Note: This page contains sample records for the topic aspergillus sp nr4617 from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

[Aspergillus insulicola Sp. Nov].  

PubMed

A strain of Aspergillus sp. is described and proposed as a new species under the name "Aspergillus insulicola sp. nov." Montemayor & Santiago, 1973. This strain was isolated from soil samples taken in "Aves Island" during a scientific expedition.--Aves Island, situated at 15 degrees, 40 feet, 42 inches N and 63 degrees, 36 feet, 47 inches W, about 665 Km of the coast of Venezuela, has very special ecological conditions. Due to its smallness: 550 m long and 40 to 120 m across and to its low profile only 3 m over sea level, it is swept by the sea during the periodical storms and hurricanes in the area. It has thus a very interesting fauna and flora. We took a series of soil samples to study its mycological flora. Forty samples were inoculated by dilution method. In this first paper a species is described and proposed as a new species because of its macroscopic and microscopic characteristics, as well as by its biological properties, under the name "Aspergillus insulicola sp. nov.". In its study we have tried to follow as closely as possible the methods recommended by Kennet B. Raper & Dorothy Fenell, world authorities on the genera Aspergillus and Penicillium. The strain is being kept in USB under the number T1, and has been sent to ATCC & CBSC to be incorporated in their collections. PMID:1128647

de Montemayor, L; Santiago, A R

1975-04-30

2

Aspergillus uvarum sp. nov., an uniseriate black Aspergillus species isolated from grapes in Europe.  

PubMed

A novel species, Aspergillus uvarum sp. nov., is described within Aspergillus section Nigri. This species can be distinguished from other black aspergilli based on internal transcribed spacers (ITS), beta-tubulin and calmodulin gene sequences, by AFLP analysis and by extrolite profiles. Aspergillus uvarum sp. nov. isolates produced secalonic acid, common to other Aspergillus japonicus-related taxa, and geodin, erdin and dihydrogeodin, which are not produced by any other black aspergilli. None of the isolates were found to produce ochratoxin A. The novel species is most closely related to two atypical strains of Aspergillus aculeatus, CBS 114.80 and CBS 620.78, and was isolated from grape berries in Portugal, Italy, France, Israel, Greece and Spain. The type strain of Aspergillus uvarum sp. nov. is IMI 388523T=CBS 127591T=ITEM 4834T=IBT26606T. PMID:18398215

Perrone, Giancarlo; Varga, János; Susca, Antonia; Frisvad, Jens C; Stea, Gaetano; Kocsubé, Sándor; Tóth, Beáta; Kozakiewicz, Zofia; Samson, Robert A

2008-04-01

3

Aspergillus brasiliensis sp. nov., a biseriate black Aspergillus species with world-wide distribution.  

PubMed

A novel species, Aspergillus brasiliensis sp. nov., is described within Aspergillus section Nigri. This species can be distinguished from other black aspergilli based on intergenic transcribed region, beta-tubulin and calmodulin gene sequences, by amplified fragment length polymorphism analysis and by extrolite profiles. A. brasiliensis isolates produced naphtho-gamma-pyrones, tensidol A and B and pyrophen in common with Aspergillus niger and Aspergillus tubingensis, but also several unique compounds, justifying their treatment as representing a separate species. None of the isolates were found to produce ochratoxin A, kotanins, funalenone or pyranonigrins. The novel species was most closely related to A. niger, and was isolated from soil from Brazil, Australia, USA and The Netherlands, and from grape berries from Portugal. The type strain of Aspergillus brasiliensis sp. nov. is CBS 101740(T) (=IMI 381727(T)=IBT 21946(T)). PMID:17684283

Varga, János; Kocsubé, Sándor; Tóth, Beáta; Frisvad, Jens C; Perrone, Giancarlo; Susca, Antonia; Meijer, Martin; Samson, Robert A

2007-08-01

4

Aspergillus baeticus sp. nov. and Aspergillus thesauricus sp. nov., two species in section Usti from Spanish caves.  

PubMed

Two novel species of Aspergillus that are clearly distinct from all known species in section Usti were revealed during a study of microfungal communities in Spanish caves. The novel species identified in this study and additional species of Aspergillus section Usti are associated with places and substrates related to human activities in caves. Novel species are described using data from four loci (ITS, benA, caM and rpb2), morphology and basic chemical and physiological analyses. Members of the species Aspergillus thesauricus sp. nov. were isolated from various substrates, including decaying organic matter, cave air and cave sediment of the Cueva del Tesoro Cave (the Treasure cave); the species is represented by twelve isolates and is most closely related to the recently described Aspergillus germanicus. Members of the species Aspergillus baeticus sp. nov. were isolated from cave sediment in the Gruta de las Maravillas Cave (the Grotto of the Marvels); the species is represented by two isolates. An additional isolate was found in the Cueva del Tesoro Cave and in the Demänovská Peace Cave (Slovakia), suggesting a potentially wide distribution of this micro-organism. The species is related to Aspergillus ustus and Aspergillus pseudoustus. Both species were unable to grow at 37 °C, and a weakly positive, light greenish yellow Ehrlich reaction was observed in A. thesauricus. Unique morphological features alone are sufficient to distinguish both species from related taxa. PMID:22505602

Nováková, Alena; Hubka, Vit; Saiz-Jimenez, Cesareo; Kolarik, Miroslav

2012-11-01

5

Aspergillus pragensis sp. nov. discovered during molecular reidentification of clinical isolates belonging to Aspergillus section Candidi.  

PubMed

The identity of nine clinical isolates recovered from Czech patients and presumptively identified as Aspergillus sp. section Candidi based on colony morphology was revised using sequences of ?-tubulin, calmodulin gene sequence, and internal transcribed spacer rDNA. Six isolates were from suspected and proven onychomycosis, one from otitis externa, and two associated with probable invasive aspergillosis. The results showed that one Aspergillus candidus isolate was the cause of otitis externa, and both isolates obtained from sputa of patients with probable invasive aspergillosis were reidentified as A. carneus (sect. Terrei) and A. flavus (sect. Flavi). Three isolates from nail scrapings were identified as A. tritici, a verified agent of nondermatophyte onychomycosis. One isolate from toenail was determined to be A. candidus and the two isolates belonged to a hitherto undescribed species, Aspergillus pragensis sp. nov. This species is well supported by phylogenetic analysis based on ?-tubulin and calmodulin gene and is distinguishable from other members of sect. Candidi by red-brown reverse on malt extract agar, slow growth on Czapek-Dox agar and inability to grow at 37°C. A secondary metabolite analysis was also provided with comparison of metabolite spectrum to other species. Section Candidi now encompasses five species for which a dichotomous key based on colony characteristics is provided. All clinical isolates were tested for susceptibilities to selected antifungal agents using the Etest and disc diffusion method. Overall sect. Candidi members are highly susceptible to common antifungals. PMID:24951723

Hubka, Vit; Lyskova, Pavlina; Frisvad, Jens C; Peterson, Stephen W; Skorepova, Magdalena; Kolarik, Miroslav

2014-08-01

6

Two new compounds from gorgonian-associated fungus Aspergillus sp.  

PubMed

One new gamma-lactone derivative 5-hydroxy-3-isopropyl-4-methoxyfuranone (1) and one new lactam derivative dehydrated-marinamide (2), along with two known compounds marinamide (3) and marinamide methyl ester (4) were isolated from the fermentation broth of the marine gorgonian-associated fungus Aspergillus sp. SCSGAF0093. Their structures were elucidated on the basis of spectroscopic and spectrometric analysis. Compound 1 showed significant toxicity to brine shrimp (Artemia salina) with a median lethal concentration (LC50) of 1.25 microM, and 3 inhibited protein tyrosine phosphatase 1B (PTP1B) with a half maximal inhibitory concentration (IC50) of 23.3 microg/mL. PMID:24079168

Xu, Xin-Ya; Zhang, Xiao-Yong; He, Fei; Peng, Jiang; Nong, Xu-Hua; Qi, Shu-Hua

2013-08-01

7

Biotransformation of one monoterpene by sporulated surface cultures of Aspergillus niger and Penicillium sp.  

PubMed

In this study, biotransformation of menthol by sporulated surface culture of Aspergillus niger and Penicillium sp. was studied. The main bioconversion product obtained from menthol of A. niger was cis-p-menthan-7-ol and the main products obtained by surface Penicillium sp. were limonene, p-cymene and gamma-terpinene using sporulated surface culture. The pathways involved in the biotransformation of menthol by A. niger and Penicillium sp. to main products are also discussed. PMID:19521921

Esmaeili, Akbar; Sharafian, Shirin; Safaiyan, Shila; Rezazadeh, Shamsali; Rustaivan, Abdolhossein

2009-01-01

8

Strain improvement of Aspergillus sp. and Penicillium sp. by induced mutation for biotransformation of alpha-pinene to verbenol.  

PubMed

Variants of Aspergillus sp. and Penicillium sp. obtained after treatment with colchicine, ethyl methanesulphonate (EMS), or ultraviolet (UV) irradiation indicated varying levels of significant increases in their efficiency to transform alpha-pinene to verbenol. In case of Aspergillus sp. the UV-induced variant was the best performer with a 15-fold increase in biotransformation efficiency compared to the wild type. In case of colchicine and EMS-induced variants the biotransformation increases were 2- and 8-fold, respectively. The UV-induced variant of Penicillium sp. was capable of eight fold increase in efficiency while the colchicine- and EMS-induced variants were 1.5- and 2-fold, respectively. The variants were characterised with respect to changes in colony morphology, spore dimension, DNA content, and products formed, viz. verbenol and verbenone. PMID:10099602

Agrawal, R; Deepika, N U; Joseph, R

1999-04-20

9

Degradation of polycaprolactone at 50 °C by a thermotolerant Aspergillus sp  

Microsoft Academic Search

A thermotolerant Aspergillus sp. strain ST-01 degrading poly(e-caprolactone) films was isolated. The polyester was degraded and assimilated giving 36 mg of cell from 100 mg sample and 10 mg yeast extract after 6 days at 50 °C. The degradation products were identified as succinic acid, butyric acid, valeric acid, and caproic acid. The isolate also degraded more than 90% film

James G. Sanchez; Akio Tsuchii; Yutaka Tokiwa

2000-01-01

10

8-Hydroxydaidzein, an aldose reductase inhibitor from okara fermented with Aspergillus sp. HK-388.  

PubMed

The aldose reductase (AR) inhibitor, 8-hydroxydaidzein, was isolated and identified from a methanolic extract of okara (soybean pulp) fermented with the fungal strain, Aspergillus sp. HK-388. 8-Hydroxydaidzein showed non-competitive inhibition of human recombinant AR with respect to DL-glyceraldehyde, its Ki value being evaluated as 7.0 microM. PMID:15277768

Fujita, Tomoyuki; Funako, Tomoyoshi; Hayashi, Hideo

2004-07-01

11

Constitutive production of extracellular glucose isomerase by an osmophillic Aspergillus sp. under submerged conditions  

Microsoft Academic Search

We report constitutive production of glucose isomerase (GI) under submerged growth of Aspergillus sp. in glucose phosphate broth (GPB). The fungus produced significant quantities of extracellular GI in GPB without supplementing\\u000a the inducer (xylose). The maximum biomass (872 mg) and highest level of GI (1126 U) were obtained in 42 h at 30 °C and 120 rpm.\\u000a Equal level of biomass and enzyme were produced

Riyaz Zafar Sayyed; G. B. Shimpi; S. B. Chincholkar

2010-01-01

12

Assessment of the efficacy of Aspergillus sp . EL2 in textile waste water treatment  

Microsoft Academic Search

Fungal biomass has the ability to decolorize a wide variety of dyes successfully through a number of mechanisms. A brown rot\\u000a isolate, previously identified as Aspergillus sp. EL-2, was used in the aerobic treatment of textile waste water efficiently. In the current work, the treated waste water\\u000a was tested chemically using more than one combined treatment. Microbial toxicity, phytotoxicity, genotoxicity

Ola M. GomaaHussein; Hussein Abd El Kareem; Reham Fatahy

13

Tetrahydrobostrycin and 1-deoxytetrahydrobostrycin, two new hexahydroanthrone derivatives, from a marine-derived fungus Aspergillus sp.  

PubMed

Two new hexahydroanthrones, tetrahydrobostrycin (1) and 1-deoxytetrahydrobostrycin (2), were isolated from a marine-derived fungus Aspergillus sp. strain 05F16 collected at the coral reef of Manado, Indonesia, together with bostrycin and abscisic acid. The structures of new compounds were determined on the basis of their spectral data. Compound 1 showed weak antibacterial activity against Staphylococcus aureus and Escherichia coli and 2 against S. aureus. PMID:18776653

Xu, Jinzhong; Nakazawa, Takahiro; Ukai, Kazuyo; Kobayashi, Hisayoshi; Mangindaan, Remy E P; Wewengkang, Defny S; Rotinsulu, Henki; Namikoshi, Michio

2008-07-01

14

A new diphenyl ether from marine-derived fungus Aspergillus sp. B-F-2.  

PubMed

A new diphenyl ether dimethyl 2,3'-dimethylosoate (1) together with three known compounds monomethylsulochrin (2), emodin (3), and questin (4) were isolated through bioassay-guided fractionations from the culture of a marine-derived fungus Aspergillus sp. B-F-2. The structures of these compounds were determined by spectroscopic methods. Cytotoxicities of compounds 1 and 2 against K562 cell line were preliminarily evaluated by the MTT method and flow cytometry. PMID:16915822

Liu, Rui; Zhu, Weiming; Zhang, Yapeng; Zhu, Tianjiao; Liu, Hongbing; Fang, Yuchun; Gu, Qianqun

2006-06-01

15

Marine Fungi Aspergillus sydowii and Trichoderma sp. Catalyze the Hydrolysis of Benzyl Glycidyl Ether  

Microsoft Academic Search

Whole cells of the marine fungi Aspergillus sydowii Gc12, Penicillium raistrickii Ce16, P. miczynskii Gc5, and Trichoderma sp. Gc1, isolated from marine sponges of the South Atlantic Ocean (Brazil), have been screened for the enzymatic resolution\\u000a of (±)-2-(benzyloxymethyl)oxirane (benzyl glycidyl ether; 1). Whole cells of A. sydowii Gc12 catalyzed the enzymatic hydrolysis of (R,S)-1 to yield (R)-1 with an enantiomeric

Mariana Provedel Martins; Ana Maria Mouad; Letícia Boschini; Mirna Helena Regali Seleghim; Lara Durăes Sette; André Luiz Meleiro Porto

2011-01-01

16

Constitutive production of extracellular glucose isomerase by an osmophillic Aspergillus sp. under submerged conditions.  

PubMed

We report constitutive production of glucose isomerase (GI) under submerged growth of Aspergillus sp. in glucose phosphate broth (GPB). The fungus produced significant quantities of extracellular GI in GPB without supplementing the inducer (xylose). The maximum biomass (872 mg) and highest level of GI (1126 U) were obtained in 42 h at 30 °C and 120 rpm. Equal level of biomass and enzyme were produced in GPB with glucose and xylose, but the amount of biomass and enzyme was drastically reduced when the fungus was grown on other carbon sources. Optimum biomass, enzyme units and enzyme activity were obtained with 40 and 1 g/l of glucose, respectively. Growth of Aspergillus sp. and enzyme synthesis even at high glucose concentration (60 g/l) indicated the osmophillic nature of the fungus. Increasing the glucose concentration above 1 and 40 g/l did not support the growth and enzyme activity. Among various organic and inorganic nitrogen sources used, yeast extract, peptone and NH4SO4 gave the best biomass and enzyme yields. Addition of Mg(2+) and Mn(2+) in GPB significantly enhanced the enzyme production. Under optimized conditions in modified GPB, the yield of biomass and synthesis and activity of GI were significantly enhanced. PMID:23572677

Sayyed, Riyaz Zafar; Shimpi, G B; Chincholkar, S B

2010-10-01

17

Gliotoxin Isolated from Marine Fungus Aspergillus sp. Induces Apoptosis of Human Cervical Cancer and Chondrosarcoma Cells  

PubMed Central

Gliotoxin, a secondary metabolite produced by marine fungus Aspergillus sp., possesses various biological activities including anticancer activity. However, the mechanism underlying gliotoxin-induced cytotoxicity on human cervical cancer (Hela) and human chondrosarcoma (SW1353) cells remains unclear. In this study, we focused on the effect of gliotoxin induction on apoptosis, the activating expressions of caspase family enzymes in the cells. Apoptotic cell levels were measured through DAPI and Annexin V/Propidium Iodide (PI) double staining analysis. The apoptotic protein expression of Bcl-2 and caspase family was detected by Western blot in Hela and SW1353 cells. Our results showed that gliotoxin treatment inhibited cell proliferation and induced significant morphological changes. Gliotoxin induced apoptosis was further confirmed by DNA fragmentation, chromatin condensation and disrupted mitochondrial membrane potential. Gliotoxin-induced activation of caspase-3, caspase-8 and caspase-9, down-regulation of Bcl-2, up-regulation of Bax and cytochromec (cyt c) release showed evidence for the gliotoxin activity on apoptosis. These findings suggest that gliotoxin isolated from marine fungus Aspergillus sp. induced apoptosis in Hela and SW1353 cells via the mitochondrial pathway followed by downstream events leading to apoptotic mode of cell death.

Nguyen, Van-Tinh; Lee, Jung Suck; Qian, Zhong-Ji; Li, Yong-Xin; Kim, Kil-Nam; Heo, Soo-Jin; Jeon, You-Jin; Park, Won Sun; Choi, Il-Whan; Je, Jae-Young; Jung, Won-Kyo

2013-01-01

18

Marine fungi Aspergillus sydowii and Trichoderma sp. catalyze the hydrolysis of benzyl glycidyl ether.  

PubMed

Whole cells of the marine fungi Aspergillus sydowii Gc12, Penicillium raistrickii Ce16, P. miczynskii Gc5, and Trichoderma sp. Gc1, isolated from marine sponges of the South Atlantic Ocean (Brazil), have been screened for the enzymatic resolution of (±)-2-(benzyloxymethyl)oxirane (benzyl glycidyl ether; 1). Whole cells of A. sydowii Gc12 catalyzed the enzymatic hydrolysis of (R,S)-1 to yield (R)-1 with an enantiomeric excess (ee) of 24-46% and 3-(benzyloxy)propane-1,2-diol (2) with ee values <10%. In contrast, whole cells of Trichoderma sp. Gc1 afforded (S)-1 with ee values up to 60% and yields up to 39%, together with (R)-2 in 25% yield and an ee of 32%. This is the first published example of the hydrolysis of 1 by whole cells of marine fungi isolated from the South Atlantic Ocean. The hydrolases from the two studied fungi exhibited complementary regioselectivity in opening the epoxide ring of racemic 1, with those of A. sydowii Gc12 showing an (S) preference and those of Trichoderma sp. Gc1 presenting an (R) preference for the substrate. PMID:20549284

Martins, Mariana Provedel; Mouad, Ana Maria; Boschini, Letícia; Regali Seleghim, Mirna Helena; Sette, Lara Durăes; Meleiro Porto, André Luiz

2011-04-01

19

Antibacterial Bisabolane-Type Sesquiterpenoids from the Sponge-Derived Fungus Aspergillus sp.  

PubMed Central

Four new bisabolane-type sesquiterpenoids, aspergiterpenoid A (1), (?)-sydonol (2), (?)-sydonic acid (3), and (?)-5-(hydroxymethyl)-2-(2?,6?,6?-trimethyltetrahydro-2H- pyran-2-yl)phenol (4) together with one known fungal metabolite (5) were isolated from the fermentation broth of a marine-derived fungus Aspergillus sp., which was isolated from the sponge Xestospongia testudinaria collected from the South China Sea. Four of them (1–4) are optically active compounds. Their structures and absolute configurations were elucidated by using NMR spectroscopic techniques and mass spectrometric analysis, and by comparing their optical rotations with those related known analogues. Compounds 1–5 showed selective antibacterial activity against eight bacterial strains with the MIC (minimum inhibiting concentrations) values between 1.25 and 20.0 µM. The cytotoxic, antifouling, and acetylcholinesterase inhibitory activities of these compounds were also examined.

Li, Dan; Xu, Ying; Shao, Chang-Lun; Yang, Rui-Yun; Zheng, Cai-Juan; Chen, Yi-Yan; Fu, Xiu-Mei; Qian, Pei-Yuan; She, Zhi-Gang; de Voogd, Nicole J.; Wang, Chang-Yun

2012-01-01

20

Antibacterial bisabolane-type sesquiterpenoids from the sponge-derived fungus Aspergillus sp.  

PubMed

Four new bisabolane-type sesquiterpenoids, aspergiterpenoid A (1), (-)-sydonol (2), (-)-sydonic acid (3), and (-)-5-(hydroxymethyl)-2-(2',6',6'-trimethyltetrahydro-2H- pyran-2-yl)phenol (4) together with one known fungal metabolite (5) were isolated from the fermentation broth of a marine-derived fungus Aspergillus sp., which was isolated from the sponge Xestospongia testudinaria collected from the South China Sea. Four of them (1-4) are optically active compounds. Their structures and absolute configurations were elucidated by using NMR spectroscopic techniques and mass spectrometric analysis, and by comparing their optical rotations with those related known analogues. Compounds 1-5 showed selective antibacterial activity against eight bacterial strains with the MIC (minimum inhibiting concentrations) values between 1.25 and 20.0 µM. The cytotoxic, antifouling, and acetylcholinesterase inhibitory activities of these compounds were also examined. PMID:22363233

Li, Dan; Xu, Ying; Shao, Chang-Lun; Yang, Rui-Yun; Zheng, Cai-Juan; Chen, Yi-Yan; Fu, Xiu-Mei; Qian, Pei-Yuan; She, Zhi-Gang; de Voogd, Nicole J; Wang, Chang-Yun

2012-01-01

21

Golmaenone, a new diketopiperazine alkaloid from the marine-derived fungus Aspergillus sp.  

PubMed

A new diketopiperazine alkaloid, golmaenone (1). and related alkaloids, neoechinulin A (2). and L-alanyl-L-tryptophan anhydride (3). have been isolated from the culture broth of the marine-derived fungus Aspergillus sp. The structure and absolute stereochemistry of the new compound (1). was assigned by spectroscopic methods and the advanced Marfey's method. Compounds 1 and 2 exhibited a significant radical scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) with IC(50) values of 20 and 24 microM, respectively, which are similar to the positive control, ascorbic acid (IC(50), 20 microM). Compounds 1 and 2 also showed an ultraviolet-A (UV-A) (320--390 nm) protecting activity with ED(50) values of 90 and 170 microM, respectively, which are more active than oxybenzone (ED(50), 350 microM) currently being used as sunscreen. PMID:14993767

Li, Yong; Li, Xifeng; Kim, Se-Kwon; Kang, Jung Sook; Choi, Hong Dae; Rho, Jung Rae; Son, Byeng Wha

2004-03-01

22

Brefeldin A, a cytotoxin produced by Paecilomyces sp. and Aspergillus clavatus isolated from Taxus mairei and Torreya grandis.  

PubMed

Paecilomyces sp. and Aspergillus clavatus, which were isolated from Taxus mairei and Torreya grandis from southeast China, produced toxic metabolites when grown in liquid culture. Nuclear magnetic resonance techniques, infrared spectrometry, electrospray ionization mass spectroscopy and X-ray analysis identified brefeldin A, a bioactive metabolite produced by a number of fungal species belonging to the genera Alternaria, Ascochyta, Penicillium, Curvularia, Cercospora and Phyllosticta. This is the first report of the isolation of the cytotoxin from Paecilomyces sp. and A. clavatus. The relevance of brefeldin A to the association between these fungi and their host plants is discussed. PMID:12208606

Wang, Jianfeng; Huang, Yaojian; Fang, Meijuan; Zhang, Yongjie; Zheng, Zhonghui; Zhao, Yufen; Su, Wenjin

2002-09-01

23

Cowpeas as growth substrate do not support the production of aflatoxin byAspergillus sp.  

PubMed

A number of 21Aspergillus sp. strains isolated from cowpeas from Benin (Africa) were characterized by RAPD methodology. Seven of these strains grouped withA. flavus in the dendrogram generated with the RAPD data. Only three were able to produce aflatoxin in significant amounts. Twelve other isolates grouped withA. parasiticus. All of these strains except 3 produced aflatoxin. Two additional strains neither fit with theA. flavus group, nor theA. parasiticus group according to their RAPD pattern. Both did not produce aflatoxin in measurable amounts.Generally the aflatoxin positive strains produced high amounts of aflatoxin after growth on YES medium. However after growth on cowpea based medium aflatoxin biosynthesis was strongly ceased, albeit the growth of the colony was only partly reduced. This was true for media made either with the whole cowpea seed or with cowpea seed without seed coat. Interestingly when the cowpea medium was heat sterilized the fungus was able to produce high amounts of aflatoxin. This, however, was not the case after the use of gamma irradiation as sterilization method for the medium. The expression of thenor- 1 gene, which is one of the early genes involved in aflatoxin biosynthesis, was significantly repressed after growth on gamma irradiated cowpea medium in contrast to YES medium. PMID:23604687

Houssou, P A; Schmidt-Heydt, M; Geisen, R; Fandohan, P; Ahohuendo, B C; Hounhouigan, D J; Jakobsen, M

2008-06-01

24

New bisabolane sesquiterpenoids from a marine-derived fungus Aspergillus sp. isolated from the sponge Xestospongia testudinaria.  

PubMed

Three new phenolic bisabolane sesquiterpenoid dimers, disydonols A-C (1-3), and one known compound (S)-(+)-sydonol (4) were isolated from the fermentation broth of a marine-derived fungus Aspergillus sp., which was isolated from the sponge Xestospongia testudinaria collected from the South China Sea. Their structures were elucidated on the basis of comprehensive spectral analysis including 1D and 2D NMR spectra and HR-ESI-MS. These compounds were evaluated for cytotoxic activity against HepG-2 and Caski human tumour cell lines. Among them, compounds 1 and 3 exhibited cytotoxicity against the two cell lines. PMID:22225637

Sun, Ling-Ling; Shao, Chang-Lun; Chen, Jian-Feng; Guo, Zhi-Yong; Fu, Xiu-Mei; Chen, Min; Chen, Yi-Yan; Li, Rui; de Voogd, Nicole J; She, Zhi-Gang; Lin, Yong-Cheng; Wang, Chang-Yun

2012-02-01

25

Stabilities of immobilized beta-galactosidase of Aspergillus sp. AF for the optimal production of galactooligosaccharides from lactose.  

PubMed

Beta-galactosidase of Aspergillus sp. AF crude homogenate was immobilized in Ca-alginate gel beads and used for the production of galactooligosaccharides (GOS) from lactose. Optimum pH and temperature, thermal and storage stability of the enzyme activity were investigated and compared with those of the free enzyme. The study on the improvement of mechanical strength of the alginate beads was carried out through various methods, which demonstrates that the hardening process, where the alginate beads were treated with 0.225 M CaCl(2) solution after three batches to compensate the lost of calcium in the beads, provided a high mechanical stability for repeated use in large-scale production. The experiment results show that GOS yield increased with the increase of lactose concentration, and also increased with excessive addition of lactose (exceeding its solubility) at the beginning of the reaction. The immobilization of beta-galactosidase of Aspergillus sp. AF crude homogenate is cheap in processing cost and easy to carry out, and the immobilized enzyme possesses high performance for industrial application. PMID:20082600

Feng, Yongmei; Chang, Xiulian; Wang, Wenhua; Ma, Runyu

2010-01-01

26

Aspergillus tanneri sp. nov., a New Pathogen That Causes Invasive Disease Refractory to Antifungal Therapy  

PubMed Central

The most common cause of invasive aspergillosis (IA) in patients with chronic granulomatous disease (CGD) is Aspergillus fumigatus followed by A. nidulans; other aspergilli rarely cause the disease. Here we review two clinical cases of fatal IA in CGD patients and describe a new etiologic agent of IA refractory to antifungal therapy. Unlike typical IA caused by A. fumigatus, the disease caused by the new species was chronic and spread from the lung to multiple adjacent organs. Mycological characteristics and the phylogenetic relationship with other aspergilli based on the sequence analysis of Mcm7, RPB2, and Tsr1 indicated that the new species, which we named as A. tanneri, belongs to Aspergillus section Circumdati. The species has a higher amphotericin B, voriconazole, and itraconazole MIC and causes more chronic infection in CGD mice than A. fumigatus. This is the first report documenting IA in CGD patients caused by a species belonging to the Aspergillus section Circumdati that is inherently resistant to azoles and amphotericin B. Unlike the results seen with many members of Aspergillus section Circumdati, ochratoxin was not detected in filtrates of cultures grown in various media. Our phenotypic and genetic characterization of the new species and the case reports will assist future diagnosis of infection caused by A. tanneri and lead to more appropriate patient management.

Sugui, Janyce A.; Peterson, Stephen W.; Clark, Lily P.; Nardone, Glenn; Folio, Les; Riedlinger, Gregory; Zerbe, Christa S.; Shea, Yvonne; Henderson, Christina M.; Zelazny, Adrian M.; Holland, Steven M.

2012-01-01

27

Nine New and Five Known Polyketides Derived from a Deep Sea-Sourced Aspergillus sp. 16-02-1  

PubMed Central

Nine new C9 polyketides, named aspiketolactonol (1), aspilactonols A–F (2–7), aspyronol (9) and epiaspinonediol (11), were isolated together with five known polyketides, (S)-2-(2?-hydroxyethyl)-4-methyl-?-butyrolactone (8), dihydroaspyrone (10), aspinotriol A (12), aspinotriol B (13) and chaetoquadrin F (14), from the secondary metabolites of an Aspergillus sp. 16-02-1 that was isolated from a deep-sea sediment sample. Structures of the new compounds, including their absolute configurations, were determined by spectroscopic methods, especially the 2D NMR, circular dichroism (CD), Mo2-induced CD and Mosher’s 1H NMR analyses. Compound 8 was isolated from natural sources for the first time, and the possible biosynthetic pathways for 1–14 were also proposed and discussed. Compounds 1–14 inhibited human cancer cell lines, K562, HL-60, HeLa and BGC-823, to varying extents.

Chen, Xiu-Wen; Li, Chang-Wei; Cui, Cheng-Bin; Hua, Wei; Zhu, Tian-Jiao; Gu, Qian-Qun

2014-01-01

28

Nine New and Five Known Polyketides Derived from a Deep Sea-Sourced Aspergillus sp. 16-02-1.  

PubMed

Nine new C9 polyketides, named aspiketolactonol (1), aspilactonols A-F (2-7), aspyronol (9) and epiaspinonediol (11), were isolated together with five known polyketides, (S)-2-(2'-hydroxyethyl)-4-methyl-?-butyrolactone (8), dihydroaspyrone (10), aspinotriol A (12), aspinotriol B (13) and chaetoquadrin F (14), from the secondary metabolites of an Aspergillus sp. 16-02-1 that was isolated from a deep-sea sediment sample. Structures of the new compounds, including their absolute configurations, were determined by spectroscopic methods, especially the 2D NMR, circular dichroism (CD), Mo2-induced CD and Mosher's 1H NMR analyses. Compound 8 was isolated from natural sources for the first time, and the possible biosynthetic pathways for 1-14 were also proposed and discussed. Compounds 1-14 inhibited human cancer cell lines, K562, HL-60, HeLa and BGC-823, to varying extents. PMID:24871461

Chen, Xiu-Wen; Li, Chang-Wei; Cui, Cheng-Bin; Hua, Wei; Zhu, Tian-Jiao; Gu, Qian-Qun

2014-01-01

29

Aspergillus felis sp. nov., an Emerging Agent of Invasive Aspergillosis in Humans, Cats, and Dogs  

PubMed Central

We describe a novel heterothallic species in Aspergillus section Fumigati, namely A. felis (neosartorya-morph) isolated from three host species with invasive aspergillosis including a human patient with chronic invasive pulmonary aspergillosis, domestic cats with invasive fungal rhinosinusitis and a dog with disseminated invasive aspergillosis. Disease in all host species was often refractory to aggressive antifungal therapeutic regimens. Four other human isolates previously reported as A. viridinutans were identified as A. felis on comparative sequence analysis of the partial ?-tubulin and/or calmodulin genes. A. felis is a heterothallic mold with a fully functioning reproductive cycle, as confirmed by mating-type analysis, induction of teleomorphs within 7 to 10 days in vitro and ascospore germination. Phenotypic analyses show that A. felis can be distinguished from the related species A. viridinutans by its ability to grow at 45°C and from A. fumigatus by its inability to grow at 50°C. Itraconazole and voriconazole cross-resistance was common in vitro.

Barrs, Vanessa R.; van Doorn, Tineke M.; Houbraken, Jos; Kidd, Sarah E.; Martin, Patricia; Pinheiro, Maria Dolores; Richardson, Malcolm; Varga, Janos; Samson, Robert A.

2013-01-01

30

Aspergillus felis sp. nov., an emerging agent of invasive aspergillosis in humans, cats, and dogs.  

PubMed

We describe a novel heterothallic species in Aspergillus section Fumigati, namely A. felis (neosartorya-morph) isolated from three host species with invasive aspergillosis including a human patient with chronic invasive pulmonary aspergillosis, domestic cats with invasive fungal rhinosinusitis and a dog with disseminated invasive aspergillosis. Disease in all host species was often refractory to aggressive antifungal therapeutic regimens. Four other human isolates previously reported as A. viridinutans were identified as A. felis on comparative sequence analysis of the partial ?-tubulin and/or calmodulin genes. A. felis is a heterothallic mold with a fully functioning reproductive cycle, as confirmed by mating-type analysis, induction of teleomorphs within 7 to 10 days in vitro and ascospore germination. Phenotypic analyses show that A. felis can be distinguished from the related species A. viridinutans by its ability to grow at 45°C and from A. fumigatus by its inability to grow at 50°C. Itraconazole and voriconazole cross-resistance was common in vitro. PMID:23798996

Barrs, Vanessa R; van Doorn, Tineke M; Houbraken, Jos; Kidd, Sarah E; Martin, Patricia; Pinheiro, Maria Dolores; Richardson, Malcolm; Varga, Janos; Samson, Robert A

2013-01-01

31

Effect of forced aeration on citric acid production by Aspergillus sp. mutants in SSF.  

PubMed

Citric acid (CA) is one of the most important products of fermentation in the world. A great variety of agro-industrial residues can be used in solid state fermentation. Aspergillus niger parental strain (CCT 7716) and two strains obtained by mutagenesis (CCT 7717 and CCT 7718) were evaluated in Erlenmeyer flasks and glass columns using citric pulp (CP) as substrate/support, sugarcane molasses and methanol. Best results using glass columns (forced aeration) were found in the fourth day of fermentation: 278.4, 294.9 and 261.1 g CA/kg of dry CP with CCT 7716, CCT 7718 and CCT 7717, respectively. In Erlenmeyer flasks (aeration by diffusion) CA reached 410.7, 446.8 and 492.7 g CA/kg of dry CP with CCT 7716, CCT 7718 and CCT 7717, respectively. The aeration by diffusion improved CA production by the three strains. A data acquisition system specially developed for biotechnological processes analysis was used to perform the respirometric parameters measurement. PMID:23760557

Rodrigues, Cristine; Vandenberghe, Luciana P S; Sturm, Wilerson; Dergint, Dario E A; Spier, Michele Rigon; de Carvalho, Júlio Cesar; Soccol, Carlos R

2013-12-01

32

Application of statistical experimental design to optimize culture requirements of Aspergillus sp. Zh-26 producing xylanase for degradation of arabinoxylans in mashing.  

PubMed

The objective of this study was to isolate and characterize a strain of Aspergillus capable of producing xylanase. According to the morphology and comparison of ITS (Internal Transcribed Spacer) rDNA gene sequence, the strain Aspergillus sp. ZH-26 was identified as a strain of Aspergillus awamori. Statistically based experimental designs were applied for the optimization of xylanase production from A. awamori ZH-26. The considered medium components included 17 components as follows: yeast extract, tryptone, urea, NH(4)Cl, (NH(4))(2)SO(4), NaNO(3), KH(2)PO(4), K(2)HPO(4), NH(4)NO(3), MgSO(4), CaCl(2), CuSO(4), ZnCl(2), FeSO(4), MnSO(4), vitamin B(1), and EDTA. Yeast extract, tryptone, (NH(4))(2)SO(4), KH(2)PO(4), and CaCl(2) were identified to have significant effects on xylanase production using the Plackett-Burman experimental design. These 5 major components were subsequently optimized using the Box-Behnken experimental design. By response surface methodology and canonical analysis, the optimal concentrations for higher production of xylanase were yeast extract 5.95 g/L, tryptone 6.79 g/L, (NH(4))(2)SO(4) 13.37 g/L, KH(2)PO(4) 1.14 g/L, CaCl(2) 0.81 g/L. Under optimal conditions, the xylanase activity from A. awamori ZH-26 reached 47.3 U/mL. A small-scale mashing was carried out to evaluate the performance of the xylanase on degradation of arabinoxylans in mashing. Results showed that polymeric arabinoxylan content and wort viscosity in mashing with grist containing wheat malt sharply decreased to the basal level (from 470 to 185 mg/L) with the addition of xylanase. PMID:17995733

Li, Y; Liu, Z; Cui, F; Xu, Y; Zhao, H; Liu, Z

2007-06-01

33

High-level production of thermotolerant ?-xylosidase of Aspergillus sp. BCC125 in Pichia pastoris: characterization and its application in ethanol production.  

PubMed

A gene coding for thermotolerant ?-xylosidase from Aspergillus sp. BCC125 was characterized. The recombinant enzyme was expressed in methylotrophic yeast Pichia pastoris KM71 and especially high yield of secreted enzyme was obtained. ?-xylosidase possessed high enzyme efficiency (Kcat/Km=198.8mM(-1)s(-1)) toward pNP-?-D-xylopyranoside (pNP?X) with optimal temperature and pH for activity of 60°C and pH 4.0-5.0, respectively. The identified ?-xylosidase showed clear synergism with previously identified xylanase for hydrolysis of xylan in vitro as well as simultaneous saccharification and fermentation process (SSF) in vivo with Pichia stipitis. PMID:23265813

Wongwisansri, Sriwan; Promdonkoy, Peerada; Matetaviparee, Panida; Roongsawang, Niran; Eurwilaichitr, Lily; Tanapongpipat, Sutipa

2013-03-01

34

Protective Effects of Emodin and Chrysophanol Isolated from Marine Fungus Aspergillus sp. on Ethanol-Induced Toxicity in HepG2/CYP2E1 Cells  

PubMed Central

Alcohol-induced liver injury progresses from fatty infiltration followed by a harmful cause of inflammation leading to an irreversible damage. In this study, two compounds (emodin and chrysophanol) isolated from marine fungus Aspergillus sp. were examined for their protective effects against ethanol-induced toxicity in vitro. Ethanol-induced HepG2/CYP2E1 cells were treated with the compounds at various concentrations, and the results showed that there was a dose-dependent decrease of gamma-glutamyl transpeptidase (GGT) activity and increase of glutathione (GSH) in the culture media with an increase in cell viability. Furthermore, the protective effects of the compounds were evaluated by protein expression levels of GGT, GSH, and CYP2E1 using Western blot. Among the compounds, emodin addressed to the ethanol-induced cytotoxicity more effectively compared to the chrysophanol. It could be suggested that emodin isolated from this genus would be a potential candidate for attenuating ethanol induced liver damage for further industrial applications such as functional food and pharmaceutical developments.

Qian, Zhong-Ji; Zhang, Chen; Li, Yong-Xin; Je, Jae-Young; Kim, Se-Kwon; Jung, Won-Kyo

2011-01-01

35

Aspergillus Keratitis  

Microsoft Academic Search

\\u000a The cornea must be perfectly transparent to allow an individual to visualize his\\/her environment. Keratitis, an inflammation\\u000a of the cornea that frequently arises due to infection, is a threat to corneal transparency. Species of Aspergillus may cause keratitis, especially in outdoor workers in agricultural communities in the developing world and in tropical and\\u000a subtropical areas. Aspergillus keratitis frequently occurs following

Philip A. Thomas

36

Aspergillus flavus.  

PubMed

Aspergillus flavus is saprophytic soil fungus that infects and contaminates preharvest and postharvest seed crops with the carcinogenic secondary metabolite aflatoxin. The fungus is also an opportunistic animal and human pathogen causing aspergillosis diseases with incidence increasing in the immunocompromised population. Whole genome sequences of A. flavus have been released and reveal 55 secondary metabolite clusters that are regulated by different environmental regimes and the global secondary metabolite regulators LaeA and VeA. Characteristics of A. flavus associated with pathogenicity and niche specialization include secondary metabolite production, enzyme elaboration, and a sophisticated oxylipin host crosstalk associated with a quorum-like development program. One of the more promising strategies in field control involves the use of atoxic strains of A. flavus in competitive exclusion studies. In this review, we discuss A. flavus as an agricultural and medical threat and summarize recent research advances in genomics, elucidation of parameters of pathogenicity, and control measures. PMID:21513456

Amaike, Saori; Keller, Nancy P

2011-01-01

37

Cyclopiazonic Acid Biosynthesis in Aspergillus sp.: Characterization of a Reductase-like R* Domain in Cyclopiazonate Synthetase that Forms and Releases cyclo-Acetoacetyl-l-tryptophan†  

PubMed Central

The fungal neurotoxin ?-cyclopiazonic acid (CPA), a nanomolar inhibitor of Ca2+-ATPase, has a pentacyclic indole tetramic acid scaffold that arises from one molecule of tryptophan, acetyl-CoA, malonyl-CoA and dimethylallyl pyrophosphate by consecutive action of three enzymes CpaS, D, O. CpaS is a hybrid, two module polyketide synthase-nonribosomal peptide synthetase (PKS-NRPS) that makes and releases cyclo-acetoacetyl-L-tryptophan (cAATrp), the tetramic acid that serves as substrate for subsequent prenylation and oxidative cyclization to the five ring CPA scaffold. The NRPS module in CpaS has a predicted four domain organization of Condensation, Adenylation, Thiolation, Reductase* (C-A-T-R*) where R* lacks the critical Ser-Tyr-Lys catalytic triad of the short chain dehydrogenase/reductase (SDR) super family. By heterologous overproduction in E. coli of the 56 kDa Aspergillus flavus CpaS TR* didomain, and the single T and R* domains, we demonstrate that CpaS catalyzes a Dieckmann type cyclization on the N-acetoacetyl-Trp intermediate bound in thioester linkage to the phosphopantetheinyl arm of the T domain to form and release cAATrp. This occurs without any participation of NAD(P)H, so R* does not function as a canonical SDR family member. Use of the T and R* domains in in trans assays enabled multiple turnovers and evaluation of specific mutants. Mutation of the D3803 residue in the R* domain, conserved in other fungal tetramate synthetases, abolished activity both in in trans and in cis (TR*) activity assays. It is likely that cyclization of ?-ketoacyl-aminoacyl-S-pantetheinyl intermediates to released tetramates represents a default cyclization/release route for redox-incompetent R* domains embedded in NRPS assembly lines.

Liu, Xinyu; Walsh, Christopher T.

2009-01-01

38

Development in Aspergillus  

PubMed Central

The genus Aspergillus represents a diverse group of fungi that are among the most abundant fungi in the world. Germination of a spore can lead to a vegetative mycelium that colonizes a substrate. The hyphae within the mycelium are highly heterogeneous with respect to gene expression, growth, and secretion. Aspergilli can reproduce both asexually and sexually. To this end, conidiophores and ascocarps are produced that form conidia and ascospores, respectively. This review describes the molecular mechanisms underlying growth and development of Aspergillus.

Krijgsheld, P.; Bleichrodt, R.; van Veluw, G.J.; Wang, F.; Muller, W.H.; Dijksterhuis, J.; Wosten, H.A.B.

2013-01-01

39

Genomics of Aspergillus fumigatus.  

PubMed

Aspergillus fumigatus is a filamentous fungal saprophyte that is ubiquitous in the environment. It is also a human pathogen and induces allergenic response, negatively impacting health care and associated costs significantly around the world. Much of the basic biology of this organism is only poorly understood, but the recent completion and publication of its genome sequence provides an excellent tool for researchers to gain insight into these processes. In this review we will summarize some of the more salient features revealed by analysis of the genome, including the search for candidate pathogenicity genes and the switch to a pathogenic lifestyle, allergen proteins, DNA repair, secondary metabolite gene clusters that produce compounds both useful and toxic, a theoretical capability of this asexual organism to reproduce sexually, signalling, and transcription. A. fumigatus was compared with the food biotechnology fungus Aspergillus oryzae and sexual fungus Aspergillus nidulans, as well as other fungi, in an attempt to discern key differences between these organisms. PMID:16499415

Ronning, Catherine M; Fedorova, Natalie D; Bowyer, Paul; Coulson, Richard; Goldman, Gustavo; Kim, H Stanley; Turner, Geoffrey; Wortman, Jennifer R; Yu, Jiujiang; Anderson, Michael J; Denning, David W; Nierman, William C

2005-12-01

40

Clavatol and patulin formation as the antagonistic principle of Aspergillus clavatonanicus , an endophytic fungus of Taxus mairei  

Microsoft Academic Search

Many endophytic fungi are known to protect plants from plant pathogens, but the antagonistic mechanism has rarely been revealed.\\u000a In this study, we wished to learn whether an endophytic Aspergillus sp., isolated from Taxus mairei, would indeed produce bioactive components, and if so whether (a) they would antagonize plant pathogenic fungi; and (b) whether\\u000a this Aspergillus sp. would produce the

Chu-Long Zhang; Bi-Qiang Zheng; Jia-Ping Lao; Li-Juan Mao; Shao-Yuan Chen; Christian P. Kubicek; Fu-Cheng Lin

2008-01-01

41

Biomarkers of Aspergillus spores  

NASA Astrophysics Data System (ADS)

We applied both matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) mass spectrometric and 1D sodium dodecylsulfate polyacrylamide gel electrophoretic (1D-PAGE) approaches for direct analysis of intact fungal spores of twenty four Aspergillus species. In parallel, we optimized various protocols for protein extraction from Aspergillus spores using acidic conditions, step organic gradient and variable sonication treatment. The MALDI-TOF mass spectra obtained from optimally prepared samples provided a reproducible fingerprint demonstrating the capability of the MALDI-TOF approach to type and characterize different fungal strains within the Aspergillus genus. Mass spectra of intact fungal spores provided signals mostly below 20 kDa. The minimum material amount represented 0.3 [mu]g (10,000 spores). Proteins with higher molecular weight were detected by 1D-PAGEE Eleven proteins were identified from three selected strains in the range 5-25 kDa by the proteomic approach. Hemolysin and hydrophobin have the highest relevance in host-pathogen interactions.

