community were evaluated. The T. pseudokoningii ecotype, which produces cellulolytic enzymes, is very promising for industrial biotechnology, and the T. harzianum ecotype can be used in soil biotechnology for the biocontrol of chernozem. The addition of a commercial trichodermin preparation into the chernozem damages the structure of its microbial community.

Biotechnology of marine fungi

Digital Repository Service at National Institute of Oceanography (India)

Damare, S.R.; Singh, P.; Raghukumar, S.

Filamentous fungi are the most widely used eukaryotes in industrial and pharmaceutical applications. Their biotechnological uses include the production of enzymes, vitamins, polysaccharides, pigments, lipids and others. Marine fungi are a still...

Schinus terebinthifolius Raddi extract and linoleic acid from Passiflora edulis synergistically decrease melanin synthesis in B16 cells and reconstituted epidermis.

Science.gov (United States)

Jorge, A T S; Arroteia, K F; Santos, I A; Andres, E; Medina, S P H; Ferrari, C R; Lourenço, C B; Biaggio, R M T T; Moreira, P L

2012-10-01

Several treatments for skin whitening are available today, but few of them are completely adequate, especially owing to the carcinogenic potential attributed to classical drugs like hydroquinone, arbutin and kojic acid. To provide an alternative and safer technology for whitening, we developed two botanical compounds originated from Brazilian biodiversity, an extract of Schinus terebinthifolius Raddi and a linoleic acid fraction isolated from Passiflora edulis oil. The whitening effect of these compounds was assessed using biochemical assays and in vitro models including cellular assays and equivalent skin. The results showed that S. terebinthifolius Raddi extract is able to reduce the tyrosinase activity in vitro, and the combination of this extract with linoleic acid is able to decrease the level of melanin produced by B16 cells cultured with melanocyte-stimulating hormone. Furthermore, melanin was also reduced in human reconstituted epidermis (containing melanocytes) treated with the compounds. The combination of the compounds may provide a synergistic positive whitening effect rather than their isolated use. Finally, we demonstrated that the performance of these mixed compounds is comparable to classical molecules used for skin whitening, as kojic acid. This new natural mixture could be considered an alternative therapeutic agent for treating hyperpigmentation and an effective component in whitening cosmetics. © 2012 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Three-dimensional multispectral optoacoustic mesoscopy reveals melanin and blood oxygenation in human skin in vivo.

Science.gov (United States)

Schwarz, Mathias; Buehler, Andreas; Aguirre, Juan; Ntziachristos, Vasilis

2016-01-01

Optical imaging plays a major role in disease detection in dermatology. However, current optical methods are limited by lack of three-dimensional detection of pathophysiological parameters within skin. It was recently shown that single-wavelength optoacoustic (photoacoustic) mesoscopy resolves skin morphology, i.e. melanin and blood vessels within epidermis and dermis. In this work we employed illumination at multiple wavelengths for enabling three-dimensional multispectral optoacoustic mesoscopy (MSOM) of natural chromophores in human skin in vivo operating at 15-125 MHz. We employ a per-pulse tunable laser to inherently co-register spectral datasets, and reveal previously undisclosed insights of melanin, and blood oxygenation in human skin. We further reveal broadband absorption spectra of specific skin compartments. We discuss the potential of MSOM for label-free visualization of physiological biomarkers in skin in vivo. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Activity of Antarctic fungi extracts against phytopathogenic bacteria.

Science.gov (United States)

Purić, J; Vieira, G; Cavalca, L B; Sette, L D; Ferreira, H; Vieira, M L C; Sass, D C

2018-06-01

This study aims to obtain secondary metabolites extracts from filamentous fungi isolated from soil and marine sediments from Antarctic ecosystems and to assess its potential antibacterial activity on Xanthomonas euvesicatoria and Xanthomonas axonopodis pv. passiflorae (phytopathogenic bacteria causing diseases in pepper and tomato and passionfruit, respectively). Among the 66 crude intracellular and extracellular extracts obtained from fungi recovered from soil and 79 obtained from marine sediment samples, 25 showed the ability to prevent the growth of X. euvesicatoria in vitro and 28 showed the ability to prevent the growth of X. axonopodis pv. passiflorae in vitro. Intracellular and extracellular extracts from soil fungi inhibited around 97% of X. euvesicatoria and 98% of X. axonopodis pv. passiflorae at 2·1 mg ml -1 . The average inhibition rates against X. euvesicatoria and X. axonopodis pv. passiflorae for intracellular and extracellular extracts from marine sediments fungi were around 96 and 97%, respectively, at 3·0 mg ml -1 . Extracts containing secondary metabolites with antimicrobial activity against X. euvesicatoria and X. axonopodis pv. passiflorae were obtained, containing possible substitutes for the products currently used to control these phytopathogens. Micro-organisms from extreme ecosystems, such as the Antarctic ecosystem, need to survive in harsh conditions with low temperatures, low nutrients and high UV radiation. Micro-organisms adapt to these conditions evolving diverse biochemical and physiological adaptations essential for survival. All this makes these micro-organisms a rich source of novel natural products based on unique chemical scaffolds. Discovering novel bioactive compounds is essential because of the rise in antibiotic-resistant micro-organisms and the emergence of new infections. Fungi from Antarctic environments have been proven to produce bioactive secondary metabolites against various micro-organisms, but few studies