Sulc, Miroslav; Peslova, Katerina; Zabka, Martin; Hajduch, Marian; Havlicek, Vladimir

2009-02-01

42

76 FR 16297 - Aspergillus flavus  

Federal Register 2010, 2011, 2012, 2013

...pesticide, Aspergillus flavus AF36, in or on corn food and feed commodities, when applied...residues of Aspergillus flavus AF36 in or on corn food and feed commodities. This notice...May 23, 2007) (FRL-8129-4) and on corn (72 FR 72965, Dec. 26, 2007)...

2011-03-23

43

Aspergillus brain abscess.  

PubMed

Aspergillus brain abscess is a rare clinical entity, which remains a challenge to diagnose and treat. Most fungi are low virulence organisms, often living as commensals. They however, pose a considerable challenge in an immune-compromised host. Systemic steroids are commonly used in treatment of various inflammatory conditions. Despite their relatively safe profile, one peril of such treatment is immune suppression. It is prudent that physicians remain aware of the risk of various opportunistic infections in such patients. We present a case of fatal intra-cranial aspergillosis in an immuno-compromised patient on systemic steroids. PMID:24015447

Bhaskar, Nutan; Mohammad, Khalid; Kaur, Varinder

2013-08-01

44

X-ray Structure Analysis and Characterization of AFUEI, an Elastase Inhibitor from Aspergillus fumigatus*  

PubMed Central

Elastase from Aspergillus sp. is an important factor for aspergillosis. AFUEI is an inhibitor of the elastase derived from Aspergillus fumigatus. AFUEI is a member of the I78 inhibitor family and has a high inhibitory activity against elastases of Aspergillus fumigatus and Aspergillus flavus, human neutrophil elastase and bovine chymotrypsin, but does not inhibit bovine trypsin. Here we report the crystal structure of AFUEI in two crystal forms. AFUEI is a wedge-shaped protein composed of an extended loop and a scaffold protein core. The structure of AFUEI shows remarkable similarity to serine protease inhibitors of the potato inhibitor I family, although they are classified into different inhibitor families. A structural comparison with the potato I family inhibitors suggests that the extended loop of AFUEI corresponds to the binding loop of the potato inhibitor I family, and AFUEI inhibits its cognate proteases through the same mechanism as the potato I family inhibitors.

Sakuma, Mayuko; Imada, Katsumi; Okumura, Yoshiyuki; Uchiya, Kei-ichi; Yamashita, Nobuo; Ogawa, Kenji; Hijikata, Atsushi; Shirai, Tsuyoshi; Homma, Michio; Nikai, Toshiaki

2013-01-01

45

Aspergillus antigen skin test (image)  

MedlinePLUS

... After 48 to 72 hours the site of injection is evaluated by a physician. If a positive reaction occurs (the test site is inflamed), the person has been exposed to the aspergillus mold and is at risk for developing aspergillosis.

46

[Metabolites of Aspergillus fumigatus].  

PubMed

Aspergillus fumigatus, a type of endophytic fungi from Erthrophleum fordii, was fermented with GPY culture medium. Fermented liquid and mycelium were extracted from fermented products after freezing and thawing treatment. After alcohol extraction, mycelium was extracted with ethyl acetate and n-butyl alcohol, respectively. According to the results of cytotoxity of tumor cells, ethyl acetate extracts were studied for their chemical constituents. Five diketopiperazine compounds were separated and purified with silica gel, MCI and Sephadex LH-20 column chromatography, reversed-phase chromatographic column and preparative HPLC, their structures were identified as cyclo- (R-Pro-R-Phe) (1), cyclo- (trans-4-OH-D-Pro-D-Phe) (2), cyclo- (R-Tyr-S-Ile) (3), cyclo-(R-Phe-S-Ile) (4), and cyclo-(R-Val-S-Tyr) (5) by using spectral methods. PMID:23311158

Ding, Guang-Zhi; Liu, Yun-Bao; Ma, Shuang-Gang; Yu, Shi-Shan

2012-10-01

47

Aspergillus prosthetic valve endocarditis.  

PubMed Central

The clinical, laboratory, and histopathological features of seven cases of Aspergillus fumigatus prosthetic valve endocarditis are presented. The exact nature of the lesion, a combination of infective fungal endocarditis and thrombosis on the prosthetic valve, is discussed and the difficulties in clinical diagnosis are emphasized. Helpful indications were sudden unexplained heart failure with the appearance of new murmurs, and emboli to large or medium-sized systemic arteries. Fever and anaemia were inconstant, and in no case was blood culture or precipitin investigation helpful. Spore contamination of operating theatre air was the likely source of infection, and measures taken to overcome this and other predisposing factors are discussed. Since medical diagnosis is usually late and the few reported cures in this condition have included replacement of the prosthesis, early surgical intervention combined with antifungal chemotherapy is advised. Images

Petheram, I S; Seal, R M

1976-01-01

48

Aspergillus fumigatus and Aspergillosis  

PubMed Central

Aspergillus fumigatus is one of the most ubiquitous of the airborne saprophytic fungi. Humans and animals constantly inhale numerous conidia of this fungus. The conidia are normally eliminated in the immunocompetent host by innate immune mechanisms, and aspergilloma and allergic bronchopulmonary aspergillosis, uncommon clinical syndromes, are the only infections observed in such hosts. Thus, A. fumigatus was considered for years to be a weak pathogen. With increases in the number of immunosuppressed patients, however, there has been a dramatic increase in severe and usually fatal invasive aspergillosis, now the most common mold infection worldwide. In this review, the focus is on the biology of A. fumigatus and the diseases it causes. Included are discussions of (i) genomic and molecular characterization of the organism, (ii) clinical and laboratory methods available for the diagnosis of aspergillosis in immunocompetent and immunocompromised hosts, (iii) identification of host and fungal factors that play a role in the establishment of the fungus in vivo, and (iv) problems associated with antifungal therapy.

Latge, Jean-Paul

1999-01-01

49

Aspergillus bronchitis without significant immunocompromise.  

PubMed

Aspergillus bronchitis is poorly understood and described. We extracted clinical data from more than 400 referred patients with persistent chest symptoms who did not fulfill criteria for allergic, chronic, or invasive aspergillosis. Symptomatic patients with a positive culture or real-time PCR for Aspergillus spp. were reviewed. Seventeen patients fulfilled the selected criteria. Fourteen were women, with a mean age of 57 years (range 39-76). Sixteen of the patients had productive cough, eight had voluminous tenacious sputum, and seven had recurrent chest infections. Eight patients had Medical Research Council dyspnea scores of 4-5; 12 had bronchiectasis; and 13 patients grew A. fumigatus, 3 A. niger, and 1 A. terreus. Twelve of the 17 patients (71%) had elevated Aspergillus IgG (47-137 mg/L, mean 89.2) and 5 (29%) had elevated Aspergillus precipitins. Six of 12 (50%) had a major response to antifungal therapy and five of 12 (42%) patients relapsed, requiring long-term therapy. Aspergillus bronchitis is a discrete clinical entity in patients with structural lung disease but who are not significantly immunocompromised. It is distinct from asymptomatic fungal colonization and other forms of aspergillosis, and may respond to antifungal therapy. PMID:23231717

Chrdle, Ales; Mustakim, Sahlawati; Bright-Thomas, Rowland J; Baxter, Caroline G; Felton, Timothy; Denning, David W

2012-12-01

50

Tracheobronchial Manifestations of Aspergillus Infections  

PubMed Central

Human lungs are constantly exposed to a large number of Aspergillus spores which are present in ambient air. These spores are usually harmless to immunocompetent subjects but can produce a symptomatic disease in patients with impaired antifungal defense. In a small percentage of patients, the trachea and bronchi may be the main or even the sole site of Aspergillus infection. The clinical entities that may develop in tracheobronchial location include saprophytic, allergic and invasive diseases. Although this review is focused on invasive Aspergillus tracheobronchial infections, some aspects of allergic and saprophytic tracheobronchial diseases are also discussed in order to present the whole spectrum of tracheobronchial aspergillosis. To be consistent with clinical practice, an approach basing on specific conditions predisposing to invasive Aspergillus tracheobronchial infections is used to present the differences in the clinical course and prognosis of these infections. Thus, invasive or potentially invasive Aspergillus airway diseases are discussed separately in three groups of patients: (1) lung transplant recipients, (2) highly immunocompromised patients with hematologic malignancies and/or patients undergoing hematopoietic stem cell transplantation, and (3) the remaining, less severely immunocompromised patients or even immunocompetent subjects.

Krenke, Rafal; Grabczak, Elzbieta M.

2011-01-01

51

Molecular genetics in Aspergillus fumigatus.  

PubMed

Manipulation of the genome of the human pathogen Aspergillus fumigatus is not well developed. Approaches and data from related model organisms are being used to develop molecular genetic systems in A. fumigatus; for example, the molecular typing of strains during infection. A genome-sequencing programme has begun and will form the basis for future development. PMID:11050444

Brookman, J L; Denning, D W

2000-10-01

52

Keratitis caused by Aspergillus pseudotamarii  

PubMed Central

A male patient presented with complaints of redness, pain and defective vision in the left eye. The infiltrate healed completely after two weeks of topical natamycin administration. A polyphasic approach was used to identify the isolate as Aspergillus pseudotamarii, which produced aflatoxins in inducing medium.

Baranyi, Nikolett; Kocsube, Sandor; Szekeres, Andras; Raghavan, Anita; Narendran, Venkatapathy; Vagvolgyi, Csaba; Panneer Selvam, Kanesan; Babu Singh, Yendremban Randhir; Kredics, Laszlo; Varga, Janos; Manikandan, Palanisamy

2013-01-01

53

Keratitis caused by Aspergillus pseudotamarii.  

PubMed

A male patient presented with complaints of redness, pain and defective vision in the left eye. The infiltrate healed completely after two weeks of topical natamycin administration. A polyphasic approach was used to identify the isolate as Aspergillus pseudotamarii, which produced aflatoxins in inducing medium. PMID:24432226

Baranyi, Nikolett; Kocsubé, Sándor; Szekeres, András; Raghavan, Anita; Narendran, Venkatapathy; Vágvölgyi, Csaba; Panneer Selvam, Kanesan; Babu Singh, Yendremban Randhir; Kredics, László; Varga, János; Manikandan, Palanisamy

2013-04-12

54

THE ASCOCARPS OF ASPERGILLUS ALLIACEUS  

Microsoft Academic Search

(WITH 11 FIGURES) Aspergillus alliaceus, described in 1926 by Thom and Church (4) as a new sclerotial species in the A. wentii Group, was based upon two strains : C.T. 4660, isolated by Eddy from a decaying garlic bulb some­ time prior to 1924 when it was discussed without name by Walker and Lindegren (6) as a wound parasite of

DOROTHY I. FENNELL; J. H. WARCUP

55

Aspergillus nomius , a new aflatoxin-producing species related to Aspergillus flavus and Aspergillus tamarii  

Microsoft Academic Search

Aspergillus nomius is described and represents a new aflatoxigenic species phenotypically similar to A. flavus. Strains examined were isolated from insects and agricultural commodities. Separation from A. flavus is based on the presence of indeterminate sclerotia and a lower growth temperature. Comparisons of DNA relatedness show A. nomius to have only relatively recently evolved from A. flavus and A. tamarii.

C. P. Kurtzman; B. W. Horn; C. W. Hesseltine

1987-01-01

56

A new diketopiperazine alkaloid from Aspergillus oryzae.  

PubMed

Investigation of bioactive secondary metabolites from terrestrial Aspergillus oryzae sp. MMAO1 using M2 medium afforded a new diketopiperazine alkaloid, 7,9-dihydroxy-3-(1H-indol-3-ylmethyl)-8-methoxy-2,3,11,11a-tetrahydro-6H-pyrazino[1,2-b]isoquinoline-1,4-dione (1a), containing the unusual amino acid L-6,8-dihydroxy-7-methoxyphenylalanine. This was co-isolated with ditryptophenaline (2), cyclo-(Tryp,Tyr) (4), cyclo-(Pro,Val), ?-cyclopiazonic acid (3), kojic acid and uridine. Re-cultivation of the fungal strain on Dox medium led to the production of bisdethio(bismethylthio)gliotoxin (5), pseurotin A (6) along with linoleic acid, ?-cyclopiazonic acid (3) and kojic acid. The chemical structure of the new diketopiperazine alkaloid including the relative configuration was determined by 1D and 2D NMR spectroscopy and HR-ESI-MS spectrometry, and by comparison with the related literature. The new alkaloid (1a) showed no antimicrobial activity or cytotoxicity against brine shrimps. PMID:24116376

Shaaban, Mohamed; El-Metwally, Mohammad Magdy; Nasr, Hamdi

2014-01-01

57

The Phylogenetics of Mycotoxin and Sclerotium Production in Aspergillus flavus and Aspergillus oryzae  

Microsoft Academic Search

Geiser, D. M., Dorner, J. W., Horn, B. W., and Taylor, J. W. 2000. The phylogenetics of mycotoxin and scle- rotium production in Aspergillus flavus and Aspergillus oryzae. Fungal Genetics and Biology 31, 169 -179. Aspergillus flavus is a common filamentous fungus that produces aflatoxins and presents a major threat to agriculture and human health. Previous phylogenetic studies of A.

David M. Geiser; Joe W. Dorner; Bruce W. Horn; John W. Taylor

2001-01-01

58

Two metabolites from Aspergillus flavipes.  

PubMed

Two novel fungal metabolites, N-benzoyl-L-phenylalaninol (1a) and asperphenamate (2) were isolated from the culture filtrate and mycelium of Aspergillus flavipes ATCC 11013. N-benzoyl-L-phenylalaninol was identified by direct comparison with an authentic sample. The structure of asperphenamate is proposed as (S)-N-benzoyl-phenylalanine-(S)-2-benzamido-3-phenyl propyl ester, based on chemical and spectroscopic evidence. PMID:875642

Clark, A M; Hufford, C D; Robertson, L W

1977-01-01

59

Nitrile biotransformation by Aspergillus niger  

Microsoft Academic Search

A nitrile-converting enzyme activity was induced in Aspergillus niger K10 by 3-cyanopyridine. The whole cell biocatalyst was active at pH 3–11 and hydrolyzed the cyano group into acid and\\/or amide functions in benzonitrile as well as in its meta- and para-substituted derivatives, cyanopyridines, 2-phenylacetonitrile and thiophen-2-acetonitrile. Amides constituted a significant part of the total biotransformation products of 2- and 4-cyanopyridine,

Radka Šnajdrová; Veronika Kristová-Mylerová; Dominique Crestia; Konstantina Nikolaou; Marek Kuzma; Marielle Lemaire; Estelle Gallienne; Jean Bolte; Karel Bezouška; Vladim??r K?en; Ludmila Mart??nková

2004-01-01

60

Degradation of ochratoxin A by Aspergillus species  

Microsoft Academic Search

Mycotoxin contamination of agricultural products is a serious health hazard throughout the world. Besides attempts to eliminate mycotoxins from contaminated substrates by physical and chemical methods, the ability of microbes to degrade mycotoxins is now being widely examined. In this study, several Aspergillus species were examined for their ability to degrade ochratoxin A. A. fumigatus and black Aspergillus strains were

János Varga; Krisztina Rigó; József Téren

2000-01-01

61

Cyclopiazonic acid biosynthesis of Aspergillus flavus and Aspergillus oryzae.  

PubMed

Cyclopiazonic acid (CPA) is an indole-tetramic acid neurotoxin produced by some of the same strains of A. flavus that produce aflatoxins and by some Aspergillus oryzae strains. Despite its discovery 40 years ago, few reviews of its toxicity and biosynthesis have been reported. This review examines what is currently known about the toxicity of CPA to animals and humans, both by itself or in combination with other mycotoxins. The review also discusses CPA biosynthesis and the genetic diversity of CPA production in A. flavus/oryzae populations. PMID:22069533

Chang, Perng-Kuang; Ehrlich, Kenneth C; Fujii, Isao

2009-12-01

62

Aspergillus--classification and antifungal susceptibilities.  

PubMed

Aspergillus is one of the most important fungal genera for the man, for its industrial use, its ability to spoil food and not least its medical impact as cause of a variety of diseases. Currently hundreds of species of Aspergillus are known; nearly fifty of them are able to cause infections in humans and animals. Recently, the genus Aspergillus is subdivided into 8 subgenera and 22 sections. The spectrum of diseases caused by Aspergillus species varies from superficial cutaneous to invasive and systemic infections. All species of Aspergillus investigated so far are resistant against the antifungals fluconazole and 5-fluorocytosine, the range of susceptibilities to currently available antifungals is discussed in this paper. PMID:23278534

Buzina, Walter

2013-01-01

63

Recombinant bacterial hemoglobin alters metabolism of Aspergillus niger.  

PubMed

The filamentous fungus Aspergillus niger is used extensively for the production of enzymes and organic acids. A major problem in industrial fermentations with this fungus is to ensure sufficient supply of oxygen required for respiratory metabolism of the fungus. In case of oxygen limitation, the fungus will produce various by-products like organic acids and polyols. In order to circumvent this problem we here study the effects of the expression of a bacterial hemoglobin protein on the metabolism of A. niger. We integrated the vgb gene from Vitreoscilla sp. into the genome at the pyrA locus behind the strong gpdA promoter from Aspergillus nidulans. Analysis of secreted metabolites, oxygen uptake, CO(2) evolution and biomass formation points towards a relief of stress in the mutant expressing VHB when it is exposed to oxygen limitation. Our findings therefore point to an interesting strategy to attenuate unwanted side effects resulting from oxygen limitation during industrial fermentations with A. niger. PMID:18694843

Hofmann, Gerald; Diano, Audrey; Nielsen, Jens

2009-01-01

64

Colorimetric Assay for Antifungal Susceptibility Testing of Aspergillus Species  

Microsoft Academic Search

A colorimetric assay for antifungal susceptibility testing of Aspergillus species (Aspergillus fumigatus, Asper- gillus flavus, Aspergillus terreus, Aspergillus nidulans, and Aspergillus ustus) is described based on the reduction of the tetrazolium salt 2,3-bis(2-methoxy-4-nitro-5-((sulphenylamino)carbonyl)-2H-tetrazolium-hydroxide (XTT) in the presence of menadione as an electron-coupling agent. The combination of 200 g of XTT\\/ml with 25 M menadione resulted in a high production of

JOSEPH MELETIADIS; JOHAN W. MOUTON; JACQUES F. G. M. MEIS; BIANCA A. BOUMAN; J. PETER DONNELLY; PAUL E. VERWEIJ

2001-01-01

65

Leporizines A-C: epithiodiketopiperazines isolated from an Aspergillus species.  

PubMed

Three new compounds named leporizines A-C have been isolated from an Aspergillus sp. strain. Their structures were elucidated by analysis of 1D and 2D NMR spectra. Leporizines A and B were isolated during dereplication of hits from a high-throughput screening campaign for correctors of the cystic fibrosis transmembrane conductance regulator (CFTR), and leporizine C was isolated while preparing additional material for characterization of leporizines A and B. CFTR activity observed for leporizines A and B was highly correlated with cell toxicity and was determined to be a nonspecific effect. Leporizine C was not cytotoxic to cells and did not elicit a response in the CFTR assays. To the best of our knowledge, leporizines A-C represent the first examples of this unusual epithiodiketopiperazine skeleton. PMID:24050204

Reategui, Ricardo; Rhea, Joshua; Adolphson, Janet; Waikins, Kathryn; Newell, Ryan; Rabenstein, John; Mocek, Ulla; Luche, Michele; Carr, Grant

2013-09-27

66

Glucan Synthase Complex of Aspergillus fumigatus  

Microsoft Academic Search

The glucan synthase complex of the human pathogenic mold Aspergillus fumigatus has been investigated. The genes encoding the putative catalytic subunit Fks1p and four Rho proteins of A. fumigatus were cloned and sequenced. Sequence analysis showed that AfFks1p was a transmembrane protein very similar to other Fksp proteins in yeasts and in Aspergillus nidulans. Heterologous expression of the conserved internal

A. Beauvais; J. M. Bruneau; P. C. Mol; M. J. Buitrago; R. Legrand; J. P. Latge

2001-01-01

67

Antifungal Susceptibility Tests of Aspergillus Species  

Microsoft Academic Search

\\u000a Although different methods are now available to assess the susceptibility of Aspergillus species to antifungal agents, there are still limited data correlating in vitro resistance with meaningful clinical endpoints.\\u000a Moreover, there is no consensus on the breakpoints to define resistance\\/susceptibility to different antifungal agents. This\\u000a chapter reviews the technical issues related to antifungal susceptibility tests for Aspergillus species, including the

Arnaldo Lopes Colombo; Viviane Reis; Patricio Godoy

68

In Vitro Antimicrobial Potential of the Lichen Parmotrema sp. Extracts against Various Pathogens.  

PubMed

Objective(s): The ongoing increasing antibiotic resistance is one of the biggest challenges faced by global public health. The perennial need for new antimicrobials against a background of increasing antibiotic resistance in pathogenic and opportunistic microorganisms obliges the scientific community to constantly develop new drugs and antimicrobial agents. Lichens are known prolific sources of natural antimicrobial drugs and biologically active natural products. This study was aimed to explore in vitro antimicrobial activity of lichen Parmotrema sp. Material and Methods: The methanol and aqueous extracts of lichen Parmotrema sp. was extracted using Soxhlet extractor. Antibiotic assessment of methanol and aqueous extracts was done against eight bacterial (Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Salmonella sp., Shigella sp., Enterococci faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae,) clinical pathogens and five plant pathogenic fungal strains (Aspergillus terreus strain JAS1, Scedosporium sp. JAS1, Ganoderma sp. JAS4, Candida tropicalis and Fusarium sp.) by Kirby-Bauer method. Results: The methanol lichen Parmotrema sp. extract inhibited all the test organisms. The highest antibacterial activity was found against Pseudomonas aeruginosa and Staphylococcus aureus. The weakest activity was manifested in Salmonella sp. and Scedosporium sp. JAS1. Strong antifungal effect was found against Ganoderma sp. JAS4 and Fusarium sp. The aqueous lichen Parmotrema sp. extract revealed neither antibacterial nor antifungal activity. Conclusion: The present study shows that tested lichen Parmotrema sp. extracts demonstrated a strong antimicrobial effect. That suggests the active components from methanol extracts of the investigated lichen Parmotrema sp. can be used as natural antimicrobial agent against pathogens. PMID:23997920

Chauhan, Ritika; Abraham, Jayanthi

2013-07-01

69

In Vitro Antimicrobial Potential of the Lichen Parmotrema sp. Extracts against Various Pathogens  

PubMed Central

Objective(s): The ongoing increasing antibiotic resistance is one of the biggest challenges faced by global public health. The perennial need for new antimicrobials against a background of increasing antibiotic resistance in pathogenic and opportunistic microorganisms obliges the scientific community to constantly develop new drugs and antimicrobial agents. Lichens are known prolific sources of natural antimicrobial drugs and biologically active natural products. This study was aimed to explore in vitro antimicrobial activity of lichen Parmotrema sp. Material and Methods: The methanol and aqueous extracts of lichen Parmotrema sp. was extracted using Soxhlet extractor. Antibiotic assessment of methanol and aqueous extracts was done against eight bacterial (Escherichia coli, Staphylococcus aureus, Proteus mirabilis, Salmonella sp., Shigella sp., Enterococci faecalis, Pseudomonas aeruginosa, Klebsiella pneumoniae,) clinical pathogens and five plant pathogenic fungal strains (Aspergillus terreus strain JAS1, Scedosporium sp. JAS1, Ganoderma sp. JAS4, Candida tropicalis and Fusarium sp.) by Kirby-Bauer method. Results: The methanol lichen Parmotrema sp. extract inhibited all the test organisms. The highest antibacterial activity was found against Pseudomonas aeruginosa and Staphylococcus aureus. The weakest activity was manifested in Salmonella sp. and Scedosporium sp. JAS1. Strong antifungal effect was found against Ganoderma sp. JAS4 and Fusarium sp. The aqueous lichen Parmotrema sp. extract revealed neither antibacterial nor antifungal activity. Conclusion: The present study shows that tested lichen Parmotrema sp. extracts demonstrated a strong antimicrobial effect. That suggests the active components from methanol extracts of the investigated lichen Parmotrema sp. can be used as natural antimicrobial agent against pathogens.

Chauhan, Ritika; Abraham, Jayanthi

2013-01-01

70

Antioxidant Activity of Aspergillus fumigatus  

PubMed Central

The antioxidant activity of Aspergillus fumigatus was assayed by different procedures and correlated with its extracellular total phenolic contents. Different physio-chemical parameters were optimized to enhance the activity. The culture grown under stationary conditions for 10 days at 25°C at pH 7 gave the best antioxidant activity. Statistical approaches demonstrated sucrose and NaNO3 to be the most suitable carbon and nitrogen sources, respectively. Response surface analysis showed 5% sucrose, 0.05% NaNO3, and incubation temperature of 35°C to be the optimal conditions for best expression of antioxidant activity. Under these conditions, the antioxidant potential assayed through different procedures was 89.8%, 70.1%, and 70.2% scavenging effect for DPPH radical, ferrous ion and nitric oxide ion, respectively. The reducing power showed an absorbance of 1.0 and FRAP assay revealed the activity of 60.5%. Extracellular total phenolic content and antioxidant activity as assayed by different procedures positively correlated.

Arora, Daljit Singh; Chandra, Priyanka

2011-01-01

71

ASPERGILLUS LUCHUENSIS , AN INDUSTRIALLY IMPORTANT BLACK ASPERGILLUS IN EAST ASIA  

PubMed Central

Aspergilli known as black- and white-koji molds which are used for awamori, shochu, makgeolli and other food and beverage fermentations, are reported in the literature as A. luchuensis, A. awamori, A. kawachii, or A. acidus. In order to elucidate the taxonomic position of these species, available ex-type cultures were compared based on morphology and molecular characters. A. luchuensis, A. kawachii and A. acidus showed the same banding patterns in RAPD, and the three species had the same rDNA-ITS, ?-tubulin and calmodulin sequences and these differed from those of the closely related A. niger and A. tubingensis. Morphologically, the three species are not significantly different from each other or from A. niger and A. tubingensis. It is concluded that A. luchuensis, A. kawachii and A. acidus are the same species, and A. luchuensis is selected as the correct name based on priority. Strains of A. awamori which are stored in National Research Institute of Brewing in Japan, represent A. niger (n?=?14) and A. luchuensis (n?=?6). The neotype of A. awamori (CBS 557.65?=? NRRL 4948) does not originate from awamori fermentation and it is shown to be identical with the unknown taxon Aspergillus welwitschiae. Extrolite analysis of strains of A. luchuensis showed that they do not produce mycotoxins and therefore can be considered safe for food and beverage fermentations. A. luchuensis is also frequently isolated from meju and nuruk in Korea and Puerh tea in China and the species is probably common in the fermentation environment of East Asia. A re-description of A. luchuensis is provided because the incomplete data in the original literature.

Hong, Seung-Beom; Lee, Mina; Kim, Dae-Ho; Varga, Janos; Frisvad, Jens C.; Perrone, Giancarlo; Gomi, Katsuya; Yamada, Osamu; Machida, Masayuki; Houbraken, Jos; Samson, Robert A.

2013-01-01

72

What does genetic diversity of Aspergillus flavus tell us about Aspergillus oryzae?  

PubMed

Aspergillus flavus and Aspergillus oryzae belong to Aspergillus section Flavi. They are closely related and are of significant economic importance. The former species has the ability to produce harmful aflatoxins while the latter is widely used in food fermentation and industrial enzyme production. This review summarizes the current understanding of the similarity of the A. flavus and A. oryzae genomes, the genetic diversity in A. flavus and A. oryzae populations, the causes of this diversity, and the relatedness of nonaflatoxigenic A. flavus strains to A. oryzae. PMID:20163884

Chang, Perng-Kuang; Ehrlich, Kenneth C

2010-04-15

73

Susceptibility testing in Aspergillus species complex.  

PubMed

Methods for susceptibility testing of Aspergillus are developed and validated by the European Committee on Antibiotic Susceptibility Testing Subcommittee on Antifungal Susceptibility Testing. Breakpoints for phenotypic antimicrobial susceptibility testing have been determined by breakpoint committees and as part of regulatory processes for the approval of new drugs. Dosages, pharmacokinetics, resistance mechanisms, MIC distributions, pharmacodynamics and epidemiological cut-off values are used in the breakpoint-setting process. Clinical breakpoints are for everyday use in the clinical laboratory to advise on patient therapy. Resistance in Aspergillus fumigatus has been increasingly reported since standards became available. PMID:24372722

Lass-Flörl, C

2014-06-01

74

Ammonium Regulation in Aspergillus nidulans  

PubMed Central

l-Glutamate uptake, thiourea uptake, and methylammonium uptake and the intracellular ammonium concentration were measured in wild-type and mutant cells of Aspergillus nidulans held in various concentrations of ammonium and urea. The levels of l-glutamate uptake, thiourea uptake, nitrate reductase, and hypoxanthine dehydrogenase activity are determined by the extracellular ammonium concentration. The level of methylammonium uptake is determined by the intracellular ammonium concentration. The uptake and enzyme characteristics of the ammonium-derepressed mutants, meaA8, meaB6, DER3, amrA1, xprD1, and gdhA1, are described. The gdhA mutants lack normal nicotinamide adenine dinucleotide phosphate-glutamate dehydrogenase (NADP-GDH) activity and are derepressed with respect to both external and internal ammonium. The other mutant classes are derepressed only with respect to external ammonium. The mutants meaA8, DER3, amrA1, and xprD1 have low levels of one or more of the l-glutamate, thiourea, and methylammonium uptake systems. A model for ammonium regulation in A. nidulans is put forward which suggests: (i) NADP-GDH located in the cell membrane complexes with extracellular ammonium. This first regulatory complex determines the level of l-glutamate uptake, thiourea uptake, nitrate reductase, and xanthine dehydrogenase by repression or inhibition, or both. (ii) NADP-GDH also complexes with intracellular ammonium. This second and different form of regulatory complex determines the level of methylammonium uptake by repression or inhibition, or both.

Pateman, J. A.; Kinghorn, J. R.; Dunn, Etta; Forbes, E.

1973-01-01

75

Diagnostic accuracy of histopathologic and cytopathologic examination of Aspergillus species.  

PubMed

To assess the diagnostic accuracy of histopatho-logic and cytopathologic examination (HCE) of Aspergillus species (spp), we performed an 11-year retrospective review to correlate surgical/cytology cases with a diagnosis of Aspergillus spp with their concurrent fungal culture results. Diagnostic accuracy was defined as the percentage of cases with culture-proven Aspergillus spp divided by the number of cases diagnosed as Aspergillus spp on HCE that had growth on fungal culture. Ninety surgical/cytology cases with concurrent fungal culture were reviewed, 58 of which grew a fungal organism. Of these 58 cases, 45 grew an Aspergillus spp, whereas 13 grew an organism other than Aspergillus spp, including both common (Scedosporium, Fusarium, and Paecilomyces spp) and uncommon mimickers (Trichosporon loubieri), resulting in a diagnostic accuracy of 78%. The low diagnostic accuracy indicates that several fungal organisms can morphologically mimic Aspergillus spp and can only be distinguished by fungal culture and DNA sequencing. PMID:23270899

Shah, Akeesha A; Hazen, Kevin C

2013-01-01

76

Amylase synthesis in Aspergillus flavus and Aspergillus niger grown on cassava peel  

Microsoft Academic Search

Summary Aspergillus flavus andAspergillus niger produce extracellular amylase into the culture medium when grown on basal medium containing 2% (w\\/v) soluble starch or cassava peel as the sole carbon source. On soluble tarch the highest amylase activities were 1.6 and 5.2 mg of starch hydrolyzed\\/min per mg protein forA. flavus andA. niger, respectively. When grown on cassava peel, the highest

Alhassan Sani; Francis A. Awe; Joseph A. Akinyanju

1992-01-01

77

The roles of surfactant protein D during Aspergillus fumigatus infection in human corneal epithelial cells  

PubMed Central

AIM To investigate roles of surfactant protein D (SP-D) and relative cytokines in human corneal epithelial(HCE) cells exposed to aspergillus fumigatus (AF) antigens. METHODS HCE cells cultured in vitro with AF antigens and sampled at 0, 0.5, 1 hour, 2, 4, 6 and 8 hours. The expression of SP-D mRNA was evaluated by semiquantitative reverse transcription-polymerase chain reaction (RT-PCR).The expression of SP-D protein was shown by ELISA and immunocytochemistry SP methods. The expression of NF-?B and relative downstream cytokines such as TNF-?, IL-1?, IL-8 and IL-10 in supernatant fluid were measured by ELISA. RESULTS SP-D mRNA and protein were detected in untreated HCE cells. The expression of SP-D and the relative downstream cytokines rose after being stimulated with AF antigens. SP-D mRNA began to rise at 0.5 hour and the most significantly peak was in 2 hours. The protein of SP-D in supernatant fluid had the same trend with mRNA. Immunocytochemistry of SP-D showed positive expression and gradually increased to 6 hours, and then the expression began to decline. NF-?B was activated after treated by AF antigens and the changes had correlation with SP-D. TNF-?, IL-1?, IL-8 and IL-10 began to rise after given AF antigens 1 hour and were 1.82, 1.43, 1.12 and 1.28 times higher than the untreated HCE cells separately. The expression of TNF-? and IL-1? reached the peak at 2 hours, separately 2.80 and 2.86 times than the untreated. The expression of IL-8 and IL-10 gradually increased with a time-dependent manner. CONCLUSION HCE cells exists SP-D and it may play a significant role in pathogenesis of keratomycosis. AF may induce human corneal epithelial cells to express inflammatory cytokines via SP-D and NF-?B pathway. SP-D possibly mediates the recognition to AF mycelium.

Che, Cheng-Ye; Jia, Wen-Yan; Xu, Qiang; Li, Na; Hu, Li-Ting; Jiang, Nan; Lin, Jing; Wang, Qing; Zhao, Gui-Qiu

2012-01-01

78

New dimeric naphthopyrones from Aspergillus niger.  

PubMed

Three new dimeric naphthopyrones, asperpyrones A (1), B (2), and C (3), together with two known compounds, fonsecinone A (4) and aurasperone A (5), have been isolated from okara that was fermented with Aspergillus niger JV-33-48. Compounds 1, 4, and 5 showed inhibitory activity on Taq DNA polymerase. PMID:12542363

Akiyama, Kohki; Teraguchi, Seigo; Hamasaki, Yukiko; Mori, Mika; Tatsumi, Kunihiko; Ohnishi, Kenji; Hayashi, Hideo

2003-01-01

79

Managing building-related Aspergillus exposure  

Microsoft Academic Search

Aspergillus exposure is difficult to avoid. Indoor dust contains spores and thermotolerant molds may colonize damp or water-damaged building materials or components. Dust control should be part of diligent maintenance since disturbing dusts, especially during building renovation, can expose occupants to spores. Colonization of HVAC systems can shed spores into a building and expose occupants. Mold colonization warrants prompt and

W. Elliott Horner

2006-01-01

80

Heavy metal biosorption sites in Aspergillus niger  

Microsoft Academic Search

Aspergillus niger is capable of removing heavy metals such as lead, cadmium and copper from aqueous solutions. The role played by various functional groups in the cell wall of A. niger in biosorption of lead, cadmium and copper was investigated. The biomass was subjected to chemical treatments to modify the functional groups, carboxyl, amino and phosphate, to study their role

Anoop Kapoor; T. Viraraghavan

1997-01-01

81

Biosynthesis of ochratoxins by Aspergillus ochraceus  

Microsoft Academic Search

Shaken liquid fermentation of an isolate of Aspergillus ochraceus showed growth-associated production of ochratoxins A and B, followed by production of a related polyketide diaporthin. Later, between 150 and 250 h, mellein accumulated transitorily. In contrast, shaken solid substrate (shredded wheat) fermentation over 14 days produced mainly ochratoxins A and B (ratio ca. 5:1) in very high yield (up to

Jonathan P Harris; Peter G Mantle

2001-01-01

82

General primer-mediated PCR for detection of Aspergillus species.  

PubMed Central

A PCR assay was developed for the diagnosis of invasive aspergillosis in immunocompromised patients. For this purpose, the complete nucleotide sequences of the genes encoding the 18S rRNA of Aspergillus nidulans, Aspergillus terreus, Aspergillus niger, and Aspergillus flavus were elucidated and aligned to the sequences of Aspergillus fumigatus and other clinically relevant prokaryotic and eukaryotic microorganisms. Genus-specific sequences could be identified in the V7 to V9 region of 18S rRNA. By using hot-start PCR, Southern blot hybridization, and restriction enzyme analysis, Aspergillus-specific and -sensitive determination was achieved. Five of six immunosuppressed mice experimentally infected with A. fumigatus developed infection, and rRNA could be detected in each case, even in livers with the absence of positive cultures. Aspergillus species were detected by PCR in four neutropenic patients with proven aspergillosis, although Aspergillus species had been isolated from only one bronchoalveolar lavage (BAL) fluid sample. Aspergillus species were detected by PCR in two more patients suspected of having infection. Positive PCR signals were obtained from the BAL samples of 3 of 8 neutropenic patients who had developed pulmonary infiltrates, but none were obtained from the samples of 14 nonimmunosuppressed patients. These results indicate the potential value of PCR to detect Aspergillus species in BAL samples and, therefore, to identify neutropenic patients at risk for invasive aspergillosis. Images

Melchers, W J; Verweij, P E; van den Hurk, P; van Belkum, A; De Pauw, B E; Hoogkamp-Korstanje, J A; Meis, J F

1994-01-01

83

Aspergillus niger contains the cryptic phylogenetic species A. awamori.  

PubMed

Aspergillus section Nigri is an important group of species for food and medical mycology, and biotechnology. The Aspergillus niger 'aggregate' represents its most complicated taxonomic subgroup containing eight morphologically indistinguishable taxa: A. niger, Aspergillus tubingensis, Aspergillus acidus, Aspergillus brasiliensis, Aspergillus costaricaensis, Aspergillus lacticoffeatus, Aspergillus piperis, and Aspergillus vadensis. Aspergillus awamori, first described by Nakazawa, has been compared taxonomically with other black aspergilli and recently it has been treated as a synonym of A. niger. Phylogenetic analyses of sequences generated from portions of three genes coding for the proteins ?-tubulin (benA), calmodulin (CaM), and the translation elongation factor-1 alpha (TEF-1?) of a population of A. niger strains isolated from grapes in Europe revealed the presence of a cryptic phylogenetic species within this population, A. awamori. Morphological, physiological, ecological and chemical data overlap occurred between A. niger and the cryptic A. awamori, however the splitting of these two species was also supported by AFLP analysis of the full genome. Isolates in both phylospecies can produce the mycotoxins ochratoxin A and fumonisin B?, and they also share the production of pyranonigrin A, tensidol B, funalenone, malformins, and naphtho-?-pyrones. In addition, sequence analysis of four putative A. awamori strains from Japan, used in the koji industrial fermentation, revealed that none of these strains belong to the A. awamori phylospecies. PMID:22036292

Perrone, Giancarlo; Stea, Gaetano; Epifani, Filomena; Varga, János; Frisvad, Jens C; Samson, Robert A

2011-11-01

84

Activity of contemporary antifungal agents, including the novel echinocandin anidulafungin, tested against Candida spp., Cryptococcus spp., and Aspergillus spp.: report from the SENTRY Antimicrobial Surveillance Program (2006 to 2007).  

PubMed

Results from the SENTRY international fungal surveillance program for 2006 to 2007 are presented. A total of 1,448 Candida sp., 49 Aspergillus fumigatus, and 33 Cryptococcus neoformans isolates were obtained from infected sterile-site sources in patients on five continents. Reference susceptibility was determined for anidulafungin, caspofungin, 5-flucytosine, fluconazole, itraconazole, posaconazole, voriconazole, and amphotericin B by CLSI methods. PMID:19386851

Messer, Shawn A; Moet, Gary J; Kirby, Jeffrey T; Jones, Ronald N

2009-06-01

85

Purification and kinetic characterization of a fructosyltransferase from Aspergillus aculeatus.  

PubMed

A fructosyltransferase present in Pectinex Ultra SP-L, a commercial enzyme preparation from Aspergillus aculeatus, was purified to 107-fold and further characterised. The enzyme was a dimeric glycoprotein (20% (w/w) carbohydrate content) with a molecular mass of around 135 kDa for the dimer. Optimal activity/stability was found in the pH range 5.0-7.0 and at 60 degrees C. It was stable or slightly activated (upto 1.4-fold) in the presence of reducing agents, such as dithiothreitol and 2-mercaptoethanol, and detergents, such as sodium dodecylsulphate and Tween 80. The enzyme was able to transfer fructosyl groups from sucrose as donor producing the corresponding series of fructooligosaccharides: 1-kestose, nystose and fructosylnystose. Using sucrose as substrate, the k(cat) and K(m) values for transfructosylating activity were 1.62+/-0.09 x 10(4)s(-1) and 0.53+/-0.05 M, whereas for hydrolytic activity the corresponding values were 775+/-25s(-1) and 27+/-3 mM. At elevated sucrose concentrations, the fructosyltransferase from A. aculeatus showed a high transferase/hydrolase ratio that confers it a great potential for the industrial production of prebiotic fructooligosaccharides. PMID:17056145

Ghazi, Iraj; Fernandez-Arrojo, Lucia; Garcia-Arellano, Humberto; Ferrer, Manuel; Ballesteros, Antonio; Plou, Francisco J

2007-01-30

86

Secondary amyloidosis in association with Aspergillus lung disease.  

PubMed

Three patients with amyloidosis secondary to bronchiectasis are described: in two patients bronchiectasis was secondary to allergic bronchopulmonary aspergillosis and in the third, post-tuberculous bronchiectasis was complicated by asthma and allergy to Aspergillus. We suggest that chronic Aspergillus allergy may cause amyloidosis and that some cases of amyloidosis ascribed to tuberculosis in the past may in fact have been secondary to Aspergillus allergy. PMID:3620326

Winter, J H; Milroy, R; Stevenson, R D; Hunter, J

1986-10-01

87

Isolation of protoplasts from Aspergillus nidulans conidiospores.  

PubMed

Protoplasts were prepared from conidiospores of Aspergillus nidulans. The mononucleated conidia gave protoplasts of a uniform size, approximately 5-micron diameter, depending on the strain and the stabilizing medium used. Conidia were preincubated with 2-deoxy-D-glucose in a minimal medium at 37 degrees C for 3 h. The swollen conidia were collected, resuspended in a buffer containing 0.4 M (NH4)2SO4 as stabilizer, and incubated with Oerskovia lytic enzymes at 30 degrees C for 3 or 4 h. Approximately 80% of the conidia were converted into protoplasts. The protoplasts were separated from cell wall fragments and intact conidia by centrifugation over 30% sucrose. This isolation procedure gives a suspension of mononucleated or binucleated protoplasts suitable for recombination experiments and other studies for which a homogenous protoplast suspension is required. The procedure was also successful for Aspergillus niger. PMID:7016284

Bos, C J; Slakhorst, S M

1981-04-01

88

Production of ochratoxin A by Aspergillus carbonarius on coffee cherries  

Microsoft Academic Search

Robusta coffee cherries collected before and during sun drying from two coffee farms in Thailand were examined for moulds producing ochratoxin A (OA). Aspergillus ochraceus was only detected in one sample, whereas Aspergillus carbonarius was isolated from 7 out of 14 samples. On ?-irradiated coffee cherries, each of the six tested A. carbonarius strains produced OA. More than 4800 ?g

H. M. L. J Joosten; J Goetz; A Pittet; M Schellenberg; P Bucheli

2001-01-01

89

Purification and characterization of mycoferritin from Aspergillus parasiticus (255)  

Microsoft Academic Search

As intracellular iron storage molecules, only hydroxymate type siderophores have been reported in ascomycetes and basidiomycetes. This is the first report documenting the presence of mycoferritin in ascomycetes. The fungus, Aspergillus parasiticus (255), is capable of producing mycoferritin only upon induction with iron in yeast extract sucrose (YES) medium. The same has been purified from Aspergillus sps by application of

J. Shashidhar; R. B. Sashidhar; Vijay Deshpande

2005-01-01

90

Fatal coinfection with Legionella pneumophila serogroup 8 and Aspergillus fumigatus  

Microsoft Academic Search

Legionella pneumophila is an important cause of community-acquired and nosocomial pneumonia. We report on a patient who simultaneously developed L. pneumophila serogroup 8 pneumonia and Aspergillus fumigatus lung abscesses. Despite appropriate treatments, Aspergillus disease progressed with metastasis. Coinfections caused by L. pneumophila and A. fumigatus remain exceptional. In apparently immunocompetent patients, corticosteroid therapy is a key risk factor for aspergillosis.

Aurélie Guillouzouic; Pascale Bemer; Françoise Gay-Andrieu; Cédric Bretonničre; Didier Lepelletier; Pierre-Joachim Mahé; Daniel Villers; Sophie Jarraud; Alain Reynaud; Stéphane Corvec

2008-01-01

91

Fatal coinfection with Legionella pneumophila serogroup 8 and Aspergillus fumigatus.  

PubMed

Legionella pneumophila is an important cause of community-acquired and nosocomial pneumonia. We report on a patient who simultaneously developed L. pneumophila serogroup 8 pneumonia and Aspergillus fumigatus lung abscesses. Despite appropriate treatments, Aspergillus disease progressed with metastasis. Coinfections caused by L. pneumophila and A. fumigatus remain exceptional. In apparently immunocompetent patients, corticosteroid therapy is a key risk factor for aspergillosis. PMID:17945454

Guillouzouic, Aurélie; Bemer, Pascale; Gay-Andrieu, Françoise; Bretonničre, Cédric; Lepelletier, Didier; Mahé, Pierre-Joachim; Villers, Daniel; Jarraud, Sophie; Reynaud, Alain; Corvec, Stéphane

2008-02-01

92

Molecular Studies Reveal Frequent Misidentification of Aspergillus fumigatus by Morphotyping  

Microsoft Academic Search

Aspergillus fumigatus has been understood to be the most common cause of invasive aspergillosis (IA) in all epidemiological surveys. However, recent studies have uncovered a large degree of genetic heterogeneity between isolates morphologically identified as A. fumigatus, leading to the description of a new species, Aspergillus lentulus. Here, we examined the genetic diversity of clinical isolates identified as A. fumigatus

S. Arunmozhi Balajee; David Nickle; Janos Varga; Kieren A. Marr

2006-01-01

93

Fulminant antiphospholipid antibody syndrome complicated by Aspergillus tracheobronchitis  

PubMed Central

Aspergillus fumigatus is a filamentous mold that causes infections in patients who are inmmunocompromised. We report a case of Aspergillus tracheobronchitis in fulminant systemic lupus erythematosus case. Diagnosis with more invasive diagnostic procedures & aggressive antifungal therapy is indicated at early stage.

Yegneswaran Prakash, Peralam; Pandit, Vinay; Rao, Sugandhi P.