Cytochalasin produced by Xylaria sp., a endophytic fungi of Piper aduncum (Piperaceae); Citocalasinas produzidas por Xylaria sp., um fungo endofitico de Piper aduncum (Piperaceae)

Energy Technology Data Exchange (ETDEWEB)

Silva, Geraldo H.; Oliveira, Camila M. de; Teles, Helder L.; Bolzani, Vanderlan da S.; Araujo, Angela R., E-mail: araujoar@iq.unesp.b [Universidade Estadual Paulista (UNESP), Araraquara, SP (Brazil). Inst. de Quimica; Pfenning, Ludwig H. [Universidade Federal de Lavras (UFLA), MG (Brazil). Dept. de Fitopatologia; Young, Maria Claudia M. [Instituto de Botanica, Sao Paulo, SP (Brazil). Secao de Fisiologia e Bioquimica de Plantas; Costa-Neto, Claudio M. [Universidade de Sao Paulo (USP/RP), Ribeirao Preto, SP (Brazil). Fac. de Medicina. Dept. de Bioquimica e Imunologia; Haddad, Renato; Eberlin, Marcos N. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Inst. de Quimica

2010-07-01

A chemical study on the EtOAc extract produced by Xylaria sp., an endophytic fungus from Piper aduncum, resulted in the isolation of a new cytochalasin 1, along with five known 19,20-epoxycytochalasin D (2), C (3), N (4), Q (5), and R (6). The 1-6 were evaluated against the fungi C. cladosporioides and C. sphaerospermum and only 5 showed weak activity. The cytotoxicity in vitro against HeLA and CHO cells lines were investigated and the cytochalasins 2-4, and 6 showed a strong activity against HeLA. The DNA damaging activity of 1-6 were also investigated against mutant strains of S. cerevisiae. (author)

Richness of endophytic fungi isolated from Opuntia ficus-indica Mill. (Cactaceae) and preliminary screening for enzyme production.

Science.gov (United States)

Bezerra, J D P; Santos, M G S; Svedese, V M; Lima, D M M; Fernandes, M J S; Paiva, L M; Souza-Motta, C M

2012-05-01

Opuntia ficus-indica Mill. (forage cactus) is farmed with relative success in the semi-arid region of the Brazilian northeast for commercial purposes, particularly as forage and food. Endophytic microorganisms are those that can be isolated inside plant tissues and can be a new source to production of enzymes with different potentialities. The objective of this study was to describe the richness of endophytic fungi from O. ficus-indica and to detect the capacity of these species to produce extracellular hydrolytic enzymes. Forty-four endophytic fungi species were isolated. Among them, the most commonly found were Cladosporium cladosporioides (20.43%) and C. sphaerospermum (15.99%). Acremonium terricola, Monodictys castaneae, Penicillium glandicola, Phoma tropica and Tetraploa aristata are being reported for the first time as endophytic fungi for Brazil. The majority of isolated fungi exhibited enzymatic potential. Aspergillus japonicus and P. glandicola presented pectinolytic activity. Xylaria sp. was the most important among the other 14 species with positive cellulase activity. All 24 isolates analysed were xylanase-positive. Protease was best produced by isolate PF103. The results indicate that there is a significant richness of endophytic fungi in O. ficus-indica, and that these isolates indicate promising potential for deployment in biotechnological processes involving production of pectinases, cellulases, xylanases and proteases.

Degradation of natural cellulose by thermophilic and thermotolerant fungi

Energy Technology Data Exchange (ETDEWEB)

Thakre, A P; Johri, B N

1981-06-01

Aspergillus fumigatus Friesen, Sporotrichum sp., Thermoascus aurantiacus Miche and Torula thermophila Cooney and Emerson were able to degrade filter paper to an appreciable extent. Absidia corymbifera (Cohn) Saccardo et Trotter, Rhizopus microsporus van Tieghem and R. rhizopodiformis (Cohn) Zopf could not degrade filter paper though they were able to grow on the media supplied. The fungi able to degrade filter paper were also capable of elaborating extracellular cellulase and produced sufficient hydrolysis of carboxymethyl cellulose. The Cx enzyme was stable at 45 degrees C for 25 days. An incubation period of 15 to 25 days was sufficient not only to degrade CMC but even more complex substrates, such as jute, cotton and filter paper. The cellulases of these fungi were inductive in nature. (Refs. 11).

Isolation, Identification And Screening Antibacterial Activity from Marine Sponge-Associated Fungi Against Multidrug-Resistant (MDR) Escherichia coli

Science.gov (United States)

Triandala Sibero, Mada; Sabdaningsih, Aninditia; Cristianawati, Olvi; Nuryadi, Handung; Karna Radjasa, Ocky; Sabdono, Agus; Trianto, Agus

2017-02-01

Irrational used of antibiotic in several decades ago causing resistant in bacteria and decreasing the cure rate of infectious diseases. Multidrug-resistant (MDR) Escherichia coli is known to cause various of infectious diseases such as urinary tract infection, nosocomial bloodstream infection, meningitis, bacteraemia, and gastrointestinal disease. Marine sponge-associated fungi have potential as source of new compound to combat MDR E. coli. The aims of this research were to isolate marine sponge-assosiated fungi, to screen potential fungi against MDR E. coli, to identify the potential fungi and its host sponge. There were 29 marine sponge-associated fungi successfully isolated from 9 sponges. Among 29 sponge-associated fungi screened, there were 7 isolates showed antibacterial activity against MDR E. coli. The best inhibition zone produced by MPS 14.1/MT 02 and MPS 14.3/MT 04 from sponge PP.SP.16.14. According to fungi identification result fungus MPS 14.1/MT 02 was identified as Trichoderma asperellum while MPS 14.3/MT 04 was identified as Trichoderma reesei. Sponge identification leaded the PP.SP.16.14 as Cinachyrella sp.

Ancient horizontal gene transfer from bacteria enhances biosynthetic capabilities of fungi.

Directory of Open Access Journals (Sweden)

Imke Schmitt

Full Text Available Polyketides are natural products with a wide range of biological functions and pharmaceutical applications. Discovery and utilization of polyketides can be facilitated by understanding the evolutionary processes that gave rise to the biosynthetic machinery and the natural product potential of extant organisms. Gene duplication and subfunctionalization, as well as horizontal gene transfer are proposed mechanisms in the evolution of biosynthetic gene clusters. To explain the amount of homology in some polyketide synthases in unrelated organisms such as bacteria and fungi, interkingdom horizontal gene transfer has been evoked as the most likely evolutionary scenario. However, the origin of the genes and the direction of the transfer remained elusive.We used comparative phylogenetics to infer the ancestor of a group of polyketide synthase genes involved in antibiotic and mycotoxin production. We aligned keto synthase domain sequences of all available fungal 6-methylsalicylic acid (6-MSA-type PKSs and their closest bacterial relatives. To assess the role of symbiotic fungi in the evolution of this gene we generated 24 6-MSA synthase sequence tags from lichen-forming fungi. Our results support an ancient horizontal gene transfer event from an actinobacterial source into ascomycete fungi, followed by gene duplication.Given that actinobacteria are unrivaled producers of biologically active compounds, such as antibiotics, it appears particularly promising to study biosynthetic genes of actinobacterial origin in fungi. The large number of 6-MSA-type PKS sequences found in lichen-forming fungi leads us hypothesize that the evolution of typical lichen compounds, such as orsellinic acid derivatives, was facilitated by the gain of this bacterial polyketide synthase.

Natural substrata for corticioid fungi

Directory of Open Access Journals (Sweden)

Eugene O. Yurchenko

2013-12-01

Full Text Available The paper reviews the types of substrata inhabited by non-poroid resupinate Homobasidiomycetes in situ in global scale with both examples from literature sources and from observations on Belarus corticioid fungi biota. The groups of organic world colonized by corticioid basidiomata and vegetative mycelium are arboreous, semi-arboreous, and herbaceous vascular plants, Bryophyta, epiphytic coccoid algae, lichenized and non-lichenized fungi, and occasionally myxomycetes and invertebrates. The fungi occur on living, dying, and dead on all decay stages parts of organisms. Besides, the fungi are known on soil, humus, stones, artificial inorganic and synthetic materials and dung.

Anti-infective properties of the melanin-glucan complex obtained from medicinal tinder bracket mushroom, Fomes fomentarius (L.: Fr.) Fr. (Aphyllophoromycetideae).