2012-01-01

94

Aflatoxigenicity in Aspergillus : molecular genetics, phylogenetic relationships and evolutionary implications  

Microsoft Academic Search

Aflatoxins (AFs) are toxic and carcinogenic secondary metabolites produced by isolates of Aspergillus section Flavi as well as a number of Aspergillus isolates that are classified outside of section Flavi. Characterization of the AF and sterigmatocystin (ST) gene clusters and analysis of factors governing regulation of their\\u000a biosynthesis has resulted in these two mycotoxins being the most extensively studied of

Jeffrey W. Cary; Kenneth C. Ehrlich

2006-01-01

95

The Phylogenetics of Mycotoxin and Sclerotium Production in Aspergillus flavus and Aspergillus oryzae  

Microsoft Academic Search

Aspergillus flavus is a common filamentous fungus that produces aflatoxins and presents a major threat to agriculture and human health. Previous phylogenetic studies of A. flavus have shown that it consists of two subgroups, called groups I and II, and morphological studies indicated that it consists of two morphological groups based on sclerotium size, called “S” and “L.” The industrially

David M Geiser; Joe W Dorner; Bruce W Horn; John W Taylor

2000-01-01

96

Effect of Serum Components on Biofilm Formation by Aspergillus fumigatus and Other Aspergillus Species.  

PubMed

Biofilm production by microorganisms is critical for their pathogenicity. Serum promotes biofilm production by Aspergillus fumigatus; however, its effects on other Aspergillus spp. have not been reported. We analyzed biofilm formation by five Aspergillus spp., i.e., A. fumigatus, A. flavus, A. nidulans, A. niger, and A. terreus, and examined the effects of serum/serum proteins such as fetal bovine serum (FBS), fetuin A, and bovine serum albumin (BSA) on hyphal growth, hyphal branching, and extracellular matrix (ECM) formation. The antifungal susceptibility of A. fumigatus isolates that formed biofilms was also examined. All serum/serum proteins promoted the growth of all these fungal species; growth promotion was most evident with FBS, followed by fetuin A and BSA. This effect was most evident in case of A. fumigatus and least evident in case of A. terreus. Electron microscopy showed thick ECM layers surrounding fungal cell walls after culture with FBS, particularly in A. fumigatus. An increase in hyphal branching caused by fetuin A was the highest in case of A. fumigatus and A. nidulans. Biofilm-forming A. fumigatus showed resistance to most antifungal agents, although a synergism of micafungin and amphotericin B was suggested. Our results indicate that serum promotes biofilm formation, including thick ECM, by many Aspergillus spp., particularly A. fumigatus, and that this may be closely related to its virulence. PMID:24858605

Wuren, Tuya; Toyotome, Takahito; Yamaguchi, Masashi; Takahashi-Nakaguchi, Azusa; Muraosa, Yasunori; Yahiro, Maki; Wang, Dan-Ni; Watanabe, Akira; Taguchi, Hideaki; Kamei, Katsuhiko

2014-01-01

97

The function and evolution of the Aspergillus genome  

PubMed Central

Species in the filamentous fungal genus Aspergillus display a wide diversity of lifestyles and are of great importance to humans. The decoding of genome sequences from a dozen species that vary widely in their degree of evolutionary affinity has galvanized studies of the function and evolution of the Aspergillus genome in clinical, industrial, and agricultural environments. Here, we synthesize recent key findings that shed light on the architecture of the Aspergillus genome, on the molecular foundations of the genus’ astounding dexterity and diversity in secondary metabolism, and on the genetic underpinnings of virulence in Aspergillus fumigatus, one of the most lethal fungal pathogens. Many of these insights dramatically expand our knowledge of fungal and microbial eukaryote genome evolution and function and argue that Aspergillus constitutes a superb model clade for the study of functional and comparative genomics.

Gibbons, John G.; Rokas, Antonis

2012-01-01

98

Nomenclatural considerations in naming species of Aspergillus and its teleomorphs  

PubMed Central

The nomenclature of Aspergillus is important in many fields of research and therefore the strategies for stable and efficient naming are important. The conservation of species names as accepted by the Aspergillus community is described. Published lists of accepted names provide that people who use Aspergillus and Penicillium taxonomies need no longer fear the overturning of names currently used. Aspergillus is a good example of a genus where the naming of both anamorph and teleomorph has been applied and arguments are given for maintaining the system of dual nomenclature. A protocol for describing new taxa in Aspergillus and their teleomorphs is proposed, including the availability of living ex type cultures, deposit of type cultures in at least two recognised culture collections, deposits of sequence data in specialised data bases and registration of the new names in MycoBank.

Pitt, J.I.; Samson, R.A.

2007-01-01

99

Discrimination of Aspergillus lentulus from Aspergillus fumigatus by Raman spectroscopy and MALDI-TOF MS.  

PubMed

In 2005, a new sibling species of Aspergillus fumigatus was discovered: Aspergillus lentulus. Both species can cause invasive fungal disease in immune-compromised patients. The species are morphologically very similar. Current techniques for identification are PCR-based or morphology-based. These techniques are labour-intense and not sufficiently discriminatory. Since A. lentulus is less susceptible to several antifungal agents, it is important to correctly identify the causative infectious agent in order to optimize antifungal therapy. In this study we determined whether Raman spectroscopy and/or MALDI-TOF MS were able to differentiate between A. lentulus and A. fumigatus. For 16 isolates of A. lentulus and 16 isolates of A. fumigatus, Raman spectra and peptide profiles were obtained using the Spectracell and MALDI-TOF MS (VITEK MS RUO, bioMérieux) respectively. In order to obtain reliable Raman spectra for A. fumigatus and A. lentulus, the culture medium needed to be adjusted to obtain colourless conidia. Only Raman spectra obtained from colourless conidia were reproducible and correctly identified 25 out of 32 (78 %) of the Aspergillus strains. For VITEK MS RUO, no medium adjustments were necessary. Pigmented conidia resulted in reproducible peptide profiles as well in this case. VITEK MS RUO correctly identified 100 % of the Aspergillus isolates, within a timeframe of approximately 54 h including culture. Of the two techniques studied here, VITEK MS RUO was superior to Raman spectroscopy in the discrimination of A. lentulus from A. fumigatus. VITEK MS RUO seems to be a successful technique in the daily identification of Aspergillus spp. within a limited timeframe. PMID:24030717

Verwer, P E B; van Leeuwen, W B; Girard, V; Monnin, V; van Belkum, A; Staab, J F; Verbrugh, H A; Bakker-Woudenberg, I A J M; van de Sande, W W J

2014-02-01

100

Aspergillus Meningitis: Diagnosis by Non-Culture-Based Microbiological Methods and Management  

Microsoft Academic Search

The performance of antibody detection, antigen detection, and Aspergillus genus-specific PCR for diagnosing Aspergillus meningitis was investigated with 26 cerebrospinal fluid (CSF) samples obtained from a single patient with proven infection caused by Aspergillus fumigatus. Immunoglobulin G antibodies directed against Aspergillus were not detected by enzyme-linked immunosorbent assay in CSF or serum. The antigen galacto- mannan was detected in the

PAUL E. VERWEIJ; KEES BRINKMAN; HERBERT P. H. KREMER; BART-JAN KULLBERG; JACQUES F. G. M. MEIS

1999-01-01

101

Lecythomycin, a new macrolactone glycoside from the endophytic fungus Lecythophora sp.  

PubMed

A new macrolactone glycoside, lecythomycin (1), 23-methyl-3-(1-O-mannosyl)-oxacyclotetracosan-1-one, was isolated from the endophytic fungus Lecythophora sp. (code 30.1), an endopyte of the Indonesian plant Alyxia reinwardtii. The structure of 1 was elucidated on the basis of NMR spectroscopic and mass spectrometric data. The isolated compound displayed antifungal activity against strains of Aspergillus fumigatus and Candida kruzei at minimal inhibitory concentrations (MIC) of 62.5-125 microg/mL. PMID:21615031

Sugijanto, Noor Erma; Diesel, Arnulf; Rateb, Mostafa; Pretsch, Alexander; Gogalic, Selma; Zaini, Noor Cholies; Ebel, Rainer; Indrayanto, Gunawan

2011-05-01

102

Bioactive alkaloids from endophytic Aspergillus fumigatus.  

PubMed

Two new alkaloids, named 9-deacetylfumigaclavine C (1) and 9-deacetoxyfumigaclavine C (2), along with 12 known compounds (3-14), were isolated from the culture of Aspergillus fumigatus. The structures of the new compounds were elucidated by comprehensive spectroscopic analyses. Compound 2 showed selectively potent cytotoxicity against human leukemia cells (K562) with an IC(50) value of 3.1 microM, which was comparable to that of doxorubicin hydrochloride, a presently prescribed drug for the treatment of leukemia. Furthermore, 14-norpseurotin (4) significantly induced neurite outgrowth of rat pheochromocytoma cells (PC12) at a 10.0 microM concentration. PMID:19256529

Ge, Hui Ming; Yu, Zhi Guo; Zhang, Jie; Wu, Jun Hua; Tan, Ren Xiang

2009-04-01

103

Immune responses to Aspergillus fumigatus infections.  

PubMed

Aspergillus fumigatus is an important fungal pathogen of the immunocompromised host. Innate inflammatory and adaptive T cell responses contribute to defense against this pathogen. Toll-like receptors are involved in the activation of innate immune defenses against fungal spores and hyphae and contribute to the recruitment of inflammatory cells to sites of infection. T cell responses to A. fumigatus are rapid and robust, and their differentiation is influenced by the metabolic activity of spores. Ongoing investigations of immune responses to A. fumigatus are likely to provide opportunities to enhance defenses against this pathogen in the immunocompromised host. PMID:16399584

Rivera, Amariliz; Hohl, Tobias; Pamer, Eric G

2006-01-01

104

Immunochemical characterization of Aspergillus fumigatus antigens.  

PubMed Central

Culture filtrate antigens of Aspergillus fumigatus Ag 534 were purified by preparative isoelectric focusing and affinity chromatography. One of the pooled antigen fractions from the preparative isoelectric focusing step (pool 2) was passed through a concanavalin A column and yielded two components, designated antigens IIa and IIb. Antigen IIb reacted more strongly than antigen IIa with all of the aspergilloma and allergic bronchopulmonary aspergillosis sera tested by enzyme-linked immunosorbent assay. The glycoprotein nature of antigen IIb was shown by the concanavalin A binding properties and staining reactions of the components.

Kurup, V P; Ting, E Y; Fink, J N

1983-01-01

105

Secretory expression of the non-secretory-type Lentinula edodes laccase by Aspergillus oryzae.  

PubMed

The shiitake mushroom, Lentinula edodes, has an extracelluar secretory-type laccase, Lcc1, and a fruiting-body-accumulation-type laccase, Lcc4. We previously reported the production of Lcc1 by plant cells, but had difficulty producing Lcc4. Here, we report the production of Lcc1 and Lcc4 by Aspergillus oryzae and the extracellular secretory production of Lcc4 using a modified secretion signal peptide (SP) from Lcc1. Sp-Lcc4 produced by A. oryzae had biochemical activities similar to Lcc4 produced by L. edodes. Lcc1 did not react with beta-(3,4-dihydroxyphenol) alanine (DOPA), but Lcc4 from L. edodes and A. oryzae could oxidize DOPA. K(M) values for the substrates 2,2'-azino-di-(3-ethylbenzthiazolinsulfonate), 2,6-dimethoxyphenol, guaiacol, pyrogallol, and catechol were similar for Lcc4 and Sp-Lcc4. In conclusion, a non-secretory-type fungal laccase is secreted into the culture media with its original enzymatic properties by exploiting modified secretory signal peptide. PMID:19230633

Yano, Akira; Kikuchi, Sayaka; Nakagawa, Yuko; Sakamoto, Yuichi; Sato, Toshitsugu

2009-01-01

106

Phytase activity in Aspergillus fumigatus isolates.  

PubMed

Extracellular phytase from Aspergillus fumigatus isolates was characterized and their genes were cloned and sequenced. Based on their banding pattern in SDS-PAGE all phytases were found to be glycosylated and have similar molecular mass. A correlation between lower optimum pH (4.0) and a higher optimum temperature (70 degrees C) was found in these enzymes. All enzymes characterized displayed a lower specific activity for phytic acid and were more susceptible to proteolytic degradation than the Aspergillus niger phytase that is now commercially available. DNA sequencing established almost no sequence variation in any of the genes and no correlation is evident between a specific amino acid sequence and any physicochemical and catalytic properties of the enzymes. Despite two of the isolates having identical deduced amino acid sequence, characterization of the enzymes encoded by these two identical genes revealed differences in both pH and temperature optimum. This suggests that differences in pH and temperature optimum in these four isolates of A. fumigatus may be due in part to subtle differences in posttranslational modification. PMID:10973795

Mullaney, E J; Daly, C B; Sethumadhavan, K; Rodriquez, E; Lei, X G; Ullah, A H

2000-09-01

107

Enhancing itaconic acid production by Aspergillus terreus.  

PubMed

Aspergillus terreus is successfully used for industrial production of itaconic acid. The acid is formed from cis-aconitate, an intermediate of the tricarboxylic (TCA) cycle, by catalytic action of cis-aconitate decarboxylase. It could be assumed that strong anaplerotic reactions that replenish the pool of the TCA cycle intermediates would enhance the synthesis and excretion rate of itaconic acid. In the phylogenetic close relative Aspergillus niger, upregulated metabolic flux through glycolysis has been described that acted as a strong anaplerotic reaction. Deregulated glycolytic flux was caused by posttranslational modification of 6-phosphofructo-1-kinase (PFK1) that resulted in formation of a highly active, citrate inhibition-resistant shorter form of the enzyme. In order to avoid complex posttranslational modification, the native A. niger pfkA gene has been modified to encode for an active shorter PFK1 fragment. By the insertion of the modified A. niger pfkA genes into the A. terreus strain, increased specific productivities of itaconic acid and final yields were documented by transformants in respect to the parental strain. On the other hand, growth rate of all transformants remained suppressed which is due to the low initial pH value of the medium, one of the prerequisites for the accumulation of itaconic acid by A. terreus mycelium. PMID:20461508

Tevz, Gregor; Bencina, Mojca; Legisa, Matic

2010-08-01

108

Acute community acquired Aspergillus pneumonia in a presumed immunocompetent host  

PubMed Central

Infection from Aspergillus results in a wide range of diseases from simple Aspergillus pneumonia to fatal invasive Aspergillosis. Though the fungus is known to predominantly affect the immunocompromised host, it has also been known to cause acute pneumonia in immunocompetent hosts which is invariably fatal. It presents as an acute pneumonia with bilateral chest infiltrates on radiograph. Early clinical suspicion and microbiological identification by measures such as broncho alveolar lavage and initiation of therapy with voricanozole significantly increase the chances of survival. In this article the authors discuss a case of acute community acquired Aspergillus pneumonia in an immunocompetent host who survived due to early identification and prompt treatment with appropriate antifungal medication.

Sridhar, Varun; Rajagopalan, Natarajan; C, Shivaprasad; Patil, Mahantesh; Varghese, Jaicob

2012-01-01

109

Actinobacteria Associated with the Marine Sponges Cinachyra sp., Petrosia sp., and Ulosa sp. and Their Culturability  

PubMed Central

Actinobacteria associated with 3 marine sponges, Cinachyra sp., Petrosia sp., and Ulosa sp., were investigated. Analyses of 16S rRNA gene clone libraries revealed that actinobacterial diversity varied greatly and that Ulosa sp. was most diverse, while Cinachyra sp. was least diverse. Culture-based approaches failed to isolate actinobacteria from Petrosia sp. or Ulosa sp., but strains belonging to 10 different genera and 3 novel species were isolated from Cinachyra sp.

Khan, Shams Tabrez; Takagi, Motoki; Shin-ya, Kazuo

2012-01-01

110

Inhibition of xyloglucanase from an alkalothermophilic Thermomonospora sp. by a peptidic aspartic protease inhibitor from Penicillium sp. VM24.  

PubMed

A bifunctional inhibitor from Penicillium sp VM24 causing inactivation of xyloglucanase from Thermomonospora sp and an aspartic protease from Aspergillus saitoi was identified. Steady state kinetics studies of xyloglucanase and the inhibitor revealed an irreversible, non-competitive, two-step inhibition mechanism with IC(50) and K(i) values of 780 and 500nM respectively. The interaction of o-phthalaldehyde (OPTA)-labeled xyloglucanase with the inhibitor revealed that the inhibitor binds to the active site of the enzyme. Far- and near-UV spectrophotometric analysis suggests that the conformational changes induced in xyloglucanase by the inhibitor may be due to irreversible denaturation of enzyme. The bifunctional inhibitor may have potential as a biocontrol agent for the protection of plants against phytopathogenic fungi. PMID:22940347

Menon, Vishnu; Rao, Mala

2012-11-01

111

Effect of gamma radiation on Aspergillus flavus and Aspergillus ochraceus ultrastructure and mycotoxin production  

NASA Astrophysics Data System (ADS)

The aim of this work was to study the effect of gamma radiation (2 kGy) on Aspergillus flavus and Aspergillus ochraceus ultrastructure. Moreover, the influence on aflatoxin B 1 and ochratoxin A production was also observed. Irradiated A. flavus strain showed a dull orangish colony while control strain showed the typical green color. Minor differences were observed on stipes, metulae and conidia size between control and irradiated A. flavus and A. ochraceus strains. Irradiated fungi showed ultrastructural changes on cell wall, plasmalema and cytoplasm levels. The levels of mycotoxins produced by irradiated strains were two times greater than those produced by control strains. Successive transferences of irradiated strains on malt extract agar allowed the fungus to recuperate morphological characteristics. Although minor changes in the fungal morphology were observed, ultrastructural changes at cell wall level and the increase of mycotoxin production ability were observed. Inappropriate storage of irradiated food and feed would allow the development of potentially more toxicogenic fungal propagules.

Ribeiro, J.; Cavaglieri, L.; Vital, H.; Cristofolini, A.; Merkis, C.; Astoreca, A.; Orlando, J.; Carú, M.; Dalcero, A.; Rosa, C. A. R.

2011-05-01

112

Aflatoxin Biosynthesis and Sclerotial Development in Aspergillus flavus and Aspergillus parasiticus  

Microsoft Academic Search

\\u000a Aflatoxins are a family of fungal secondary metabolites. They are produced by species in the genus Aspergillus. The commonly recognized producers of aflatoxins include A. flavus, A. parasiticus, A. nomius, A. tamarii, A. pseudotamarii, A. bombycis, and A. ochraceoroseus (Cary et al. 2005). Aflatoxin contamination of agricultural commodities can arise from field conditions conducive to fungal\\u000a growth before harvest as

Perng-Kuang Chang

113

Survey of Vietnamese peanuts, corn and soil for the presence of Aspergillus flavus and Aspergillus parasiticus.  

PubMed

Aspergillus flavus and Aspergillus parasiticus cause perennial infection of agriculturally important crops in tropical and subtropical areas. Invasion of crops by these fungi may result in contamination of food and feed by potent carcinogenic aflatoxins. Consumption of aflatoxin contaminated foods is a recognised risk factor for human hepatocellular carcinoma (HCC) and may contribute to the high incidence of HCC in Southeast Asia. This study conducted a survey of Vietnamese crops (peanuts and corn) and soil for the presence of aflatoxigenic fungi and used microsatellite markers to investigate the genetic diversity of Vietnamese Aspergillus strains. From a total of 85 samples comprising peanut (25), corn (45) and soil (15), 106 strains were isolated. Identification of strains by colony morphology and aflatoxin production found all Vietnamese strains to be A. flavus with no A. parasiticus isolated. A. flavus was present in 36.0% of peanut samples, 31.1% of corn samples, 27.3% of farmed soil samples and was not found in virgin soil samples. Twenty-five per cent of the strains produced aflatoxins. Microsatellite analysis revealed a high level of genetic diversity in the Vietnamese A. flavus population. Clustering, based on microsatellite genotype, was unrelated to aflatoxin production, geographic origin or substrate origin. PMID:19693687

Tran-Dinh, N; Kennedy, I; Bui, T; Carter, D

2009-11-01

114

Okaramines H and I, new okaramine congeners, from aspergillus aculeatus  

PubMed

Two new congeners of okaramine, okaramines H (3) and I (4), were isolated from okara fermented with Aspergillus aculeatus KF-428. Their structures were elucidated by spectroscopic methods. Neither okaramine H nor I showed insecticidal activity against silkworms. PMID:10075772

Hayashi; Furutsuka; Shiono

1999-02-01

115

Growth pattern of the surface of fungus Aspergillus colony  

NASA Astrophysics Data System (ADS)

Aspergillus oryzae colonies were grown under various glucose concentrations, temperatures, and agar concentrations, and the effects on the pattern were investigated. Patterns of colony were found to vary from uniform to diffusion-limited aggregation type.

Matsuura, Shu; Miyazima, Sasuke

1992-05-01

116

Aspergillus flavus endaortitis following aortic valvotomy  

PubMed Central

Aspergillar endaortitis does not seem to have been described before in the English literature. Our patient had undergone aortic valvotomy and subsequently developed leg pains, migratory arthralgias, periarticular swelling, and general malaise. Mild intermittent pyrexia, evanescent petechiae, splinter haemorrhages, and peripheral small artery occlusion characterized the early course in hospital. Dramatic popliteal artery occlusion led to surgical recovery of embolic material packed with mycelia of Aspergillus flavus, but the patient died despite intravenous amphotericin B therapy. Necropsy revealed endaortitis and aspergilli were demonstrated in the wall of a saccular dilatation of the ascending aorta close to non-absorbable sutures. The relevant literature is reviewed and attention is drawn to the current implications of knowledge relating to risk factors, diagnosis, and treatment. We suggest that cardiovascular aspergillosis will now be encountered more frequently and that a different therapeutic approach is justified. Images

Malcolm, A. D.; Bakerspigel, A.; Enriquez, A. A.

1971-01-01

117

Genetics of Polyketide Metabolism in Aspergillus nidulans  

PubMed Central

Secondary metabolites are small molecules that show large structural diversity and a broad range of bioactivities. Some metabolites are attractive as drugs or pigments while others act as harmful mycotoxins. Filamentous fungi have the capacity to produce a wide array of secondary metabolites including polyketides. The majority of genes required for production of these metabolites are mostly organized in gene clusters, which often are silent or barely expressed under laboratory conditions, making discovery and analysis difficult. Fortunately, the genome sequences of several filamentous fungi are publicly available, greatly facilitating the establishment of links between genes and metabolites. This review covers the attempts being made to trigger the activation of polyketide metabolism in the fungal model organism Aspergillus nidulans. Moreover, it will provide an overview of the pathways where ten polyketide synthase genes have been coupled to polyketide products. Therefore, the proposed biosynthesis of the following metabolites will be presented; naphthopyrone, sterigmatocystin, aspyridones, emericellamides, asperthecin, asperfuranone, monodictyphenone/emodin, orsellinic acid, and the austinols.

Klejnstrup, Marie L.; Frandsen, Rasmus J. N.; Holm, Dorte K.; Nielsen, Morten T.; Mortensen, Uffe H.; Larsen, Thomas O.; Nielsen, Jakob B.

2012-01-01

118

Histopathological implications of Aspergillus infection in lung.  

PubMed

This paper opens with a discussion on the significance of invasive fungal infections in advanced contemporary medicine, with an emphasis on the intractability of disease management and the difficulties of diagnosis. This is followed by a discussion concerning classification, histopathological features, and pathophysiology. While it has been largely accepted that Aspergillus species is recognized by cellular receptors and attacked by neutrophils, the radiological and macroscopic findings linking infection with neutropenia remain unconfirmed. In an effort to gain a better understanding of the pathophysiology and pathogenesis of invasive aspergillosis, we wish to emphasize the utility of radiological and histopathological examinations since these can provide detailed information on the extremely complex interaction between the causative microbes and tissue responses. A review of noninvasive or semi-invasive aspergillosis is also provided, with particular emphasis on chronic necrotizing pulmonary aspergillosis, which is recognized as a transition form of simple pulmonary aspergilloma and invasive pulmonary aspergillosis, although few findings have been reported in this area. PMID:24347836

Tochigi, Naobumi; Okubo, Yoichiro; Ando, Tsunehiro; Wakayama, Megumi; Shinozaki, Minoru; Gocho, Kyoko; Hata, Yoshinobu; Ishiwatari, Takao; Nemoto, Tetsuo; Shibuya, Kazutoshi

2013-01-01

119

Environmental fungicides and triazole resistance in Aspergillus.  

PubMed

Fungal diseases are problematic in both human health and agriculture. Treatment options are limited and resistance may emerge. The relatively recent recognition of triazole resistance in Aspergillus fumigatus has prompted questioning of the origin of resistance. While multiple mechanisms are described in clinical isolates from triazole-treated patients, some de novo resistance is also recognised, especially attributable to TR34 /L98H. Such strains probably arose in the environment, and, indeed, multiple studies have now demonstrated TR(34) /L98H triazole resistance strains of A. fumigatus from soil. Docking and other in vitro studies are consistent with environmental resistance induction through exposure to certain triazole fungicides, notably difenoconazole, propiconazole, epoxiconazole, bromuconazole and tebuconazole. This article addresses the potential implications of this issue for both human health and food security. PMID:23616354

Bowyer, Paul; Denning, David W

2014-02-01

120

Characterization of Recombinant Terrelysin, a Hemolysin of Aspergillus terreus  

Microsoft Academic Search

Fungal hemolysins are potential virulence factors. Some fungal hemolysins belong to the aegerolysin protein family that includes\\u000a cytolysins capable of lysing erythrocytes and other cells. Here, we describe a hemolysin from Aspergillus terreus called terrelysin. We used the genome sequence database to identify the terrelysin sequence based on homology with other\\u000a known aegerolysins. Aspergillus terreus mRNA was isolated, transcribed to

Ajay P. Nayak; Françoise M. Blachere; Justin M. Hettick; Slawomir Lukomski; Detlef Schmechel; Donald H. Beezhold

2011-01-01

121

Effect of building construction on Aspergillus concentrations in a hospital.  

PubMed

Air samples taken in a hospital undergoing construction and analyzed with a quantitative polymerase chain reaction (qPCR) assay for the Aspergillus genus did not show elevated concentrations of Aspergillus or particulate matter with a diameter of 5 microm or less in patient areas. Air samples from the construction zone indicated the containment system, which used polyethylene film barrier and negative pressure, was effective. PMID:18419373

Goebes, Marian D; Baron, Ellen Jo; Mathews, Kathleen L; Hildemann, Lynn M

2008-05-01

122

Ribonuclease production by free and immobilized Aspergillus clavatus cells  

Microsoft Academic Search

Several fungal strains ofAspergillus andPenicillium were immobilized by cryopolymerization in polyvinyl alcohol cryogel beads.Aspergillus clavatus was the best producer of extracellular ribonuclease. Enzyme productivity and growth of free and immobilized cells in shake flasks and agitated bioreactor were studied. Ribonuclease production and growth behaviour depended on concentrations of glucose, peptone and soybean in the culture medium. Enzyme production was influenced

R. J. Manolov

1993-01-01

123

Production of citric acid with immobilized Aspergillus niger  

Microsoft Academic Search

The spores of Aspergillus niger were entrapped in calcium-alginate beads and precultivated in growth media with various amounts of nitrogen. During the following citric acid production in shaking cultures an optimum of acid formation and yield was observed after the precultivation with 100–200 mg\\/l NH4NO3. The productivity of the immobilized Aspergillus was found to be 1.5 times higher than in

H. Eikmeier; H. J. Rehm

1984-01-01

124

Ageratum conyzoides essential oil as aflatoxin suppressor of Aspergillus flavus  

Microsoft Academic Search

Aflatoxin B1 (AFB1) is a highly toxic and carcinogenic metabolite produced by Aspergillus species on food and agricultural commodities. Inhibitory effects of essential oil of Ageratum conyzoides, on the mycelial growth and aflatoxin B1 production by Aspergillus flavus were studied. Cultures were incubated in yeast extract-sucrose (YES) broth for days at 25°C at the following different concentrations of the essential

Juliana H. C. Nogueira; Edlayne Gonçalez; Silvia R. Galleti; Roseane Facanali; Márcia O. M. Marques; Joana D. Felício

2010-01-01

125

New and revisited species in Aspergillus section Nigri  

PubMed Central

Four new species, Aspergillus eucalypticola, A. neoniger, A. fijiensis and A. indologenus are described and illustrated. Aspergillus eucalypticola was isolated from Eucalyptus leaf from Australia, and is related to A. tubingensis and A. costaricaensis, but could clearly be distinguished from them based on either ?-tubulin or calmodulin sequence data. Aspergillus eucalypticola produced pyranonigrin A, funalenone, aurasperone B and other naphtho-?-pyrones. Aspergillus neoniger is also a biseriate species isolated from desert sand in Namibia, and mangrove water in Venezuela, which produces aurasperone B and pyranonigrin A. Aspergillus fijiensis is a uniseriate species related to A. aculeatinus, and was isolated from soil in Fiji, and from Lactuca sativa in Indonesia. This species is able to grow at 37 °C, and produces asperparalines and okaramins. Aspergillus indologenus was isolated from soil, India. This species also belongs to the uniseriate group of black aspergilli, and was found to be related to, but clearly distinguishable from A. uvarum based on ?-tubulin, calmodulin and ITS sequence data. Aspergillus indologenus produced the insecticidal compounds okaramins A, B, H, and two types of indol-alkaloids which have not been structure elucidated. Two other species, A. violaceofuscus and A. acidus, are revalidated based on molecular and extrolite data. Aspergillus violaceofuscus was found to be related to A. japonicus, and produced some of the same interesting indol-alkaloids as A. indologenus, and also produced several families of partially characterised extrolites that were also found in A. heteromorphus. Aspergillus acidus (previously known as A. foetidus var. pallidus and A. foetidus var. acidus) is also a valid species, while A. foetidus is a synonym of A. niger based on molecular and physiological data. Two other species described previously, A. coreanus and A. lacticoffeatus, were found to be colour mutants of A. acidus and A. niger, respectively. Methods which could be used to distinguish the two closely related and economically important species A. niger and A. awamori are also detailed. Although these species differ in their occurrence and several physiological means (elastase activities, abilities to utilise 2-deoxy-D-glucose as sole carbon source), our data indicate that only molecular approaches including sequence analysis of calmodulin or ?-tubulin genes, AFLP analysis, UP-PCR analysis or mtDNA RFLP analysis can be used reliably to distinguish these sibling species. Aspergillus section Nigri now includes 26 taxa.

Varga, J.; Frisvad, J.C.; Kocsube, S.; Brankovics, B.; Toth, B.; Szigeti, G.; Samson, R.A.

2011-01-01

126

New and revisited species in Aspergillus section Nigri.  

PubMed

Four new species, Aspergillus eucalypticola, A. neoniger, A. fijiensis and A. indologenus are described and illustrated. Aspergillus eucalypticola was isolated from Eucalyptus leaf from Australia, and is related to A. tubingensis and A. costaricaensis, but could clearly be distinguished from them based on either ?-tubulin or calmodulin sequence data. Aspergillus eucalypticola produced pyranonigrin A, funalenone, aurasperone B and other naphtho-?-pyrones. Aspergillus neoniger is also a biseriate species isolated from desert sand in Namibia, and mangrove water in Venezuela, which produces aurasperone B and pyranonigrin A. Aspergillus fijiensis is a uniseriate species related to A. aculeatinus, and was isolated from soil in Fiji, and from Lactuca sativa in Indonesia. This species is able to grow at 37 °C, and produces asperparalines and okaramins. Aspergillus indologenus was isolated from soil, India. This species also belongs to the uniseriate group of black aspergilli, and was found to be related to, but clearly distinguishable from A. uvarum based on ?-tubulin, calmodulin and ITS sequence data. Aspergillus indologenus produced the insecticidal compounds okaramins A, B, H, and two types of indol-alkaloids which have not been structure elucidated. Two other species, A. violaceofuscus and A. acidus, are revalidated based on molecular and extrolite data. Aspergillus violaceofuscus was found to be related to A. japonicus, and produced some of the same interesting indol-alkaloids as A. indologenus, and also produced several families of partially characterised extrolites that were also found in A. heteromorphus. Aspergillus acidus (previously known as A. foetidus var. pallidus and A. foetidus var. acidus) is also a valid species, while A. foetidus is a synonym of A. niger based on molecular and physiological data. Two other species described previously, A. coreanus and A. lacticoffeatus, were found to be colour mutants of A. acidus and A. niger, respectively. Methods which could be used to distinguish the two closely related and economically important species A. niger and A. awamori are also detailed. Although these species differ in their occurrence and several physiological means (elastase activities, abilities to utilise 2-deoxy-D-glucose as sole carbon source), our data indicate that only molecular approaches including sequence analysis of calmodulin or ?-tubulin genes, AFLP analysis, UP-PCR analysis or mtDNA RFLP analysis can be used reliably to distinguish these sibling species. Aspergillus section Nigri now includes 26 taxa. PMID:21892239

Varga, J; Frisvad, J C; Kocsubé, S; Brankovics, B; Tóth, B; Szigeti, G; Samson, R A

2011-06-30

127

Functional expression of a foreign gene in Aspergillus oryzae producing new pyrone compounds.  

PubMed

Fungi from the genus Xylaria produce a wide range of polyketides with diverse structures, which provide important sources for pharmaceutical agents. At least seven polyketide synthase (PKS) genes, including pksmt, were found in Xylaria sp. BCC 1067. The multifunctional enzyme pksmt contains the following catalytic motifs: ?-ketosynthase (KS), acyltransferase (AT), dehydratase (DH), methyltransferase (MT), enoylreductase (ER), ketoreductase (KR), and acyl carrier region (ACP). The presence of multiple domains indicated that pksmt was an iterative type I highly-reduced-type PKS gene. To identify the gene function, pksmt was fused with a gene encoding green fluorescent protein (GFP) and introduced into a surrogate host, Aspergillus oryzae, and expressed under the control of a constitutive gpdA promoter. In the transformant, the pksmt gene was functionally expressed and translated as detected by a green fluorescence signal. This transformant produced two new 2-pyrone compounds, 4-(hydroxymethyl)-5,6-dihydro-pyran-2-one and 5-hydroxy-4-methyl-5,6-dihydro-pyran-2-one, as well as a previously identified 4-methyl-5,6-dihydro-pyran-2-one. Our results suggested that pksmt from Xylaria sp. BCC 1067 represents a family of fungal PKSs that can synthesize 2-pyrone-containing compounds. PMID:23174282

Punya, Juntira; Tachaleat, Anuwat; Wattanachaisaereekul, Songsak; Haritakun, Rachada; Boonlarppradab, Chollaratt; Cheevadhanarak, Supapon

2013-01-01

128

Aspergillus fumigatus Invasion Increases with Progressive Airway Ischemia  

PubMed Central

Despite the prevalence of Aspergillus-related disease in immune suppressed lung transplant patients, little is known of the host-pathogen interaction. Because of the mould’s angiotropic nature and because of its capacity to thrive in hypoxic conditions, we hypothesized that the degree of Aspergillus invasion would increase with progressive rejection-mediated ischemia of the allograft. To study this relationship, we utilized a novel orthotopic tracheal transplant model of Aspergillus infection, in which it was possible to assess the effects of tissue hypoxia and ischemia on airway infectivity. Laser Doppler flowmetry and FITC-lectin were used to determine blood perfusion, and a fiber optic microsensor was used to measure airway tissue oxygen tension. Fungal burden and depth of invasion were graded using histopathology. We demonstrated a high efficacy (80%) for producing a localized fungal tracheal infection with the majority of infection occurring at the donor-recipient anastomosis; Aspergillus was more invasive in allogeneic compared to syngeneic groups. During the study period, the overall kinetics of both non-infected and infected allografts was similar, demonstrating a progressive loss of perfusion and oxygenation, which reached a nadir by days 10-12 post-transplantation. The extent of Aspergillus invasion directly correlated with the degree of graft hypoxia and ischemia. Compared to the midtrachea, the donor-recipient anastomotic site exhibited lower perfusion and more invasive disease; a finding consistent with clinical experience. For the first time, we identify ischemia as a putative risk factor for Aspergillus invasion. Therapeutic approaches focused on preserving vascular health may play an important role in limiting Aspergillus infections.

Hsu, Joe L.; Khan, Mohammad A.; Sobel, Raymond A.; Jiang, Xinguo; Clemons, Karl V.; Nguyen, Tom T.; Stevens, David A.; Martinez, Marife; Nicolls, Mark R.

2013-01-01

129

21 CFR 173.120 - Carbohydrase and cellulase derived from Aspergillus niger.  

Code of Federal Regulations, 2013 CFR

...PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173...Aspergillus niger. Carbohydrase and cellulase enzyme preparation derived from Aspergillus niger... from the carbohydrase and cellulase enzyme product. (d) The additive is...

2013-04-01

130

What is the importance of classifying Aspergillus disease in cystic fibrosis patients?  

PubMed

Aspergillus species are commonly isolated from lower respiratory tract samples of patients with cystic fibrosis (CF) and markers of immunological sensation to Aspergillus are frequently encountered in this group of patients; however, the contribution of Aspergillus to CF lung disease outside of the typical complications of ABPA and aspergilloma formation remains largely unclear. Patients with CF show discretely different responses to Aspergillus, though the underlying reasons for this variation are unknown. Recent work has begun to allow us to categorize patient responses to Aspergillus based upon molecular markers of infection and immune sensitization. Aspergillus sensitization and/or airway infection is associated with worse FEV1, in CF and other patients (asthma, chronic obstructive pulmonary disease, bronchiectasis). Classification of different clinical phenotypes of Aspergillus will enable future studies to determine the natural history of different manifestations of Aspergillus disease and evaluate the effects of intervention with antifungal therapy. PMID:24869560

Jones, Andrew M; Horsley, Alex; Denning, David W

2014-08-01

131

Galactosaminogalactan from cell walls of Aspergillus niger.  

PubMed Central

A new heteropolysaccharide has been isolated by alkaline extraction of hyphal walls of Aspergillus niger NRRL 326 grown in surface culture. Its composition by weight, as determined by paper and gas chromatography and colorimetric analyses, is 70% galactose, 20% galactosamine, 6% glucose, and 1% acetyl. Two independent experiments have been used to ascertain copolymer structure: permeation chromatography in 6 M guanidinium hydrochloride, with controlled-pore glass columns of two fractionation ranges, and nitrous acid deaminative cleavage of galactosaminogalactan followed by reduction of fragments with [3H]borohydride and gel filtration chromatography. One of the tritiated fragments is tentatively identified as the disaccharide derivative galactopyranosyl 2,5-anhydrotalitol, on the basis of chromatographic properties and by kinetics of its acid hydrolysis. Smith degradation, methylation, deamination, and optical rotation studies indicate that the galactosaminogalactan consists of a linear array of hexopyranosyl units joined almost exclusively by alpha-(1 leads to 4) linkages. Hexosaminyl moieties are distributed randomly along the chains, which have an average degree of polymerization of about 100. The possible significance of this macromolecule in hyphal structure is considered.

Bardalaye, P C; Nordin, J H

1976-01-01

132

The Tip Growth Apparatus of Aspergillus nidulans  

PubMed Central

Hyphal tip growth in fungi is important because of the economic and medical importance of fungi, and because it may be a useful model for polarized growth in other organisms. We have investigated the central questions of the roles of cytoskeletal elements and of the precise sites of exocytosis and endocytosis at the growing hyphal tip by using the model fungus Aspergillus nidulans. Time-lapse imaging of fluorescent fusion proteins reveals a remarkably dynamic, but highly structured, tip growth apparatus. Live imaging of SYNA, a synaptobrevin homologue, and SECC, an exocyst component, reveals that vesicles accumulate in the Spitzenkörper (apical body) and fuse with the plasma membrane at the extreme apex of the hypha. SYNA is recycled from the plasma membrane by endocytosis at a collar of endocytic patches, 1–2 ?m behind the apex of the hypha, that moves forward as the tip grows. Exocytosis and endocytosis are thus spatially coupled. Inhibitor studies, in combination with observations of fluorescent fusion proteins, reveal that actin functions in exocytosis and endocytosis at the tip and in holding the tip growth apparatus together. Microtubules are important for delivering vesicles to the tip area and for holding the tip growth apparatus in position.

Taheri-Talesh, Naimeh; Horio, Tetsuya; Araujo-Bazan, Lidia; Dou, Xiaowei; Espeso, Eduardo A.; Penalva, Miguel A.; Osmani, Stephen A.

2008-01-01

133

Spotlight on Aspergillus nidulans photosensory systems.  

PubMed

Aspergilli are ubiquitous soil-borne fungi growing within or on the surface of numerous organic substrates. Growth within a substrate or growth on the surface correlates to different growth conditions for the hyphae due to significant changes in oxygen or reactive oxygen species levels and variations in humidity or temperature. The production of air-borne spores is supported by the substrate-air interphase and also requires a sensing system to adapt appropriately. Here we focus on light as important parameter for the mycelium to discriminate between different habitats. The fungal 'eye' includes several light sensors which react to a broad plethora of wavelengths. Aspergillus nidulans light receptors comprise a phytochrome for red-light sensing, white collar-like blue-light signaling proteins, a putative green-light sensing opsin and a cryptochrome/photolyase as distinct sensory systems. Red- and blue-light receptors are assembled into a light-sensing protein complex. Light receptors transmit their signal to a number of other regulatory proteins including a bridging protein, VeA, as part of a trimeric complex. VeA plays a central role in the balance of asexual and sexual development and in the coordination of morphogenesis and secondary metabolism. PMID:20573560

Bayram, Ozgür; Braus, Gerhard H; Fischer, Reinhard; Rodriguez-Romero, Julio

2010-11-01

134

Receptor-mediated signaling in Aspergillus fumigatus  

PubMed Central

Aspergillus fumigatus is the most pathogenic species among the Aspergilli, and the major fungal agent of human pulmonary infection. To prosper in diverse ecological niches, Aspergilli have evolved numerous mechanisms for adaptive gene regulation, some of which are also crucial for mammalian infection. Among the molecules which govern such responses, integral membrane receptors are thought to be the most amenable to therapeutic modulation. This is due to the localization of these molecular sensors at the periphery of the fungal cell, and to the prevalence of small molecules and licensed drugs which target receptor-mediated signaling in higher eukaryotic cells. In this review we highlight the progress made in characterizing receptor-mediated environmental adaptation in A. fumigatus and its relevance for pathogenicity in mammals. By presenting a first genomic survey of integral membrane proteins in this organism, we highlight an abundance of putative seven transmembrane domain (7TMD) receptors, the majority of which remain uncharacterized. Given the dependency of A. fumigatus upon stress adaptation for colonization and infection of mammalian hosts, and the merits of targeting receptor-mediated signaling as an antifungal strategy, a closer scrutiny of sensory perception and signal transduction in this organism is warranted.

Grice, C. M.; Bertuzzi, M.; Bignell, E. M.

2013-01-01

135

Solubilization of Morocco phosphorite by Aspergillus niger.  

PubMed

Phosphorus containing fertilizers have an important role in agriculture. Conventionally phosphate fertilizers are obtained by rock phosphate (RP) dissolution using mineral acids. Biotechnological methods can be a promising alternative in RP processing. The influence of Aspergillus niger strain, the composition of a nutritive medium, Morocco phosphorite (MP) concentration in the liquid medium, the time of bioconversion and the preliminary mechanical activation (PMA) of MP on the phosphorite microbial solubilization has been presented. The phosphorus concentration (as P2O5), citric acid production, glucose concentration and pH in the cultural medium were monitored. The phosphate concentration was expressed as water soluble - alpha1 (in the native cultural liquid), citrate soluble - alpha2 (after treating the biomass and remaining mineral mass with citric acid) and biomass available phosphorus - alpha3. Phosphate dissolution was not strongly correlated both with the citric acid production and the incubation period. When the fungi were grown without water soluble phosphorus compounds the MP solubilization had higher values. A maximum of 94.80% total P2O5 extraction was achieved. The PMA activity does not facilitate MP dissolution during the bioconversion. PMID:18468889

Bojinova, D; Velkova, R; Ivanova, R

2008-10-01

136

Rat monoclonal antibodies against Aspergillus galactomannan.  

PubMed Central

Monoclonal antibodies (MAbs) against Aspergillus fumigatus galactomannan were produced in rats. Seven of them, EB-A1 through EB-A7, were characterized in more detail. They were all immunoglobulin M antibodies, reacting in an indirect enzyme-linked immunosorbent assay with purified A. fumigatus galactomannan, with avidity constants of between 2 x 10(9) and 5 x 10(9)/M. Enzyme-linked immunosorbent assay inhibition experiments with modified galactomannan and synthetic oligomers of beta (1----5)galactofuranose demonstrated that the MAbs bound to an epitope located on the beta(1----5)galactofuranose-containing side chains of the galactomannan molecule. An identical or similar epitope also seemed to be present in other fungi. Immunofluorescence and immunoelectron microscopy experiments with EB-A2 revealed the presence of the antigen in the fungal wall and inside the cell. Immunoblotting experiments demonstrated that the epitope recognized by the MAbs was a common oligosaccharide moiety of a wide range of intracellular and extracellular glycoproteins in A. fumigatus. The characteristics of the MAbs justify their use in the diagnosis of invasive aspergillosis by antigen detection. Images

Stynen, D; Sarfati, J; Goris, A; Prevost, M C; Lesourd, M; Kamphuis, H; Darras, V; Latge, J P

1992-01-01

137

Fingernail Onychomycosis Due to Aspergillus niger  

PubMed Central

Onychomycosis is usually caused by dermatophytes, but some species of nondermatophytic molds and yeasts are also associated with nail invasion. Aspergillus niger is a nondermatophytic mold which exists as an opportunistic filamentous fungus in all environments. Here, we report a case of onychomycosis caused by A. niger in a 66-year-old female. The patient presented with a black discoloration and a milky white base and onycholysis on the proximal portion of the right thumb nail. Direct microscopic examination of scrapings after potassium hydroxide (KOH) preparation revealed dichotomous septate hyphae. Repeated cultures on Sabouraud's dextrose agar (SDA) without cycloheximide produced the same black velvety colonies. No colony growth occurred on SDA with cycloheximide slants. Biseriate phialides covering the entire vesicle with radiate conidial heads were observed on the slide culture. The DNA sequence of the internal transcribed spacer region of the clinical sample was a 100% match to that of A. niger strain ATCC 16888 (GenBank accession number AY373852). A. niger was confirmed by KOH mount, colony identification, light microscopic morphology, and DNA sequence analysis. The patient was treated orally with 250 mg terbinafine daily and topical amorolfine 5% nail lacquer for 3 months. As a result, the patient was completely cured clinically and mycologically.

Kim, Dong Min; Ha, Gyoung Yim; Sohng, Seung Hyun

2012-01-01

138

N-Glycan Modification in Aspergillus Species?  

PubMed Central

The production by filamentous fungi of therapeutic glycoproteins intended for use in mammals is held back by the inherent difference in protein N-glycosylation and by the inability of the fungal cell to modify proteins with mammalian glycosylation structures. Here, we report protein N-glycan engineering in two Aspergillus species. We functionally expressed in the fungal hosts heterologous chimeric fusion proteins containing different localization peptides and catalytic domains. This strategy allowed the isolation of a strain with a functional ?-1,2-mannosidase producing increased amounts of N-glycans of the Man5GlcNAc2 type. This strain was further engineered by the introduction of a functional GlcNAc transferase I construct yielding GlcNAcMan5GlcNac2 N-glycans. Additionally, we deleted algC genes coding for an enzyme involved in an early step of the fungal glycosylation pathway yielding Man3GlcNAc2 N-glycans. This modification of fungal glycosylation is a step toward the ability to produce humanized complex N-glycans on therapeutic proteins in filamentous fungi.

Kainz, Elke; Gallmetzer, Andreas; Hatzl, Christian; Nett, Juergen H.; Li, Huijuan; Schinko, Thorsten; Pachlinger, Robert; Berger, Harald; Reyes-Dominguez, Yazmid; Bernreiter, Andreas; Gerngross, Tillmann; Wildt, Stefan; Strauss, Joseph

2008-01-01

139

N-glycan modification in Aspergillus species.  

PubMed

The production by filamentous fungi of therapeutic glycoproteins intended for use in mammals is held back by the inherent difference in protein N-glycosylation and by the inability of the fungal cell to modify proteins with mammalian glycosylation structures. Here, we report protein N-glycan engineering in two Aspergillus species. We functionally expressed in the fungal hosts heterologous chimeric fusion proteins containing different localization peptides and catalytic domains. This strategy allowed the isolation of a strain with a functional alpha-1,2-mannosidase producing increased amounts of N-glycans of the Man5GlcNAc2 type. This strain was further engineered by the introduction of a functional GlcNAc transferase I construct yielding GlcNAcMan5GlcNac2 N-glycans. Additionally, we deleted algC genes coding for an enzyme involved in an early step of the fungal glycosylation pathway yielding Man3GlcNAc2 N-glycans. This modification of fungal glycosylation is a step toward the ability to produce humanized complex N-glycans on therapeutic proteins in filamentous fungi. PMID:18083888

Kainz, Elke; Gallmetzer, Andreas; Hatzl, Christian; Nett, Juergen H; Li, Huijuan; Schinko, Thorsten; Pachlinger, Robert; Berger, Harald; Reyes-Dominguez, Yazmid; Bernreiter, Andreas; Gerngross, Tillmann; Wildt, Stefan; Strauss, Joseph

2008-02-01

140

Diversity and specificity of microsatellites within Aspergillus section Fumigati  

PubMed Central

Background Microsatellites (or short tandem repeats, STRs) are the genetic markers of choice for studying Aspergillus fumigatus molecular epidemiology due to its reproducibility and high discrimination power. However, the specificity of these markers must be investigated in a group of isolates from closely related species. The aim of this work was to test a microsatellite-based PCR multiplex previously designed for A. fumigatus in a set of species belonging to section Fumigati, namely Aspergillus fumigatiaffinis, Aspergillus lentulus, Aspergillus novofumigatus, Aspergillus unilateralis, Aspergillus viridinutans, Neosartorya fischeri, Neosartorya hiratsukae, Neosartorya pseudofischeri and Neosartorya udagawae. Results The reference A. fumigatus strain ATCC 46645 was easily genotyped in standard conditions showing a final electrophoretic profile of 8 expected peaks corresponding to each microsatellite locus. Inversely, no peaks were observed for all other species from section Fumigati, with an exception for marker MC6b in A. unilateralis. By screening the genome sequence of Neosartorya fischeri NRRL 181, the results showed that MC3, MC6a and MC7 might be employed for N. fischeri genotyping since these markers present several repeats of each motif. The accumulation of insertions and deletions was frequently observed in the genomic regions surrounding the microsatellites, including those where the A. fumigatus primers are located. The amplification of microsatellite markers in less stringent amplification conditions resulted in a distinct electrophoretic profile for species within section Fumigati. Conclusions Therefore, the microsatellite-based PCR multiplex allow simple identification of A. fumigatus and, with a slight modification of temperature conditions, it also allows discriminating other pathogenic species within section Fumigati, particularly A. fumigatiaffinis, N. fischeri and N. udagawae.

2012-01-01

141

Humoral immunity in disseminated Aspergillus terreus infection in the dog.  

PubMed

Aspects of humoral immunity were studied in 17 dogs with disseminated aspergillosis (16 cases Aspergillus terreus, 1 case Aspergillus flavipes). All dogs had markedly raised serum IgG levels by single radial immunodiffusion (range 1500-6000 mg dl-1). Despite this, serum antibody to A. terreus was demonstrated in only 7/16 cases by agar gel diffusion, 9/16 cases by counter immunoelectrophoresis, 10/16 by ELISA and 11/16 by an indirect immunofluorescence assay. Serum antibody was also detected in 2/5 clinically normal relatives of 2 cases, indicating previous exposure or subclinical infection. PMID:3131949

Day, M J; Penhale, W J

1988-03-01

142

The complete nucleotide sequence of a totivirus from Aspergillus foetidus.  

PubMed

Virus infection of Aspergillus foetidus was first described in the 1970s, and the purified virus, named Aspergillus foetidus virus (AfV), contains at least two types of icosahedral particles, called AfV-fast (-F) and AfV-slow (-S) virions, based on their relative electrophoretic mobilities. AfV-S consists of a mixture of two viruses, the larger of which, called AfV-S1, is a dsRNA-containing member of the genus Victorivirus in the family Totiviridae, and its complete nucleotide sequence is described here. PMID:22729614

Kozlakidis, Zisis; Herrero, Noemi; Coutts, Robert H A

2013-01-01

143

Modern taxonomy of biotechnologically important Aspergillus and Penicillium species.  

PubMed

Taxonomy is a dynamic discipline and name changes of fungi with biotechnological, industrial, or medical importance are often difficult to understand for researchers in the applied field. Species belonging to the genera Aspergillus and Penicillium are commonly used or isolated, and inadequate taxonomy or uncertain nomenclature of these genera can therefore lead to tremendous confusion. Misidentification of strains used in biotechnology can be traced back to (1) recent changes in nomenclature, (2) new taxonomic insights, including description of new species, and/or (3) incorrect identifications. Changes in the recent published International Code of Nomenclature for Algae, Fungi and Plants will lead to numerous name changes of existing Aspergillus and Penicillium species and an overview of the current names of biotechnological important species is given. Furthermore, in (biotechnological) literature old and invalid names are still used, such as Aspergillus awamori, A. foetidus, A. kawachii, Talaromyces emersonii, Acremonium cellulolyticus, and Penicillium funiculosum. An overview of these and other species with their correct names is presented. Furthermore, the biotechnologically important species Talaromyces thermophilus is here combined in Thermomyces as Th. dupontii. The importance of Aspergillus, Penicillium, and related genera is also illustrated by the high number of undertaken genome sequencing projects. A number of these strains are incorrectly identified or atypical strains are selected for these projects. Recommendations for correct strain selection are given here. Phylogenetic analysis shows a close relationship between the genome-sequenced strains of Aspergillus, Penicillium, and Monascus. Talaromyces stipitatus and T. marneffei (syn. Penicillium marneffei) are closely related to Thermomyces lanuginosus and Th. dupontii (syn. Talaromyces thermophilus), and these species appear to be distantly related to Aspergillus and Penicillium. In the last part of this review, an overview of heterothallic reproduction in Aspergillus and Penicillium is given. The new insights in the taxonomy of Aspergillus, Penicillium, and related genera will help to interpret the results generated with comparative genomics studies or other studies dealing with evolution of, for example, enzymes, mating-type loci, virulence genes, and secondary metabolite biosynthetic gene clusters. PMID:24377856

Houbraken, Jos; de Vries, Ronald P; Samson, Robert A

2014-01-01

144

Functional Analysis of the Aspergillus nidulans Kinome  

PubMed Central

The filamentous fungi are an ecologically important group of organisms which also have important industrial applications but devastating effects as pathogens and agents of food spoilage. Protein kinases have been implicated in the regulation of virtually all biological processes but how they regulate filamentous fungal specific processes is not understood. The filamentous fungus Aspergillus nidulans has long been utilized as a powerful molecular genetic system and recent technical advances have made systematic approaches to study large gene sets possible. To enhance A. nidulans functional genomics we have created gene deletion constructs for 9851 genes representing 93.3% of the encoding genome. To illustrate the utility of these constructs, and advance the understanding of fungal kinases, we have systematically generated deletion strains for 128 A. nidulans kinases including expanded groups of 15 histidine kinases, 7 SRPK (serine-arginine protein kinases) kinases and an interesting group of 11 filamentous fungal specific kinases. We defined the terminal phenotype of 23 of the 25 essential kinases by heterokaryon rescue and identified phenotypes for 43 of the 103 non-essential kinases. Uncovered phenotypes ranged from almost no growth for a small number of essential kinases implicated in processes such as ribosomal biosynthesis, to conditional defects in response to cellular stresses. The data provide experimental evidence that previously uncharacterized kinases function in the septation initiation network, the cell wall integrity and the morphogenesis Orb6 kinase signaling pathways, as well as in pathways regulating vesicular trafficking, sexual development and secondary metabolism. Finally, we identify ChkC as a third effector kinase functioning in the cellular response to genotoxic stress. The identification of many previously unknown functions for kinases through the functional analysis of the A. nidulans kinome illustrates the utility of the A. nidulans gene deletion constructs.

De Souza, Colin P.; Hashmi, Shahr B.; Osmani, Aysha H.; Andrews, Peter; Ringelberg, Carol S.; Dunlap, Jay C.; Osmani, Stephen A.

2013-01-01

145

Aspergillus fumigatus generates an enhanced Th2-biased immune response in mice with defective cystic fibrosis transmembrane conductance regulator.  

PubMed

Cystic fibrosis (CF) lung disease is characterized by persistent airway inflammation and airway infection that ultimately leads to respiratory failure. Aspergillus sp. are present in the airways of 20-40% of CF patients and are of unclear clinical significance. In this study, we demonstrate that CF transmembrane conductance regulator (CFTR)-deficient (CFTR knockout, Cftr(tm1Unc-)TgN(fatty acid-binding protein)CFTR) and mutant (DeltaF508) mice develop profound lung inflammation in response to Aspergillus fumigatus hyphal Ag exposure. CFTR-deficient mice also develop an enhanced Th2 inflammatory response to A. fumigatus, characterized by elevated IL-4 in the lung and IgE and IgG1 in serum. In contrast, CFTR deficiency does not promote a Th1 immune response. Furthermore, we demonstrate that CD4+ T cells from naive CFTR-deficient mice produce higher levels of IL-4 in response to TCR ligation than wild-type CD4+ T cells. The Th2 bias of CD4+ T cells in the absence of functional CFTR correlates with elevated nuclear levels of NFAT. Thus, CFTR is important to maintain the Th1/Th2 balance in CD4+ T cells. PMID:17015704

Allard, Jenna B; Poynter, Matthew E; Marr, Kieren A; Cohn, Lauren; Rincon, Mercedes; Whittaker, Laurie A

2006-10-15

146

Antifungal activity of some essential oils against toxigenic Aspergillus species.  

PubMed

Increasing attentions have been paid on the application of essential oils and plant extracts for control of postharvest pathogens due to their natural origin and less appearance of resistance in fungi pathogens. Some Aspergillus species are toxigenic and responsible for many cases of food and feed contamination. Some Toxins that produce with some Aspergillus species are known to be potent hepatocarcinogens in animals and humans. The present work evaluated the parameters of antifungal activity of the essential oils of Zataria multiflora, Thymus migricus, Satureja hortensis, Foeniculum vulgare, Carum capticum and thiabendazol fungicide on survival and growth of different species of Aspergillus. Aerial part and seeds of plant species were collected then dried and its essential oils isolated by means of hydrodistillation. Antifungal activity was evaluated in vitro by poisonous medium technique with PDA medium at six concentrations. Results showed that all essential oils could inhibit the growth of Aspergillus species. The essential oil with the best effect and lowest EC50 and MIC (Minimum Inhibitory Concentration) was Z. multiflora (223 microl/l and 650 microl/l, respectively). The chemical composition of the Z. multiflora essential oil was analyzed by GC-MS. PMID:21534488

Alizadeh, Alireza; Zamani, Elham; Sharaifi, Rohollah; Javan-Nikkhah, Mohammad; Nazari, Somayeh

2010-01-01

147

Integrative analysis of the heat shock response in Aspergillus fumigatus  

Microsoft Academic Search

BACKGROUND: Aspergillus fumigatus is a thermotolerant human-pathogenic mold and the most common cause of invasive aspergillosis (IA) in immunocompromised patients. Its predominance is based on several factors most of which are still unknown. The thermotolerance of A. fumigatus is one of the traits which have been assigned to pathogenicity. It allows the fungus to grow at temperatures up to and

Daniela Albrecht; Reinhard Guthke; Axel A Brakhage; Olaf Kniemeyer

2010-01-01

148

Aspergillus niser for the study of in vitro drug metabolism  

Microsoft Academic Search

Drug metabolism is an important aspect for the study of toxic effect in human being. However, the occurrence of several regulatory issues and high cost involved in experimental study on drug metabolism, restrict the study using human as a model system. Keeping this in view, in the present study, the fungus Aspergillus niser was chosen as a model organism for

K. Pramanik; N. Panda; J. Satapathy; A. Biswas

2010-01-01

149

Expression profiling of pectinolytic genes from Aspergillus niger  

Microsoft Academic Search

The expression of 26 pectinolytic genes from Aspergillus niger was studied in a wild type strain and a CreA derepressed strain, under 16 different growth conditions, to obtain an expression profile for each gene. These expression profiles were then submitted to cluster analysis to identify subsets of genes with similar expression profiles. With the exception of the feruloyl esterase encoding

Ronald P. de Vries; Jenny Jansen; Guillermo Aguilar; Lucie Pa?enicová; Vivi Joosten; Florian Wülfert; Jacques A. E. Benen; Jaap Visser

2002-01-01

150

Novel metabolites in phenanthrene and pyrene transformation by Aspergillus niger.  

PubMed Central

Aspergillus niger, isolated from hydrocarbon-contaminated soil, was examined for its potential to degrade phenanthrene and pyrene. Two novel metabolites, 1-methoxyphenanthrene and 1-methoxypyrene, were identified by conventional chemical techniques. Minor metabolites identified were 1- and 2-phenanthrol and 1-pyrenol. No 14CO2 evolution was observed in either [14C]phenanthrene or [14C]pyrene cultures.

Sack, U; Heinze, T M; Deck, J; Cerniglia, C E; Cazau, M C; Fritsche, W

1997-01-01

151

Pectinases of Aspergillus niger: A Molecular and Biochemical Characterisation  

Microsoft Academic Search

The major topics of this thesis are the microfilamentous fungus Aspergillus niger and the pectinases a group of extracellular enzymes. Many 'products' of this species hold the GRAS (Generally Regarded As Safe) status and thus pectinases find a broad range of applications in food, feed and beverage industries.Pectinases are enzymes which degrade pectin, a heteropolysaccharide found in the middle lamella

L. Parenicová

2000-01-01

152

Successful treatment of exogenous aspergillus endophthalmitis: a case report.  

PubMed Central

We describe the first case of successfully treated exogenous aspergillus endophthalmitis following penetrating injury and primary scleral wound repair. After repeated vitreous surgery with multiple intravitreous instillations of amphotericin B combined with intravenous antifungal therapy the patient's visual acuity was 6/18. A vigorous approach in the management of mycotic endophthalmitis is emphasised and the role of closed vitrectomy discussed. Images

Ho, P. C.; Tolentino, F. I.; Baker, A. S.

1984-01-01

153

Polyphasic taxonomy of Aspergillus fumigatus and related species  

Microsoft Academic Search

The variability within Aspergillus fumigatus Fresenius and related species was examined using macro-, micro-morphology, growth temperature re- gimes and extrolite patterns. In addition, DNA analyses including partial b-tubulin, calmodulin and actin gene sequences were used. Detailed examina- tion of strains, considered as A. fumigatus earlier, showed that they could be divided into four groups including A. fumigatus sensu stricto, A.

Seung-Beom Hong; Seung-Joo Go; H.-D. Shin; J. C. Frisvad; R. A. Samson

2005-01-01

154

Fumonisin and Ochratoxin Production in Industrial Aspergillus niger Strains  

Microsoft Academic Search

Aspergillus niger is perhaps the most important fungus used in biotechnology, and is also one of the most commonly encountered fungi contaminating foods and feedstuffs, and occurring in soil and indoor environments. Many of its industrial applications have been given GRAS status (generally regarded as safe). However, A. niger has the potential to produce two groups of potentially carcinogenic mycotoxins:

Jens C. Frisvad; Thomas O. Larsen; Ulf Thrane; Martin Meijer; Janos Varga; Robert A. Samson; Kristian F. Nielsen

2011-01-01

155

Mycotoxin risk evaluation in feeds contaminated by Aspergillus fumigatus  

Microsoft Academic Search

Aspergillus fumigatus, a common feed contaminant particularly ubiquitous in conserved forages, produces several mycotoxins that can affect the health of animals. The aim of this work was to assess the ability of A. fumigatus to produce toxins, particularly gliotoxin, on laboratory media and natural feed substrates. The ability of fourteen A. fumigatus strains to produce gliotoxin, verruculogen, fumagillin, and helvolic

H. Boudra; D. P. Morgavi

2005-01-01

156

Growth and ?-amylase production by Aspergillus oryzae during continuous cultivations  

Microsoft Academic Search

Continuous cultivations of an ?-amylase producing strain of Aspergillus oryzae were carried out using a chemically defined medium with glucose as the growth limiting component. For steady-state cultures the recovery of carbon was about 99%, indicating that all major carbon components i.e. biomass, carbon dioxide and ?-amylase were measured. The rates of sugar consumption, oxygen consumption and carbon dioxide production

Morten Carlsen; Jens Nielsen; John Villadsen

1996-01-01

157

Aspergillus genomes: secret sex and the secrets of sex  

Microsoft Academic Search

The genomic sequences of three species of Aspergillus, including the model organism A. nidulans (which is homothallic: having no differentiated mating types, a strain being able to cross with itself), suggest that A. fumigatus and A. oryzae, considered to be asexual, might in fact be heterothallic (having two differentiated mating types, a strain being able to cross only with strains

Claudio Scazzocchio

2006-01-01

158

Aspergillus pneumonia in adult patients with acute leukemia.  

PubMed

Aspergillus pneumonia often is a fatal consequence of prolonged neutropenia in patients with acute leukemia. Despite prompt diagnosis and adequate antifungal therapy, mortality remains high among these patients. Recognizing early signs and symptoms, as well as risk factors, is the key to reducing morbidity and mortality. PMID:24675261

Cadogan, Stacey; Miller, Sharon

2014-04-01

159

New ochratoxin A producing species of Aspergillus section Circumdati  

Microsoft Academic Search

Abstract: Aspergillus section Circumdati contains species with yellow to ochre conidia and non-black sclerotia that produce atleast one of the following extrolites: ochratoxins, penicillic acids, xanthomegnins or melleins. The exception to this is A. robustus, which produces black sclerotia, phototropic conidiophores and none of the extrolites listed above. Based on a polyphasic approach using morphological characters, extrolites and partial ?-tubulin

Jens C. Frisvad; J. Mick Frank; Jos A. M. P. Houbraken; Angelina F. A. Kuijpers; Robert A. Samson

2004-01-01

160

A case of onychomycosis caused by Aspergillus candidus  

PubMed Central

Based on epidemiological studies, Aspergillus candidus has been demonstrated as an emerging fungal agent of toenail onychomycosis. Here we report a case of a toenail infection caused by A. candidus in a healthy 60-year-old woman. Based on macroscopic and microscopic characteristics of the culture as well as nucleotide sequencing of 28S region, the causative agent was identified as A. candidus.

Ahmadi, Bahram; Hashemi, Seyed Jamal; Zaini, Farideh; Shidfar, Mohammad Reza; Moazeni, Maryam; Mousavi, Bita; Noorbakhsh, Fatemeh; Gheramishoar, Mohsen; Hossein pour, Leila; Rezaie, Sassan

2012-01-01

161

Thoracic Intradural Aspergillus Abscess Formation following Epidural Steroid Injection  

Microsoft Academic Search

Summary: We report an extremely unusual iatrogenic in- fection of the spinal canal with Aspergillus fumigatus that resulted in intradural abscess formation following epidural steroid injection in an immunocompetent young individual. Although the imaging findings of the infection were rela- tively nonspecific, MR imaging not only allowed for a prompt diagnosis, but also helped in surgical localization to the intradural

Gaurav Saigal; M. Judith; Donovan Post; Dusko Kozic

162

Bioleaching of spent fluid catalytic cracking catalyst using Aspergillus niger  

Microsoft Academic Search

The use of the fungus Aspergillus niger for the bioleaching of heavy metals from spent catalyst was investigated, with fluid catalytic cracking (FCC) catalyst as a model. Bioleaching was examined in batch cultures with the spent catalysts at various pulp densities (1–12%). Chemical leaching was also performed using mineral acids (sulphuric and nitric acids) and organic acids (citric, oxalic and

Khin Moh Moh Aung; Yen-Peng Ting

2005-01-01

163

Lovastatin Biosynthesis by Aspergillus terreus in a Chemically Defined Medium  

Microsoft Academic Search

Lovastatin is a secondary metabolite produced by Aspergillus terreus. A chemically defined medium was developed in order to investigate the influence of carbon and nitrogen sources on lovastatin biosynthesis. Among several organic and inorganic defined nitrogen sources metabolized by A. terreus, glutamate and histidine gave the highest lovastatin biosynthesis level. For cultures on glucose and glutamate, lovastatin synthesis initiated when

HASSAN HAJJAJ; PETER NIEDERBERGER; PHILIPPE DUBOC

2001-01-01

164

Solubilization of rock phosphate by immobilized Aspergillus niger  

Microsoft Academic Search

Aspergillus niger, an acid-producing filamentous fungus, was immobilized on polyurethane foam. Various amounts of foam cubes and spore suspension were tested in order to obtain an efficient immobilization process. The best combination selected for further experiments was 0.2 g polyurethane foam and 3 ml spore suspension. Immobilized cells were reused, with higher levels of acid formation being maintained for longer

Nikolay Vassilev; Maria Vassileva; Rosario Azcon

1997-01-01

165

Citric acid production by Aspergillus niger immobilized on polyurethane foam  

Microsoft Academic Search

Citric acid was produced using Aspergillus niger immobilized on polyurethane foam in a bubble column reactor. Most of the adsorbed cells remained on the support and, as a result, high oxygen tension was maintained during the reactor operation. However, uncontrolled growth of the pellets made continuous reactor operation difficult. The citric acid productivity obtained from 15 vol.% foam particles containing

Yong Hee Lee; Chang Woo Lee; Ho Nam Chang

1989-01-01

166

Hymenopsins A and B and a Macrophorin Analogue from a Fungicolous Hymenopsis Sp.?  

PubMed Central

Hymenopsin A (1), hymenopsin B (2), and a new macrophorin analogue, 2?,3?-epoxy-13-hydroxy-4?-oxomacrophorin A (3), have been isolated from a fungicolous isolate of Hymenopsis sp. (MYC-1703; NRRL 37638). The structures and relative configurations of these compounds were assigned on the basis of 2D NMR and MS data, and the identity of 1 was confirmed by X-ray crystallographic analysis. The absolute configuration of 2 was proposed on the basis of CD analysis using both empirical and computational methods. Compounds 2 and 3 showed antibacterial activity against Staphylococcus aureus and Bacillus subtilis. Compound 3 was also active against Aspergillus flavus and Fusarium verticillioides.

Schmidt, Lori E.; Deyrup, Stephen T.; Baltrusaitis, Jonas; Swenson, Dale C.; Wicklow, Donald T.; Gloer, James B.

2009-01-01

167

The relationship of Aspergillus flavus and Aspergillus parasiticus with reference to production of aflatoxins and cyclopiazonic acid  

Microsoft Academic Search

Forty-seven isolates of Aspergillus parasiticus were analyzed for production of aflatoxins B1, B2, G1, G2, and cyclopiazonic acid. None produced cyclopiazonic acid, whereas 46 of 47 produced aflatoxins B1 and G1. These data are related to previous studies pertaining to A. flavus and illustrate species validity from a biochemical standpoint.

Joe W. Dorner; Richard J. Cole; Urban L. Diener

1984-01-01

168

Performance Characteristics of the Platelia Aspergillus Enzyme Immunoassay for Detection of Aspergillus Galactomannan Antigen in Bronchoalveolar Lavage Fluid  

Microsoft Academic Search

We have evaluated the Platelia Aspergillus enzyme immunoassay for detection of galactomannan in bron- choalveolar lavage (BAL) specimens in solid organ transplant patients with aspergillosis. The precision and reproducibility in serum or BAL to which galactomannan was added were similar. Sensitivity was 81.8% in patients with aspergillosis, and specificity was 95.8% in lung transplant patients who underwent BAL for surveillance

S. Husain; C. J. Clancy; M. H. Nguyen; S. Swartzentruber; H. Leather; A. M. LeMonte; M. M. Durkin; K. S. Knox; C. A. Hage; C. Bentsen; N. Singh; J. R. Wingard; L. J. Wheat

2008-01-01

169

In vitro susceptibilities of Aspergillus spp. causing otomycosis to amphotericin B, voriconazole and itraconazole.  

PubMed

Otomycosis is worldwide in distribution and most commonly caused by Aspergillus species. Amphotericin B, itraconazole and voriconazole are used for the treatment of aspergillosis, but recently an increase in resistance to these agents has been reported. We aimed at investigating the in vitro activities of amphotericin B, voriconazole and itraconazole against Aspergillus isolates causing otomycosis. Mycological analysis of samples from the ear canals of patients was performed by culturing onto Sabouraud Dextrose Agar and by evaluating microscopically. Aspergillus species were identified with colony morphology and microscopic appearance, and tested for susceptibilities to amphotericin B, itraconazole and voriconazole by the CLSI reference broth microdilution method (M38-A document). A total of 120 isolates from 120 patients, comprising 57 Aspergillus niger, 42 Aspergillus fumigatus, nine Aspergillus flavus, six Aspergillus nidulans and six Aspergillus terreus strains were tested. No resistance was determined against amphotericin B and voriconazole, while six A. fumigatus and three A. niger isolates were resistant to itraconazole. In vitro data obtained in this study showed the resistance to itraconazole, while all of the isolates were susceptible to voriconazole and amphotericin B. Voriconazole seemed to be an alternative in the treatment of infections related to Aspergillus spp. but further studies are needed to learn more about the antifungal resistance of different species of Aspergillus to different agents. PMID:17944704

Kaya, Ayse Demet; Kiraz, Nuri

2007-11-01

170

Sp(2)-BRST  

SciTech Connect

A general method is given for the construction of gauge-fixed actions for theories with local gauge symmetries. The method is based on the single requirement that the space of fields carries an irreducible representation of the Sp(2)-BRST algebra, with respect to which the resultant actions are then automatically invariant.

Twisk, S.; Zhang, R.B.

1988-09-01

171

Invertase production of common storage moulds in food and feed grains as a possibility for rapid detection of aspergillus flavus group and Aspergillus fumigatus  

Microsoft Academic Search

Invertase production of grain storage moulds was studied. Aspergillus spp. and Penicillium spp. were grown in a sucrose based liquid medium, at 37°C. The A. flavus group (A. flavus, A. parasiticus, A. nomius, A. oryzae) and A. fumigatus showed a fast growth and intense invertase activity, while other Aspergillus spp. and Penicillium spp. grew slower and produced less invertase. The

T. Mátrai; Susan Mayer; Susan Kókai; Irene Salamon

2000-01-01

172

Activity of essential oil and its major compound, 1,8-cineole, from Eucalyptus globulus Labill., against the storage fungi Aspergillus flavus Link and Aspergillus parasiticus Speare  

Microsoft Academic Search

The essential oil from leaves of Eucalyptus globulus obtained by hydrodistillation, as well as its major compound 1,8-cineole, identified by gas chromatography coupled with a mass selective detector, were evaluated for their effectiveness against the storage fungi Aspergillus flavus and Aspergillus parasiticus. The evaluation was performed by compound dissolution in yeast extract sucrose (YES) medium and exposure to headspace volatiles.

Georgia Rocha Vilela; Gustavo Steffen de Almeida; Marisa Aparecida Bismara Regitano D'Arce; Maria Heloisa Duarte Moraes; José Otávio Brito; Maria Fátima das G. F. da Silva; Sebastiăo Cruz Silva; Sônia Maria de Stefano Piedade; Maria Antonia Calori-Domingues; Eduardo Micotti da Gloria

2009-01-01

173

Purification and characterization of endo-xylanases from aspergillus Niger. II. An enzyme of PL 45  

SciTech Connect

A homogeneous endo-xylanase (1,4-..beta..-D-xylan xylano-hydrolase, EC 3.2.1.8) was obtained from a crude Aspergillus niger pentosanase by chromatography with Ultrogel AcA 54, SP-Sephadex C-25 at pH 4.5, DEAE-Sephadex A-25 at pH 5.4, Sephadex G-50, and SP-Sephadex C-25 with a gradient from pH 2.8 to pH 4.6. It was much more active on soluble than on insoluble xylan yielding large amounts of unreacted xylan and a mixture of oligosaccharides with chain lengths from two to six. No xylose or L-arabinose was produced. There was high activity on a xylopentaose through xylononaose mixture, but not on xylobiose, xylotriose, or xylotetraose. The enzyme had slight activity on untreated cellulose, carboxymethylcellulose, and pectin. Molecular weight was ca. 1.4 x 10/sup 4/, with an isoelectric point of 4.5 and an amino acid profile high in acidic but low in sulfur-containing residues. In a 25-min assay at pH 4.7, this endo-xylanase was most active at 45 degrees C, with an activation energy from 5 to 35 degrees C of 33.3 kJ/mol. The optimum pH for activity was 4.9. Decay in buffer was first order, with an activation energy at pH 4.7 from 48 to 53 degrees C of 460 kJ/mol. Optimum pH for stability was about 5.6, where the half-life at 48 degrees C in buffer was ca. 40 h.

Shei, J.C.; Fratzke, A.R.; Frederick, M.M.; Frederick, J.R.; Reilly, P.J.

1985-04-01

174

An Aspergillus chitosanase with potential for large-scale preparation of chitosan oligosaccharides.  

PubMed

A chitosan-degrading fungus, designated Aspergillus sp. Y2K, was isolated from soil. The micro-organism was used for producing chitosanase (EC 3.2.1.132) in a minimal medium containing chitosan as the sole carbon source. The induced chitosanase was purified to homogeneity from the culture filtrate by concentration and cationic SP-Sepharose chromatography. The purified enzyme is a monomer with an estimated molecular mass of 25 kDa by SDS/PAGE and of 22 kDa by gel-filtration chromatography. pI, optimum pH and optimum temperature values were 8.4, 6.5 and 65-70 degrees C, respectively. The chitosanase is stable in the pH range from 4 to 7.5 at 55 degrees C. Higher deacetylated chitosan is a better substrate. Chitin, xylan, 6-O-sulphated chitosan and O-carboxymethyl chitin were indigestible by the purified enzyme. By endo-splitting activity, the chitosanase hydrolysed chitosan to form chitosan oligomers with chitotriose, chitotetraose and chitopentaose as the major products. The enzyme hydrolyses chitohexaose to form chitotriose, while the chitopentaose and shorter oligomers remain intact. The N-terminal amino acid sequence of the enzyme was determined as YNLPNNLKQIYDDHK, which provides useful information for further gene cloning of this enzyme. A 275 g-scale hydrolysis of chitosan was performed. The product distribution was virtually identical to that of the small-scale reaction. Owing to the simple purification process and high stability of the enzyme, it is potentially valuable for industrial applications. PMID:11115392

Cheng, C Y; Li, Y K

2000-12-01

175

Enzymatic transformation of polydatin to resveratrol by piceid-?-D-glucosidase from Aspergillus oryzae.  

PubMed

Resveratrol is now gaining much attention because of its pharmacological properties. Polygonum cuspidatum has the highest content of resveratrol in plants and is the best material offering resveratrol. However, the content of resveratrol in P. cuspidatum is much lower compared with its glycoside polydatin. In this study, enzymatic transformation of polydatin to resveratrol by piceid-?-D-glucosidase from Aspergillus oryzae sp. 100 was investigated. The biotransformation conditions were optimized. Under the optimized conditions of 60 °C, pH 5.0, substrate concentration of 40 g/L and piceid-?-D-glucosidase activity of 5 U/mL, enzymatic transformation of polydatin from P. cuspidatum was successfully performed, during which 22.5 g/L of resveratrol was produced after reacting for 4 h, with the substrate conversion rate of 2 g/h/U of piceid-?-D-glucosidase. A feasible and environment friendly process of enzymatic transformation of polydatin to resveratrol was developed, which provides a promising and competitive alternative for the production of resveratrol. PMID:24362562

Chen, Ming; Li, Dai; Gao, Ziqing; Zhang, Chunzhi

2014-07-01

176

Bioactive phenylalanine derivatives and cytochalasins from the soft coral-derived fungus, Aspergillus elegans.  

PubMed

One new phenylalanine derivative 4'-OMe-asperphenamate (1), along with one known phenylalanine derivative (2) and two new cytochalasins, aspochalasin A1 (3) and cytochalasin Z24 (4), as well as eight known cytochalasin analogues (5-12) were isolated from the fermentation broth of Aspergillus elegans ZJ-2008010, a fungus obtained from a soft coral Sarcophyton sp. collected from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods. The absolute configuration of 1 was determined by chemical synthesis and Marfey's method. All isolated metabolites (1-12) were evaluated for their antifouling and antibacterial activities. Cytochalasins 5, 6, 8 and 9 showed strong antifouling activity against the larval settlement of the barnacle Balanus amphitrite, with the EC50 values ranging from 6.2 to 37 ?M. This is the first report of antifouling activity for this class of metabolites. Additionally, 8 exhibited a broad spectrum of antibacterial activity, especially against four pathogenic bacteria Staphylococcus albus, S. aureus, Escherichia coli and Bacillus cereus. PMID:23752358

Zheng, Cai-Juan; Shao, Chang-Lun; Wu, Lu-Yong; Chen, Min; Wang, Kai-Ling; Zhao, Dong-Lin; Sun, Xue-Ping; Chen, Guang-Ying; Wang, Chang-Yun

2013-06-01

177

Bioactive Phenylalanine Derivatives and Cytochalasins from the Soft Coral-Derived Fungus, Aspergillus elegans  

PubMed Central

One new phenylalanine derivative 4?-OMe-asperphenamate (1), along with one known phenylalanine derivative (2) and two new cytochalasins, aspochalasin A1 (3) and cytochalasin Z24 (4), as well as eight known cytochalasin analogues (5–12) were isolated from the fermentation broth of Aspergillus elegans ZJ-2008010, a fungus obtained from a soft coral Sarcophyton sp. collected from the South China Sea. Their structures and the relative configurations were elucidated using comprehensive spectroscopic methods. The absolute configuration of 1 was determined by chemical synthesis and Marfey’s method. All isolated metabolites (1–12) were evaluated for their antifouling and antibacterial activities. Cytochalasins 5, 6, 8 and 9 showed strong antifouling activity against the larval settlement of the barnacle Balanus amphitrite, with the EC50 values ranging from 6.2 to 37 ?M. This is the first report of antifouling activity for this class of metabolites. Additionally, 8 exhibited a broad spectrum of antibacterial activity, especially against four pathogenic bacteria Staphylococcus albus, S. aureus, Escherichia coli and Bacillus cereus.

Zheng, Cai-Juan; Shao, Chang-Lun; Wu, Lu-Yong; Chen, Min; Wang, Kai-Ling; Zhao, Dong-Lin; Sun, Xue-Ping; Chen, Guang-Ying; Wang, Chang-Yun

2013-01-01

178

Purification and characterization of a beta-glucuronidase from Aspergillus niger.  

PubMed

A beta-glucuronidase from Pectinex Ultra SP-L, a commercial pectolytic enzyme preparation from Aspergillus niger, was purified 170-fold by ion-exchange chromatography and gel filtration. Apparent M(r) of the purified enzyme, estimated by denaturing gel electrophoresis and size-exclusion chromatography, were 68,000 and 71,000, respectively, indicating that the enzyme is a monomeric protein. It released uronic acids not only from p-nitrophenyl beta-glucosiduronic acid (PNP-GlcA) but also from acidic galactooligosaccharides carrying either beta-D-glucosyluronic or 4-O-methyl-beta-D-glucosyluronic residues at the nonreducing termini through beta-(1-->6)-glycosidic linkages. The enzyme exhibited a maximal activity toward these substrates at pH 3.0. A regioisomer, 3-O-beta-glucosyluronic acid-galactose, was unsusceptible to the enzyme. The enzyme did act on a polymer substrate, releasing uronic acid from the carbohydrate portion of a radish arabinogalactan-protein modified by treatment with fungal alpha-L-arabinofuranosidase. The enzyme produced acidic oligosaccharides by transglycosylation, catalyzing the transfer of uronic acid residues of PNP-GlcA and 6-O-beta-glucosyluronic acid-galactose to certain exogenous acceptor sugars such as Gal, N-acetylgalactosamine, Glc, and xylose. PMID:11423108

Kuroyama, H; Tsutsui, N; Hashimoto, Y; Tsumuraya, Y

2001-06-22

179

Purification and characterization of endo-xylanases from Aspergillus Niger. III. An enzyme of PL 365  

SciTech Connect

An endo-xylanase (1,4-..beta..-D-xylan xylanohydrolase, EC 3.2.1.8) from Aspergillus niger was purified to homogeneity by chromatography with Ultrogel AcA 54, SP-Sephadex C-25 at pH 4.5, DEAE-Sephadex A-25 at pH 5.4, Sephadex G-50, and DEAE-Sephadex A-25 at pH 5.15. The enzyme was active on soluble xylan, on insoluble xylan only after arabinosyl-initiated branch points were removed, and on xylooligosaccharides longer than xylotetraose. There was slight activity on carboxymethyl-cellulose, arabinogalactan, glucomannan, and p-nitrophenyl-..beta..-D- glucopyranoside. The main products of the hydrolysis of soluble and insoluble xylan were oligosaccharides of intermediate length, especially the tri- and pentasaccharides. The isolectric point of the enzyme was 3.65. It had a molecular weight of 2.8 x 10/sup 4/ by SDS-gel electrophoresis, and was high in acidic amino acids but low in those containing sulfur. Highest activity in a 20-min assay at pH 5 was between 40 and 45 degrees C, with an activation energy up to 40 degrees C of 11.1 kJ/mol. The optimum pH for activity was at 5.0. The enzyme was strongly activated by Ca/sup 2 +/. 15 references.

Fournier, R.A.; Frederick, M.M.; Frederick, J.R.; Reilly, P.J.

1985-04-01

180

Volatile Flavor Compounds Produced by Molds of Aspergillus, Penicillium, and Fungi imperfecti.  

PubMed

Strains of molds Aspergillus niger, A. ochraceus, A. oryzae, A. parasiticus, Penicillium chrysogenum, P. citrinum, P. funiculosum, P. raistrickii, P. viridicatum, Alternaria, Cephalosporium, and Fusarium sp. were grown on sterile coarse wheat meal at 26 to 28 C for 120 h. The volatiles from mature cultures were distilled at low temperature under reduced pressure. The distillates from traps -40 and -78 C were extracted with methylene chloride and subsequently concentrated. All the concentrates thus obtained were analyzed by gas-liquid chromatography, mass spectrometry, chemical reactions of functional groups, and olfactory evaluation. Six components detected in the culture distillates were identified positively: 3-methylbutanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and 2-octen-1-ol. They represented 67 to 97% of all the volatiles occurring in the concentrated distillate. The following 14 components were identified tentatively: octane, isobutyl alcohol, butyl alcohol, butyl acetate, amyl acetate, octyl acetate, pyridine, hexanol, nonanone, dimethylpyrazine, tetramethylpyrazine, benzaldehyde, propylbenzene, and phenethyl alcohol. Among the volatiles produced by molds, 1-octen-3-ol yielding a characteristic fungal odor was found predominant. PMID:16349989

Kaminski, E; Stawicki, S; Wasowicz, E

1974-06-01

181

Volatile Flavor Compounds Produced by Molds of Aspergillus, Penicillium, and Fungi imperfecti  

PubMed Central

Strains of molds Aspergillus niger, A. ochraceus, A. oryzae, A. parasiticus, Penicillium chrysogenum, P. citrinum, P. funiculosum, P. raistrickii, P. viridicatum, Alternaria, Cephalosporium, and Fusarium sp. were grown on sterile coarse wheat meal at 26 to 28 C for 120 h. The volatiles from mature cultures were distilled at low temperature under reduced pressure. The distillates from traps -40 and -78 C were extracted with methylene chloride and subsequently concentrated. All the concentrates thus obtained were analyzed by gas-liquid chromatography, mass spectrometry, chemical reactions of functional groups, and olfactory evaluation. Six components detected in the culture distillates were identified positively: 3-methylbutanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and 2-octen-1-ol. They represented 67 to 97% of all the volatiles occurring in the concentrated distillate. The following 14 components were identified tentatively: octane, isobutyl alcohol, butyl alcohol, butyl acetate, amyl acetate, octyl acetate, pyridine, hexanol, nonanone, dimethylpyrazine, tetramethylpyrazine, benzaldehyde, propylbenzene, and phenethyl alcohol. Among the volatiles produced by molds, 1-octen-3-ol yielding a characteristic fungal odor was found predominant.

Kaminski, E.; Stawicki, S.; Wasowicz, E.

1974-01-01

182

Aspergillus infections in transplant and non-transplant surgical patients.  

PubMed

Background: Aspergillus infections are associated commonly with immunocompromised states, such as transplantation and hematologic malignant disease. Although Aspergillus infections among patients having surgery occur primarily in transplant recipients, they are found in non-recipients of transplants, and have a mortality rate similar to that seen among transplant recipients. Methods: We conducted a retrospective analysis of a prospective data base collected from 1996 to 2010, in which we identified patients with Aspergillus infections. We compared demographic data, co-morbidities, and outcomes in non-transplant patients with those in abdominal transplant recipients. Continuous data were evaluated with the Student t-test, and categorical data were evaluated through ?(2) analysis. Results: Twenty-three patients (11 transplant patients and 12 non-transplant patients) were identified as having had Aspergillus infections. The two groups were similar with regard to their demographics and co-morbidities, with the exceptions of their scores on the Acute Physiology and Chronic Health Evaluation II (APACHE II), of 23.6±8.1 points for transplant patients vs. 16.8±6.1 points for non-transplant patients (p=0.03); Simplified Acute Physiology Score (SAPS) of 16.6±8.3 points vs. 9.2±4.1 points, respectively (p=0.02); steroid use 91.0% vs. 25.0%, respectively (p=0.003); and percentage of infections acquired in the intensive care unit (ICU) 27.3% vs. 83.3%, respectively (p=0.01). The most common site of infection in both patient groups was the lung. The two groups showed no significant difference in the number of days from admission to treatment, hospital length of stay following treatment, or mortality. Conclusions: Although Aspergillus infections among surgical patients have been associated historically with solid-organ transplantation, our data suggest that other patients may also be susceptible to such infections, especially those in an ICU who are deemed to be critically ill. This supports the idea that critically ill surgical patients exist in an immunocompromised state. Surgical intensivists should be familiar with the diagnosis and treatment of Aspergillus infections even in the absence of an active transplant program. PMID:24799182

Davies, Stephen; Guidry, Christopher; Politano, Amani; Rosenberger, Laura; McLeod, Matthew; Hranjec, Tjasa; Sawyer, Robert

2014-06-01

183

In vitro antifungal activity of farnesyltransferase inhibitors against clinical isolates of Aspergillus and Candida  

PubMed Central

Background Protein farnesylation is an important tosttranslational modification in fungi. We evaluated the antifungal activity of two farnesyltransferase inhibitors against clinical isolates of Aspergillus and Candida. Methods Disk diffusion assay and broth microdilution assay were used to determine the antifungal susceptibility of two farnesyltransferase inhibitors (manumycin A and tipifarnib) against clinical isolates of Aspergillus and Candida. Results Disk diffusion assay demonstrated both agents had activity against Aspergillus and Candida. The minimal inhibitory concentration (MIC) ranges for manumycin A against Aspergillus and Candida were 200 to 400 ?M and 13 to >25 ?M, respectively. Unfortunately, the MIC were vastly higher than the concentrations that inhibit the proliferation and viability of mammalian cells. The MICs of tipifarnib against Aspergillus and Candida were >1600 ?M. Conclusion The outcome of present study showed that farnesyltransferase inhibitors have activity against Aspergillus and Candida. This suggests that farnesyltransferase may be used as anifungal target in designing and developing new drugs.

2013-01-01

184

Cladal relatedness among Aspergillus oryzae isolates and Aspergillus flavus S and L morphotype isolates.  

PubMed

Aspergillus flavus is the main etiological agent for aflatoxin contamination of crops. Its close relative, A. oryzae, does not produce aflatoxins and has been widely used to produce fermented foods. We compared the phylogeny of A. oryzae isolates and L- and S-type sclerotial isolates of A. flavus using single nucleotide polymorphisms in the omtA gene in the aflatoxin biosynthesis gene cluster and deletions in and distal to the norB-cypA intergenic region as phylogenetic signals. Aflatoxin-producing ability and sclerotial size also were weighted in the analysis. Like A. flavus, the A. oryzae isolates form a polyphyletic assemblage. A. oryzae isolates in one clade strikingly resemble an A. flavus subgroup of atoxigenic L-type isolates. All toxigenic S-type isolates closely resemble another subgroup of atoxigenic L-type isolates. Because atoxigenic S-type isolates are extremely rare, we hypothesize that loss of aflatoxin production in S-type isolates may occur concomitantly with a change to L-type sclerotia. All toxigenic L-type isolates, unlike A. oryzae, have a 1.0 kb deletion in the norB-cypA region. Although A. oryzae isolates, like S-type, have a 1.5 kb deletion in the norB-cypA region, none were cladally related to S-type A. flavus isolates. Our results show that A. flavus populations are genetically diverse. A. oryzae isolates may descend from certain atoxigenic L-type A. flavus isolates. PMID:16430983

Chang, Perng-Kuang; Ehrlich, Kenneth C; Hua, Sui-Sheng T

2006-04-25

185

Amphotericin B und Flucytosin-Therapie bei Aspergillus -Pneumonie und akutem Nierenversagen  

Microsoft Academic Search

Summary Kidney failure and pneumonia byAspergillus flavus andA. fumigatus were found in a 56-year-old woman who had received antibiotic and corticoid treatment to control high fever. Her bloody tracheal secretion was a suspension of granule-like spore-free colonies of bothAspergillus species. Hemorrhages in mucous membranes and skin suggested a hematogenous dissemination of the fungi. Aspergillus spores in the soil of ornamental

F. Staib; I. Bennhold; H.-W. Voigt; C. Bangel; A. Blisse

1987-01-01

186

Prevalence of Aspergillus sensitisation in pulmonary tuberculosis-related fibrocavitary disease.  