Science.gov (United States)

Seniuk, Olga F; Gorovoj, Leontiy F; Beketova, Galina V; Savichuk, Hatalia O; Rytik, Petr G; Kucherov, Igor I; Prilutskay, Alla B; Prilutsky, Alexandr I

2011-01-01

The goal of this investigation was to comparatively study the efficiency of traditionally used anti-infective drugs and biopolymer complexes originated from the medicinal mushroom Fomes fomentarius (L.:Fr.) Fr.: 1) water-soluble melanin-glucan complex (MGC; -80% melanins and -20% beta-glucans) and 2) insoluble chitin-glucan-melanin complex (ChGMC; -70% chitin, -20% beta-glucans, and -10% melanins). Infectious materials (Helicobacter pylori, Candida albicans, and Herpes vulgaris I and HIV-1(zmb) were used in pure cultures of in vitro and in vivo models on experimental animals. Comparison studies of fungal biopolymers and effective modern antifungal, antibacterial, and antiviral drugs were used in in vitro models. The comparative clinical efficiency of ChGMC and of etiotropic pharmaceuticals in models of H. pylori, C. albicans, and H. vulgaris I infection contamination were studied. Using in vitro models, it was established that MGC completely depresses growth of C. albicans. MGC had an antimicrobial effect on H. pylori identical to erythromycin in all concentrations, and had a stronger action on this bacterium than other tested antibiotics. Tested MGC possesses simultaneously weak toxicity and high anti-HIV-1 activity in comparison with zidovudine (Retrovir). The obtained results show that CLUDDT therapy in Wistar rats with the application of ChGMC is, on average, 1.35-1.43 times as effective as a traditional one. Considering the absence of MGC and ChGMC toxic properties on blood cells even in very high concentrations, these complexes may be used as a source of biopolymers for the creation of essentially new agents for wide application in infectious pathology.

Importance of nuclear technology in the conservation and production of nutritional fungi

International Nuclear Information System (INIS)

Sajet, A.S.

2008-01-01

The shortfall in food and field crops due to bad weather and the incidence of insects and microbes during harvesting, handling and storage under non-suitable conditions, called the attention of researchers to try to minimize the damage happening and by various means, whether to develop sources of new food, such as producing nutritional fungi, or by following non-traditional methods of anti-microbes and insects such as the use of radiation as a safe and successful way to save the food without any toxic effects. Permits have been issued for food irradiation by many international organizations including IAEA, World Health Organization and FAO. Nutritional fungi is one of the food sources used as food fit for human consumption in various countries around the world due to their importance which includes many aspects: the nutritional and health value; medical significance; environmental importance and industrial importance. Nuclear technology has contributed in many of the developments in the production and conservation of nutritional fungi, notably, biological studies of nutritional fungi, production technology of fungus, the role of radiation in the preparation and improvement of the nutritional media, improvement of the fungus strains, the use of radiation in the conservation of nutritional fungi and the detection of irradiated nutritional fungus.

Lipid droplets of arbuscular mycorrhizal fungi emerge in concert with arbuscule collapse.

Science.gov (United States)

Kobae, Yoshihiro; Gutjahr, Caroline; Paszkowski, Uta; Kojima, Tomoko; Fujiwara, Toru; Hata, Shingo

2014-11-01

Plants share photosynthetically fixed carbon with arbuscular mycorrhizal (AM) fungi to maintain their growth and nutrition. AM fungi are oleogenic fungi that contain numerous lipid droplets in their syncytial mycelia during most of their life cycle. These lipid droplets are probably used for supporting growth of extraradical mycelia and propagation; however, when and where the lipid droplets are produced remains unclear. To address these issues, we investigated the correlation between intracellular colonization stages and the appearance of fungal lipid droplets in roots by a combination of vital staining of fungal structures, selective staining of lipids and live imaging. We discovered that a surge of lipid droplets coincided with the collapse of arbuscular branches, indicating that arbuscule collapse and the emergence of lipid droplets may be associated processes. This phenomenon was observed in the model AM fungus Rhizophagus irregularis and the ancestral member of AM fungi Paraglomus occultum. Because the collapsing arbuscules were metabolically inactive, the emerged lipid droplets are probably derived from preformed lipids but not de novo synthesized. Our observations highlight a novel mode of lipid release by AM fungi. © The Author 2014. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Structure-activity relationship of prenyl-substituted polyphenols from Artocarpus heterophyllus as inhibitors of melanin biosynthesis in cultured melanoma cells.

Science.gov (United States)

Arung, Enos Tangke; Shimizu, Kuniyoshi; Kondo, Ryuichiro

2007-09-01

A series of prenylated, flavone-based polyphenols, compounds 1-8, were isolated from the wood of Artocarpus heterophyllus. These compounds, which have previously been shown not to inhibit tyrosinase activity, were found to be active inhibitors of the in vivo melanin biosynthesis in B16 melanoma cells, with little or no cytotoxicity. To clarify the structural requirement for inhibition, some structure-activity relationships were studied, in comparison with related compounds lacking prenyl side chains. Our experiments indicate that both prenyl and OH groups, as well as the type of substitution pattern, are crucial for the inhibition of melanin production in B16 melanoma cells.