PubMed

SETTING Aspergillus complicates the course of healed pulmonary tuberculosis (PTB), causing aspergilloma and chronic pulmonary aspergillosis. Whether Aspergillus also causes allergic sensitisation in PTB-related fibrocavitary disease and bronchiectasis remains unknown. OBJECTIVE To investigate the prevalence of Aspergillus sensitisation in healed fibrocavitary PTB. DESIGN In a case-control design, consecutive symptomatic new referrals with PTB-related fibrocavitary disease underwent spirometry, Aspergillus skin test and computed tomography of the chest, determination of serum IgE levels (total and Aspergillus fumigatus-specific), serum precipitins against A. fumigatus and eosinophil count. Aspergillus sensitisation was defined as either a positive Aspergillus skin test or A. fumigatus IgE >0.35 kUA/l. RESULTS A total of 100 subjects (50 PTB-related fibrocavitary disease, 50 controls) with a mean age of 40.8 years (standard deviation [SD] 12.2) were enrolled. Aspergillus sensitisation was present in 16 (32%) cases and two (4%) controls. Fourteen cases (one control) had IgE values >1000 IU/ml, while two cases manifested eosinophilia. Aspergillus precipitins were positive in 13 cases (two controls); of these, 8 did not have Aspergillus sensitisation. The presence of airflow obstruction on spirometry was significantly associated with Aspergillus sensitisation on univariate analysis (OR 4.96, 95%CI 1.36-18.03). CONCLUSIONS There is a high prevalence of Aspergillus sensitisation in PTB-related fibrocavitary disease. The clinical relevance and therapeutic implications of this finding require further investigation. PMID:24902565

Dhooria, S; Kumar, P; Saikia, B; Aggarwal, A N; Gupta, D; Behera, D; Chakrabarti, A; Agarwal, R

2014-07-01

187

Aspergillus as a multi-purpose cell factory: current status and perspectives  

Microsoft Academic Search

Aspergilli have a long history in biotechnology as expression platforms for the production of food ingredients, pharmaceuticals\\u000a and enzymes. The achievements made during the last years, however, have the potential to revolutionize Aspergillus biotechnology and to assure Aspergillus a dominant place among microbial cell factories. This mini-review will highlight most recent breakthroughs in fundamental\\u000a and applied Aspergillus research with a

Vera Meyer; Bo Wu; Arthur F. J. Ram

2011-01-01

188

The Mediterranean red alga Asparagopsis taxiformis has antifungal activity against Aspergillus species.  

PubMed

The red algae Asparagopsis taxiformis collected from the Straits of Messina (Italy) were screened for antifungal activity against Aspergillus species. EUCAST methodology was applied and extracts showed antifungal activity against A. fumigatus, A. terreus and A. flavus. The lowest minimum inhibitory concentrations observed were <0.15 mg ml(-1) and the highest were >5 mg ml(-1) for Aspergillus spp. tested. Agar diffusion assays confirmed antifungal activity of A. taxiformis extracts in Aspergillus species. PMID:23437896

Genovese, Giuseppa; Leitner, Sandra; Minicante, Simona A; Lass-Flörl, Cornelia

2013-09-01

189

An endophytic/pathogenic Phoma sp. from creosote bush producing biologically active volatile compounds having fuel potential.  

PubMed

A Phoma sp. was isolated and characterized as endophytic and as a pathogen of Larrea tridentata (creosote bush) growing in the desert region of southern Utah, USA. This fungus produces a unique mixture of volatile organic compounds (VOCs), including a series of sesquiterpenoids, some alcohols and several reduced naphthalene derivatives. Trans-caryophyllene, a product in the fungal VOCs, was also noted in the VOCs of this pungent plant. The gases of Phoma sp. possess antifungal properties and is markedly similar to that of a methanolic extract of the host plant. Some of the test organisms with the greatest sensitivity to the Phoma sp. VOCs were Verticillium, Ceratocystis, Cercospora and Sclerotinia while those being the least sensitive were Trichoderma, Colletotrichum and Aspergillus. We discuss the possible involvement of VOC production by the fungus and its role in the biology/ecology of the fungus/plant/environmental relationship with implications for utilization as an energy source. PMID:21535100

Strobel, Gary; Singh, Sanjay K; Riyaz-Ul-Hassan, Syed; Mitchell, Angela M; Geary, Brad; Sears, Joe

2011-07-01

190

Histone deacetylase activity regulates chemical diversity in Aspergillus.  

PubMed

Bioactive small molecules are critical in Aspergillus species during their development and interaction with other organisms. Genes dedicated to their production are encoded in clusters that can be located throughout the genome. We show that deletion of hdaA, encoding an Aspergillus nidulans histone deacetylase (HDAC), causes transcriptional activation of two telomere-proximal gene clusters--and subsequent increased levels of the corresponding molecules (toxin and antibiotic)--but not of a telomere-distal cluster. Introduction of two additional HDAC mutant alleles in a DeltahdaA background had minimal effects on expression of the two HdaA-regulated clusters. Treatment of other fungal genera with HDAC inhibitors resulted in overproduction of several metabolites, suggesting a conserved mechanism of HDAC repression of some secondary-metabolite gene clusters. Chromatin regulation of small-molecule gene clusters may enable filamentous fungi to successfully exploit environmental resources by modifying chemical diversity. PMID:17616629

Shwab, E Keats; Bok, Jin Woo; Tribus, Martin; Galehr, Johannes; Graessle, Stefan; Keller, Nancy P

2007-09-01

191

Antifungal Activity of Eugenol against Penicillium, Aspergillus, and Fusarium Species.  

PubMed

The antifungal activity of eugenol in a model system against aspergilli (Aspergillus niger, Aspergillus terreus, and Emericella nidulans), penicilli (Penicillium expansum, Penicillium glabrum, and Penicillium italicum), and fusaria (Fusarium oxysporum and Fusarium avenaceum) was investigated. Minimum detection time (time to attain a colony diameter of 1 cm) and the kinetic parameters were evaluated. The effectiveness of the active compound seemed to be strain or genus dependent; 100 mg/liter represented a critical value for P. expansum, P. glabrum, P. italicum, A. niger, and E. nidulans because a further increase of eugenol resulted in fungistatic activity. The radial growth of A. terreus and F. avenaceum was inhibited at 140 mg/liter, and growth of F. oxysporum was completely inhibited at 150 mg/liter. PMID:20537272

Campaniello, Daniela; Corbo, Maria Rosaria; Sinigaglia, Milena

2010-06-01

192

Monitoring environmental Aspergillus spp. contamination and meteorological factors in a haematological unit.  

PubMed

The opportunistic pathogens belonging to the Aspergillus genus are present in almost all seasons of the year, and their concentration is related to meteorological conditions. The high density of Aspergillus spp. conidia in a haematological hospital ward may be a significant risk factor for developing invasive fungal diseases in immunocompromised patients. Aim of the present study was to evaluate the variability of airborne Aspergillus spp. conidia contamination in a Haematological Unit (HU) within a period of 16 months in relation with some meteorological parameters. An environmental Aspergillus surveillance was conducted in the HU in four rooms and their bathrooms, in the corridor and in three external sites using an agar impact sampler. During each sampling, temperature and relative humidity at each site were recorded and current wind speed and rainfall events were taken from the official weather service. Aspergillus spp. conidia concentration differed significantly across the sampling sites. Internal Aspergillus spp. loads were significantly dependent on temperature, internal relative humidity and rain. External conidia concentrations were significantly influenced by outdoor temperature and relative humidity. A suitable indicator was introduced to evaluate the seasonal distribution of Aspergillus spp. conidia in the sampling sites, and a significant dependence on this indicator was observed inside the HU. Seventeen different fungal species belonging to the Aspergillus genus were detected during the sampling period. Aspergillus fumigatus was the most frequently isolated species and its distribution depended significantly on the seasonal indicator both inside and outside the hospital ward. PMID:24158616

Cavallo, M; Andreoni, S; Martinotti, M G; Rinaldi, M; Fracchia, L

2013-12-01

193

Advances in molecular detection of Aspergillus : an update  

Microsoft Academic Search

Filamentous cosmopolitan fungi of the genus Aspergillus can be harmful in two ways, directly they can be opportunistic pathogens causing aspergillosis and indirectly due to aflatoxin\\u000a production on food products which can lead to aflatoxicosis. Therefore, a number of methods have been proposed so far for\\u000a detection of the fungi with lowest possible concentration at the earliest. Molecular methods such

M. Z. Abdin; Malik M. Ahmad; Saleem Javed

2010-01-01

194

Catalytic Properties of Lipase Extracts from Aspergillus niger  

Microsoft Academic Search

Summary Screening of lipolytic strains using Rhodamine-B\\/olive oil plate technique allowed the selection of Aspergillus niger MYA 135. Lipase production in submerged culture containing 2 % olive oil was enhanced by more than 50 % compared to basal cultural conditions. Op- timal catalytic conditions for olive oil-induced lipase were pH=6.5 and 30-35 °C. These values were shifted to the acid

Licia M. Pera; Cintia M. Romero; Mario D. Baigori; Guillermo R. Castro

2006-01-01

195

Sodium gluconate production by Aspergillus niger with intermittent broth replacement  

Microsoft Academic Search

Intermittent broth replacement was carried out to enhance the productivity and purity of sodium gluconate usingAspergillus niger by reducing the concentration of unmetabolized glucose. As inoculum size increased, length of lag phase was shortened and\\u000a high initial production rate of sodium gluconate was achieved. However, too high inoculum concentration lowered productivity\\u000a during the later stage of fermentation and increased residual

Sang-Yoon Lee; Bu-Su Park; Jin-Hyup Kim; Byung-Gee Kim; Dong-Il Kim

1999-01-01

196

Immobilization of ? galactosidase from Aspergillus oryzae via immunoaffinity support  

Microsoft Academic Search

Polyclonal antibody bound cellulose support has been exploited for the immobilization and stabilization of ? galactosidase from Aspergillus oryzae. Immunoaffinity bound ? galactosidase retained 96.5% of the initial activity on the support. Immobilized ? galactosidase showed broad-spectrum pH optima, pH 4.6–5.5 and temperature at 50–60°C whereas the soluble enzyme exhibited activity peak at pH 4.6 and 50°C. Immunoaffinity bound enzyme

Toshiba Haider; Qayyum Husain

2009-01-01

197

Stereochemistry of hydrolysis of glycosidic linkage by three Aspergillus polygalacturonases  

Microsoft Academic Search

The stereochemistry of the hydrolytic action of endopolygalacturonases I and II (PGI and PGII, respectively) from Aspergillus niger and of an exopolygalacturonase (PGX) from A. tubingensis was investigated by 1H-NMR spectroscopy by following the configuration of the reducing ends in the products formed in D2O reaction mixtures. It has been shown that all three polygalacturonases are inverting enzymes; the newly

P. Biely; J. A. E. Benen; H. C. M. Kester; K. Heinrichova; J. Visser

1996-01-01

198

Storability of onion bulbs contaminated by Aspergillus niger mold  

Microsoft Academic Search

In the course of pre- and postharvest epidemiological studies on bulbs contamination byAspergillus niger, two Sudanese onion cultivars were tested: ‘Saggai Red’ and ‘El-Hilo White’.A. niger spores, whether seedborne, soilborne or airborne, were avirulent to the healthy growing onion plants. The fungus heavily\\u000a contaminated the dead onion tissues, mainly the dead leaves followed by the dry scales, the dead roots

S. A. F. El-Nagerabi; A. H. M. Ahmed

2003-01-01

199

Immunochemical detection of ochratoxin A in black Aspergillus strains  

Microsoft Academic Search

One hundred and fifty-seven strains belonging to Aspergillus section Nigri were tested for ochratoxin A production using three different methods: a relatively new immunochemical method based on an\\u000a enzyme-linked immunosorbent assay (ELISA), thin-layer chromatography (TLC) and high-performance liquid chromatography (HPLC).\\u000a The monoclonal antibody-based ELISA technique was successfully used to screen for low levels of ochratoxin A in the black\\u000a Aspergilli

József Téren; János Varga; Zsuzsanna Hamari; Ferenc Kevei

1996-01-01

200

Removal of heavy metals using the fungus Aspergillus niger  

Microsoft Academic Search

There is a need to develop technologies that can remove toxic heavy metal ions found in wastewaters. Microorganisms are known to remove heavy metal ions from water. In this study the potential of the fungus Aspergillus niger to remove lead, cadmium, copper and nickel ions was evaluated. A. niger biomass pretreated by boiling in 0.1N NaOH solution for 15 min

Anoop Kapoor; T Viraraghavan; D. Roy Cullimore

1999-01-01

201

Phylogenetic analysis of polyketide synthase genes from Aspergillus ochraceus  

Microsoft Academic Search

A number of polyketide synthase gene sequences fromAspergillus ochraceus were isolated by both SSH-PCR and degenerate PCR. The deduced amino acid sequences of the corresponding clonedpks DNA fragments were then aligned with the amino acid sequences of other polyketide synthase enzymes. One of thesepks genes is essential for ochratoxin A biosynthesis (OTA-PKS). The OTA-PKS was most similar to methylsalicylic acid

J. O'Callaghan; A. D. W. Dobson

2006-01-01

202

?1,3 Glucans Are Dispensable in Aspergillus fumigatus  

PubMed Central

A triple ?1,3 glucan synthase mutant of Aspergillus fumigatus obtained by successive deletions of the three ?1,3 glucan synthase genes (AGS1, AGS2, and AGS3) has a cell wall devoid of ?1,3 glucans. The lack of ?1,3 glucans affects neither conidial germination nor mycelial vegetative growth and is compensated by an increase in ?1,3 glucan and/or chitin content.

Henry, Christine; Latge, Jean-Paul

2012-01-01

203

Genetic analysis of benzoate metabolism in Aspergillus niger  

Microsoft Academic Search

The benzoate metabolism of Aspergillus niger was studied as part of a design to clone the benzoate-4-hydroxylase gene of this fungus on the basis of complementation. Filtration enrichment techniques yielded mutants defective for different steps of benzoate degradation: bph (benzoate-4-hydroxylase), phh (4-hydroxybenzoate-3-hydroxylase) and prc (protocatechuate ring cleavage) mutants. In this way the degradation pathway for benzoate, involving the formation of

J. G. Boschloo; A. Paffen; T. Koot; W. J. J. van den Tweel; R. F. M. van Gorcom; J. H. G. Cordewener; C. J. Bos

1990-01-01

204

Single cell transcriptomics of neighboring hyphae of Aspergillus niger  

PubMed Central

Single cell profiling was performed to assess differences in RNA accumulation in neighboring hyphae of the fungus Aspergillus niger. A protocol was developed to isolate and amplify RNA from single hyphae or parts thereof. Microarray analysis resulted in a present call for 4 to 7% of the A. niger genes, of which 12% showed heterogeneous RNA levels. These genes belonged to a wide range of gene categories.

2011-01-01

205

Impact of Aspergillus oryzae genomics on industrial production of metabolites  

Microsoft Academic Search

Aspergillus oryzae is used extensively for the production of the traditional Japanese fermented foods sake (rice wine), shoyu (soy sauce), and miso (soybean paste). In recent years, recombinant DNA technology has been used to enhance industrial enzyme production by A. oryzae. Recently completed genomic studies using expressed sequence tag (EST) analyses and whole-genome sequencing are quickly expanding\\u000a the industrial potential

Keietsu Abe; Katusya Gomi; Fumihiko Hasegawa; Masayuki Machida

2006-01-01

206

Production of aflatoxin by Aspergillus parasiticus and its control  

Microsoft Academic Search

The aim of the present work was to investigate the production of aflatoxin byAspergillus parasiticus and to find out the possible ways to control it. Of 40 food samples collected from Abha region, Saudi Arabia, only 25% were\\u000a contaminated with aflatoxins. Oil-rich commodities had the highly contaminated commodities by fungi and aflatoxins while spices\\u000a were free from aflatoxins.Bacillus megatertum andB

Hamdy Aly Emara

1997-01-01

207

Aspergillus nidulans 5S rRNA genes and pseudogenes  

Microsoft Academic Search

The sequence of four Aspergillus nidulans 5S rRNA genes and of two pseudogenes has been determined. A conserved sequence about 100 by upstream of the 5S rRNA coding sequences has been found in three genes and one pseudogene. The two pseudogenes correspond to the 5' half of the 5S rRNA coding sequence and their 3' flanking sequences which are not

Ewa Bartnik; S?awomir Bartoszewski; Piotr Borsuk; Joanna Empel

1986-01-01

208

Aflatoxin production by Aspergillus flavus in Brazil nuts  

Microsoft Academic Search

Experiments were conducted to evaluate the effects of relative humidity (r.h.; 75%, 80%, 85%, 97%) and temperature (10, 13, 15, 25, 30°C) on aflatoxin production in previously dried (3.5% moisture content; m.c.) Brazil nuts. Initially Aspergillus spp. were isolated from the surfaces of whole in-shell (WIS) Brazil nuts imported from Peru using A. flavus and A. parasiticus agar (AFPA). Isolates

K. Arrus; G. Blank; D. Abramson; R. Clear; R. A. Holley

2005-01-01

209

The current status of species recognition and identification in Aspergillus  

PubMed Central

The species recognition and identification of aspergilli and their teleomorphs is discussed. A historical overview of the taxonomic concepts starting with the monograph of Raper & Fennell (1965) is given. A list of taxa described since 2000 is provided. Physiological characters, particularly growth rates and the production of extrolites, often show differences that reflect phylogenetic species boundaries and greater emphasis should be placed on extrolite profiles and growth characteristics in species descriptions. Multilocus sequence-based phylogenetic analyses have emerged as the primary tool for inferring phylogenetic species boundaries and relationships within subgenera and sections. A four locus DNA sequence study covering all major lineages in Aspergillus using genealogical concordance theory resulted in a species recognition system that agrees in part with phenotypic studies and reveals the presence of many undescribed species not resolved by phenotype. The use of as much data from as many sources as possible in making taxonomic decisions is advocated. For species identification, DNA barcoding uses a short genetic marker in an organism”s DNA to quickly and easily identify it to a particular species. Partial cytochrome oxidase subunit 1 sequences, which are used for barcoding animal species, were found to have limited value for species identification among black aspergilli. The various possibilities are discussed and at present partial ?-tubulin or calmodulin are the most promising loci for Aspergillus identification. For characterising Aspergillus species one application would be to produce a multilocus phylogeny, with the goal of having a firm understanding of the evolutionary relationships among species across the entire genus. DNA chip technologies are discussed as possibilities for an accurate multilocus barcoding tool for the genus Aspergillus.

Geiser, D.M.; Klich, M.A.; Frisvad, J.C.; Peterson, S.W.; Varga, J.; Samson, R.A.

2007-01-01

210

The 18-kilodalton antigen secreted by Aspergillus fumigatus.  

PubMed Central

One of the major antigens secreted in vitro by Aspergillus fumigatus is an 18-kDa basic protein which has been purified by cation-exchange chromatography. It is recognized by sera from aspergilloma patients. It is also the major circulating antigen found in urine of patients with invasive aspergillosis. Our results indicated that this antigen has potential for the diagnosis of both aspergilloma and invasive aspergillosis. Images

Latge, J P; Moutaouakil, M; Debeaupuis, J P; Bouchara, J P; Haynes, K; Prevost, M C

1991-01-01

211

Aspergillus antigen testing in bone marrow transplant recipients  

PubMed Central

Aims—To assess the clinical usefulness of a commercial aspergillus antigen enzyme linked immunosorbent assay (ELISA) in the diagnosis of invasive aspergillosis (IA) in bone marrow transplant recipients, and to compare it with a commercial latex agglutination (LA) test. Methods—In total, 2026 serum samples from 104 bone marrow transplant recipients were tested. These comprised 67 sera from seven patients who had died with confirmed IA, 268 sera from nine patients who had died with suspected IA, and 1691 sera from 88 patients with no clinical, radiological, or microbiological signs of IA. Results—The ELISA was more sensitive than the LA test. All patients who were ELISA positive were also LA positive, and a positive LA result never preceded a positive ELISA. Twelve of 16 patients with confirmed or suspected IA were ELISA positive on two or more occasions, compared with 10 of 15 who were LA positive. ELISA was positive before LA in five patients (range, 2–14 days), and became positive on the same day in the remainder. Aspergillus antigen was detected by ELISA a median of 15 days before death (range, 4–233). Clinical and/or radiological evidence of IA was noted in all patients, and a positive ELISA was never the sole criterion for introduction of antifungal treatment. Two samples (one from each of two patients without IA) gave false positive results. Conclusions—The aspergillus ELISA is a specific indicator of invasive aspergillosis if the criterion of two positive samples is required to confirm the diagnosis. However, the test is insufficiently sensitive to diagnose aspergillosis before other symptoms or signs are apparent, and hence is unlikely to lead to earlier initiation of antifungal treatment. It is therefore unsuitable for screening of asymptomatic patients at risk of invasive aspergillosis, but does have a useful role in confirming the diagnosis in symptomatic patients. Key Words: invasive aspergillosis • aspergillus antigen • Platelia enzyme linked immunosorbent assay

Williamson, E; Oliver, D; Johnson, E; Foot, A; Marks, D; Warnock, D

2000-01-01

212

Ergosteroid derivatives from an algicolous strain of Aspergillus ustus.  

PubMed

One new ergosteroid derivative, isocyathisterol (1), and eight known compounds (2-9) were isolated from the culture of an algicolous strain (cf-42) of Aspergillus ustus obtained from the fresh tissue of marine green alga Codium fragile. The structure and absolute configuration of 1 were unequivocally identified by using NMR and mass spectroscopic methods as well as quantum chemical calculations. Compound 1 exhibited weak antibacterial activity. PMID:24896666

Liu, Xiang-Hong; Miao, Feng-Ping; Liang, Xiao-Rui; Ji, Nai-Yun

2014-08-01

213

Biosynthesis of diaporthin and orthosporin by Aspergillus ochraceus  

Microsoft Academic Search

Diaporthin and orthosporin were characterised from the fungus Aspergillus ochraceus D2306. Diaporthin was identified by high-resolution electron impact mass spectrometry and 1H and 13C NMR spectroscopy, from which new spectroscopic assignments were made. Orthosporin was also identified by mass spectrometry and both fungal metabolites are reported for the first time as co-metabolites and also as products of A. ochraceus. The

Jonathan P Harris; Peter G Mantle

2001-01-01

214

Purification, characterization and immobilization of a keratinase from Aspergillus oryzae  

Microsoft Academic Search

A keratinase enzyme was isolated and purified from a feather-degrading culture of Aspergillus oryzae. Fractional precipitation of the crude enzyme with ethanol, acetone and ammonium sulfate yielded 21 fractions. The fraction obtained at 75–85% ammonium sulfate saturation showed the highest activity and about 3.3-fold purification. This fraction was further purified by gel filtration in Sephadex G-75 followed by ion exchange

Aida M Farag; Maha A Hassan

2004-01-01

215

Mannitol is required for stress tolerance in Aspergillus niger conidiospores  

Microsoft Academic Search

D-Mannitol is the predominant carbon compound in conidiospores of the filamentous fungus Aspergillus niger and makes up 10 to 15?f the dry weight. A number of physiological functions have been ascribed to mannitol, including serving as a reserve carbon source, as an antioxidant, and to store reducing power. In this study, we cloned and characterized the A. niger mpdA gene,

George J. G. Ruijter; Maarten Bax; Hema Patel; Simon J. Flitter; Vondervoort van de P. J. I; Vries de R. P; Kuyk van P. A; Jaap Visser

2003-01-01

216

Effect of Butyrolactone I on the Producing Fungus, Aspergillus terreus  

Microsoft Academic Search

Butyrolactone I (a-oxo-b-(p-hydroxyphenyl)-g-(p-hydroxy-m-3,3-dimethylallyl-benzyl)-g-methoxycarbonyl- g-butyrolactone) is produced as a secondary metabolite by Aspergillus terreus. Because small butyrolactone- containing molecules act as self-regulating factors in some bacteria, the effects of butyrolactone I on the producing organism were studied; specifically, changes in morphology, sporulation, and secondary metabolism were studied. Threefold or greater increases in hyphal branching (with concomitant decreases in the average hyphal

TIMOTHY G. SCHIMMEL; ALLEN D. COFFMAN; SARAH J. PARSONS

1998-01-01

217

SP-100 Power Program  

NASA Astrophysics Data System (ADS)

This paper presents a brief summary of the SP-100 project accomplishments and the tasks remaining to complete the space reactor power system development. A fast-track development approach was started in 1992 which would use near-term technology for early nuclear electric propulsion (NEP) planetary missions. In parallel, the technology would be improved for the more aggressive NEP missions. A conceptual design for a twenty-kilowatt space reactor thermoelectric power system was completed using near-term technology. The SP-100 near-term technology is developed except for (1) the converter, (2) the pump, and (3) the control drive actuator (CDA). The first converter was fabricated in September 1993. A CDA subassembly was put on test at the end of September 1993. The critical bonding steps for assembling the TE cells and the pump ducts were developed by the end of September 1993. The remaining technology development tasks for the early systems are primarily building and testing a converter, a pump, and an actuator. The SP-100 technology is well documented and therefore available when the need for space reactor power systems returns.

Mondt, Jack F.

1994-07-01

218

Complement Attack against Aspergillus and Corresponding Evasion Mechanisms  

PubMed Central

Invasive aspergillosis shows a high mortality rate particularly in immunocompromised patients. Perpetually increasing numbers of affected patients highlight the importance of a clearer understanding of interactions between innate immunity and fungi. Innate immunity is considered to be the most significant host defence against invasive fungal infections. Complement represents a crucial part of this first line defence and comprises direct effects against invading pathogens as well as bridging functions to other parts of the immune network. However, despite the potency of complement to attack foreign pathogens, the prevalence of invasive fungal infections is increasing. Two possible reasons may explain that phenomenon: First, complement activation might be insufficient for an effective antifungal defence in risk patients (due to, e.g., low complement levels, poor recognition of fungal surface, or missing interplay with other immune elements in immunocompromised patients). On the other hand, fungi may have developed evasion strategies to avoid recognition and/or eradication by complement. In this review, we summarize the most important interactions between Aspergillus and the complement system. We describe the various ways of complement activation by Aspergillus and the antifungal effects of the system, and also show proven and probable mechanisms of Aspergillus for complement evasion.

Speth, Cornelia; Rambach, Gunter

2012-01-01

219

Aspergillus Flavus Keratitis after Deep Anterior Lamellar Keratoplasty  

PubMed Central

Purpose To report the clinical, microbiologic, confocal scan and histopathologic features of Aspergillus flavus keratitis which developed immediately after deep anterior lamellar keratoplasty (DALK). Case Report A 28-year-old woman underwent DALK using the big-bubble technique for keratoconus. The operation was uneventful, yielding a bare Descemet’s membrane (DM) followed by transplantation of a corneal graft devoid of DM and endothelium. Four days after keratoplasty, mild infiltrates were noticed in the inferonasal margin of the graft, which rapidly progressed to involve the adjacent recipient cornea. Confocal scan findings suggested filamentous fungal keratitis, leading to initiation of topical and systemic antifungal medications followed by immediate replacement of the graft. Histopathologic examination disclosed keratitis caused by a filamentous fungus, which was determined by microbiologic cultures to be Aspergillus flavus. Early diagnosis and appropriate management resulted in complete recovery from this potentially devastating infection. Conclusion Aspergillus Flavus can cause graft ulcers immediately after DALK. Confocal scan proved to be a valuable tool for early diagnosis and prompt intervention to control this otherwise devastating infection.

Jafarinasab, Mohammad-Reza; Feizi, Sepehr; Yazdizadeh, Forouzan; Rezaei Kanavi, Mozhgan; Moein, Hamid-Reza

2012-01-01

220

In vitro activity of disinfectants against Aspergillus spp.  

PubMed

Fungi of the Aspergillus genus are widespread and contaminate the environment. Thousands of conidia are released from each phialide and dispersed in the air every day. These fungi are considered important mycose-causing agents in hospitals. Due to this, research to determine prevalent fungi from the Aspergillus genus in hospital environments, and an adequate disinfection program in these areas is are needed. This study evaluated the susceptibility of Aspergillus spp. isolated from a veterinary environment against four disinfectants. Successive dilutions of disinfectants (log2) were used according to CLSI M38-A2 microdilution technique adapted to chemical agents against 18 isolates of this genus. After 72 hours of incubation, the Minimum Inhibiting Concentration and Minimum Fungicidal Concentration capable of inhibiting 50% and 90% of the isolates were determined. Chlorexidine-cetrimine, benzalconium chloride and a chlorophenol derivative proved to be effective against all isolates with a lower MIC than that suggested by the manufacturer, except for the A. flavus strain. Sodium hypochlorite was ineffective against three A. fumigatus, three A. flavus and one A. niger isolate. These results demonstrated that all studied disinfectants were effective against environmental isolates, with the exception of sodium hypochlorite, which showed lower effectiveness. PMID:24294243

Mattei, A S; Madrid, I M; Santin, R; Schuch, L F D; Meireles, M C A

2013-01-01

221

Recombinant Aspergillus ?-galactosidases as a robust glycomic and biotechnological tool.  

PubMed

Galactosidases are widespread enzymes that are used for manifold applications, including production of prebiotics, biosynthesis of different transgalactosylated products, improving lactose tolerance and in various analytical approaches. The nature of these applications often require galactosidases to be present in a purified form with clearly defined properties, including precisely determined substrate specificities, low sensitivity to inhibitors, and high efficiency and stability under distinct conditions. In this study, we present the recombinant expression and purification of two previously uncharacterized ?-galactosidases from Aspergillus nidulans as well as one ?-galactosidase from Aspergillus niger. All enzymes were active toward p-nitrophenyl-?-D-galactopyranoside as substrate and displayed similar temperature and pH optima. The purified recombinant galactosidases digested various complex substrates containing terminal galactose ?-1,4 linked to either N-acetylglucosamine or fucose, such as N-glycans derived from bovine fibrin and Caenorhabditis elegans. In our comparative study of the recombinant galactosidases with the commercially available galactosidase from Aspergillus oryzae, all enzymes also displayed various degrees of activity toward complex oligosaccharides containing ?-1,3-linked terminal galactose residues. All recombinant enzymes were found to be robust in the presence of various organic solvents, temperature variations, and freeze/thaw cycles and were also tested for their ability to synthesize galactooligosaccharides. Furthermore, the use of fermentors considerably increased the yield of recombinant galactosidases. Taken together, we demonstrate that purified recombinant galactosidases from A. niger and from A. nidulans are suitable for various glycobiological and biotechnological applications. PMID:24037406

Dragosits, Martin; Pflügl, Stefan; Kurz, Simone; Razzazi-Fazeli, Ebrahim; Wilson, Iain B H; Rendic, Dubravko

2014-04-01

222

Association of airborne Aspergillus with asthma exacerbation in Southern Pakistan  

PubMed Central

Background Exposure to airborne fungi has been related with exacerbation of asthma in adults and children leading to increased outpatient, emergency room visits, and hospitalizations. Hypersensitivity to these airborne fungi may be an important initial predisposing factor in the development and exacerbation of asthma. Objective This study was conducted to determine an association between fungal types and spore concentrations with the risk of asthma exacerbation in adults. Methods This cross-sectional study was conducted from May 2008 to August 2009 at the Aga Khan University Hospital Karachi, Pakistan. All adult (age?16 years) patients presenting to the hospital with acute asthma exacerbation were enrolled after informed consent. A home survey was conducted for each patient to assess their environmental characteristics. Indoor air samples were also obtained from the patient's home to determine the type and spore concentration of fungi within the week of their enrollment in the study. Results Three hundred and ninety-one patients with an acute asthma exacerbation were enrolled during the study period. The mean age of participants was 46 years (standard deviation, ±18 years) and 247 (63.2%) were females. A trend of higher asthma enrollment associated with higher Aspergillus concentrations was found in two consecutive summers. A total of nineteen types of fungi were found in air samples. Aspergillus spp. was the most frequently isolated fungus with acute asthma exacerbation. Conclusion An association of higher concentration of indoor Aspergillus spp. with asthma exacerbation in adults was observed in this study.

Zubairi, Ali Bin Sarwar; Azam, Iqbal; Awan, Safia; Zafar, Afia

2014-01-01

223

Colonization of rye green manure and peanut fruit debris by Aspergillus falvus and Aspergillus niger group in field soils.  

PubMed Central

Aspergillus flavus and Aspergillus niger group colonization of deep-plowed, decomposing rye green manure cover crops in peanut field soils was studied in four fields during 1972 and 1973; colonization of decomposing peanut fruits was studied in 1972 in two fields. A. flavus colonization of rye and peanut fruits was greater in soils of heavy texture, and an A. flavus population as high as 165 propagules per g of soil was observed in soil adjacent to rye, whereas A. flavus populations in soils not associated with rye were 18 propagules per g of soil or lower. Highest A. flavus populations in soil adjacent to decomposing peanut fruits were usually comparable to populations associated with rye. Little decomposing rye or peanut fruit colonization was generally observed by the A. flavus competitor, A. niger group. A. flavus may maintain or increase its inoculum potential by colonization of these and other moribund plant tissues.

Griffin, G J; Garren, K H

1976-01-01

224

Constitutive expression of fluorescent protein by Aspergillus var. niger and Aspergillus carbonarius to monitor fungal colonization in maize plants.  

PubMed

Aspergillus niger and Aspergillus carbonarius are two species in the Aspergillus section Nigri (black-spored aspergilli) frequently associated with peanut (Arachis hypogea), maize (Zea mays), and other plants as pathogens. These infections are symptomless and as such are major concerns since some black aspergilli produce important mycotoxins, ochratoxins A, and the fumonisins. To facilitate the study of the black aspergilli-maize interactions with maize during the early stages of infections, we developed a method that used the enhanced yellow fluorescent protein (eYFP) and the monomeric red fluorescent protein (mRFP1) to transform A. niger and A. carbonarius, respectively. The results were constitutive expressions of the fluorescent genes that were stable in the cytoplasms of hyphae and conidia under natural environmental conditions. The hyphal in planta distribution in 21-day-old seedlings of maize were similar wild type and transformants of A. niger and A. carbonarius. The in planta studies indicated that both wild type and transformants internally colonized leaf, stem and root tissues of maize seedlings, without any visible disease symptoms. Yellow and red fluorescent strains were capable of invading epidermal cells of maize roots intercellularly within the first 3 days after inoculation, but intracellular hyphal growth was more evident after 7 days of inoculation. We also tested the capacity of fluorescent transformants to produce ochratoxin A and the results with A. carbonarius showed that this transgenic strain produced similar concentrations of this secondary metabolite. This is the first report on the in planta expression of fluorescent proteins that should be useful to study the internal plant colonization patterns of two ochratoxigenic species in the Aspergillus section Nigri. PMID:23899775

Palencia, Edwin Rene; Glenn, Anthony Elbie; Hinton, Dorothy Mae; Bacon, Charles Wilson

2013-09-01

225

Phytase Production by Aspergillus niger CFR 335 and Aspergillus ficuum SGA 01 through Submerged and Solid-State Fermentation  

PubMed Central

Fermentation is one of the industrially important processes for the development of microbial metabolites that has immense applications in various fields. This has prompted to employ fermentation as a major technique in the production of phytase from microbial source. In this study, a comparison was made between submerged (SmF) and solid-state fermentations (SSF) for the production of phytase from Aspergillus niger CFR 335 and Aspergillus ficuum SGA 01. It was found that both the fungi were capable of producing maximum phytase on 5th day of incubation in both submerged and solid-state fermentation media. Aspergillus niger CFR 335 and A. ficuum produced a maximum of 60.6?U/gds and 38?U/gds of the enzyme, respectively, in wheat bran solid substrate medium. Enhancement in the enzyme level (76 and 50.7?U/gds) was found when grown in a combined solid substrate medium comprising wheat bran, rice bran, and groundnut cake in the ratio of 2?:?1?:?1. A maximum of 9.6 and 8.2?U/mL of enzyme activity was observed in SmF by A. niger CFR 335 and A.ficuum, respectively, when grown in potato dextrose broth.

Shivanna, Gunashree B.; Venkateswaran, Govindarajulu

2014-01-01

226

Phytase Production by Aspergillus niger CFR 335 and Aspergillus ficuum SGA 01 through Submerged and Solid-State Fermentation.  

PubMed

Fermentation is one of the industrially important processes for the development of microbial metabolites that has immense applications in various fields. This has prompted to employ fermentation as a major technique in the production of phytase from microbial source. In this study, a comparison was made between submerged (SmF) and solid-state fermentations (SSF) for the production of phytase from Aspergillus niger CFR 335 and Aspergillus ficuum SGA 01. It was found that both the fungi were capable of producing maximum phytase on 5th day of incubation in both submerged and solid-state fermentation media. Aspergillus niger CFR 335 and A. ficuum produced a maximum of 60.6?U/gds and 38?U/gds of the enzyme, respectively, in wheat bran solid substrate medium. Enhancement in the enzyme level (76 and 50.7?U/gds) was found when grown in a combined solid substrate medium comprising wheat bran, rice bran, and groundnut cake in the ratio of 2?:?1?:?1. A maximum of 9.6 and 8.2?U/mL of enzyme activity was observed in SmF by A. niger CFR 335 and A.ficuum, respectively, when grown in potato dextrose broth. PMID:24688383

Shivanna, Gunashree B; Venkateswaran, Govindarajulu

2014-01-01

227

An anti-Aspergillus protein from Escherichia coli DH5?: putative inhibitor of siderophore biosynthesis in Aspergillus fumigatus.  

PubMed

An antifungal protein designated as anti-Aspergillus protein (AAP), produced by Escherichia coli DH5?, was purified and characterised. It exhibited a molecular weight of 60 kDa on Sodium dodecyl sulphate-polyacrylamide gel electrophoresis analysis and depicted 99% purity on ultra performance liquid chromatography. The purified protein manifested antimycotic potential against pathogenic isolates of Aspergillus spp., depicting a minimum inhibitory concentration in the range 15.62-31.25 ?g ml(-1) and 5.0-10.0 ?g per disc, using microbroth dilution, spore germination inhibition and disc diffusion assays respectively. In vitro toxicity tests demonstrated that it showed no toxicity against human erythrocytes at doses up to 1000 ?g ml(-1) . Matrix-assisted laser desorption ionisation-Time-of-flight analysis of trypsin-digested peptides of purified protein and subsequent Mascot search revealed that several peptides of AAP have identity with bacterial siderophore biosynthetic protein, i.e. non-ribosomal peptide synthetase enzyme, involved in critical step of fungal siderophore biosynthesis. Siderophore-based inhibition was further corroborated by Chrome azurol S assay. Hence, the antagonistic effect might be the result of impediment in siderophore-mediated iron uptake and transport process which may cause critical consequences on Aspergillus growth and virulence. PMID:23968167

Balhara, Meenakshi; Ruhil, Sonam; Kumar, Manish; Dhankhar, Sandeep; Chhillar, A K

2014-03-01

228

Overexpression of Aspergillus tubingensis faeA in protease-deficient Aspergillus niger enables ferulic acid production from plant material.  

PubMed

The production of ferulic acid esterase involved in the release of ferulic acid side groups from xylan was investigated in strains of Aspergillus tubingensis, Aspergillus carneus, Aspergillus niger and Rhizopus oryzae. The highest activity on triticale bran as sole carbon source was observed with the A. tubingensis T8.4 strain, which produced a type A ferulic acid esterase active against methyl p-coumarate, methyl ferulate and methyl sinapate. The activity of the A. tubingensis ferulic acid esterase (AtFAEA) was inhibited twofold by glucose and induced twofold in the presence of maize bran. An initial accumulation of endoglucanase was followed by the production of endoxylanase, suggesting a combined action with ferulic acid esterase on maize bran. A genomic copy of the A. tubingensis faeA gene was cloned and expressed in A. niger D15#26 under the control of the A. niger gpd promoter. The recombinant strain has reduced protease activity and does not acidify the media, therefore promoting high-level expression of recombinant enzymes. It produced 13.5 U/ml FAEA after 5 days on autoclaved maize bran as sole carbon source, which was threefold higher than for the A. tubingensis donor strain. The recombinant AtFAEA was able to extract 50 % of the available ferulic acid from non-pretreated maize bran, making this enzyme suitable for the biological production of ferulic acid from lignocellulosic plant material. PMID:24664515

Zwane, Eunice N; Rose, Shaunita H; van Zyl, Willem H; Rumbold, Karl; Viljoen-Bloom, Marinda

2014-06-01

229

Effect of increasing inoculum sizes of Aspergillus hyphae on MICs and MFCs of antifungal agents by broth microdilution method  

Microsoft Academic Search

In order to investigate the influence of different hyphal inoculum sizes on minimal inhibition concentrations (MICs) and minimum fungicidal concentrations (MFCs) of amphotericin B (AMB), voriconazole and itraconazole, five isolates each of Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger and Aspergillus terreus were studied using a broth microdilution method. Three inoculum sizes were used: 1×103–5×103, 1×104–5×104 and 1×105–5×105 cfu\\/ml. MICs and

Cornelia Lass-Flörl; C Speth; G Kofler; M. P Dierch; E Gunsilius; R Würzner

2003-01-01

230

SP-100 program developments  

NASA Technical Reports Server (NTRS)

An update is provided on the status of the Sp-100 Space Reactor Power Program. The historical background that led to the program is reviewed and the overall program objectives and development approach are discussed. The results of the mission studies identify applications for which space nuclear power is desirable and even essential. Results of a series of technology feasibility experiments are expected to significantly improve the earlier technology data base for engineering development. The conclusion is reached that a nuclear reactor space power system can be developed by the early 1990s to meet emerging mission performance requirements.

Schnyer, A. D.; Sholtis, J. A., Jr.; Wahlquist, E. J.; Verga, R. L.; Wiley, R. L.

1985-01-01

231

Triazole Fungicides Can Induce Cross-Resistance to Medical Triazoles in Aspergillus fumigatus  

Microsoft Academic Search

Background Azoles play an important role in the management of Aspergillus diseases. Azole resistance is an emerging global problem in Aspergillus fumigatus, and may develop through patient therapy. In addition, an environmental route of resistance development has been suggested through exposure to 14?-demethylase inhibitors (DMIs). The main resistance mechanism associated with this putative fungicide-driven route is a combination of alterations

E. Snelders; S. M. T. Camps; A. Karawajczyk; G. Schaftenaar; G. H. J. Kema; Lee van der H. A; C. H. Klaassen; W. J. G. Melchers; P. E. Verweij

2012-01-01

232

Isolation and Identification of Indigenous Aspergillus oryzae for Saccharification of Rice Starch  

Microsoft Academic Search

A study was undertaken to isolate an indigenous Aspergillus oryzae strain for use in saccharification of high amylose rice starch. Bread, black gram, soya grains, 'kevum', and cooked rice samples assumed to be contaminated with Aspergillus oryzae were used in the isolation. Ten pure cultures obtained by culturing and sub- culturing on Potato Dextrose Agar (PDA) were maintained on PDA

S. S. Sooriyamoorthy; K. F. S. T. Silva; M. H. W. Gunawardhane; C. K. Illeperuma

233

Correlation between Gliotoxin Production and Virulence of Aspergillus fumigatus in Galleria mellonella  

Microsoft Academic Search

Aspergillus fumigatus is a pathogenic fungus capable of causing both allergic lung disease and invasive aspergillosis, a serious, life-threatening condition in neutropenic patients. Aspergilli express an array of mycotoxins and enzymes which may facilitate fungal colonisation of host tissue. In this study we investigated the possibility of using the insect, Galleria mellonella, for in vivo pathogenicity testing of Aspergillus species.

Emer P. Reeves; C. G. M. Messina; S. Doyle; K. Kavanagh

2004-01-01

234

Aspergillus nidulans as a model system to characterize the DNA damage response in eukaryotes  

Microsoft Academic Search

Interest in DNA repair in Aspergillus nidulans had mainly grown out of studies of three different biological processes, namely mitotic recombination, inducible responses to detrimental environmental changes, and genetic control of the cell cycle. Ron Morris started the investigation of the genetic control of the cell cycle by screening hundreds of cell cycle temperature sensitive Aspergillus mutants. The sequencing and

Gustavo H Goldman; Etta Kafer

2004-01-01

235

Immunohistologic Identification of Aspergillus spp. and Other Hyaline Fungi by Using Polyclonal Fluorescent Antibodies  

Microsoft Academic Search

Infections caused by Aspergillus and Fusarium spp. are being seen with increasing frequency among immunocompromised patients. Patients with these diseases demonstrate lesions that are clinically and histopathologically similar (8). Accurate di- agnosis is essential for delivery of appropriate therapy (12), but diagnosis of these infections can be difficult. Isolation and identification of pathogenic Aspergillus and Fusarium spp. from clinical materials

LEO KAUFMAN; MAXINE JALBERT; DOROTHY E. KRAFT

1997-01-01

236

Mixed allergic bronchopulmonary fungal disease due to Pseudallescheria boydii and Aspergillus.  

PubMed Central

A 24 year old asthmatic woman with mixed allergic bronchopulmonary fungal disease due to Pseudallescheria boydii and Aspergillus is reported. No previous cases due to P boydii have been described. This patient provides evidence that fungi other than Aspergillus species may cause the condition. Images

Lake, F R; Tribe, A E; McAleer, R; Froudist, J; Thompson, P J

1990-01-01

237

Influence of manganese on morphology and cell wall composition of Aspergillus niger during citric acid fermentation  

Microsoft Academic Search

Morphology and cell wall composition of Aspergillus niger were studied under conditions of manganese sufficient or deficient cultivation in an otherwise citric acid producing medium. Omission of Mn2+ (less than 10-7 M) from the nutrient medium of Aspergillus niger results in abnormal morphological development which is characterized by increased spore swelling, and squat, bulbeous hyphae. Fractionation and analysis of manganese

Monika Kisser; C. P. Kubicek; M. Röhr

1980-01-01

238

A Versatile and Efficient Gene-Targeting System for Aspergillus nidulans  

Microsoft Academic Search

Aspergillus nidulans is an important experimental organism, and it is a model organism for the genus Aspergillus that includes serious pathogens as well as commercially important organisms. Gene targeting by homologous recombination during transformation is possible in A. nidulans, but the frequency of cor- rect gene targeting is variable and often low. We have identified the A. nidulans homolog (nkuA)

Tania Nayak; Edyta Szewczyk; C. Elizabeth Oakley; Aysha Osmani; Leena Ukil; Sandra L. Murray; Michael J. Hynes; Stephen A. Osmani; Berl R. Oakley

2005-01-01

239

Development and evaluation of a real-time quantitative PCR assay for Aspergillus flavus  

Microsoft Academic Search

Aspergillus flavus is a ubiquitous mold and the most common mold contaminating foodstuffs. Many strains of A. flavus produce aflatoxins. In addition it is an allergen and an opportunistic pathogen of animals and plants. A. flavus often is underestimated in traditional culture analyses due to the expertise required and the cost associated with speciating members of the genus Aspergillus. The

Patricia Cruz; Mark P. Buttner

2008-01-01

240

Study of the Ochratoxin A effect on Aspergillus parasiticus growth and aflatoxin B 1 production  

Microsoft Academic Search

Aflatoxin B1 (AFB1) is a carcinogenic metabolite produced by certain Aspergillus species. Ochratoxin A (OTA) is a metabolite of Aspergillus ochraceus and Penicillium verrucosum. AFB1 and OTA are amongst the most frequent combinations of mycotoxins found in plant products. Thus, synergistic effects or interactions between the two mycotoxins could be taking place. The aim of the present study was to

V. Dimitrokallis; D. M. Meimaroglou; P. Markaki

2008-01-01

241

Mycotoxin production by different ochratoxigenic Aspergillus and Penicillium species on coffee and wheat-based media  

Microsoft Academic Search

Ochratoxin A (OTA) is one of the most widespread mycotoxins, and is produced by several Aspergillus or Penicillium species. Human exposure to OTA is mainly by intake of contaminated food, with cereal products, followed by coffee and red\\u000a wine as the main sources of OTA. In this study, the OTA production of four ochratoxigenic fungi (two Aspergillus and two Penicillium

Katherine Muńoz; Mario Vega; Gisela Rios; Rolf Geisen; Gisela H. Degen

242

Comparison of four media for the isolation of Aspergillus flavus group fungi  

Microsoft Academic Search

Four agar media used to isolate aflatoxin producing fungi were compared for utility in isolating fungi in theAspergillus flavus group from agricultural soils collected in 15 fields and four states in the southern United States. The four media wereAspergillus flavus andparasiticus Agar (AFPA, 14), the rose bengal agar described by Bell and Crawford (BCRB; 3), a modified rose bengal agar

Peter J. Cotty

1994-01-01

243

Molecular cloning and heterologous expression of the isopullulanase gene from Aspergillus niger A.T.C.C. 9642.  

PubMed Central

Isopullulanase (IPU) from Aspergillus niger A.T.C.C. (American Type Culture Collection) 9642 hydrolyses pullulan to isopanose. IPU is important for the production of isopanose and is used in the structural analysis of oligosaccharides with alpha-1,4 and alpha-1,6 glucosidic linkages. We have isolated the ipuA gene encoding IPU from the filamentous fungi A. niger A.T.C.C. 9642. The ipuA gene encodes an open reading frame of 1695 bp (564 amino acids). IPU contained a signal sequence of 19 amino acids, and the molecular mass of the mature form was calculated to be 59 kDa. IPU has no amino-acid-sequence similarity with the other pullulan-hydrolysing enzymes, which are pullulanase, neopullulanase and glucoamylase. However, IPU showed a high amino-acid-sequence similarity with dextranases from Penicillium minioluteum (61%) and Arthrobacter sp. (56%). When the ipuA gene was expressed in Aspergillus oryzae, the expressed protein (recombinant IPU) had IPU activity and was immunologically reactive with antibodies raised against native IPU. The substrate specificity, thermostability and pH profile of recombinant IPU were identical with those of the native enzyme, but recombinant IPU (90 kDa) was larger than the native enzyme (69-71 kDa). After deglycosylation with peptide-N-glycosidase F, the deglycosylated recombinant IPU had the same molecular mass as deglycosylated native enzyme (59 kDa). This result suggests that the carbohydrate chain of recombinant IPU differed from that of the native enzyme.

Aoki, H; Yopi; Sakano, Y

1997-01-01

244

Isolation and identification of Aspergillus spp. from brown kiwi (Apteryx mantelli) nocturnal houses in New Zealand.  

PubMed

Aspergillosis, a disease caused by infection with Aspergillus spp., is a common cause of death in birds globally and is an irregular cause of mortality of captive kiwi (Apteryx spp.). Aspergillus spp. are often present in rotting plant material, including the litter and nesting material used for kiwi in captivity. The aim of this study was to survey nocturnal kiwi houses in New Zealand to assess the levels of Aspergillus currently present in leaf litter. Samples were received from 11 nocturnal kiwi houses from throughout New Zealand, with one site supplying multiple samples over time. Aspergillus was isolated and quantified by colony counts from litter samples using selective media and incubation temperatures. Isolates were identified to the species level by amplification and sequencing of ITS regions of the ribosomal. Aspergillus spp. were recovered from almost every sample; however, the levels in most kiwi houses were below 1000 colony-forming units (CFU)/g of wet material. The predominant species was Aspergillus fumigatus, with rare occurrences of Aspergillus niger, Aspergillus nidulans, and Aspergillus parasiticus. Only one site had no detectable Aspergillus. The limit of detection was around 50 CFU/g wet material. One site was repeatedly sampled as it had a high loading of A. fumigatus at the start of the survey and had two recent clinical cases of aspergillosis diagnosed in resident kiwi. Environmental loading at this site with Aspergillus spp. reduced but was not eliminated despite changes of the litter. The key finding of our study is that the background levels of Aspergillus spores in kiwi nocturnal houses in New Zealand are low, but occasional exceptions occur and are associated with the onset of aspergillosis in otherwise healthy birds. The predominant Aspergillus species present in the leaf litter was A. fumigatus, but other species were also present. Further research is needed to confirm the optimal management of leaf litter to minimize Aspergillus spore counts. However, in the interim, our recommendations are that leaf litter should be freshly collected from areas of undisturbed forest areas and spread immediately after collection, without interim storage. PMID:24758108

Glare, Travis R; Gartrell, Brett D; Brookes, Jenny J; Perrott, John K

2014-03-01

245

Allergy to Aspergillus-derived enzymes in the baking industry: Identification of ?-xylosidase from Aspergillus niger as a new allergen (Asp n 14)  

Microsoft Academic Search

Background:Aspergillus-derived enzymes are used in dough improvers in bakeries. Some of these enzymes are identified as causing IgE-mediated sensitization in up to 25% of bakers with workplace-related symptoms. Objective: The aim of this study was to compare the frequency of sensitization to Aspergillus xylanase, cellulase, and glucoamylase with the sensitization to ?-amylase (Asp o 2) and to identify IgE-reactive proteins

Ingrid Sander; Monika Raulf-Heimsoth; Christoph Siethoff; Christiane Lohaus; Helmut E. Meyer; Xaver Baur

1998-01-01

246

ITS-based detection and quantification of Aspergillus ochraceus and Aspergillus westerdijkiae in grapes and green coffee beans by real-time quantitative PCR  

Microsoft Academic Search

Aspergillus ochraceus and A. westerdijkiae are considered the most important Ochratoxin A (OTA) producing species included in Aspergillus section Circumdati which contaminate foodstuffs and beverages for human consumption. In this work a real-time quantitative PCR protocol was developed to detect both species using SYBR® Green and primers designed on the basis of the multicopy ITS1 region of the rDNA. The

Jéssica Gil-Serna; Amaia González-Salgado; Ma Teresa González-Jaén; Covadonga Vázquez; Belén Patińo

2009-01-01

247

Identification of antifungal niphimycin from Streptomyces sp. KP6107 by screening based on adenylate kinase assay.  

PubMed

Microbial culture extracts are used for natural product screening to find antifungal lead compounds. A microbial culture extract library was constructed using 343 actinomycete isolates to examine the value of the adenylate kinase (AK) assay for screening to identify antifungal metabolites that disrupt cell integrity in plant pathogenic fungi. A culture extract of Streptomyces sp. strain KP6107 lysed cells of Fusarium oxysporum f.sp. lycopersici which resulted in high AK activity. The active ingredient N-1 was purified from the culture extract using various chromatographic procedures and identified to be the guanidyl-polyol macrolide antibiotic, niphimycin, which is a potent fungal cell membrane disruptor. Niphimycin showed broad-spectrum antifungal activity against Alternaria mali, Aspergillus oryzae, Colletotrichum coccodes, Colletotrichum gloeosporioides, Cercospora canescens, Cylindrocarpon destructans, F. oxysporum f.sp. cucumerinum, F. oxysporum f.sp. lycopersici, and Rhizoctonia solani at concentrations of 8-64?µg?ml(-1). Anthracnose development in pepper plants was completely inhibited by treatment with 50 µg?ml(-1) niphimycin, which was as effective as chlorothalonil. These results show that the AK assay is an efficient and selective tool in screening for cell membrane/wall disruptors of plant pathogenic fungi. PMID:22915202

Kim, Hye Yoon; Kim, Jeong Do; Hong, Jin Sung; Ham, Jong Hyun; Kim, Beom Seok

2013-07-01

248

A peanut seed lipoxygenase responsive to Aspergillus colonization.  

PubMed

Several lines of evidence have indicated that lipoxygenase enzymes (LOX) and their products, especially 9S- and 13S-hydroperoxy fatty acids, could play a role in the Aspergillus/seed interaction. Both hydroperoxides exhibit sporogenic effects on Aspergillus spp. (Calvo, A., Hinze, L., Gardner, H.W. and Keller, N.P. 1999. Appl. Environ. Microbiol. 65: 3668-3673) and differentially modulate aflatoxin pathway gene transcription (Burow, G.B., Nesbitt, T.C., Dunlap, J. and Keller, N.P. 1997. Mol. Plant-Microbe Interact. 10: 380-387). To examine the role of seed LOXs at the molecular level, a peanut (Arachis hypogaea L.) seed gene, PnLOX1, was cloned and characterized. Analysis of nucleotide sequence suggests that PnLOX1 encodes a predicted 98 kDa protein highly similar in sequence and biochemical properties to soybean LOX2. The full-length PnLOX1 cDNA was subcloned into an expression vector to determine the type(s) of hydroperoxide products the enzyme produces. Analysis of the oxidation products of PnLOX1 revealed that it produced a mixture of 30% 9S-HPODE (9S-hydroperoxy-10E, 12Z-octadecadienoic acid) and 70% 13S-HPODE (13S-hydroperoxy-9Z, 11E-octadecadienoic acid) at pH 7. PnLOX1 is an organ-specific gene which is constitutively expressed in immature cotyledons but is highly induced by methyl jasmonate, wounding and Aspergillus infections in mature cotyledons. Examination of HPODE production in infected cotyledons suggests PnLOX1 expression may lead to an increase in 9S-HPODE in the seed. PMID:10809442

Burow, G B; Gardner, H W; Keller, N P

2000-03-01

249

?- l Rhamnosidase of Aspergillus terreus immobilized on ferromagnetic supports  

Microsoft Academic Search

?-l-Rhamnosidase from Aspergillus terreus was covalently immobilized on the following ferromagnetic supports: polyethylene terephthalate (Dacron-hydrazide), polysiloxane\\/polyvinyl\\u000a alcohol (POS\\/PVA), and chitosan. The powdered supports were magnetized by thermal coprecipitation method using ferric and\\u000a ferrous chlorides, and the immobilization was carried out via glutaraldehyde. The activity of the Dacron-hydrazide (0.53 nkat\\/?g\\u000a of protein) and POS\\/PVA (0.59 nkat\\/?g of protein) immobilized enzyme was significantly higher

Fernando Soria; Guillermo Ellenrieder; Givanildo Bezerra Oliveira; Mariana Cabrera; Luiz Bezerra Carvalho Jr

250

Production of Chlorflavonin, an Antifungal Metabolite of Aspergillus candidus  

PubMed Central

Production of chlorflavonin, a new antifungal antibiotic, by strains of Aspergillus candidus is described. Two wild strains of the fungus had distinctly different chlorflavonin-producing capabilities. One strain produced 25 ?g of chlorflavonin per ml per 4 to 5 days in a pilot scale fermentor with stirring, using a medium containing corn steep liquor and glucose. Production of antibiotic was favored by high rates of agitation-aeration. Crude chlorflavonin was extracted from the whole brew with a hydrocarbon solvent and then purified by recrystallization from benzene and petroleum ether. The overall yield from fermentation brew to pure product was 50%.

Munden, J. E.; Butterworth, D.; Hanscomb, G.; Verrall, M. S.

1970-01-01

251

Orbital tuberculosis with coexisting fungal (Aspergillus flavus) infection  

PubMed Central

Background: A coexisting invasive fungal and tubercular involvement of the skull base is a rare event. Co-infection has been reported with involvement of paranasal sinuses and middle ear cleft. Case Description: We herein report a case of an elderly male diabetic patient who presented with gradually progressive visual loss, which on imaging showed an orbital lesion. Surgical decompression and microbiological evaluation showed growth of Mycobacterium tuberculosis and Aspergillus flavus. Conclusion: Rare combinations of such infections do exist and should be treated aggressively to achieve good outcomes in a losing battle with fastidious organisms in the backdrop of compromised immunity.

Reddy, Sunkara Srikanth; Penmmaiah, Devi Chendira; Rajesh, Alugolu; Patil, Madhusudan

2014-01-01

252

Invasive Aspergillosis Caused by Aspergillus ustus: Case Report and Review  

PubMed Central

A case of invasive pulmonary aspergillosis in an allogeneic bone marrow transplant recipient caused by Aspergillus ustus is presented. A. ustus was also recovered from the hospital environment, which may indicate that the infection was nosocomially acquired. A literature review revealed seven cases of invasive infections caused by A. ustus, and three of these were primarily cutaneous infections. In vitro susceptibility testing of 12 A. ustus isolates showed that amphotericin B and terbinafine had fungicidal activity and that itraconazole and voriconazole had fungistatic activity.

Verweij, Paul E.; van den Bergh, Marjolein F. Q.; Rath, Peter M.; de Pauw, Ben E.; Voss, Andreas; Meis, Jacques F. G. M.

1999-01-01

253

In vitro reconstruction of the Aspergillus (= Emericella) nidulans?genome  

PubMed Central

A physical map of the 31-megabase Aspergillus nidulans genome is reported, in which 94% of 5,134 cosmids are assigned to 49 contiguous segments. The physical map is the result of a two-way ordering process, in which clones and probes were ordered simultaneously on a binary DNA/DNA hybridization matrix. Compression by elimination of redundant clones resulted in a minimal map, which is a chromosome walk. Repetitive DNA is nonrandomly dispersed in the A. nidulans genome, reminiscent of heterochromatic banding patterns of higher eukaryotes. We hypothesize gene clusters may arise by horizontal transfer and spread by transposition to explain the nonrandom pattern of repeats along?chromosomes.

Prade, Rolf A.; Griffith, James; Kochut, Krys; Arnold, Jonathan; Timberlake, William E.

1997-01-01

254

Properties of a purified thermostable glucoamylase from Aspergillus niveus  

Microsoft Academic Search

A glucoamylase from Aspergillus niveus was produced by submerged fermentation in Khanna medium, initial pH 6.5 for 72 h, at 40°C. The enzyme was purified by DEAE-Fractogel\\u000a and Concanavalin A-Sepharose chromatography. The enzyme showed 11% carbohydrate content, an isoelectric point of 3.8 and a\\u000a molecular mass of 77 and 76 kDa estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis or Bio-Sil-Sec-400\\u000a gel filtration,

Tony Marcio da Silva; Alexandre Maller; André Ricardo de Lima Damásio; Michele Michelin; Richard John Ward; Izaura Yoshico Hirata; Joăo Atilio Jorge; Héctor Francisco Terenzi; Maria Lourdes T. M. de Polizeli

2009-01-01

255

Isolation and characterization of alpha-glucosidase from Aspergillus niger.  

PubMed

alpha-Glucosidase is an enzyme widely used in biochemical analytical methods. Aspergillus niger was selected as a potential source for its production. Conditions for glucosidase production were optimized and the enzyme was isolated from the culture supernatant by dialysis and anion-exchange chromatography. The activity of the enzyme was determined by maltose hydrolysis to glucose, which was determined using a glucose-specific electrode or by high-performance liquid chromatography. The isolated enzyme was further characterized by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, substrate specificity and fast protein liquid chromatography. The Michaelis constant, optimal temperature and stability of the enzyme preparation were determined. PMID:1639895

Brízová, K; Králová, B; Demnerová, K; Vins, I

1992-02-28

256

Pyopneumothorax secondary to Aspergillus infection: a case report.  

PubMed

A 32 -year- old male presented with complaints of fever, dry cough, breathlessness and right sided chest pain of two months duration. Chest radiograph showed right sided hydropneumothorax which revealed frank pus on diagnostic thoracocentesis, for which tube thoracostomy was done. Despite vigorous broad spectrum antibiotic coverage, postural drainage and chest physiotherapy, there was no clinical improvement. Further work up included serology, pleural fluid culture, closed as well as thoracoscopic guided pleural biopsy revealed growth of Aspergillus fumigatus. Patient was prescribed antifungal medication (Voriconazole) and subsequent thoracotomy with right sided pneumonectomy showed good clinical recovery. PMID:23226822

Kant, Surya; Saheer, S; Singh, Abhijjeet; Hassan, Ghulam

2012-11-01

257

Funalenone, a novel collagenase inhibitor produced by Aspergillus niger.  

PubMed

Funalenone, a phenalene compound that inhibits type I collagenase (MMP-1), was isolated from mycelium of Aspergillus niger FO-5904 by solvent extaction, ODS column chromatography, Sephadex LH-20 column chromatography and reversed phase HPLC. Funalenone inhibited 50% of type I collagenase activity at a concentration of 170 microM, but inhibited 18.3% and 38.7% against 72 kDa and 92 kDa type IV collagenase, respectively, at a concentration of 400 microM. PMID:10695672

Inokoshi, J; Shiomi, K; Masuma, R; Tanaka, H; Yamada, H; Omura, S

1999-12-01

258

Formation of aflatoxins by some Egyptian Aspergillus flavus strains.  

PubMed

In all the fifteen investigated Aspergillus flavus and A. parasiticus strains the maximum quantities of aflatoxins, produced on rice powder-corn steep (RC) medium, ranged from 1.17 to 23.29 times as much as those produced on yeast extract-sucrose (YES) medium. The shake cultures lowered aflatoxin formation. The maximum yields of aflatoxins did not coincide with maximum fungal growth. In most A. flavus strains investigated, the total aflatoxin content of the mycelia highly exceeded that of the culture filtrates. PMID:6792813

Mabrouk, S S; El-Shayeb, N M

1981-01-01

259

Production of extremophilic bacterial cellulase enzymes in aspergillus niger.  

SciTech Connect

Enzymes can be used to catalyze a myriad of chemical reactions and are a cornerstone in the biotechnology industry. Enzymes have a wide range of uses, ranging from medicine with the production of pharmaceuticals to energy were they are applied to biofuel production. However, it is difficult to produce large quantities of enzymes, especially if they are non-native to the production host. Fortunately, filamentous fungi, such as Aspergillus niger, are broadly used in industry and show great potential for use a heterologous enzyme production hosts. Here, we present work outlining an effort to engineer A. niger to produce thermophilic bacterial cellulases relevant to lignocellulosic biofuel production.

Gladden, John Michael

2013-09-01

260

Indoloditerpenes from an algicolous isolate of Aspergillus oryzae.  

PubMed

Two new indoloditerpene derivatives asporyzin A (1) and asporyzin B (2), one new indoloditerpene asporyzin C (3), and three known related indoloditerpenes JBIR-03 (4), emindole SB (5), and emeniveol (6) were isolated from an endophytic fungus Aspergillus oryzae, isolated from the marine red alga Heterosiphonia japonica. Their structures were unambiguously established by spectroscopic techniques. In addition, all the isolates were evaluated preliminarily for insecticidal and antimicrobial activities in order to probe into their chemical defensive function. Compound 4 was more active against brine shrimp than the others, and 3 possessed potent activity against Escherichia coli. PMID:20797856

Qiao, Ming-Feng; Ji, Nai-Yun; Liu, Xiang-Hong; Li, Ke; Zhu, Qing-Mei; Xue, Qin-Zhao

2010-10-01

261

Crystals of beta-xylanase from Aspergillus oryzae.  

PubMed

An endo-xylanase was isolated from the culture of fungus Aspergillus oryzae variant D5. The purified enzyme had a molecular weight of 24,000 and the isoelectric point of 3.6. Xylanase crystals were obtained from a polyethylene glycol 6000 solution by the hanging-drop method. Seeding was used for the enlargement of the crystal size. Crystals belong to the monoclinic space group P2(1) with cell dimensions a = 54.9 A, b = 74.5 A, c = 50.8 A, and beta = 108.7 degrees. Crystals diffract beyond 2.5 A resolution. PMID:8464071

Golubev, A M; Kilimnik AYu; Neustroev, K N; Pickersgill, R W

1993-03-20

262

Sp1\\/Sp3 compound heterozygous mice are not viable: Impaired erythropoiesis and severe placental defects  

Microsoft Academic Search

The ubiquitously expressed zinc finger transcription factors Sp1 and Sp3 play critical roles in embryonic development. Sp1 knockout mice die around embryonic day 10.5. Mice lacking Sp3 are postnatal lethal. Mice heterozygous for either Sp1 or Sp3 are apparently normal, although slightly smaller. Here, we show that compound heterozygosity of Sp1 and Sp3 results in embryonic lethality accompanied by a

Imme Krüger; Marion Vollmer; David G. Simmons; Hans-Peter Elsässer; Sjaak Philipsen; Guntram Suske

2007-01-01

263

Occurrence of toxigenic Aspergillus spp. and aflatoxins in selected food commodities of Asian origin sourced in the West of Scotland.  

PubMed

The occurrence of Aspergillus moulds and aflatoxins in 12 commercially-available dried foods of Asian origin were examined. All food samples, except green beans and three types of dried fruit, contained multiple genera of moulds of which Aspergillus (55%) was the most frequently detected. Penicillium (15%), Rhizopus (11%), Mucor (3%), Monascus (1%), Eurotium (1%) and unidentified (14%) were also observed. The occurrence of aflatoxigenic moulds, however, did not correspond with the occurrence of aflatoxins in foods. Aflatoxigenic Aspergillus spp. (39 isolates) were recovered from long grain rice, fragrant rice, peanuts, black beans and black pepper. The predominant Aspergillus species was A. parasiticus (61%) while Aspergillus oryzae (3%), Aspergillus utus (5%), Aspergillus niger (5%), Aspergillus ochraceus (3%) and unidentified (23%) were also observed. Long grain rice, fragrant rice, peanuts, black beans and black pepper were positive for Aspergillus but contained undetectable aflatoxins. In contrast, Jasmine brown rice and crushed chilli contained 14.7 and 11.4?g/kg of total aflatoxins, respectively, in the absence of Aspergillus so aflatoxigenic Aspergillus was present at some stage of food production. The results from this study emphasise the need for stricter control measures in reducing occurrence of aflatoxins in foods for export and domestic use. PMID:23416649

Ruadrew, Sayan; Craft, John; Aidoo, Kofi

2013-05-01

264

?-Glucosylated 6-gingerol: chemoenzymatic synthesis using ?-glucosidase from Halomonas sp. H11, and its physical properties.  

PubMed

6-Gingerol [(S)-5-hydroxy-1-(4-hydroxy-3-methoxyphenyl)decan-3-one] is a biologically active compound and is abundant in the rhizomes of ginger (Zingiber officinale). It has some beneficial functions in healthcare, but its use is limited because of its insolubility in water and its heat-instability. To improve these physical properties, the glucosylation of 6-gingerol was investigated using ?-glucosidases (EC. 3.2.1.20) from Aspergillus niger, Aspergillus nidulans ABPU1, Acremonium strictum, Halomonas sp. H11, and Saccharomyces cerevisiae, and cyclodextrin glucanotransferases (CGTase, EC. 2.4.1.19) from Bacillus coagulans, Bacillus sp. No. 38-2, Bacillus clarkii 7364, and Geobacillus stearothermophilus. Among these, only ?-glucosidase from Halomonas sp. H11 (HaG) transferred a glucosyl moiety to 6-gingerol, and produced glucosylated compounds. The chemical structure of the reaction product, determined by nuclear magnetic resonance spectroscopy and mass spectrometry, was (S)-5-(O-?-D-glucopyranosyl)-1-(4-hydroxy-3-methoxyphenyl)decan-3-one (5-?-Glc-gingerol). Notably, the regioisomer formed by glucosylation of the phenolic OH was not observed at all, indicating that HaG specifically transferred the glucose moiety to the 5-OH of the ?-hydroxy keto group in 6-gingerol. Almost 60% of the original 6-gingerol was converted into 5-?-Glc-gingerol by the reaction. In contrast to 6-gingerol, 5-?-Glc-gingerol, in the form of an orange powder prepared by freeze-drying, was water-soluble and stable at room temperature. It was also more stable than 6-gingerol under acidic conditions and to heat. PMID:22537860

Ojima, Teruyo; Aizawa, Kenta; Saburi, Wataru; Yamamoto, Takeshi

2012-06-01

265

Enzyme profile and immunochemical characterization of Aspergillus fumigatus antigens.  

PubMed

We have compared the immunochemical characteristics of culture-filtrate antigens (Ag) from Aspergillus fumigatus extracted in our laboratory with commercially available Ags. A total of 20 different preparations were studied for protein and carbohydrate content, presence of endotoxins, mycotoxins, and hemolytic toxins. These extracts were analyzed by two-dimensional electrophoresis for protein components. The immunogenicity of the preparations was determined by rocket electrophoresis with rabbit anti-A. fumigatus sera and by agar gel diffusion with sera from patients with allergic bronchopulmonary aspergillosis, aspergilloma, and normal control subjects. In order to have dependable immunologic results, the Ags must be sufficiently pure and reproducible. Until such time as pure and standardized Ags are available, the crude Ags used should be characterized to the extent that adequate reproducibility between preparations can be ascertained. The enzyme profile of the Ag preparations provides a fair indication of the quality of antigenic components, and together with other immunochemical parameters, it will be of use in determining the suitability of the extracts in immunodiagnosis. Immunochemical results demonstrate that commercial Ags contain less proteins and carbohydrates and fewer enzymes than the homemade antigens. In addition, fewer patients demonstrated specific precipitins against commercial Ags than with homemade Ags. This study once again confirms the need for pure standardized Ags for studying the immunologic response in patients with Aspergillus-induced diseases. Until such preparations are readily available, partially purified or crude Ags with known immunochemical properties and enzyme profile may be the choice for immunodiagnosis. PMID:3097110

Kurup, V P; Resnick, A; Scribner, G H; Gunasekaran, M; Fink, J N

1986-12-01

266

Isolation and Characterization of Sexual Spore Pigments from Aspergillus nidulans  

PubMed Central

The homothallic ascomycete Aspergillus nidulans produces two types of pigmented spores: conidia and ascospores. The synthesis and localization of the spore pigments is developmentally regulated and occurs in specialized cell types. On the basis of spectroscopic evidence, we propose that the major ascospore pigment of A. nidulans (ascoquinone A) is a novel dimeric hydroxylated anthraquinone. The structure of ascoquinone A, as well as a comparison to model compounds, suggests that it is the product of a polyketide synthase. Previous studies have revealed that the conidial pigments from A. nidulans and a related Aspergillus species (A. parasiticus) also appear to be produced via polymerization of polyketide precursors (D. W. Brown, F. M. Hauser, R. Tommasi, S. Corlett, and J. J. Salvo, Tetrahedron Lett. 34:419-422, 1993; M. E. Mayorga and W. E. Timberlake, Mol. Gen. Genet. 235:205-212, 1992). The structural similarity between the ascospore pigment and the toxic anthraquinone norsolorinic acid, the first stable intermediate in the aflatoxin pathway, suggests an evolutionary relationship between the respective polyketide synthase systems.

Brown, Daren W.; Salvo, Joseph J.

1994-01-01

267

Viriditoxin production by Aspergillus viridi-nutans and related species.  

PubMed

Bioproduction of viriditoxin on various substrates by strains of the Aspergillus fumigatus group was determined under several incubation conditions. Aspergillus viridi-nutans strains NRRL 4365 and 576 produced the largest quantities of toxin, A. brevipes gave reduced yields, and there was no detectable synthesis by isolates of four related species. After 30 days in static culture at 20 C on various autoclaved agricultural commodities, optimal yields of 440 and 380 mg of toxin were observed per kilogram of sorghum and rice. Toxin levels were reduced on corn, rye, and wheat (40-200 mg/kg); yields were low on cottonseed, barley, and oats. Incubation at 10 C restricted biosynthesis of viriditoxin, and no toxin accumulated on substrates maintained at 5 C for 120 days. In a liquid, yeast extract-sucrose medium, maximal mycotoxin production developed in shake flasks; after 156 h, 10 mg of toxin accumulated per gram of mycelium. Viriditoxin produced in submerged culture was associated with the mycelium; less than 1% was detected in the filtered broth after 156 h of incubation. PMID:4582816

Lillehoj, E B; Milburn, M S

1973-08-01

268

Characterization of the velvet regulators in Aspergillus fumigatus.  

PubMed

Fungal development and secondary metabolism is intimately associated via activities of the fungi-specific velvet family proteins. Here we characterize the four velvet regulators in the opportunistic human pathogen Aspergillus fumigatus. The deletion of AfuvosA, AfuveA and AfuvelB causes hyperactive asexual development (conidiation) and precocious and elevated accumulation of AfubrlA during developmental progression. Moreover, the absence of AfuvosA, AfuveA or AfuvelB results in the abundant formation of conidiophores and highly increased AfubrlA mRNA accumulation in liquid submerged culture, suggesting that they act as repressors of conidiation. The deletion of AfuvosA or AfuvelB causes a reduction in conidial trehalose amount, long-term spore viability, conidial tolerance to oxidative and UV stresses, and accelerated and elevated conidial germination regardless of the presence or absence of an external carbon source, suggesting an interdependent role of them in many aspects of fungal biology. Genetic studies suggest that AfuAbaA activates AfuvosA and AfuvelB expression during the mid to late phase of conidiation. Finally, the AfuveA null mutation can be fully complemented by Aspergillus nidulans VeA, which can physically interact with AfuVelB and AfuLaeA in vivo. A model depicting the similar yet different roles of the velvet regulators governing conidiation and sporogenesis in A.?fumigatus is presented. PMID:22970834

Park, Hee-Soo; Bayram, Ozgür; Braus, Gerhard H; Kim, Sun Chang; Yu, Jae-Hyuk

2012-11-01

269

Characterization of recombinant terrelysin, a hemolysin of Aspergillus terreus.  

PubMed

Fungal hemolysins are potential virulence factors. Some fungal hemolysins belong to the aegerolysin protein family that includes cytolysins capable of lysing erythrocytes and other cells. Here, we describe a hemolysin from Aspergillus terreus called terrelysin. We used the genome sequence database to identify the terrelysin sequence based on homology with other known aegerolysins. Aspergillus terreus mRNA was isolated, transcribed to cDNA and the open reading frame for terrelysin amplified by PCR using specific primers. Using the pASK-IBA6 cloning vector, we produced recombinant terrelysin (rTerrelysin) as a fusion product in Escherichia coli. The recombinant protein was purified and using MALDI-TOF MS determined to have a mass of 16,428 Da. Circular dichroism analysis suggests the secondary structure of the protein to be predominantly ?-sheet. Results from thermal denaturation of rTerrelysin show that the protein maintained the ?-sheet confirmation up to 65°C. Polyclonal antibody to rTerrelysin recognized a protein of approximately 16.5 kDa in mycelial extracts from A. terreus. PMID:20632211

Nayak, Ajay P; Blachere, Françoise M; Hettick, Justin M; Lukomski, Slawomir; Schmechel, Detlef; Beezhold, Donald H

2011-01-01

270

Update on antifungal resistance in Aspergillus and Candida.  

PubMed

Antifungal resistance in Candida and Aspergillus may be either intrinsic or acquired and may be encountered in the antifungal drug exposed but also the antifungal drug-naďve patient. Prior antifungal treatment confers a selection pressure and notoriously raises the awareness of possible resistance in patients failing therapy, thus calling for susceptibility testing. On the contrary, antifungal resistance in the drug-naďve patient is less expected and therefore more challenging. This is particularly true when it concerns pathogens with acquired resistance which cannot be predicted from the species identification itself. This scenario is particularly relevant for A. fumigatus infections due to the increasing prevalence of azole-resistant isolates in the environment. For Candida, infections resistance is most common in the context of increasing prevalence of species with intrinsic resistance. Candida glabrata which has intrinsically reduced susceptibility to fluconazole is increasingly common particularly among the adult and elderly population on the Northern Hemisphere where it may be responsible for as many as 30% of the blood stream infections in population-based surveillance programmes. Candida parapsilosis is prevalent in the paediatric setting, at centres with increasing echinocandin use and at the southern or pacific parts of the world. In the following, the prevalence and drivers of intrinsic and acquired resistance in Aspergillus and Candida will be reviewed. PMID:24372701

Arendrup, M C

2014-06-01

271

DOPA and DHN pathway orchestrate melanin synthesis in Aspergillus species.  

PubMed

Melanins are high molecular weight hydrophobic pigments that have been studied for their role in the virulence of fungal pathogens. We investigated the amount and type of melanin in 20 isolates of Aspergillus spp.; A. niger (n = 3), A. flavus (n = 5), A. tamarii (n = 3), A. terreus (n = 3), A. tubingensis (n = 3), A. sydowii (n = 3). Aspergillus spp. were identified by sequencing the internal transcribed spacer (ITS) region. Extraction of melanin from culture filtrate and fungal biomass was done and followed by qualitative and quantitative analysis of melanin pigment. Ultraviolet (UV), Fourier transformed infrared (FT-IR), and electron paramagnetic resonance (EPR) spectra analyses confirmed the presence of melanin. The melanin pathway was studied by analyzing the effects of inhibitors; kojic acid, tropolone, phthalide, and tricyclazole. The results indicate that in A. niger and A. tubingensis melanin was found in both culture filtrate and fungal biomass. For A. tamarii and A. flavus melanin was extracted from biomass only, whereas melanin was found only in culture filtrate for A. terreus. A negligible amount of melanin was found in A. sydowii. The maximum amount of melanin from culture filtrate and fungal biomass was found in A. niger and A. tamarrii, respectively. The DOPA (3,4-dihydroxyphenylalanine) pathway produces melanin in A. niger, A. tamarii and A. flavus, whereas the DHN (1,8-dihydroxynaphthalene) pathway produces melanin in A. tubingensis and A. terreus. It can be concluded that the amount and type of melanin in aspergilli largely differ from species to species. PMID:23998343

Pal, Anuradha K; Gajjar, Devarshi U; Vasavada, Abhay R

2014-01-01

272

Aspergillus terreus complex: an emergent opportunistic agent of Onychomycosis.  

PubMed

The incidence of onychomycosis due to non-dermatophyte moulds (NDM) is increasing. Aspergillus terreus is relatively undocumented as an agent of this fungal infection. The aim of this work is to show the prevalence of onychomycosis caused by A. terreus and to describe its clinical features. Nail samples were collected for microscopic examination and culturing in selective media. All cases of onychomycosis due to NDM were confirmed by a second sample. Aspergillus terreus isolates were identified through their morphological characteristics and using molecular methods. A total of 2485 samples were obtained. Positive cultures were obtained in 1639 samples. From 124 NDM confirmed cultures, 23 were identified as A. terreus (18.5%). Superficial white onychomycosis was the most frequent clinical pattern. A high percentage was found in fingernails. The prevalence of A. terreus in this study considerably exceeded the percentages reported by other authors. Onychomycosis due to A. terreus presents similar clinical patterns to those caused by dermatophytes, but is difficult to eradicate and is associated with less predictable treatment outcomes. Better knowledge of the aetiology of A. terreus may be important for accomplishing more accurate and effective treatment. PMID:23448599

Fernández, Mariana S; Rojas, Florencia D; Cattana, María E; Sosa, María de Los Ángeles; Mangiaterra, Magdalena L; Giusiano, Gustavo E

2013-07-01

273

Enhanced cellulase producing mutants developed from heterokaryotic Aspergillus strain.  

PubMed

A heterokaryon 28, derived through protoplast fusion between Aspergillus nidulans and Aspergillus tubingensis (Dal8), was subjected cyclic mutagenesis followed by selection on increasing levels of 2-deoxy glucose (2-DG) as selection marker. The derived deregulated cellulase hyper producing mutant '64', when compared to fusant 28, produced 9.83, 7.8, 3.2, 4.2 and 19.74 folds higher endoglucanase, ?-glucosidase, cellobiohydrolase, FPase and xylanase, respectively, under shake cultures. The sequence analysis of PCR amplified ?-glucosidase gene from wild and mutant showed nucleotide deletion/substitution. The mutants showed highly catalytic efficient ?-glucosidase as evident from low Km and high Vmax values. The expression profiling through zymogram analysis also indicated towards over-expression of cellulases. The up/down regulated expressed proteins observed through SDS-PAGE were identified by Peptide mass fingerprinting The cellulase produced by mutants in conjunction with cellulase free xylanase derived from Thermomyces lanuginosus was used for efficient utilization of alkali treated rice straw for obtaining xylo-oligosaccharides and ethanol. PMID:24491293

Kaur, Baljit; Oberoi, H S; Chadha, B S

2014-03-01

274

Terrein Biosynthesis in Aspergillus terreus and Its Impact on Phytotoxicity.  

PubMed

Terrein is a fungal metabolite with ecological, antimicrobial, antiproliferative, and antioxidative activities. Although it is produced by Aspergillus terreus as one of its major secondary metabolites, not much is known about its biosynthetic pathway. Here, we describe an unexpected discovery of the terrein biosynthesis gene locus made while we were looking for a PKS gene involved in production of conidia coloration pigments common for Aspergilli. The gene, ATEG_00145, here named terA, is essential for terrein biosynthesis and heterologous production of TerA in Aspergillus niger revealed an unusual plasticity in the products formed, yielding a mixture of 4-hydroxy-6-methylpyranone, orsellinic acid, and 6,7-dihydroxymellein. Biochemical and molecular genetic analyses indicate a low extension cycle specificity of TerA. Furthermore, 6-hydroxymellein was identified as a key intermediate in terrein biosynthesis. We find that terrein production is highly induced on plant-derived media, that terrein has phytotoxic activity on plant growth, and induces lesions on fruit surfaces. PMID:24816227

Zaehle, Christoph; Gressler, Markus; Shelest, Ekaterina; Geib, Elena; Hertweck, Christian; Brock, Matthias

2014-06-19

275

Six novel constitutive promoters for metabolic engineering of Aspergillus niger.  

PubMed

Genetic tools for the fine-tuning of gene expression levels are a prerequisite for rational strain optimization through metabolic engineering. While Aspergillus niger is an industrially important fungus, widely used for production of organic acids and heterologous proteins, the available genetic tool box for this organism is still rather limited. Here, we characterize six novel constitutive promoters of A. niger providing different expression levels. The selection of the promoters was based on published transcription data of A. niger. The promoter strength was determined with the ?-glucuronidase (gusA) reporter gene of Escherichia coli. The six promoters covered a GUS activity range of two to three orders of magnitude depending on the strain background. In order to demonstrate the power of the newly characterized promoters for metabolic engineering, they were used for heterologous expression of the cis-aconitate decarboxylase (cad1) gene of Aspergillus terreus, allowing the production of the building block chemical itaconic acid with A. niger. The CAD activity, dependent on the choice of promoter, showed a positive correlation with the specific productivity of itaconic acid. Product titers from the detection limit to up to 570 mg/L proved that the set of constitutive promoters is a powerful tool for the fine-tuning of metabolic pathways for the improvement of industrial production processes. PMID:22707054

Blumhoff, Marzena; Steiger, Matthias G; Marx, Hans; Mattanovich, Diethard; Sauer, Michael

2013-01-01

276

The Prevalence of Aflatoxinogenic Aspergillus parasiticus in Jordan  

PubMed Central

Aflatoxins are potent carcinogens and produced by almost all Aspergillus parasiticus isolates and about 35% of Aspergillus flavus isolates. Chemical methods are used for detection of aflatoxins in food and feed. These methods cannot detect aflatoxinogenic fungi in samples, which contain undetectable amounts of aflatoxins. The objective of this research work was to ascertain the importance of molecular and microbiological methods in detection of aflatoxinogenic fungus A. parasiticus in food and feed samples in Jordan. Specific media for the detection of aflatoxins showed the prevalence of A. parasiticus (6–22%) in contaminated food and feed samples. HPLC method confirmed the presence of aflatoxins B1, B2, G1, and G2 in food sample contaminated with A. parasiticus. Primer set OmtBII-F and OmtBII-R amplified DNA fragment of 611 base pairs from genomic DNA of aflatoxinogenic A. parasiticus isolated from food and feed samples but could not amplify DNA fragment of nonaflatoxinogenic A. flavus. The results of this study showed the prevalence of aflatoxinogenic A. parasiticus in food and feed samples in Jordan and give further evidence of suitability of microbiological and molecular methods in detection of aflatoxins, which are reliable low-cost approach to determine food and feed biosafety.

Al-Hmoud, Nisreen; Ibrahim, Mohammed A.; Al-Rousan, Hiyam; Alseyah, Abbas

2012-01-01

277

Testing an innovative device against airborne Aspergillus contamination.  

PubMed

Aspergillus fumigatus is a major airborne nosocomial pathogen that is responsible for severe mycosis in immunocompromised patients. We studied the efficacy of an innovative mobile air-treatment device in eliminating A. fumigatus from the air following experimental massive contamination in a high-security room. Viable mycological particles were isolated from sequential air samples in order to evaluate the device's effectiveness in removing the fungus. The concentration of airborne conidia was reduced by 95% in 18 min. Contamination was reduced below the detection threshold in 29 min, even when the machine was at the lowest airflow setting. In contrast, during spontaneous settling with no air treatment, conidia remained airborne for more than 1 h. This indoor air contamination model provided consistent and reproducible results. Because the air purifier proved to be effective at eliminating a major contaminant, it may prove useful in preventing air-transmitted disease agents. In an experimental space mimicking a hospital room, the AirLyse air purifier, which uses a combination of germicidal ultraviolet C irradiation and titanium photocatalysis, effectively eliminated Aspergillus conidia. Such a mobile device may be useful in routine practice for lowering microbiological air contamination in the rooms of patients at risk. PMID:24965945

Desoubeaux, Guillaume; Bernard, Marie-Charlotte; Gros, Valérie; Sarradin, Pierre; Perrodeau, Elodie; Vecellio, Laurent; Piscopo, Antoine; Chandenier, Jacques; Bernard, Louis

2014-08-01

278

Cross-Reactivity of Fusarium spp. in the Aspergillus Galactomannan Enzyme-Linked Immunosorbent Assay  

PubMed Central

Nine of 11 hematological patients with disseminated/deep-seated Fusarium infection tested at least twice for Aspergillus galactomannan (GM) had repeated positive results in the absence of Aspergillus isolation in culture. The centrifuged supernatants of 12 Fusarium isolates were tested by a GM enzyme-linked immunosorbent assay (EIA). All the isolates produced positive reactions when tested undiluted. These results show cross-reactivity of Fusarium spp. with Aspergillus GM that may constitute a drawback with respect to the specificity of the Platelia EIA.

Esposto, Maria Carmela; Prigitano, Anna; Grancini, Anna; Ossi, Cristina; Cavanna, Caterina; Cascio, Giuliana Lo

2012-01-01

279

Isolation and Identification of Aspergillus Section Fumigati Strains from Arable Soil in Korea  

PubMed Central

63 strains of Aspergillus section Fumigati were isolated from 17 samples of arable soil in a central province of Korea. Based on the results of genotypic and phenotypic analyses, they were identified as Aspergillus fumigatus, A. lentulus, Neosartorya coreana, N. fennelliae, N. fischeri, N. glabra, N. hiratsukae, N. laciniosa, N. pseudofischeri, N. quadricincta, N. spinosa and N. udagawae. Among these, N. fennelliae, N. hiratsukae, N. quadricincta, and N. udagawae had not been previously recorded in Korea. The diversity of Aspergillus section Fumigati species from arable soil in Korea is also addressed.

Kim, Dae-Ho; Park, In-Cheol; Samson, Robert A.; Shin, Hyeon-Dong

2010-01-01

280

SP-100 space reactor safety  

SciTech Connect

The SP-100 space reactor power system is being developed to meet the large electrical power requirements of civilian and military missions planned for the 1990's and beyond. It will remove the restrictions on electrical power generation that have tended to limit missions and will enable the fuller exploration and utilization of space. This booklet describes the SP-100 space reactor power system and its development. Particular emphasis is given to safety. The design aand operational features as well as the design and safety review process that will assure that the SP-100 can be launched nd operated safely are described.

Not Available

1987-05-01

281

Aspergillus Collagen-Like Genes (acl): Identification, Sequence Polymorphism, and Assessment for PCR-Based Pathogen Detection  

PubMed Central

The genus Aspergillus is a burden to public health due to its ubiquitous presence in the environment, its production of allergens, and wide demographic susceptibility among cystic fibrosis, asthmatic, and immunosuppressed patients. Current methods of detection of Aspergillus colonization and infection rely on lengthy morphological characterization or nonstandardized serological assays that are restricted to identifying a fungal etiology. Collagen-like genes have been shown to exhibit species-specific conservation across the noncollagenous regions as well as strain-specific polymorphism in the collagen-like regions. Here we assess the conserved region of the Aspergillus collagen-like (acl) genes and explore the application of PCR amplicon size-based discrimination among the five most common etiologic species of the Aspergillus genus, including Aspergillus fumigatus, A. flavus, A. nidulans, A. niger, and A. terreus. Genetic polymorphism and phylogenetic analysis of the aclF1 gene were additionally examined among the available strains. Furthermore, the applicability of the PCR-based assay to identification of these five species in cultures derived from sputum and bronchoalveolar fluid from 19 clinical samples was explored. Application of capillary electrophoresis on nanogels was additionally demonstrated to improve the discrimination between Aspergillus species. Overall, this study demonstrated that Aspergillus acl genes could be used as PCR targets to discriminate between clinically relevant Aspergillus species. Future studies aim to utilize the detection of Aspergillus acl genes in PCR and microfluidic applications to determine the sensitivity and specificity for the identification of Aspergillus colonization and invasive aspergillosis in immunocompromised subjects.

Tuntevski, Kiril; Durney, Brandon C.; Snyder, Anna K.; LaSala, P. Rocco; Nayak, Ajay P.; Green, Brett J.; Beezhold, Donald H.; Rio, Rita V. M.; Holland, Lisa A.