Genomic Encyclopedia of Fungi

Energy Technology Data Exchange (ETDEWEB)

Grigoriev, Igor

2012-08-10

Genomes of fungi relevant to energy and environment are in focus of the Fungal Genomic Program at the US Department of Energy Joint Genome Institute (JGI). Its key project, the Genomics Encyclopedia of Fungi, targets fungi related to plant health (symbionts, pathogens, and biocontrol agents) and biorefinery processes (cellulose degradation, sugar fermentation, industrial hosts), and explores fungal diversity by means of genome sequencing and analysis. Over 150 fungal genomes have been sequenced by JGI to date and released through MycoCosm (www.jgi.doe.gov/fungi), a fungal web-portal, which integrates sequence and functional data with genome analysis tools for user community. Sequence analysis supported by functional genomics leads to developing parts list for complex systems ranging from ecosystems of biofuel crops to biorefineries. Recent examples of such parts suggested by comparative genomics and functional analysis in these areas are presented here.

Fight Fungi with Fungi: Antifungal Properties of the Amphibian Mycobiome

Directory of Open Access Journals (Sweden)

Patrick J. Kearns

2017-12-01

Full Text Available Emerging infectious diseases caused by fungal taxa are increasing and are placing a substantial burden on economies and ecosystems worldwide. Of the emerging fungal diseases, chytridomycosis caused by the fungus Batrachochytrium dendrobatidis (hereafter Bd is linked to global amphibian declines. Amphibians have innate immunity, as well as additional resistance through cutaneous microbial communities. Despite the targeting of bacteria as potential probiotics, the role of fungi in the protection against Bd infection in unknown. We used a four-part approach, including high-throughput sequencing of bacterial and fungal communities, cultivation of fungi, Bd challenge assays, and experimental additions of probiotic to Midwife Toads (Altyes obstetricans, to examine the overlapping roles of bacterial and fungal microbiota in pathogen defense in captive bred poison arrow frogs (Dendrobates sp.. Our results revealed that cutaneous fungal taxa differed from environmental microbiota across three species and a subspecies of Dendrobates spp. frogs. Cultivation of host-associated and environmental fungi realved numerous taxa with the ability to inhibit or facilitate the growth of Bd. The abundance of cutaneous fungi contributed more to Bd defense (~45% of the fungal community, than did bacteria (~10% and frog species harbored distinct inhibitory communities that were distinct from the environment. Further, we demonstrated that a fungal probiotic therapy did not induce an endocrine-immune reaction, in contrast to bacterial probiotics that stressed amphibian hosts and suppressed antimicrobial peptide responses, limiting their long-term colonization potential. Our results suggest that probiotic strategies against amphibian fungal pathogens should, in addition to bacterial probiotics, focus on host-associated and environmental fungi such as Penicillium and members of the families Chaetomiaceae and Lasiosphaeriaceae.

Production of Antagonistic Compounds by Bacillus sp. with Antifungal Activity against Heritage Contaminating Fungi

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Mara Silva

2018-03-01

Full Text Available In recent years, the population has become acutely aware of the need to conserve the world’s resources. The study of new compounds produced by natural means is important in the search for alternative green solutions that act against biodeteriogenic fungi, which promote biodeterioration of built cultural heritage sites. The present paper reports new solutions, derived from Bacillus sp. CCLBH 1053 cultures, to produce lipopeptides (LPP that can act as green biocides to promote the safeguarding of stone artwork. In the stationary phases of bacteria growth, peptone supplementation and sub-lethal heat activation improve the second cycle of sporulation, greatly enhancing LPP production. The bioactive compounds produced by Bacillus cultures suppress biodeteriogenic fungi growth on stone materials, and, hence, provide an important contribution to the development of new biocides for cultural heritage rehabilitation.

Comparative analysis of fungal genomes reveals different plant cell wall degrading capacity in fungi