2013-01-01

282

SP-100 Advanced Technology Program  

NASA Technical Reports Server (NTRS)

The goal of the triagency SP-100 Program is to develop long-lived, compact, lightweight, survivable nuclear reactor space power systems for application to the power range 50 kWe to 1 MWe. The successful development of these systems should enable or significantly enhance many of the future NASA civil and commercial missions. The NASA SP-100 Advanced Technology Program strongly augments the parallel SP-100 Ground Engineering System Development program and enhances the chances for success of the overall SP-100 program. The purpose of this paper is to discuss the key technical elements of the Advanced Technology Program and the progress made in the initial year and a half of the project.

Sovie, Ronald J.

1987-01-01

283

Restriction analysis of an amplified rodA gene fragment to distinguish Aspergillus fumigatus var. ellipticus from Aspergillus fumigatus var. fumigatus.  

PubMed

A previous multidisciplinary study indicated that gliotoxin-producing Aspergillus fumigatus Fresen. isolates from silage commodities mostly belonged to its variant A. fumigatus var. ellipticus Raper & Fennell. Sequence analysis revealed the presence of a single nucleotide polymorphism at five positions in a fragment of the rodA gene (coding for a hydrophobin rodletA protein) between Aspergillus fumigatus var. fumigatus and Aspergillus fumigatus var. ellipticus. A method was developed to distinguish these two types of isolates based on restriction analysis of this rodA gene fragment using the HinfI restriction enzyme. In addition, in silico analysis of 113 rodA gene fragments retrieved from GenBank was performed and confirmed the suitability of this method. In conclusion, the method developed in this study allows easy distinction between A. fumigatus var. fumigatus and its variant ellipticus. In combination with the earlier developed PCR-restriction fragment length polymorphism method of Staab et al. (2009, J Clin Microbiol 47: 2079), this method is part of a sequencing-independent identification scheme that allows for rapid distinction between similar species/variants within Aspergillus section Fumigati, specifically A. fumigatus, A. fumigatus var. ellipticus, Aspergillus lentulus Balajee & K.A. Marr, Neosartorya pseudofischeri S.W. Peterson and Neosartorya udagawae Y. Horie, Miyaji & Nishim. PMID:22670589

Van Pamel, Els; Daeseleire, Els; De Clercq, Nikki; Herman, Lieve; Verbeken, Annemieke; Heyndrickx, Marc; Vlaemynck, Geertrui

2012-08-01

284

Multilocus sequence analysis of Aspergillus Sect. Nigri in dried vine fruits of worldwide origin.  

PubMed

Dried vine fruits may be heavily colonized by Aspergillus species. The molecular biodiversity of an Aspergillus population (234 strains) isolated from dried vine fruit samples of worldwide origin were analyzed by investigating four housekeeping gene loci (calmodulin, ?-tubulin, elongation factor 1-?, RPB2). Aspergillus Sect. Nigri was dominant and the strains were identified as A. tubingensis (138), A. awamori (38), A. carbonarius (27), A. uvarum (16) and A. niger (11). Four Aspergillus flavus strains were also identified from Chilean raisins. Two clusters closely related to the A. tubingensis species with a significant bootstrap (60% and 99%) were identified as distinct populations. Among the four loci, RPB2 showed the highest genetic variability. This is the first complete study on the worldwide distribution of black Aspergilli occurring on dried vine fruits identified by a molecular approach. PMID:23732831

Susca, Antonia; Perrone, Giancarlo; Cozzi, Giuseppe; Stea, Gaetano; Logrieco, Antonio F; Mulč, Giuseppina

2013-07-15

285

Osteomyelitis caused by Aspergillus species: a review of 310 reported cases.  

PubMed

Aspergillus osteomyelitis is a rare infection. We reviewed 310 individual cases reported in the literature from 1936 to 2013. The median age of patients was 43 years (range, 0-86 years), and 59% were males. Comorbidities associated with this infection included chronic granulomatous disease (19%), haematological malignancies (11%), transplantation (11%), diabetes (6%), pulmonary disease (4%), steroid therapy (4%), and human immunodeficiency virus infection (4%). Sites of infection included the spine (49%), base of the skull, paranasal sinuses and jaw (18%), ribs (9%), long bones (9%), sternum (5%), and chest wall (4%). The most common infecting species were Aspergillus fumigatus (55%), Aspergillus flavus (12%), and Aspergillus nidulans (7%). Sixty-two per cent of the individual cases were treated with a combination of an antifungal regimen and surgery. Amphotericin B was the antifungal drug most commonly used, followed by itraconazole and voriconazole. Several combination or sequential therapies were also used experimentally. The overall crude mortality rate was 25%. PMID:24303995

Gabrielli, E; Fothergill, A W; Brescini, L; Sutton, D A; Marchionni, E; Orsetti, E; Staffolani, S; Castelli, P; Gesuita, R; Barchiesi, F

2014-06-01

286

Non-Aflatoxigenic 'Aspergillus parasiticus' Species and Their Use in Controlling Aflatoxin Contamination.  

National Technical Information Service (NTIS)

A process for biologically controlling the preharvest accumulation of aflatoxin in soil-borne crops is taught. Non-aflatoxigenic strains of Aspergillus parasiticus having the relevant identifying characteristics of NRRL 18786 and NRRL 13539 are shown to i...

R. J. Cole J. W. Dorner P. D. Blankenship

1991-01-01

287

Antifungal therapy of aspergillosis of the central nervous system and aspergillus endophthalmitis.  

PubMed

Cerebral Aspergillosis is the most lethal manifestation of infection due to Aspergillus species arising most commonly as hematogenous dissemination from a pulmonary focus, direct extension from paranasal sinus infection or direct inoculation through trauma and surgery of the central nervous system (CNS). Voriconazole is currently considered the standard of treatment of CNS aspergillosis with liposomal amphotericin B being the next best alternative. Neurosurgical resection of infected cerebral tissue in addition to antifungal therapy is frequently performed in patients with CNS aspergillosis to prevent neurological deficits and improve outcome. Aspergillus endophthalmitis may occur endogenously mostly from a pulmonary focus or exogenously following eye surgery or trauma. Although amphotericin B is still described as the primary therapy, voriconazole is increasingly considered the first line treatment of Aspergillus endophthalmitis. Vitrectomy is recommended in most cases of Aspergillus endophthalmitis. PMID:23278539

Hoenigl, Martin; Krause, Robert

2013-01-01

288

Antifungal activity of micafungin against Candida and Aspergillus spp. isolated from pediatric patients in Japan.  

PubMed

The in vitro antifungal activities of micafungin in comparison to caspofungin, fluconazole, itraconazole, voriconazole, and amphotericin B were evaluated against 93 Candida and 23 Aspergillus isolates recovered from pediatric patients with fungal infections. MICs were determined by the CLSI M27-A2 and M38-A for Candida and Aspergillus species, respectively. Micafungin showed potent activity against Candida albicans, Candida tropicalis, and Candida glabrata with a MIC range of <= 0.002 to 0.015mug/ml. In contrast, micafungin demonstrated higher MIC levels against Candida parapsilosis with a MIC range of 0.12 to 2 mug/ml. Micafungin showed potent antifungal activity against Aspergillus species tested with a MIC range of 0.004 to 0.015 mug/ml. Overall, micafungin had excellent in vitro antifungal activities against Candida and Aspergillus species recovered from pediatric patients with fungal infections. PMID:18668422

Ikeda, Fumiaki; Saika, Takeshi; Sato, Yumie; Suzuki, Makoto; Hasegawa, Miyuki; Mikawa, Takashi; Kobayashi, Intetsu; Tsuji, Akiyoshi

2009-03-01

289

Immobilization of Aminoacylase from 'Aspergillus oryzae' on Functionalized Acrylamide-Methylarcrylate Copolymers.  

National Technical Information Service (NTIS)

Poly(acrylamide-methyl acrylate) beads have been synthesized by oil phase suspensions. These polymers were functionalized by amination with diamines or polyethylene polyamines in order to be applied to the immobilization of aminoacylase from Aspergillus o...

D. Wang J. Zhou M. Li B. He

1994-01-01

290

A patient with allergic bronchopulmonary mycosis caused by Aspergillus fumigatus and Candida albicans.  

PubMed

Allergic Bronchopulmonary Mycosis (ABPM) is an exagregated immunologic response to fungal colonization in the lower airways. It may cause by many kinds of fungal, but Aspergillus fumigatus is the most common cause of ABPM, although other Aspergillus and other fungal organisms, like Candida albicans, have been implicated. Aspergllus fumigatus and Candida albicans may be found as outdoor and indoor fungi, and cause the sensitization, elicitation of the disease pathology, and its clinical manifestations. Several diagnostic procedurs may be impicated to support the diagnosis of ABPM caused by Aspergillus fumigatus and Candida albicans. A case of allergic bronchopulmonary mycosis caused by Aspergillus fumigatus and Candida albicans in a 48 year old man was discussed. The patient was treated with antifungal, corticosteroids, and antibiotic for the secondary bacterial infection. The patient's condition is improved without any significant side effects. PMID:23314973

Wardhana; Datau, E A

2012-10-01

291

Fermentative Production and Thermostability Characterization of ? Amylase from Aspergillus Species and Its Application Potential Evaluation in Desizing of Cotton Cloth  

PubMed Central

The production of extracellular amylase was investigated employing our laboratory isolate, Aspergillus niger sp. MK 07 and effect of process variables on enzyme production, was studied in a fermentor. It was found that amylase production was maximum when the fermentor volume was maintained at 70%, rate of agitation at 250?rpm, air supply at 2.5?vvm, inoculum concentration of 10%, and a pH of 5.0. Highest enzyme production obtained under all optimized conditions was 1734?U/mL with sucrose as carbon substrate and corn steep liquor as nitrogen source. Enzyme purification studies by ammonium sulphate precipitation and Sephadex G-100 chromatography was evaluated for obtaining purified enzyme. Thermostability of amylase were evaluated with varying concentrations from 0.2 to 0.5?M concentrations of calcium chloride and the highest activity obtained was 3115?U/mL with 0.3?M calcium chloride at 55°C. Effect of temperature and pH on the activity of purified enzyme was evaluated and the purified enzyme showed an activity till 75°C and a pH of 6.5. Application potential of partially purified alpha amylase on desizing of cotton cloth was evaluated with varying enzyme concentrations from 50 to 500?U/mL and the highest desizing activity was found to be at 300?U/mL.

Chimata, Murali Krishna; Chetty, Chellu S.; Suresh, Challa

2011-01-01

292

Fermentative Production and Thermostability Characterization of ? Amylase from Aspergillus Species and Its Application Potential Evaluation in Desizing of Cotton Cloth.  

PubMed

The production of extracellular amylase was investigated employing our laboratory isolate, Aspergillus niger sp. MK 07 and effect of process variables on enzyme production, was studied in a fermentor. It was found that amylase production was maximum when the fermentor volume was maintained at 70%, rate of agitation at 250?rpm, air supply at 2.5?vvm, inoculum concentration of 10%, and a pH of 5.0. Highest enzyme production obtained under all optimized conditions was 1734?U/mL with sucrose as carbon substrate and corn steep liquor as nitrogen source. Enzyme purification studies by ammonium sulphate precipitation and Sephadex G-100 chromatography was evaluated for obtaining purified enzyme. Thermostability of amylase were evaluated with varying concentrations from 0.2 to 0.5?M concentrations of calcium chloride and the highest activity obtained was 3115?U/mL with 0.3?M calcium chloride at 55°C. Effect of temperature and pH on the activity of purified enzyme was evaluated and the purified enzyme showed an activity till 75°C and a pH of 6.5. Application potential of partially purified alpha amylase on desizing of cotton cloth was evaluated with varying enzyme concentrations from 50 to 500?U/mL and the highest desizing activity was found to be at 300?U/mL. PMID:21977326

Chimata, Murali Krishna; Chetty, Chellu S; Suresh, Challa

2011-01-01

293

Aspergillus fumigatus SidJ Mediates Intracellular Siderophore Hydrolysis  

PubMed Central

Siderophore-mediated iron handling is crucial for the virulence of Aspergillus fumigatus. Here we identified a new component of its siderophore metabolism, termed SidJ, which is encoded by AFUA_3G03390. The encoding gene is localized in a siderophore biosynthetic gene cluster that is conserved in a variety of fungi. During iron starvation, SidJ deficiency resulted in decreased growth and increased intracellular accumulation of hydrolysis products of the siderophore fusarinine C. The implied role in siderophore hydrolysis is consistent with a putative esterase domain in SidJ, which now represents the first functionally characterized member of the DUF1749 (domain of unknown function) protein family, with members found exclusively in fungi and plants.

Grundlinger, Mario; Gsaller, Fabio; Schrettl, Markus; Lindner, Herbert

2013-01-01

294

Purification and Characterization of Acid Phosphatase V from Aspergillus nidulans  

PubMed Central

Acid phosphatase V of Aspergillus nidulans was purified by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography. The enzyme demonstrated a charge microheterogeneity on starch and acrylamide gel electrophoresis, but proved to be homogeneous on ultracentrifugation and gel filtration. Phosphatase V was found to be a classic acid orthophosphoric monoester phosphohydrolase, and it cleaved p-nitrophenylphosphate, glucose-6-phosphate, and uridine-5?-monophosphate at maximal rates. It was inhibited by fluoride, borate, and molybdate ions, and demonstrated end-product inhibition by inorganic phosphate. Metallic ions or cofactors were not required for activity. The molecular weight was estimated to be 100,000, the S20,w was calculated to be 4.1, and the pH optimum was found to be 6.1. Images

Harsanyi, Zsolt; Dorn, Gordon L.

1972-01-01

295

Origin of monacolin L from Aspergillus terreus cultures.  

PubMed

In freshly harvested Aspergillus terreus cultures grown for the production of lovastatin (formerly called mevinolin), no monacolin L could be detected. However, during the isolation of lovastatin, significant quantities of monacolin L appeared. It has been discovered that a new metabolite structurally related to the members of the monacolin series is present. This metabolite is unstable and under mildly acidic conditions and elevated temperature, it converts to monacolin L. The subject metabolite is proven to be a hydroxylated derivative of dihydromonacolin L identified as 3 alpha-hydroxy-3,5-dihydromonacolin L. It seems that all monacolin L found later during various treatments of the broth and broth extracts is formed from that precursor via a dehydration reaction. The new metabolite was converted to its phenacyl ester, by means of extractive alkylation, for isolation and structure elucidation by chemical, chromatographic and spectroscopic methods. This ester, on standing, gradually formed the corresponding lactone. PMID:2921224

Treiber, L R; Reamer, R A; Rooney, C S; Ramjit, H G

1989-01-01

296

Nanosulfur: A Potent Fungicide Against Food Pathogen, Aspergillus niger  

SciTech Connect

Elemental sulfur (S{sup 0}), man's oldest eco-friendly fungicide for curing fungal infections in plants and animals, is registered in India as a non-systemic and contact fungicide. However due to its high volume requirement, Indian agrochemical industry and farmers could not effectively use this product till date. We hypothesize that intelligent nanoscience applications might increase the visibility of nanosulfur in Indian agriculture as a potent and eco-safe fungicide. Sulfur nanoparticles (NPs) were synthesized bottom-up via a liquid synthesis method with average particle size in the range of 50-80 nm and the shapes of the NPs were spherical. A comparative study of elemental and nano-sulfur produced has been tested against facultative fungal food pathogen, Aspergillus niger. Results showed that nanosulfur is more efficacious than its elemental form.

Choudhury, Samrat Roy; Goswami, Arunava [Agricultural and Ecological Research Unit, Biological Sciences Division, Indian Statistical Institute, 203 B. T. Road, Kolkata, West Bengal-700108 (India); Nair, Kishore K.; Kumar, Rajesh; Gopal, Madhuban; Devakumar, C. [Department of Agricultural Chemicals, Pusa Campus, New Delhi (India); Gogoi, Robin [Plant Pathology, Pusa Campus, New Delhi (India); Srivastava, Chitra; Subhramanyam, B. S. [Entomology, Indian Agricultural Research Institute, Pusa Campus, New Delhi (India)

2010-10-04

297

Aspergillus nidulans Pmts form heterodimers in all pairwise combinations.  

PubMed

Eukaryotic protein O-mannosyltransferases (Pmts) are divided into three subfamilies (Pmt1, Pmt2, and Pmt4) and activity of Pmts in yeasts and animals requires assembly into complexes. In Saccharomyces cerevisiae, Pmt1 and Pmt2 form a heteromeric complex and Pmt 4 forms a homomeric complex. The filamentous fungus Aspergillus nidulans has three Pmts: PmtA (subfamily 2), PmtB (subfamily 1), and PmtC (subfamily 4). In this study we show that A. nidulans Pmts form heteromeric complexes in all possible pairwise combinations and that PmtC forms homomeric complexes. We also show that MsbA, an ortholog of a Pmt4-modified protein, is not modified by PmtC. PMID:24936400

Kriangkripipat, Thanyanuch; Momany, Michelle

2014-01-01

298

Aspergillus nidulans Pmts form heterodimers in all pairwise combinations  

PubMed Central

Eukaryotic protein O-mannosyltransferases (Pmts) are divided into three subfamilies (Pmt1, Pmt2, and Pmt4) and activity of Pmts in yeasts and animals requires assembly into complexes. In Saccharomyces cerevisiae, Pmt1 and Pmt2 form a heteromeric complex and Pmt 4 forms a homomeric complex. The filamentous fungus Aspergillus nidulans has three Pmts: PmtA (subfamily 2), PmtB (subfamily 1), and PmtC (subfamily 4). In this study we show that A. nidulans Pmts form heteromeric complexes in all possible pairwise combinations and that PmtC forms homomeric complexes. We also show that MsbA, an ortholog of a Pmt4-modified protein, is not modified by PmtC.

Kriangkripipat, Thanyanuch; Momany, Michelle

2014-01-01

299

Purification and characterization of acid phosphatase V from Aspergillus nidulans.  

PubMed

Acid phosphatase V of Aspergillus nidulans was purified by ammonium sulfate precipitation, gel filtration, and ion-exchange chromatography. The enzyme demonstrated a charge microheterogeneity on starch and acrylamide gel electrophoresis, but proved to be homogeneous on ultracentrifugation and gel filtration. Phosphatase V was found to be a classic acid orthophosphoric monoester phosphohydrolase, and it cleaved p-nitrophenylphosphate, glucose-6-phosphate, and uridine-5'-monophosphate at maximal rates. It was inhibited by fluoride, borate, and molybdate ions, and demonstrated end-product inhibition by inorganic phosphate. Metallic ions or cofactors were not required for activity. The molecular weight was estimated to be 100,000, the S(20,w) was calculated to be 4.1, and the pH optimum was found to be 6.1. PMID:4552990

Harsanyi, Z; Dorn, G L

1972-04-01

300

Proteolysis by toxigenic Aspergillus nidulans from Nigerian palm produce.  

PubMed

The submerged cultures of Aspergillus nidulans had optimal growth and protease production at 37 degrees C and within 6 days of incubation. A rapid drop in pH of the growth medium from 6.9 to 4.8 and a subsequent gradual rise was recorded with the period of incubation. The acid-protease produced was purified by a combination of ethanolic precipitation, ultrafiltration and fractionation on DEAE-cellulose and Sephadex G-200. A single peak showing protease activity was subsequently obtained with a 16-fold increase in specific activity and a recovery value of 36%. The purified enzyme had optimal activity on casein and gelatin at pH 5.4 and a temperature of 40 degrees C. PMID:3302717

Ogundero, V W

1987-01-01

301

Secondary Metabolites from an Algicolous Aspergillus versicolor Strain  

PubMed Central

Two new compounds, asperversin A (1) and 9?-O-2(2,3-dimethylbut-3-enyl)brevianamide Q (2), and nine known compounds, brevianamide K (3), brevianamide M (4), aversin (5), 6,8-di-O-methylnidurufin (6), 6,8-di-O-methylaverufin (7), 6-O-methylaverufin (8), 5?,8?-epidioxyergosta-6,22-dien-3?-ol (9), ergosta-7,22-diene-3?,5?,6?-triol (10), and 6?-methoxyergosta-7,22-diene-3?,5?-diol (11), were obtained from the culture of Aspergillus versicolor, an endophytic fungus isolated from the marine brown alga Sargassum thunbergii. The structures of these compounds were established by spectroscopic techniques. Compounds 4, 7 and 8 exhibited antibacterial activities against Escherichia coli and Staphyloccocus aureus, and 7 also showed lethality against brine shrimp (Artemia salina) with an LC50 value of 0.5 ?g/mL.

Miao, Feng-Ping; Li, Xiao-Dong; Liu, Xiang-Hong; Cichewicz, Robert H.; Ji, Nai-Yun

2012-01-01

302

Optimization of triacetylfusarinine C and ferricrocin productions in Aspergillus fumigatus.  

PubMed

Iron is an essential element for all microorganisms. Bacteria and fungi produce versatile siderophores for binding and storing this essential transition metal when its availability is limited in the environment. The aim of the study was to optimize the fermentation medium of Aspergillus fumigatus for siderophore production. Triacetyl-fusarinine C and ferricrocin yields were dependent on glucose and glycine supplementations as well as the initial pH of the culture media. The optimal fermentation medium for triacetylfusarinine C production contained 8% glucose, 0.4% glycine and the initial pH was set to 5.9. Meanwhile, maximal ferricrocin yields were recorded in the presence of 10% glucose, 0.5% glycine and at an initial pH of 7.4. Under optimized fermentation conditions, the yields for triacetylfusarinine C and ferricrocin increased up to 2.9 g/l culture medium and 18.9 mg/g mycelium, respectively. PMID:24939680

Szigeti, Zsuzsa M; Szaniszló, Szilvia; Fazekas, Erika; Gyémánt, Gyöngyi; Szabon, Judit; Antal, Károly; Emri, Tamás; Balla, József; Balla, György; Csernoch, László; Pócsi, István

2014-06-01

303

Cloning and characterization of two flavohemoglobins from Aspergillus oryzae  

SciTech Connect

Two flavohemoglobin (FHb) genes, fhb1 and fhb2, were cloned from Aspergillus oryzae. The amino acid sequences of the deduced FHb1 and FHb2 showed high identity to other FHbs except for the predicted mitochondrial targeting signal in the N-terminus of FHb2. The recombinant proteins displayed absorption spectra similar to those of other FHbs. FHb1 and FHb2 were estimated to be a monomer and a dimer in solution, respectively. Both of the isozymes exhibit high NO dioxygenase (NOD) activity. FHb1 utilizes either NADH or NADPH as an electron donor, whereas FHb2 can only use NADH. These results suggest that FHb1 and FHb2 are fungal counterparts of bacterial FHbs and act as NO detoxification enzymes in the cytosol and mitochondria, respectively. This study is the first to show that a microorganism contains two isozymes of FHb and that intracellular localization of the isozymes could differ.

Zhou Shengmin; Fushinobu, Shinya; Nakanishi, Yoshito; Kim, Sang-Wan; Wakagi, Takayoshi [Department of Biotechnology, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan); Shoun, Hirofumi [Department of Biotechnology, Graduate School of Agricultural and Life Sciences, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657 (Japan)], E-mail: ahshoun@mail.ecc.u-tokyo.ac.jp

2009-03-27

304

Utility of Aspergillus niger citrate synthase promoter for heterologous expression.  

PubMed

Citrate synthase is a central player in the acidogenic metabolism of Aspergillus niger. The 5' upstream sequence (0.9kb DNA) of citrate synthase gene (citA) from A. niger NCIM 565 was analyzed and its promoter function demonstrated through the heterologous expression of two proteins. The cloned citrate synthase promoter (PcitA) sequence was able to express bar coding sequence thereby conferring phosphinothricin resistance. This sequence was further analyzed by systematic deletions to define an effective but compact functional promoter. The PcitA driven egfp expression showed that PcitA was active in all differentiation cell-stages of A. niger. EGFP expression was highest on non-repressible carbon sources like acetate and glycerol. Mycelial EGFP levels increased during acidogenic growth suggesting that PcitA is functional throughout this cultivation. A. niger PcitA is the first Krebs cycle gene promoter used to express heterologous proteins in filamentous fungi. PMID:21723343

Dave, Kashyap; Punekar, Narayan S

2011-09-10

305

A novel selectable marker based on Aspergillus niger arginase expression.  

PubMed

Selectable markers are valuable tools in transforming asexual fungi like Aspergillus niger. An arginase (agaA) expression vector and a suitable arginase-disrupted host would define a novel nutritional marker/selection for transformation. The development of such a marker was successfully achieved in two steps. The single genomic copy of A. niger arginase gene was disrupted by homologous integration of the bar marker. The agaA disruptant was subsequently complemented by transforming it with agaA expression vectors. Both citA and trpC promoters were able to drive the expression of arginase cDNA. Such agaA+ transformants displayed arginase expression pattern distinct from that of the parent strain. The results are also consistent with a single catabolic route for arginine in this fungus. A simple yet novel arginine-based selection for filamentous fungal transformation is thus described. PMID:22579391

Dave, Kashyap; Ahuja, Manmeet; Jayashri, T N; Sirola, Rekha Bisht; Punekar, Narayan S

2012-06-10

306

Targeted Lipid Analysis of Haemolytic Mycelial Extracts of Aspergillus niger.  

PubMed

Ethanolic extracts of mycelia from Aspergillus niger (strain N402) grown in liquid media were observed to have haemolytic activity on bovine erythrocytes. This haemolytic activity decreased significantly during the time of growth (1-3 days). Moreover, when A. niger was grown on carbon-deprived medium, the efficiency of this haemolytic activity in the ethanolic extracts was much lower than when grown in carbon-enriched medium, and became almost undetectable after 3 days of growth in carbon-deprived medium. The lipid composition of these ethanolic extracts was analysed by liquid chromatography-electrospray ionisation tandem mass spectrometry. This haemolytic activity can be mainly linked to the relative levels of the molar ratios of the unsaturated fatty acids and lysophosphatidylcholines. PMID:24983857

Novak, Maruša; Sep?i?, Kristina; Kraševec, Nada; Križaj, Igor; Ma?ek, Peter; Anderluh, Gregor; Guella, Graziano; Mancini, Ines

2014-01-01

307

Tandem shock waves to enhance genetic transformation of Aspergillus niger.  

PubMed

Filamentous fungi are used in several industries and in academia to produce antibiotics, metabolites, proteins and pharmaceutical compounds. The development of valuable strains usually requires the insertion of recombinant deoxyribonucleic acid; however, the protocols to transfer DNA to fungal cells are highly inefficient. Recently, underwater shock waves were successfully used to genetically transform filamentous fungi. The purpose of this research was to demonstrate that the efficiency of transformation can be improved significantly by enhancing acoustic cavitation using tandem (dual-pulse) shock waves. Results revealed that tandem pressure pulses, generated at a delay of 300?s, increased the transformation efficiency of Aspergillus niger up to 84% in comparison with conventional (single-pulse) shock waves. This methodology may also be useful to obtain new strains required in basic research and biotechnology. PMID:24680880

Loske, Achim M; Fernández, Francisco; Magańa-Ortíz, Denis; Coconi-Linares, Nancy; Ortíz-Vázquez, Elizabeth; Gómez-Lim, Miguel A

2014-08-01

308

Genetic diversity among clinical and environmental isolates of Aspergillus fumigatus.  

PubMed Central

To determine if cases of invasive aspergillosis (IA) were caused by strains of Aspergillus fumigatus with unique characteristics, strains from immunosuppressed patients with IA were compared to strains obtained from sputa of patients with cystic fibrosis and to strains from the environment. An extremely high genomic diversity was observed among the 879 strains typed by Southern blotting with a retrotransposon-like element from A. fumigatus (C. Neuvéglise, J. Sarfati, J. P. Latgé, and S. Paris, Nucleic Acids Res. 24:1428-1434, 1996). Analysis of Southern blot hybridization patterns showed the absence of clustering between environmental isolates and clinical isolates from patients with IA or cystic fibrosis. In addition, strains could not be clustered depending on their geographical location. This study implies that practically any strain of A. fumigatus is potentially pathogenic and can provoke a case of IA when it encounters a favorable environment in an immunosuppressed host.

Debeaupuis, J P; Sarfati, J; Chazalet, V; Latge, J P

1997-01-01

309

Impact of Aspergillus fumigatus in allergic airway diseases  

PubMed Central

For decades, fungi have been recognized as associated with asthma and other reactive airway diseases. In contrast to type I-mediated allergies caused by pollen, fungi cause a large number of allergic diseases such as allergic bronchopulmonary mycoses, rhinitis, allergic sinusitis and hypersensitivity pneumonitis. Amongst the fungi, Aspergillus fumigatus is the most prevalent cause of severe pulmonary allergic disease, including allergic bronchopulmonary aspergillosis (ABPA), known to be associated with chronic lung injury and deterioration in pulmonary function in people with chronic asthma and cystic fibrosis (CF). The goal of this review is to discuss new understandings of host-pathogen interactions in the genesis of allergic airway diseases caused by A. fumigatus. Host and pathogen related factors that participate in triggering the inflammatory cycle leading to pulmonary exacerbations in ABPA are discussed.

2011-01-01

310

Lovastatin Biosynthesis by Aspergillus terreus in a Chemically Defined Medium  

PubMed Central

Lovastatin is a secondary metabolite produced by Aspergillus terreus. A chemically defined medium was developed in order to investigate the influence of carbon and nitrogen sources on lovastatin biosynthesis. Among several organic and inorganic defined nitrogen sources metabolized by A. terreus, glutamate and histidine gave the highest lovastatin biosynthesis level. For cultures on glucose and glutamate, lovastatin synthesis initiated when glucose consumption levelled off. When A. terreus was grown on lactose, lovastatin production initiated in the presence of residual lactose. Experimental results showed that carbon source starvation is required in addition to relief of glucose repression, while glutamate did not repress biosynthesis. A threefold-higher specific productivity was found with the defined medium on glucose and glutamate, compared to growth on complex medium with glucose, peptonized milk, and yeast extract.

Hajjaj, Hassan; Niederberger, Peter; Duboc, Philippe

2001-01-01

311

Aspergillus Niger Genomics: Past, Present and into the Future  

SciTech Connect

Aspergillus niger is a filamentous ascomycete fungus that is ubiquitous in the environment and has been implicated in opportunistic infections of humans. In addition to its role as an opportunistic human pathogen, A. niger is economically important as a fermentation organism used for the production of citric acid. Industrial citric acid production by A. niger represents one of the most efficient, highest yield bioprocesses in use currently by industry. The genome size of A. niger is estimated to be between 35.5 and 38.5 megabases (Mb) divided among eight chromosomes/linkage groups that vary in size from 3.5 - 6.6 Mb. Currently, there are three independent A. niger genome projects, an indication of the economic importance of this organism. The rich amount of data resulting from these multiple A. niger genome sequences will be used for basic and applied research programs applicable to fermentation process development, morphology and pathogenicity.

Baker, Scott E.

2006-09-01

312

Secretion of calf chymosin from the filamentous fungus Aspergillus oryzae.  

PubMed

Active calf chymosin was secreted from Aspergillus oryzae transformants when the chymosin cDNA was expressed under the control of glucoamylase gene (glaA) promoter. Secreted prochymosin was autocatalytically activated to the chymosin (0.07-0.16 mg/l). Western blot analysis showed that a secreted protein immunoreactive with an anti-chymosin antibody was of similar size to authentic chymosin. Northern blot analysis revealed that mRNA of the chymosin cDNA was expressed at as high level as that of the glaA gene. The size and the level of the transcript were different among transformants, due to the integration position of the plasmid on the chromosome. PMID:7764387

Tsuchiya, K; Gomi, K; Kitamoto, K; Kumagai, C; Tamura, G

1993-11-01

313

Characterization of a neutral ceramidase orthologue from Aspergillus oryzae.  

PubMed

Ceramide is an important molecule not only structurally but also regulationally as a modulator of various cellular events. Ceramidase (CDase) are classified into three different types (acid, alkaline, and neutral CDases). Neutral CDase could play an important role in the regulation of ceramide levels in the extracellular space. In this study, we describe the characterization of a neutral CDase orthologue from the filamentous fungus Aspergillus oryzae. The gene encoding the neutral CDase orthologue was cloned and overexpressed in A. oryzae. The purified recombinant enzyme was optimally active at pH 4.0-4.5 and 40 degrees C. The apparent K(m) and V(max) values of the enzyme for C12-NBD-ceramide were 3.32 microM and 0.085 micromol min(-1) mg(-1), respectively. PMID:19650849

Tada, Sawaki; Matsushita-Morita, Mayumi; Suzuki, Satoshi; Kusumoto, Ken-Ichi; Kashiwagi, Yutaka

2009-09-01

314

Some properties of the protease from Aspergillus terricola.  

PubMed

The protease from Aspergillus terricola (terrilytin) was isolated and purified by the ion exchange method and by gel chromatography. The data on its molecular weight, isoelectric point, N-terminal amino acids were described. The protease included polysaccharide which stabilized the enzyme activity under the storage and lyophylization. Polysaccharides isolated from different fungi and yeasts were found to stabilize and activate terrilytin rising the affinity of enzyme to substrate. Terrilytin was revealed to exhibit the thrombolytic effect and expressive affinity to the fibrin in comparison with other substrates of high and low molecular weight. The enzyme showed the antigenic activity. From immune rabbit sera 7S gamma-globulins inhibiting proteolysis of caseine and 19S gamma-globulins activating the proteolysis of fibrin and fibrinogen by terrilytin were isolated by gel chromatography. PMID:1207716

Zaikina, N A; Shataeva, L K; Elinov, N P; Samsonov, G V

1975-11-21

315

Antimicrobial textile treated with chitosan from Aspergillus niger mycelial waste.  

PubMed

The waste biomass of Aspergillus niger, following citric acid production, was used as a source for fungal chitosan extraction. The produced chitosan was characterized with deacetylation degree of 89.6%, a molecular weight of 25,000 dalton, 97% solubility in 1% acetic acid solution and comparable FT-IR spectra to standard shrimp chitosan. Fungal chitosan was applied as a cotton fabric finishing agent using pad-dry-cure method. The topographical structure of chitosan-treated fabrics (CTF) was much improved compared with control fabrics. CTF, after durability tests, exhibited a powerful antimicrobial activity against both E. coli and Candida albicans, the captured micrographs for E. coli cells contacted with CTF showed a complete lysis of cell walls with the prolonging contact time. The produced antimicrobial CTF could be proposed as a suitable material for many medical and hygienic applications. PMID:21596059

Tayel, Ahmed A; Moussa, Shaaban H; El-Tras, Wael F; Elguindy, Nihal M; Opwis, Klaus

2011-08-01

316

Potential of Aspergillus flavus genomics for applications in biotechnology.  

PubMed

Aspergillus flavus is a common saprophyte and opportunistic pathogen that produces numerous secondary metabolites. The primary objectives of the A. flavus genomics program are to reduce and eliminate aflatoxin contamination in food and feed and to discover genetic factors that contribute to plant and animal pathogenicity. A. flavus expressed sequence tags (ESTs) and whole-genome sequencing have been completed. Annotation of the A. flavus genome has revealed numerous genes and gene clusters that are potentially involved in the formation of aflatoxin and other secondary metabolites, as well as in the degradation of complex carbohydrate polymers. Analysis of putative secondary metabolism pathways might facilitate the discovery of new compounds with pharmaceutical properties, as well as new enzymes for biomass degradation. PMID:19195728

Cleveland, Thomas E; Yu, Jiujiang; Fedorova, Natalie; Bhatnagar, Deepak; Payne, Gary A; Nierman, William C; Bennett, Joan W

2009-03-01

317

Structure of the catalytic domain of glucoamylase from Aspergillus niger.  

PubMed

Glucoamylase from Aspergillus niger is an industrially important biocatalyst that is utilized in the mass production of glucose from raw starch or soluble oligosaccharides. The G1 isoform consists of a catalytic domain and a starch-binding domain connected by a heavily glycosylated linker region. The amino-terminal catalytic domain of the G1 isoform generated by subtilisin cleavage has been crystallized at pH 8.5, which is a significantly higher pH condition than used for previously characterized glucoamylase crystals. The refined structure at 1.9 Ĺ resolution reveals the active site of the enzyme in complex with both Tris and glycerol molecules. The ligands display both unique and analogous interactions with the substrate-binding site when compared with previous structures of homologous enzymes bound to inhibitors. PMID:21301084

Lee, Jaeyong; Paetzel, Mark

2011-02-01

318

Predominance of Bacteriophage SP82 over Bacteriophage SP01 in Mixed Infections of Bacillus subtilis  

PubMed Central

In mixed infections with Bacillus subtilis phages SP82 and SP01, the SP82 genotype is predominant among the progeny. This predominance is determined by a specific region of the genome, the pos region, which apparently is located near genes 29 to 32 (by the SP01 numbering system). Recombination between SP82 and SP01 yields phage which have both the SP82 pos region and an SP01 mutation. This mutation then behaves in mixed infection as if it were part of an SP82 genome.

Stewart, Charles R.; Franck, Michelle

1981-01-01

319

Population structure and Aflatoxin production by Aspergillus Sect. Flavi from maize in Nigeria and Ghana.  

PubMed

Aflatoxins are highly toxic carcinogens that contaminate crops worldwide. Previous studies conducted in Nigeria and Ghana found high concentrations of aflatoxins in pre- and post-harvest maize. However, little information is available on the population structure of Aspergillus Sect. Flavi in West Africa. We determined the incidence of Aspergillus Sect. Flavi and the level of aflatoxin contamination in 91 maize samples from farms and markets in Nigeria and Ghana. Aspergillus spp. were recovered from 61/91 maize samples and aflatoxins B1 and/or B2 occurred in 36/91 samples. Three samples from the farms also contained aflatoxin G1 and/or G2. Farm samples were more highly contaminated than were samples from the market, in terms of both the percentage of the samples contaminated and the level of mycotoxin contamination. One-hundred-and-thirty-five strains representative of the 1163 strains collected were identified by using a multilocus sequence analysis of portions of the genes encoding calmodulin, ?-tubulin and actin, and evaluated for aflatoxin production. Of the 135 strains, there were 110 - Aspergillus flavus, 20 - Aspergillus tamarii, 2 - Aspergillus wentii, 2 - Aspergillus flavofurcatus, and 1 - Aspergillus parvisclerotigenus. Twenty-five of the A. flavus strains and the A. parvisclerotigenus strain were the only strains that produced aflatoxins. The higher contamination of the farm than the market samples suggests that the aflatoxin exposure of rural farmers is even higher than previously estimated based on reported contamination of market samples. The relative infrequency of the A. flavus SBG strains, producing small sclerotia and high levels of both aflatoxins (B and G), suggests that long-term chronic exposure to this mycotoxin are a much higher health risk in West Africa than is the acute toxicity due to very highly contaminated maize in east Africa. PMID:24750813

Perrone, Giancarlo; Haidukowski, Miriam; Stea, Gaetano; Epifani, Filomena; Bandyopadhyay, Ranajit; Leslie, John F; Logrieco, Antonio

2014-08-01

320

Modification of Rapid Susceptibility Assay for Antifungal Susceptibility Testing of Aspergillus fumigatus  

Microsoft Academic Search

To improve objectivity and speed of current antifungal mold susceptibility testing, the yeast Rapid Suscep- tibility Assay (RSA) was adapted for Aspergillus species. The RSA is based on glucose utilization in the presence of an antifungal drug. Aspergillus fumigatus conidia were incubated in 0.2% glucose RPMI 1640 containing 0.03 to 16 g of amphotericin B or itraconazole\\/ml. Drug-related inhibition of

Tracy J. Wetter; Kevin C. Hazen; Jim E. Cutler

321

Aflatoxins in sunflower seeds: effect of zinc in aflatoxin production by two strains of Aspergillus parasiticus.  

PubMed

Growth and aflatoxin production by Aspergillus parasiticus NRRL 2999 and Aspergillus parasiticus RC 12 were studied both in sunflower seed and a synthetic culture medium (with and without zinc enrichment). On a synthetic culture medium the strains behaved in different ways according to the zinc concentration. In sunflower seed medium the influence of zinc was not so evident. Thus the results show that the influence of zinc is not the same for different strains and substrates. PMID:3657905

Chulze, S; Fusero, S; Dalcero, A; Etcheverry, M; Varsavsky, E

1987-08-01

322

Efficient expression and secretion of Aspergillus niger RH5344 polygalacturonase in Saccharomyces cerevisiae  

Microsoft Academic Search

An Aspergillus niger endopolygalacturonase (EC 3.2.1.15) cDNA was expressed in the yeast Saccharomyces cerevisiae. Secretion of the protein into the growth medium was efficiently directed by the fungal leader sequence, and processing occurred at the same site as in Aspergillus. The expression level was significantly enhanced by using a “short” version of the yeast ADHI promoter. An additional increase in

C. Lang; A. C. Looman

1995-01-01

323

The role of the Aspergillus fumigatusareA gene in invasive pulmonary aspergillosis  

Microsoft Academic Search

The areA gene of Aspergillus nidulans is a positive-acting transcriptional factor required for the expression of genes involved in the utilization of a broad range\\u000a of nitrogen sources other than ammonium and glutamine. We have investigated the role in pathogenesis of the corresponding\\u000a gene (AfareA) of Aspergillus fumigatus, a causative agent of invasive pulmonary aspergillosis. Stable and unstable AfareA\\u000a ?

M. Hensel; H. N. Arst Jr; A. Aufauvre-Brown; D. W. Holden

1998-01-01

324

Co?production of aflatoxins and cyclopiazonic acid in isolates of Aspergillus flavus  

Microsoft Academic Search

The distribution of total aflatoxin (AFT) and cyclopiazonic acid (CPA) between conidia and mycelial matrix was studied in five isolates of Aspergillus flavus Link cultured on maize grain for 20 days at 30°C. Total aflatoxin and CPA production differed between the isolates with Aspergillus flavus F2R4FP 1–5 producing the most AFT (conidia—0.245 ?g\\/g; mycelial matrix—83 ?g\\/g) and CPA (conidia—0.091 ?g\\/g;

N. Gqaleni; J. E. Smith; J. Lacey

1996-01-01

325

Purification and characterization of a nitrilase from Aspergillus niger K10  

Microsoft Academic Search

Aspergillus niger K10 cultivated on 2-cyanopyridine produced high levels of an intracellular nitrilase, which was partially purified (18.6-fold) with a 24% yield. The N-terminal amino acid sequence of the enzyme was highly homologous with that of a putative nitrilase from Aspergillus fumigatus Af293. The enzyme was copurified with two proteins, the N-terminal amino acid sequences of which revealed high homology

Ond?ej Kaplan; Vojt?ch Vejvoda; Ond?ej Plíhal; Petr Pompach; Daniel Kavan; Pavla Bojarová; Karel Bezouška; Martina Macková; Maria Cantarella; Vladimír Jirk?; Vladimír K?en; Ludmila Martínková

2006-01-01

326

Immunosuppressive compounds exhibit particular effects on functional properties of human anti-Aspergillus Th1 cells.  

PubMed

Allogeneic hematopoietic stem cell transplant (HSCT) recipients are at high risk for invasive aspergillosis. Whereas adoptive immunotherapy transferring donor-derived anti-Aspergillus TH1 cells has been shown to be beneficial for HSCT recipients suffering from invasive aspergillosis, little is known about the impact of commonly used immunosuppressants on the functional properties of anti-Aspergillus TH1 cells. Anti-Aspergillus TH1 cells were coincubated with different concentrations of methylprednisolone, cyclosporine (CsA), mycophenolic acid (MPA), the active component of mycophenolate mofetil, and rapamycin. Immunosuppressants were tested in concentrations reflecting common target levels in serum and in significantly lower and higher concentrations. Apoptosis of anti-Aspergillus TH1 cells, as well as proliferation and production of gamma interferon (IFN-?) and CD154 upon restimulation, was evaluated in the presence and absence of immunosuppressive compounds. All dosages of CsA, MPA, and methylprednisolone significantly decreased the number of viable anti-Aspergillus TH1 cells in the cell culture, which was due partly to an impaired proliferative capacity of the cells and partly to an increased rate of apoptosis. In addition, CsA significantly decreased the number of IFN-?-producing cells and had the highest impact of all immunosuppressants on IFN-? levels in the supernatant. CsA also significantly decreased the expression of CD154 by anti-Aspergillus TH1 cells. Variant dosages of immunosuppressants exhibit particular effects on essential functional properties of anti-Aspergillus TH1 cells. Our findings may have an important impact on the design of clinical trials evaluating the therapeutic benefit of anti-Aspergillus TH1 cells in allogeneic HSCT recipients suffering from invasive aspergillosis. PMID:24711569

Tramsen, Lars; Schmidt, Stanislaw; Roeger, Frauke; Schubert, Ralf; Salzmann-Manrique, Emilia; Latgé, Jean-Paul; Klingebiel, Thomas; Lehrnbecher, Thomas

2014-06-01

327

Method for measuring postantifungal effect in Aspergillus species.  

PubMed

An in vitro method for determination of postantifungal effect (PAFE) in molds was developed by using three isolates each of Aspergillus fumigatus, A. flavus, A. terreus, A. nidulans, and A. ustus. MICs of amphotericin B and itraconazole were determined by using National Committee for Clinical Laboratory Standards guidelines (M38-P). The inoculum was prepared in RPMI 1640 broth buffered with MOPS (morpholinepropanesulfonic acid) at pH 7.0, and conidia were exposed to amphotericin B and itraconazole at concentrations of 4, 1, and 0.25 times the MIC, each for 4, 2, and 1 h at 37 degrees C. The same procedure was followed for controls with drug-free medium. Following exposure, the conidia were washed three times in saline and the numbers of CFU per milliliter were determined. Exposed and control conidia were then inoculated into microtitration plates and incubated at 37 degrees C for 48 h in a spectrophotometer reader. The optical density (OD) was measured automatically at 10-min intervals, resulting in growth curves. PAFE was quantified by comparing three arbitrary points in the control growth curve, the first increase of OD and the points when 20 and 50% of the maximal growth were reached, with the growth curve of drug-exposed conidia. Amphotericin B induced PAFE in A. fumigatus at four times the MIC after 2 and 4 h of exposure ranging from 1.83 to 6.00 h and 9.33 to 10.80 h, respectively. Significantly shorter PAFEs or lack of PAFE was observed for A. terreus, A. ustus, and A. nidulans. Itraconazole did not induce measurable PAFE in the Aspergillus isolates at any concentration or exposure time tested. Further studies are warranted to investigate the implications of PAFE in relation to clinical efficacy and dosing frequency. PMID:12019115

Vitale, Roxana G; Mouton, Johan W; Afeltra, Javier; Meis, Jacques F G M; Verweij, Paul E

2002-06-01

328

Method for Measuring Postantifungal Effect in Aspergillus Species  

PubMed Central

An in vitro method for determination of postantifungal effect (PAFE) in molds was developed by using three isolates each of Aspergillus fumigatus, A. flavus, A. terreus, A. nidulans, and A. ustus. MICs of amphotericin B and itraconazole were determined by using National Committee for Clinical Laboratory Standards guidelines (M38-P). The inoculum was prepared in RPMI 1640 broth buffered with MOPS (morpholinepropanesulfonic acid) at pH 7.0, and conidia were exposed to amphotericin B and itraconazole at concentrations of 4, 1, and 0.25 times the MIC, each for 4, 2, and 1 h at 37°C. The same procedure was followed for controls with drug-free medium. Following exposure, the conidia were washed three times in saline and the numbers of CFU per milliliter were determined. Exposed and control conidia were then inoculated into microtitration plates and incubated at 37°C for 48 h in a spectrophotometer reader. The optical density (OD) was measured automatically at 10-min intervals, resulting in growth curves. PAFE was quantified by comparing three arbitrary points in the control growth curve, the first increase of OD and the points when 20 and 50% of the maximal growth were reached, with the growth curve of drug-exposed conidia. Amphotericin B induced PAFE in A. fumigatus at four times the MIC after 2 and 4 h of exposure ranging from 1.83 to 6.00 h and 9.33 to 10.80 h, respectively. Significantly shorter PAFEs or lack of PAFE was observed for A. terreus, A. ustus, and A. nidulans. Itraconazole did not induce measurable PAFE in the Aspergillus isolates at any concentration or exposure time tested. Further studies are warranted to investigate the implications of PAFE in relation to clinical efficacy and dosing frequency.