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2013-01-01

Background Fungi produce a variety of carbohydrate activity enzymes (CAZymes) for the degradation of plant polysaccharide materials to facilitate infection and/or gain nutrition. Identifying and comparing CAZymes from fungi with different nutritional modes or infection mechanisms may provide information for better understanding of their life styles and infection models. To date, over hundreds of fungal genomes are publicly available. However, a systematic comparative analysis of fungal CAZymes across the entire fungal kingdom has not been reported. Results In this study, we systemically identified glycoside hydrolases (GHs), polysaccharide lyases (PLs), carbohydrate esterases (CEs), and glycosyltransferases (GTs) as well as carbohydrate-binding modules (CBMs) in the predicted proteomes of 103 representative fungi from Ascomycota, Basidiomycota, Chytridiomycota, and Zygomycota. Comparative analysis of these CAZymes that play major roles in plant polysaccharide degradation revealed that fungi exhibit tremendous diversity in the number and variety of CAZymes. Among them, some families of GHs and CEs are the most prevalent CAZymes that are distributed in all of the fungi analyzed. Importantly, cellulases of some GH families are present in fungi that are not known to have cellulose-degrading ability. In addition, our results also showed that in general, plant pathogenic fungi have the highest number of CAZymes. Biotrophic fungi tend to have fewer CAZymes than necrotrophic and hemibiotrophic fungi. Pathogens of dicots often contain more pectinases than fungi infecting monocots. Interestingly, besides yeasts, many saprophytic fungi that are highly active in degrading plant biomass contain fewer CAZymes than plant pathogenic fungi. Furthermore, analysis of the gene expression profile of the wheat scab fungus Fusarium graminearum revealed that most of the CAZyme genes related to cell wall degradation were up-regulated during plant infection. Phylogenetic analysis also

Influence of cadmium and mycorrhizal fungi on the fatty acid profile of flax (Linum usitatissimum) seeds.

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Kaplan, Matthew E; Simmons, Ellen R; Hawkins, Jack C; Ruane, Lauren G; Carney, Jeffrey M

2015-09-01

The soil environment can affect not only the quantity of crops produced but also their nutritional quality. We examined the combined effects of below-ground cadmium (0, 5, and 15 ppm) and mycorrhizal fungi (presence and absence) on the concentration of five major fatty acids within flax seeds (Linum usitatissimum). Plants grown with mycorrhizal fungi produced seeds that contained higher concentrations of unsaturated (18:1, 18:2 and 18:3), but not saturated (16:0 and 18:0) fatty acids. The effects of mycorrhizal fungi on the concentration of unsaturated fatty acids in seeds were most pronounced when plant roots were exposed to 15 ppm Cd (i.e. the concentrations of 18:1, 18:2 and 18:3 increased by 169%, 370% and 150%, respectively). The pronounced effects of mycorrhizal fungi on the concentration of unsaturated fatty acids at 15 ppm Cd may have been due to the presence of elevated levels of Cd within seeds. Our results suggest that, once the concentration of cadmium within seeds reaches a certain threshold, this heavy metal may improve the efficiency of enzymes that convert saturated fatty acids to unsaturated fatty acids. © 2014 Society of Chemical Industry.

Marine fungi: A critique

Digital Repository Service at National Institute of Oceanography (India)

Raghukumar, S.; Raghukumar, C.

in the sea have been ignored to a large extent. However, several instances of terrestrial species of fungi, active in marine environment have been reported. The arguments to support the view that terrestrial species of fungi by virtue of their physiological...

Sequestration of Carbon in Mycorrhizal Fungi Under Nitrogen Fertilization

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Treseder, K. K.; Turner, K. M.

2005-12-01

Mycorrhizal fungi are root symbionts that facilitate plant uptake of soil nutrients in exchange for plant carbohydrates. They grow in almost every terrestrial ecosystem on earth, form relationships with about 80% of plant species, and receive 10 to 20% of the carbon fixed by their host plants. As such, they could potentially sequester a significant amount of carbon in ecosystems. We hypothesized that nitrogen fertilization would decrease carbon storage in mycorrhizal fungi, because plants should reduce investment of carbon in mycorrhizal fungi when nitrogen availability is high. We measured the abundance of two major groups of mycorrhizal fungi, arbuscular mycorrhizal (AM) and ectomycorrhizal (ECM) fungi, in control and nitrogen-fertilized plots within three boreal ecosystems of inland Alaska. The ecosystems represented different recovery stages following severe fire, and comprised a young site dominated by AM fungi, an old site dominated by ECM fungi, and an intermediate site co-dominated by both groups. Pools of mycorrhizal carbon included root-associated AM and ECM structures, soil-associated AM hyphae, and soil-associated glomalin. Glomalin is a glycoprotein produced only by AM fungi. It is present in the cell walls of AM hyphae, and then is deposited in the soil as the hyphae senesce. Nitrogen significantly altered total mycorrhizal carbon pools, but its effect varied by site (site * N interaction, P = 0.05). Under nitrogen fertilization, mycorrhizal carbon was reduced from 99 to 50 g C m2 in the youngest site, was increased from 124 to 203 g C m2 in the intermediate-aged site, and remained at 35 g C m2 in the oldest site. The changes in total mycorrhizal carbon stocks were driven mostly by changes in glomalin (site * N interaction, P = 0.05), and glomalin stocks were strongly correlated with AM hyphal abundance (P stocks within root-associated AM structures increased significantly with nitrogen fertilization across all sites (P = 0.001), as did root

Post-genomic approaches to understanding interactions between fungi and their environment.

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de Vries, Ronald P; Benoit, Isabelle; Doehlemann, Gunther; Kobayashi, Tetsuo; Magnuson, Jon K; Panisko, Ellen A; Baker, Scott E; Lebrun, Marc-Henri

2011-06-01

Fungi inhabit every natural and anthropogenic environment on Earth. They have highly varied life-styles including saprobes (using only dead biomass as a nutrient source), pathogens (feeding on living biomass), and symbionts (co-existing with other organisms). These distinctions are not absolute as many species employ several life styles (e.g. saprobe and opportunistic pathogen, saprobe and mycorrhiza). To efficiently survive in these different and often changing environments, fungi need to be able to modify their physiology and in some cases will even modify their local environment. Understanding the interaction between fungi and their environments has been a topic of study for many decades. However, recently these studies have reached a new dimension. The availability of fungal genomes and development of post-genomic technologies for fungi, such as transcriptomics, proteomics and metabolomics, have enabled more detailed studies into this topic resulting in new insights. Based on a Special Interest Group session held during IMC9, this paper provides examples of the recent advances in using (post-)genomic approaches to better understand fungal interactions with their environments.

Analysis of potential fumonisin-producing Fusarium species in corn products from three main maize-producing areas in eastern China.

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Zhang, Liping; Wang, Jiansheng; Zhang, Chulong; Wang, Qiaomei

2013-02-01

Fusarium species are common fungal contaminants of maize and a number of them can produce mycotoxin fumonisins. China is one of the largest maize producers in the world. This study investigated the contamination of maize samples from three areas in eastern China by Fusarium and fumonisin-producing fungi as well as their fumonisin-producing potential. A total of 22 Fusarium strains were isolated, 19 of which were able to produce fumonisin. Among the 19 strains, 16 belonged to F. verticillioides, two to F. subglutinans and one to F. proliferatum. The majority (17/19) of the fumonisin-forming strains were high FB(1) producers, which is a potential health risk for the population in these areas. Fusarium contamination in samples from the mideastern area was the most serious (11 Fusarium strains, with nine producing fumonisin, isolated from 24 samples), followed by the northeastern area (nine Fusarium strains, with all nine producing fumonisin, isolated from 21 samples) and the southeastern area (two Fusarium strains, with one producing fumonisin, isolated from 19 samples). Although the overall levels of FBs and contamination by fumonisin-producing fungi in corn samples were not serious, the contaminating Fusarium strains possessed fairly strong toxicogenic ability and potential risk for food safety. Copyright © 2012 Society of Chemical Industry.

Autophagy in plant pathogenic fungi.

Science.gov (United States)

Liu, Xiao-Hong; Xu, Fei; Snyder, John Hugh; Shi, Huan-Bin; Lu, Jian-Ping; Lin, Fu-Cheng

2016-09-01

Autophagy is a conserved cellular process that degrades cytoplasmic constituents in vacuoles. Plant pathogenic fungi develop special infection structures and/or secrete a range of enzymes to invade their plant hosts. It has been demonstrated that monitoring autophagy processes can be extremely useful in visualizing the sequence of events leading to pathogenicity of plant pathogenic fungi. In this review, we introduce the molecular mechanisms involved in autophagy. In addition, we explore the relationship between autophagy and pathogenicity in plant pathogenic fungi. Finally, we discuss the various experimental strategies available for use in the study of autophagy in plant pathogenic fungi. Copyright © 2016 Elsevier Ltd. All rights reserved.

OPTIMIZATION OF PRODUCED WATER TREATMENT PROCESS - A CASE STUDY FOR DISPOSAL IN THE NIGER DELTA

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BONIFACE A. ORIJI

2017-12-01

Full Text Available Produced water is the interstitial reservoir water that flows to the surface with the crude oil into the production separators. This study addressed the effects of some chemicals on produced water and the challenges of finding the optimal concentrations of these chemicals for treating produced water. In this study, produced water treatment was carried out in an oil production platform located in the Niger Delta so as to determine the effect of a particular scale inhibitor, biocide, demulsifier and water clarifier, also to obtain the optimum concentrations of these chemicals in the treatment of produced water. The physico-chemical properties and microbial content of the produced water were determined. The results showed that the conductivity, hardness, pH and alkalinity reduced with increasing concentration of the scale inhibitor. The total heterotrophic bacteria count (THBC, heterotrophic fungi count (THFC and the Sulphate reducing bacteria count (SRBC were found to reduce with increasing concentration of biocide and exposure time. The increase in biocide concentration from 64 PPM to 100 PPM resulted in the reduction of THBC by 99.78%, THFC by 81.32% and SRBC 99.85%. The water clarifier gave the optimum concentration for oil and grease in the produced water at 7.3 PPM.

Proteomics of Filamentous Fungi

NARCIS (Netherlands)

Passel, van M.W.J.; Schaap, P.J.; Graaff, de L.H.

2013-01-01

Filamentous fungi, such as Aspergillus niger and Aspergillus oryzae traditionally have had an important role in providing enzymes and enzyme cocktails that are used in food industry. In recent years the genome sequences of many filamentous fungi have become available. This combined with

Aqueous fraction from Cuscuta japonica seed suppresses melanin synthesis through inhibition of the p38 mitogen-activated protein kinase signaling pathway in B16F10 cells.

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Jang, Ji Yeon; Kim, Ha Neui; Kim, Yu Ri; Choi, Yung Hyun; Kim, Byung Woo; Shin, Hwa Kyoung; Choi, Byung Tae

2012-05-07

Semen cuscutae has been used traditionally to treat pimples and alleviate freckles and melasma in Korea. The present study aimed to investigate the inhibitory effect of Cuscuta japonica Choisy seeds on alpha-melanocyte-stimulating hormone (α-MSH)-induced melanogenesis. The aqueous fraction from Semen cuscutae (AFSC) was used to determine anti-melanogenic effects by examination of cellular melanin contents, tyrosinase activity assay, cAMP assay and Western blot analysis for melanin synthesis-related signaling proteins in B16F10 mouse melanoma cells. AFSC markedly inhibited α-MSH-induced melanin synthesis and tyrosinase activity, and also decreased α-MSH-induced expression of microphthalmia-associated transcription factor (MITF) and tyrosinase-related proteins (TRPs). Moreover, AFSC significantly decreased the level of phosphorylated p38 mitogen-activated protein kinase (MAPK) signaling through the down-regulation of α-MSH-induced cAMP. Furthermore, we confirmed that the specific inhibitor of p38 MAPK (SB203580)-mediated suppressed melanin synthesis and tyrosinase activity was further attenuated by AFSC. AFSC also further decreased SB203580-mediated suppression of MITF and TRP expression. These results indicate that AFSC inhibits p38 MAPK phosphorylation with suppressed cAMP levels and subsequently down-regulate MITF and TRP expression, which results in a marked reduction of melanin synthesis and tyrosinase activity in α-MSH-stimulated B16F10 cells. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Endolithic fungi from deep sea calcareous substrata: isolation and laboratory studies

Digital Repository Service at National Institute of Oceanography (India)

Raghukumar, C.; Raghukumar, S.; Sharma, S.; Chandramohan, D.

substrata at 100 atm. in 25 days. This fungus was not capable of acid production on nutrient media in the presence of various carbon sources, nor did it produce proteases. The role of fungi in calcareous substrata in the sea is discussed with reference...

[Effect of flooding time length on mycorrhizal colonization of three AM fungi in two wetland plants].

Science.gov (United States)

Ma, Lei-Meng; Wang, Peng-Teng; Wang, Shu-Guang

2014-01-01

In order to provide information for elucidating effect of flooding on the formation and function of AM in wetland plants, three AM fungi (Glomus intraradices, Glomus versiforme, Glomus etunicatum) were used to investigate the effects of flooding time length on their colonization in cattail (Typha orientalis) and rice (Oryza sativa L. ). The results showed that the mycorrhizal colonization rate (MCR) presented downtrend with increasing flooding time length. In cattail, MCR of the fungus F3 was higher than those of fungi F1 and F2, but no significant difference in MCR was found between fungi F1 and F2. In rice, the MCRs of fungi F2 and F3 were higher than that of E1. In both plants, the proportional frequency of hyphae was the highest while the proportional frequency of arbuscules and vesicles was very low in all treatments, indicating that hyphal colonization was the main route for AM formation. The proportional frequency of hyphae in cattail increased with the flooding time length, but no significant trend was observed in rice plant. The proportional frequency of arhuscules decreased with the increase of flooding time, and was the highest in the treatment without flooding (treatment IV). The number of spores produced by AM fungi increased with increasing flooding time, and reached the highest in the treatment of long time flooding (treatment I). In the same treatment, the fungus F3 produced more spores than fungi F1 and F2. Changes in wet weight of the two plants showed that AM could increase cattail growth under flooding, hut little effect on rice growth was found. It is concluded that flooding time length significantly affected the mycorrhizal colonization rate and the proportional frequency of colonization. AM could enhance the growth of wetland plant, but this depends on the mycorrhizal dependence of host plant on AM fungi. Therefore, flooding time length should be considered in the inoculation of wetland plants with AM fungi.