Vitale, Roxana G.; Mouton, Johan W.; Afeltra, Javier; Meis, Jacques F. G. M.; Verweij, Paul E.

2002-01-01

329

Polyphasic taxonomy of Aspergillus fumigatus and related species.  

PubMed

The variability within Aspergillus fumigatus Fresenius and related species was examined using macro-, micro-morphology, growth temperature regimes and extrolite patterns. In addition, DNA analyses including partial beta-tubulin, calmodulin and actin gene sequences were used. Detailed examination of strains, considered as A. fumigatus earlier, showed that they could be divided into four groups including A. fumigatus sensu stricto, A. lentulus and two new species. The intraspecific genetic variability within A. fumigatus sensu stricto was low, the sequence differences among 23 strains of the species was at most two bases in each partial beta-tubulin and calmodulin gene. However, intraspecific morphological diversity within the species was high and delineation of the species was equivocal. Therefore, beta-tubulin and calmodulin gene sequences could be critical determinants for the delineation of the A. fumigatus sensu stricto species. A. lentulus including isolates from clinical origin, Korean soil and from a dolphin clustered into an isolated group based on beta-tubulin, calmodulin and actin gene sequences, differing from A. fumigatus by morphological characters, growth temperature and extrolite profile. A. lentulus produces the extrolites auranthine, cyclopiazonic acid, a dimeric indole of unknown structure, neosartorin, some pyripyropens, terrein and some tryptoquivalins and tryptoquivalons. Two pair of isolates (CBS 117194, 117186 and 117520, 117519) clustered into separate groups from A. fumigatus and the other Aspergillus section Fumigati species, including the teleomorph Neosartorya, are proposed as two new species. A. fumigatiaffinis spec. nov. produces the extrolites auranthine, cycloechinulin, helvolic acid, neosartorin, palitantin, pyripyropens, tryptoquivalins and tryptoquivalons, and A. novofumigatus spec. nov. produces the extrolites cycloechinuline, helvolic acid, neosartorin, palitantin and terrein. PMID:16722222

Hong, Seung-Beom; Go, Seung-Joo; Shin, Hyeon-Dong; Frisvad, Jens C; Samson, Robert A

2005-01-01

330

Current understanding of HOG-MAPK pathway in Aspergillus fumigatus.  

PubMed

Aspergillus fumigatus is an important opportunistic fungal pathogen that causes lethal systemic invasive aspergillosis. It must be able to adapt to stress in the microenvironment during host invasion and systemic spread. The high-osmolarity glycerol (HOG) mitogen-activated protein kinase (MAPK) signaling pathway is a key element that controls adaptation to environmental stress. It plays a critical role in the virulence of several fungal pathogens. In this review, we summarize the current knowledge about the functions of different components of the HOG-MAPK pathway in A. fumigatus through mutant analysis or inferences from the genome annotation, focusing on their roles in adaptation to stress, regulation of infection-related morphogenesis, and effect on virulence. We also briefly compare the functions of the HOG pathway in A. fumigatus with those in the model fungi Saccharomyces cerevisiae and Aspergillus nidulans as well as several other human and plant pathogens including Candida albicans, Cryptococcus neoformans, and Magnaporthe oryzae. The genes described in this review mainly include tcsB, fos1, skn7, sho1, pbs2, and sakA whose deletion mutants have already been established in A. fumigatus. Among them, fos1 has been considered a virulence factor in A. fumigatus, indicating that components of the HOG pathway may be suitable as targets for developing new fungicides. However, quite a few of the genes of this pathway, such as sskA (ssk1), sskB, steC, and downstream regulator genes, are not well characterized. System biology approaches may contribute to a more comprehensive understanding of HOG pathway functions with dynamic details. PMID:23161019

Ma, Dongmei; Li, Ruoyu

2013-02-01

331

Fumonisin and Ochratoxin Production in Industrial Aspergillus niger Strains  

PubMed Central

Aspergillus niger is perhaps the most important fungus used in biotechnology, and is also one of the most commonly encountered fungi contaminating foods and feedstuffs, and occurring in soil and indoor environments. Many of its industrial applications have been given GRAS status (generally regarded as safe). However, A. niger has the potential to produce two groups of potentially carcinogenic mycotoxins: fumonisins and ochratoxins. In this study all available industrial and many non-industrial strains of A. niger (180 strains) as well as 228 strains from 17 related black Aspergillus species were examined for mycotoxin production. None of the related 17 species of black Aspergilli produced fumonisins. Fumonisins (B2, B4, and B6) were detected in 81% of A. niger, and ochratoxin A in 17%, while 10% of the strains produced both mycotoxins. Among the industrial strains the same ratios were 83%, 33% and 26% respectively. Some of the most frequently used strains in industry NRRL 337, 3112 and 3122 produced both toxins and several strains used for citric acid production were among the best producers of fumonisins in pure agar culture. Most strains used for other biotechnological processes also produced fumonisins. Strains optimized through random mutagenesis usually maintained their mycotoxin production capability. Toxigenic strains were also able to produce the toxins on media suggested for citric acid production with most of the toxins found in the biomass, thereby questioning the use of the remaining biomass as animal feed. In conclusion it is recommended to use strains of A. niger with inactive or inactivated gene clusters for fumonisins and ochratoxins, or to choose isolates for biotechnological uses in related non-toxigenic species such as A. tubingensis, A. brasiliensis, A vadensis or A. acidus, which neither produce fumonisins nor ochratoxins.

Frisvad, Jens C.; Larsen, Thomas O.; Thrane, Ulf; Meijer, Martin; Varga, Janos; Samson, Robert A.; Nielsen, Kristian F.

2011-01-01

332

Properties of a purified thermostable glucoamylase from Aspergillus niveus.  

PubMed

A glucoamylase from Aspergillus niveus was produced by submerged fermentation in Khanna medium, initial pH 6.5 for 72 h, at 40 degrees C. The enzyme was purified by DEAE-Fractogel and Concanavalin A-Sepharose chromatography. The enzyme showed 11% carbohydrate content, an isoelectric point of 3.8 and a molecular mass of 77 and 76 kDa estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis or Bio-Sil-Sec-400 gel filtration, respectively. The pH optimum was 5.0-5.5, and the enzyme remained stable for at least 2 h in the pH range of 4.0-9.5. The temperature optimum was 65 degrees C and retained 100% activity after 240 min at 60 degrees C. The glucoamylase remained completely active in the presence of 10% methanol and acetone. After 120 min hydrolysis of starch, glucose was the unique product formed, confirming that the enzyme was a glucoamylase (1,4-alpha-D-glucan glucohydrolase). The K(m) was calculated as 0.32 mg ml(-1). Circular dichroism spectroscopy estimated a secondary structure content of 33% alpha-helix, 17% beta-sheet and 50% random structure, which is similar to that observed in the crystal structures of glucoamylases from other Aspergillus species. The tryptic peptide sequence analysis showed similarity with glucoamylases from A. niger, A. kawachi, A. ficcum, A. terreus, A. awamori and A. shirousami. We conclude that the reported properties, such as solvent, pH and temperature stabilities, make A. niveus glucoamylase a potentially attractive enzyme for biotechnological applications. PMID:19697071

da Silva, Tony Marcio; Maller, Alexandre; Damásio, André Ricardo de Lima; Michelin, Michele; Ward, Richard John; Hirata, Izaura Yoshico; Jorge, Joăo Atilio; Terenzi, Héctor Francisco; de Polizeli, Maria Lourdes T M

2009-12-01

333

[Expression of endopolygalacturonase A of Aspergillus oryzae in Escherichia coli].  

PubMed

Pectinases are mainly used in the food industry to clarify fruit juices and wine, improve oil extraction, remove the peel from the citrus fruit, increase the firmness of some fruits and degum fibres. The filamentous fungus Aspergillus oryzae, used for the production of traditional fermented foods, only could produce less pectinases under general conditions. So far only a few of PGs expressed in yeast or E. coli were reported but they did not show higher activity. The cDNA of mature PGA (without signal peptide) was synthesized with specific primers from total RNA of Aspergillus oryzae by RT-PCR. PGA cDNA was ligated into pET-28a( + ) expression vector, creating plasmid pET-28a( + )-pgA. The plasmid pET-28a( + )-pgA was transformed into E. coli Turner (DE3) plac I cells to express PGA heterogeneously. For improving the efficiency of PGA expression in E. coli, the conditions for expression of the PGA in E. coli were optimized. E. coli Turner (DE3) plac I cells with pET-28a( + )-pgA was first cultivated at 37 degrees, 220r/min until OD600nm reached about 0.8. Then, cultivation broth was added with 0.5 mmol/L IPTG and incubated at 15 degrees C, 170r/min for other 24 h for induced-expression of PGA. Our data showed that the activity of recombinant expressed PGA could reach to 70u/mL medium, which is 87.5-fold of the activity of PGA produced in culture of A. oryzae and superior than known recombinant expression amount of PGA reported by other researchers. PMID:17366896

Zhang, Yu-Ling; Zhao, Qing-Xin; Zhu, Hong; Sun, Jing; Han, Feng-Min; Yuan, Sheng

2007-01-01

334

Analyses of black Aspergillus species of peanut and maize for ochratoxins and fumonisins.  

PubMed

The genus Aspergillus section Nigri, or the black aspergilli, represents genetically closely related species that produce the mycotoxins, ochratoxins and the fumonisins. Fumonisin B1 (FB1) is of an added concern because it is also a virulence factor for maize. Our preliminary data indicated that black aspergilli could develop asymptomatic infections with maize and peanuts plants. Symptomless infections are potential problems, because under favorable conditions, there is a potential for accumulation of ochratoxins and the fumonisins in contaminated postharvest crops. In the present report, the ability of black aspergilli from peanuts and maize to produce ochratoxin A and FB1 on maize kernels was assessed. One hundred fifty strains from peanuts and maize were isolated from several southeastern and midwestern states. Aspergillus nigri (A. nigri var. nigri) was the dominant species (87%), while Aspergillus foetidus, Aspergillus japonicus, Aspergillus tubingensis, and Aspergillus carbonarius were infrequently isolated. None of the wild isolates produced detectable amounts of ochratoxins. However, we do report the occurrence of the fumonisins B1, B2, and B3. Of 54 field isolates, 30% (n = 16) produced FB1, 61% (n = 33) produced FB2, and 44% (n = 24) produced FB3. The amounts of fumonisins produced during the test period of 30 days suggest that these strains might be weak to moderate producers of fumonisin on maize. To our knowledge, this is a first report of FB1 and FB3 production by isolates of black aspergilli from an American cereal and legume. PMID:24780336

Palencia, Edwin R; Mitchell, Trevor R; Snook, Maurice E; Glenn, Anthony E; Gold, Scott; Hinton, Dorothy M; Riley, Ronald T; Bacon, Charles W

2014-05-01

335

Biodiversity of Aspergillus section Nigri populations in Argentinian vineyards and ochratoxin A contamination.  

PubMed

Aspergillus section Nigri are described as the main source of ochratoxin A (OTA) contamination in grapes and wine worldwide. The knowledge of the factors affecting grape contamination by species included in this section and OTA production is essential to be able to reduce their presence, not only to improve wine quality, but also to maintain their safety. Therefore, the aims of this study were to determine the incidence of Aspergillus section Nigri species harvested in different grape-growing regions from Argentina, their ability to produce OTA, to correlate with meteorological conditions and geographical coordinates with their prevalence and to evaluate the OTA natural occurrence in grapes and wines. The morphological identification showed that Aspergillus niger aggregate species were the most prevalent ones, followed by Aspergillus carbonarius and Aspergillus uniseriate. These populations were confirmed through using AFLP markers and sequencing and, Aspergillus tubingensis was separated from A. niger aggregate. Climatic factors, altitude, longitude and latitude have influenced on the distribution of species included in the section. A. carbonarius and A. niger were OTA producers but differed in their OTA producing ability. Temperature was the factor which influenced the most over the highest incidence of A. carbonarius in La Rioja and San Juan regions. The trellis system in vineyards and drip irrigation also influenced the species isolation. The OTA levels detected in grapes and wines were low, but grape variety was more important in susceptibility to fungal infection and OTA levels. PMID:24010597

Chiotta, María L; Ponsone, María L; Sosa, Débora M; Combina, Mariana; Chulze, Sofía N

2013-12-01

336

Antimycotic activity of 5'-prenylisoflavanones of the plant Geoffroea decorticans, against Aspergillus species.  

PubMed

The antifungal activity of the ethanolic extract (EE), (3R)-5,7,2',3'-tetrahydroxy-4'-methoxy-5'-prenylisoflavanone (1) and (3R)-7-2'-3'-trihydroxy-4'-methoxy-5'-prenylisoflavanone (2) isolated from Geoffroea decorticans was evaluated against four different species of Aspergillus. Their effect was compared with that displayed by synthetic products. The antifungal activity was assayed by bioautography, hyphal radial growth, hyphal extent and microdilution in liquid medium. The percentage of hyphal radial growth inhibition produced by EE varied between 18.4+/-0.1 and 39.6+/-0.2 for Aspergillus nomius VSC23 and Aspergillus nomius 13137, respectively; and the same value for 1 and 2 were between 31.2+/-0.1-60.8+/-1.5 and 28.9+/-0.7-57.2+/-0.6 for Aspergillus flavus (IEV 018) and Aspergillus nomius 13137, respectively. The values of MIC/MFC determined for EE, 1 and 2 were compared with the actions of ascorbic and sorbic acids, and clotrimazole. The sequence of antifungal potency was clotrimazole>1>2>ascorbic acid>sorbic acid>EE. Consequently, EE as well as the purified substances from Geoffroea decorticans would be used as biopesticides against Aspergillus species. The cytotoxicity was evaluated. PMID:19375811

Quiroga, Emma N; Sampietro, Diego A; Sgariglia, Melina A; Soberón, José R; Vattuone, Marta A

2009-06-01

337

Aflatoxins in sunflower seeds: influence of Alternaria alternata on aflatoxin production by Aspergillus parasiticus.  

PubMed

The aim of the present work was to determine the influence of Alternaria alternata upon aflatoxin production by Aspergillus parasiticus. A mixture of spores of both strains was inoculated in sunflower seeds at 0.90 aw and incubated for 42 days at 28 degrees C +/- 1. The cultures were observed and analyzed every 7 days to determine the infection level of the seeds and the production of aflatoxins. Results showed that when the seeds were inoculated only with Aspergillus parasiticus, 100% were infected from the 7th day. When Aspergillus parasiticus and Alternaria alternata were simultaneously inoculated the infection level of the seeds was 100% for Aspergillus parasiticus following 7 days of inoculation and 0% for Alternaria alternata. After the 14th day of inoculation there was no significant difference in the infection percentage of both strains (approximately 80% of each one). As far as toxin production is concerned a remarkable decrease was observed when seeds were inoculated with both strains simultaneously. In accordance to the results, Alternaria alternata would not compete with Aspergillus parasiticus in colonization of seeds but would either degrade the aflatoxins by Aspergillus parasiticus or compete for aflatoxin biosynthesis precursors. Alternaria alternata could also secrete some substance that specifically inhibits aflatoxin synthesis. PMID:2615799

Dalcero, A; Chulze, S; Etcheverry, M; Farnochi, C; Varsavsky, E

1989-10-01

338

Antigens of aspergillus fumigatus. 1. Purification of a cytoplasmic antigen reactive with sera of patients with aspergillus-related disease.  

PubMed Central

An antigen has been purified from the mycelial cell sap of Aspergillus fumigatus (strain 507). The same component appears to be present in the extracellular phase (culture filtrate) in a partially degraded form. The cell sap protein has a structure composed of four polypeptides of 45,000 daltons linked through disulphide bonds. The isoelectric point (5.2-5.6) and carbohydrate content (12.5% neutral hexose) indicate that this protein is an acidic glycoprotein. It shows reactions with 75% of sera from patients with aspergilloma and allergic bronchopulmonary aspergillosis and is not reactive with sera from normal individuals of patients with other fungal diseases. It also appears to be a component of other A. fumigatus strains. Images Fig. 1 Fig. 4 Fig. 5

Calvanico, N J; Du Pont, B L; Huang, C J; Patterson, R; Fink, J N; Kurup, V P

1981-01-01

339

Bipolamides A and B, triene amides isolated from the endophytic fungus Bipolaris sp. MU34.  

PubMed

As a result of the continued screening for new metabolites produced by endophytic fungi from Thai medicinal plants, two new triene fatty acid amides, bipolamides A (1) and B (2), were discovered from the endophytic fungus Bipolaris sp. MU34. The structures of all of the isolated compounds were elucidated on the basis of the spectroscopic data of NMR and MS. An antimicrobial assay revealed that bipolamide B (2) had moderate antifungal activity against Cladosporium cladosporioides FERMS-9, Cladosporium cucumerinum NBRC 6370, Saccharomyces cerevisiae ATCC 9804, Aspergillus niger ATCC 6275 and Rhisopus oryzae ATCC 10404, with Minimum inhibitory concentration (MIC) values of 16, 32, 32, 64 and 64??g?ml(-1), respectively. PMID:24192556

Siriwach, Ratklao; Kinoshita, Hiroshi; Kitani, Shigeru; Igarashi, Yasuhiro; Pansuksan, Kanokthip; Panbangred, Watanalai; Nihira, Takuya

2014-02-01

340

G?-like CpcB plays a crucial role for growth and development of Aspergillus nidulans and Aspergillus fumigatus.  

PubMed

Growth, development, virulence and secondary metabolism in fungi are governed by heterotrimeric G proteins (G proteins). A G?-like protein called Gib2 has been shown to function as an atypical G? in Gpa1-cAMP signaling in Cryptococcus neoformans. We found that the previously reported CpcB (cross pathway control B) protein is the ortholog of Gib2 in Aspergillus nidulans and Aspergillus fumigatus. In this report, we further characterize the roles of CpcB in governing growth, development and toxigenesis in the two aspergilli. The deletion of cpcB results in severely impaired cellular growth, delayed spore germination, and defective asexual sporulation (conidiation) in both aspergilli. Moreover, CpcB is necessary for proper expression of the key developmental activator brlA during initiation and progression of conidiation in A. nidulans and A. fumigatus. Somewhat in accordance with the previous study, the absence of cpcB results in the formation of fewer, but not micro-, cleistothecia in A. nidulans in the presence of wild type veA, an essential activator of sexual development. However, the cpcB deletion mutant cleistothecia contain no ascospores, validating that CpcB is required for progression and completion of sexual fruiting including ascosporogenesis. Furthermore, unlike the canonical G?SfaD, CpcB is not needed for the biosynthesis of the mycotoxin sterigmatocystin (ST) as the cpcB null mutant produced reduced amount of ST with unaltered STC gene expression. However, in A. fumigatus, the deletion of cpcB results in the blockage of gliotoxin (GT) production. Further genetic analyses in A. nidulans indicate that CpcB may play a central role in vegetative growth, which might be independent of FadA- and GanB-mediated signaling. A speculative model summarizing the roles of CpcB in conjunction with SfaD in A. nidulans is presented. PMID:23936193

Kong, Qing; Wang, Long; Liu, Zengran; Kwon, Nak-Jung; Kim, Sun Chang; Yu, Jae-Hyuk

2013-01-01

341

Terpenoid composition and antifungal activity of three commercially important essential oils against Aspergillus flavus and Aspergillus niger.  

PubMed

Hydro-distilled essential oils extracted from three commercially important aromatic plants were analysed by capillary gas chromatography-flame ionization detector and gas chromatography/quadrupole mass spectrometry and subjected to antifungal activity. Fifteen compounds, which accounted for 97.8% of Acorus calamus root oil composition have been identified. Besides the major constituent (Z)-asarone (81.1-92.4%), (Z)-methyl isoeugenol (1.8-2.1%), (Z)-isoelemicin (1.2-1.3%), (E)-asarone (1.0-2.6%), (E)-methyl isoeugenol (0.2-0.4%), (Z)-?-ocimene (0.2-0.4%), elemicin (0.2-0.3%), linalool (0.1-0.9%) and kessane (t-0.2%) were identified. Monoterpenes constituted the main fraction of Origanum vulgare essential oil attaining 90.5% of the total oil composition. p-Cymene (10.3%) was the major component of the monoterpene hydrocarbon fraction while thymol (53.2%) and carvacrol (3.9%) were the most abundant oxygenated monoterpenes among the 33 identified constituents. Cinnamomum tamala leaf oil contained (E)-cinnamaldehyde as the principal component. Quantitative variations in (Z)-cinnamaldehyde (5.8-7.1%), linalool (6.4-8.5%) and (E)-cinnamyl acetate (4.7-5.2%) were significant. The antifungal activity of the hydro-distilled essential oils of A. calamus, O. vulgare and C. tamala were evaluated against Aspergillus flavus and Aspergillus niger. Disc diffusion method was used for the determination of the inhibitory effect. O. vulgare essential oil exhibited the highest activity. Moreover, all three essential oils inhibit the growth of A. flavus and A. niger. PMID:21707253

Bisht, Deepa; Pal, Anirban; Chanotiya, C S; Mishra, Dhirendra; Pandey, K N

2011-12-01

342

Structural and functional characterization of the porcine proline-rich antifungal peptide SP-B isolated from salivary gland granules.  

PubMed

A 1905-Da cationic proline-rich peptide, named SP-B, was recently isolated by our group as the main component of salivary gland granules, and its primary sequence fully characterized by means of automated Edman sequencing and LC-MS/MS tools. In the present study SP-B is shown to possess antifungal activity when challenged with strains of Cryptococcus neoformans, Candida albicans and Aspergillus fumigatus, while only negligible antibacterial activity was detected. Furthermore, SP-B was found to be non-cytotoxic when tested on fibroblast cell lines. To obtain information regarding its structure affinity, capillary electrophoresis (CE), circular dichroism (CD) and attenuated total reflection (ATR)-FT/IR experiments were performed. CE revealed a pH dependence of the hydrodynamic radial dimensions both in aqueous and 2,2,2-trifluoroethanol solutions. CD and ATR-FT/IR measurements confirmed the structure-pH relationship, revealing a secondary structure composed of mixed proportions of polyproline-II, unordered and turn motifs, the last being more evident in the zwitterionic form of the peptide. From these findings SP-B peptide could be classified as a new member of the proline-rich antimicrobial peptide family. PMID:17883246

Cabras, T; Longhi, R; Secundo, F; Nocca, G; Conti, S; Polonelli, L; Fanali, C; Inzitari, R; Petruzzelli, R; Messana, I; Castagnola, M; Vitali, A

2008-03-01

343

Determination of Isavuconazole Susceptibility of Aspergillus and Candida Species by the EUCAST Method  

PubMed Central

Isavuconazole is a novel expanded-spectrum triazole, which has recently been approved by the FDA as an orphan drug to treat invasive aspergillosis and is currently being studied in phase III clinical trials for invasive candidiasis. The susceptibility of relatively few clinical isolates has been reported. In this study, the isavuconazole susceptibilities of 1,237 Aspergillus and 2,010 Candida geographically diverse clinical isolates were determined by EUCAST methodology at four European mycology laboratories, producing the largest multicenter data set thus far for this compound. In addition, a blinded collection of 30 cyp51A mutant Aspergillus fumigatus clinical isolates and 10 wild-type isolates was tested. From these two data sets, the following preliminary epidemiological cutoff (ECOFF) values were suggested: 2 mg/liter for Aspergillus fumigatus, Aspergillus terreus, and Aspergillus flavus; 4 mg/liter for Aspergillus niger; 0.25 mg/liter for Aspergillus nidulans; and 0.03 mg/liter for Candida albicans, Candida parapsilosis, and Candida tropicalis. Unfortunately, ECOFFs could not be determined for Candida glabrata or Candida krusei due to an unexplained interlaboratory MIC variation. For the blinded collection of A. fumigatus isolates, all MICs were ?2 mg/liter for wild-type isolates. Differential isavuconazole MICs were observed for triazole-resistant A. fumigatus isolates with different cyp51A alterations: TR34/L98H mutants had elevated isavuconazole MICs, whereas isolates with G54 and M220 alterations had MICs in the wild-type range, suggesting that the efficacy of isavuconazole may not be affected by these alterations. This study will be an aid in interpreting isavuconazole MICs for clinical care and an important step in the future process of setting official clinical breakpoints.

Howard, Susan J.; Lass-Florl, Cornelia; Cuenca-Estrella, Manuel; Gomez-Lopez, Alicia

2013-01-01

344

Determination of isavuconazole susceptibility of Aspergillus and Candida species by the EUCAST method.  

PubMed

Isavuconazole is a novel expanded-spectrum triazole, which has recently been approved by the FDA as an orphan drug to treat invasive aspergillosis and is currently being studied in phase III clinical trials for invasive candidiasis. The susceptibility of relatively few clinical isolates has been reported. In this study, the isavuconazole susceptibilities of 1,237 Aspergillus and 2,010 Candida geographically diverse clinical isolates were determined by EUCAST methodology at four European mycology laboratories, producing the largest multicenter data set thus far for this compound. In addition, a blinded collection of 30 cyp51A mutant Aspergillus fumigatus clinical isolates and 10 wild-type isolates was tested. From these two data sets, the following preliminary epidemiological cutoff (ECOFF) values were suggested: 2 mg/liter for Aspergillus fumigatus, Aspergillus terreus, and Aspergillus flavus; 4 mg/liter for Aspergillus niger; 0.25 mg/liter for Aspergillus nidulans; and 0.03 mg/liter for Candida albicans, Candida parapsilosis, and Candida tropicalis. Unfortunately, ECOFFs could not be determined for Candida glabrata or Candida krusei due to an unexplained interlaboratory MIC variation. For the blinded collection of A. fumigatus isolates, all MICs were ?2 mg/liter for wild-type isolates. Differential isavuconazole MICs were observed for triazole-resistant A. fumigatus isolates with different cyp51A alterations: TR34/L98H mutants had elevated isavuconazole MICs, whereas isolates with G54 and M220 alterations had MICs in the wild-type range, suggesting that the efficacy of isavuconazole may not be affected by these alterations. This study will be an aid in interpreting isavuconazole MICs for clinical care and an important step in the future process of setting official clinical breakpoints. PMID:23959309

Howard, Susan J; Lass-Flörl, Cornelia; Cuenca-Estrella, Manuel; Gomez-Lopez, Alicia; Arendrup, Maiken C

2013-11-01

345

Analysis of Aspergillus nidulans metabolism at the genome-scale  

PubMed Central

Background Aspergillus nidulans is a member of a diverse group of filamentous fungi, sharing many of the properties of its close relatives with significance in the fields of medicine, agriculture and industry. Furthermore, A. nidulans has been a classical model organism for studies of development biology and gene regulation, and thus it has become one of the best-characterized filamentous fungi. It was the first Aspergillus species to have its genome sequenced, and automated gene prediction tools predicted 9,451 open reading frames (ORFs) in the genome, of which less than 10% were assigned a function. Results In this work, we have manually assigned functions to 472 orphan genes in the metabolism of A. nidulans, by using a pathway-driven approach and by employing comparative genomics tools based on sequence similarity. The central metabolism of A. nidulans, as well as biosynthetic pathways of relevant secondary metabolites, was reconstructed based on detailed metabolic reconstructions available for A. niger and Saccharomyces cerevisiae, and information on the genetics, biochemistry and physiology of A. nidulans. Thereby, it was possible to identify metabolic functions without a gene associated, and to look for candidate ORFs in the genome of A. nidulans by comparing its sequence to sequences of well-characterized genes in other species encoding the function of interest. A classification system, based on defined criteria, was developed for evaluating and selecting the ORFs among the candidates, in an objective and systematic manner. The functional assignments served as a basis to develop a mathematical model, linking 666 genes (both previously and newly annotated) to metabolic roles. The model was used to simulate metabolic behavior and additionally to integrate, analyze and interpret large-scale gene expression data concerning a study on glucose repression, thereby providing a means of upgrading the information content of experimental data and getting further insight into this phenomenon in A. nidulans. Conclusion We demonstrate how pathway modeling of A. nidulans can be used as an approach to improve the functional annotation of the genome of this organism. Furthermore we show how the metabolic model establishes functional links between genes, enabling the upgrade of the information content of transcriptome data.

David, Helga; Ozcelik, Ilknur S; Hofmann, Gerald; Nielsen, Jens

2008-01-01

346

Structure-function relationships of bovine pulmonary surfactant proteins: SP-B and SP-C.  

PubMed

Pulmonary surfactant contains at least three unique proteins: SP-A, SP-B and SP-C. SP-B and SP-C from bovine surfactant are markedly hydrophobic and have molecular masses between 3 and 26 kDa. We identify surfactant proteins under nonreducing conditions on polyacrylamide gels with approximate molecular mass of 5, 14, 26 kDa (SP-5, 14, 26) when organic solvent-soluble material is eluted from a Sephadex LH-20 size exclusion column followed by separation on a high-performance reverse-phase chromatography system. These bands correspond to monomeric SP-C, oligomeric SP-C and oligomeric SP-B, respectively. Computer analysis (Eisenberg-hydrophobic moment) of sequences for these proteins suggests that SP-B contains surface-seeking amphiphilic segments. In contrast, SP-C resembles a more hydrophobic transmembrane anchoring peptide. Dispersions containing dipalmitoylphosphatidylcholine, phosphatidylglycerol, palmitic acid and multimeric SP-B and SP-C duplicate the surface activity of natural surfactant when assayed in a pulsating bubble surfactometer. We speculate that oligomers of SP-B and monomers and oligomers of SP-C may act cooperatively in affecting surfactant function. An important function of SP-B and SP-C may be to affect the ordering of surfactant lipids so that rates of transport of surfactant lipids to the hypophase surface in the alveoli are enhanced. PMID:2160285

Takahashi, A; Waring, A J; Amirkhanian, J; Fan, B; Taeusch, H W

1990-05-01

347

SP Josephson Array Voltage Standard.  

National Technical Information Service (NTIS)

The SP Josephson array voltage standard has since 1993 been used to realize the Swedish unit of DC voltage. The report describes the voltage standard and how the Josephson voltage is used to determine the voltage of primary voltage standards as Weston cel...

G. Eklund H. Pajander

1995-01-01

348

Argonne's SpEC Module  

ScienceCinema

Jason Harper, an electrical engineer in Argonne National Laboratory's EV-Smart Grid Interoperability Center, discusses his SpEC Module invention that will enable fast charging of electric vehicles in under 15 minutes. The module has been licensed to BTCPower.

Harper, Jason

2014-06-05

349

Molecular and enzymic properties of recombinant 1, 2-alpha-mannosidase from Aspergillus saitoi overexpressed in Aspergillus oryzae cells.  

PubMed Central

For the construction of an overexpression system of the intracellular 1,2-alpha-mannosidase (EC 3.2.1.113) gene (msdS) from Aspergillus saitoi (now designated Aspergillus phoenicis), the N-terminal signal sequence of the gene was replaced with that of the aspergillopepsin I (EC 3.4.23.18) gene (apnS) signal, one of the same strains as described previously. Then the fused 1, 2-alpha-mannosidase gene (f-msdS) was inserted into the NotI site between P-No8142 and T-agdA in the plasmid pNAN 8142 (9.5 kbp) and thus the Aspergillus oryzae expression plasmid pNAN-AM1 (11.2 kbp) was constructed. The fused f-msdS gene has been overexpressed in a transformant A. oryzae niaD AM1 cell. The recombinant enzyme expressed in A. oryzae cells was purified to homogeneity in two steps. The system is capable of making as much as about 320 mg of the enzyme/litre of culture. The recombinant enzyme has activity with methyl-2-O-alpha-d-mannopyranosyl alpha-D-mannopyranoside at pH 5.0, while no activity was determined with methyl-3-O-alpha-D-mannopyranosyl alpha-D-mannopyranoside or methyl-6-O-alpha-D-mannopyranosyl alpha-D-mannopyranoside. The substrate specificity of the enzyme was analysed by using pyridylaminated (PA)-oligomannose-type sugar chains, Man9-6(GlcNAc)2-PA (Man is mannose; GlcNAc is N-acetylglucosamine). The enzyme hydrolysed Man8GlcNAc2-PA (type 'M8A') fastest, and 'M6C' żManalpha1-3[Manalpha1-2Manalpha1-3(Manalpha1-6) Manalpha1-6]Manbeta1- 4GlcNAcbeta1-4GlcNAc-PAż slowest, among the PA-sugar chains. Molecular-mass values of the enzyme were determined to be 63 kDa by SDS/PAGE and 65 kDa by gel filtration on Superose 12 respectively. The pI value of the enzyme was 4.6. The N-terminal amino acid sequence of the enzyme was GSTQSRADAIKAAFSHAWDGYLQY, and sequence analysis indicated that the signal peptide from apnS gene was removed. The molar absorption coefficient, epsilon, at 280 nm was determined as 91539 M-1.cm-1. Contents of the secondary structure (alpha-helix, beta-structure and the remainder of the enzyme) by far-UV CD determination were about 55, 38 and 7% respectively. The melting temperature, Tm, of the enzyme was 71 degrees C by differential scanning calorimetry. The calorimetric enthalpy, DeltaHcal, of the enzyme was calculated as 13.3 kJ.kg of protein-1. Determination of 1 g-atom of Ca2+/mol of enzyme was performed by atomic-absorption spectrophotometry.

Ichishima, E; Taya, N; Ikeguchi, M; Chiba, Y; Nakamura, M; Kawabata, C; Inoue, T; Takahashi, K; Minetoki, T; Ozeki, K; Kumagai, C; Gomi, K; Yoshida, T; Nakajima, T

1999-01-01

350

Purification and Characterization of Extracellular Proteinases of Aspergillus oryzae  

PubMed Central

The extracellular proteinases of Aspergillus oryzae EI 212 were separated into two active fractions by (NH4)2SO4 and ethanol fractionation followed by diethyl-aminoethyl-Sephadex A-50 and hydroxyapatite chromatography. The molecular weight was estimated by gel filtration to be about 70,000 and 35,000 for proteinases I and II, respectively. Optimum pH for casein and hemoglobin hydrolysis was 6.5 at 60 C for proteinase I and 10.0 at 45 C for proteinase II, and for gelatin hydrolysis it was 6.5 at 45 C for both enzymes. The enzymes were stable over the pH range 6 to 8 at 30 C for 60 min. The enzyme activity for both the proteinases was accelerated by Cu2+ and inhibited by Fe2+, Fe3+, Hg2+, and Ag+. Halogenators (e.g., N-chlorosuccinimide) and diisopropyl fluorophosphate inhibited proteinase II. Sulfhydryl reagents such as p-chloromercuribenzoate and iodoacetate inhibited proteinase I. Sulfhydryl compounds accelerated the action of both enzymes.

Kundu, A. K.; Manna, S.

1975-01-01

351

Cloning and characterization of three Aspergillus niger promoters.  

PubMed

An Aspergillus niger (An) genomic library was constructed using the promoter-trap vector, pLX2A, which contains a hygromycin B (Hy) phosphotransferase-encoding gene (hph) for selection of DNA fragments with promoter activity. This library was transformed in Escherichia coli and 80,000 colonies were obtained, 94% of which contained inserts. Transformations of plasmid DNA from the library into An resulted in 53 Hy-resistant (HyR) colonies. Southern blot analysis of 21 transformants confirmed the integration of hph into the An genome. Using the sib selection procedure, three functional promoters, PX6, PX18 and PX21, were identified from this library. Both DNA strands of all three fragments were sequenced and their sequences showed no significant homology to those in the database. Comparison of the sequences of all known promoters from An suggested that C+T-rich stretches are probably important for promoter structures. The promoter activity was analysed further using beta-galactosidase (beta Gal) as a quantitative marker. The results suggest that while PX21 is a much stronger promoter than the known alpha-amylase promoter of A. oryzae, PX6 promotes only weak expression of beta Gal. PMID:7557461

Luo, X

1995-09-22

352

Bioleaching of spent fluid catalytic cracking catalyst using Aspergillus niger.  

PubMed

The use of the fungus Aspergillus niger for the bioleaching of heavy metals from spent catalyst was investigated, with fluid catalytic cracking (FCC) catalyst as a model. Bioleaching was examined in batch cultures with the spent catalysts at various pulp densities (1-12%). Chemical leaching was also performed using mineral acids (sulphuric and nitric acids) and organic acids (citric, oxalic and gluconic acids), as well as a mixture of organic acids at the same concentrations as that biogenically produced. It was shown that bioleaching realised higher metal extraction than chemical leaching, with A. niger mobilizing Ni (9%), Fe (23%), Al (30%), V (36%) and Sb (64%) at 1% pulp density. Extraction efficiency generally decreased with increased pulp density. Compared with abiotic controls, bioleaching gave rise to higher metal extractions than leaching using fresh medium and cell-free spent medium. pH decreased during bioleaching, but remained relatively constant in both leaching using fresh medium and cell-free spent medium, thus indicating that the fungus played a role in effecting metal extraction from the spent catalyst. PMID:15664080

Aung, Khin Moh Moh; Ting, Yen-Peng

2005-03-16

353

abaA controls phialide differentiation in Aspergillus nidulans.  

PubMed Central

Aspergillus nidulans is an ascomycetous fungus that reproduces asexually by forming multicellular conidiophores and uninucleate spores called conidia. Loss of function mutations in the abacus A (abaA) regulatory locus result in formation of aberrant conidiophores that fail to produce conidia. Wild-type conidiophores form two tiers of sterigmata. The first tier, metulae, divide to produce the second tier, phialides. Phialides are sporogenous cells that produce conidia through a specialized apical budding process. We have examined conidiophore development in an abaA- strain at the ultrastructural level. The results showed that in the mutant metulae produce supernumerary tiers of cells with metula-like, rather than phialide-like, properties. Temperature shift experiments with an abaA14ts strain demonstrated that abaA+ function induced phialide formation by the aberrant abacus cells and was continuously required for maintenance of phialide function. In the absence of abaA+ activity, metulae simply proliferated and later developmental steps never occurred. We conclude that abaA+ directs the differentiation of phialides and is continuously required for maintenance of their function.

Sewall, T C; Mims, C W; Timberlake, W E

1990-01-01

354

Identification of many crystal forms of Aspergillus nidulans dehydroquinate synthase.  

PubMed

Extensive crystallization trials of Aspergillus nidulans dehydroquinate synthase, a potential novel target for antimicrobial drugs, in complexes with different ligands have resulted in the identification of nine crystal forms. Crystals of unliganded DHQS, binary complexes with either the substrate analogue, carbaphosphonate or the cofactor NADH, as well as the ternary DHQS-carbaphosphonate-cofactor complex, were obtained. The ternary complex crystallizes from ammonium sulfate and CoCl(2) in space group P2(1)2(1)2, with unit-cell parameters a = 133.8, b = 86.6, c = 74.9 A. The binary carbaphosphonate complex crystallizes from PEG 6000 in space group P2(1)2(1)2(1), with a = 70.0, b = 64.0, c = 197.6 A, and the binary cofactor complex crystallizes from PEG 3350 and sodium potassium tartrate in space group P2(1), with a = 83.7, b = 70.4, c = 144.3 A, beta = 89.2 degrees. DHQS in the absence of ligands crystallizes in space group P2(1), with a = 41.0, b = 68.9, c = 137.7 A, beta = 94.8 degrees. Each of these crystal forms are suitable for high-resolution structure determination. Structures of a range of DHQS-ligand complexes will be of value in the structure-based design of novel antimicrobial drugs. PMID:11173489

Nichols, C E; Ren, J; Lamb, H; Haldane, F; Hawkins, A R; Stammers, D K

2001-02-01

355

Enrichment of Auxotrophic Mutants of Aspergillus flavus by Tritium Suicide  

PubMed Central

A method based on tritium suicide was developed to enrich auxotrophic mutants of Aspergillus flavus. N-methyl-N?-nitro-N-nitrosoguanidine (NG) was chosen as a mutagen, since a wide variety of mutations were induced by the action of 0.1% NG on A. flavus conidia suspended in phosphate buffer (pH 7.0). The decimal reduction time under these conditions was about 30 min, and the surviving population contained 4 to 6% auxotrophs after 1 hr of mutagenesis. This proportion was then increased by tritium suicide of wild-type cells. At a concentration of 1.3 ?m, 3H-leucine was incorporated better than 3H-proline or 3H-thymidine into the germinating conidia. With about 20 hr of incubation and a short treatment in a high-speed mixer to disentangle mycelia and conidia, a 5- to 20-fold decrease in the number of survivors resulted from the incorporated 3H-leucine (5 c/mmole) after 1 week of storage at 5 C. At a 10-fold lower concentration, the uptake of radioactivity and the subsequent suicide rate were much lower. With 3H-leucine, the proportion of auxotrophs in the surviving population rose from 5 to about 20% during 2 weeks of storage at 5 C. Mutants requiring various intermediates for protein or nucleic acid synthesis or requiring vitamins were isolated. Finally, it was noted that A. flavus shows a much higher resistance to tritium suicide than does Escherichia coli.

Donkersloot, J. A.; Mateles, R. I.

1968-01-01

356

Genotypic and phenotypic versatility of Aspergillus flavus during maize exploitation.  

PubMed

Aspergillus flavus is a cosmopolitan fungus able to respond to external stimuli and to shift both its trophic behaviour and the production of secondary metabolites, including that of the carcinogen aflatoxin (AF). To better understand the adaptability of this fungus, we examined genetic and phenotypic responses within the fungus when grown under four conditions that mimic different ecological niches ranging from saprophytic growth to parasitism. Global transcription changes were observed in both primary and secondary metabolism in response to these conditions, particularly in secondary metabolism where transcription of nearly half of the predicted secondary metabolite clusters changed in response to the trophic states of the fungus. The greatest transcriptional change was found between saprophytic and parasitic growth, which resulted in expression changes in over 800 genes in A. flavus. The fungus also responded to growth conditions, putatively by adaptive changes in conidia, resulting in differences in their ability to utilize carbon sources. We also examined tolerance of A. flavus to oxidative stress and found that growth and secondary metabolism were altered in a superoxide dismutase (sod) mutant and an alkyl-hydroperoxide reductase (ahp) mutant of A. flavus. Data presented in this study show a multifaceted response of A. flavus to its environment and suggest that oxidative stress and secondary metabolism are important in the ecology of this fungus, notably in its interaction with host plant and in relation to changes in its lifestyle (i.e. saprobic to pathogenic). PMID:23894339

Reverberi, Massimo; Punelli, Marta; Scala, Valeria; Scarpari, Marzia; Uva, Paolo; Mentzen, Wieslawa I; Dolezal, Andrea L; Woloshuk, Charles; Pinzari, Flavia; Fabbri, Anna A; Fanelli, Corrado; Payne, Gary A

2013-01-01

357

Distinct responses of human monocyte subsets to Aspergillus fumigatus conidia.  

PubMed

Aspergillus fumigatus is an environmental fungus that causes life-threatening infections in neutropenic patients. In the absence of intact innate immunity, inhaled A. fumigatus spores (conidia) germinate in the lung, forming hyphae that invade blood vessels and disseminate to other tissues. Although macrophages and neutrophils are postulated to provide defense against invasive fungal infection, animal models and human studies suggest that circulating monocytes also contribute to antifungal immunity. Although human monocyte subsets, defined as either CD14(+)CD16(-) or CD14(+)CD16(+), have been extensively characterized, their respective roles during fungal infection remain undefined. We isolated CD14(+)CD16(-) and CD14(+)CD16(+) monocytes from healthy allogeneic hematopoietic stem cell transplantation donors and compared their ability to phagocytose and inhibit A. fumigatus conidia. Both monocyte subsets efficiently phagocytose conidia, but only CD14(+)CD16(-) monocytes inhibit conidial germination yet secrete little TNF. In contrast CD14(+)CD16(+) do not inhibit conidial germination and secrete large amounts of TNF. Although CD14(+)CD16(-) and CD14(+)CD16(+) monocytes differ in their response to dormant conidia, responses are similar if conidia are already germinated at the time of monocyte uptake. Our study demonstrates that functional CD14(+)CD16(-) and CD14(+)CD16(+) monocytes can be isolated from allogeneic hematopoietic stem cell transplantation donors and that these subsets differ in their response to A. fumigatus conidia. PMID:19635902

Serbina, Natalya V; Cherny, Mathew; Shi, Chao; Bleau, Sharon A; Collins, Nancy H; Young, James W; Pamer, Eric G

2009-08-15

358

Modulation of antimicrobial metabolites production by the fungus Aspergillus parasiticus  

PubMed Central

Biosynthesis of active secondary metabolites by fungi occurs as a specific response to the different growing environments. Changes in this environment alter the chemical and biological profiles leading to metabolites diversification and consequently to novel pharmacological applications. In this work, it was studied the influence of three parameters (fermentation length, medium composition and aeration) in the biosyntheses of antimicrobial metabolites by the fungus Aspergillus parasiticus in 10 distinct fermentation periods. Metabolism modulation in two culturing media, CYA and YES was evaluated by a 22 full factorial planning (ANOVA) and on a 23 factorial planning, role of aeration, medium composition and carbohydrate concentration were also evaluated. In overall, 120 different extracts were prepared, their HPLC profiles were obtained and the antimicrobial activity against A. flavus, C. albicans, E. coli and S. aureus of all extracts was evaluated by microdilution bioassay. Yield of kojic acid, a fine chemical produced by the fungus A. parasiticus was determined in all extracts. Statistical analyses pointed thirteen conditions able to modulate the production of bioactive metabolites by A. parasiticus. Effect of carbon source in metabolites diversification was significant as shown by the changes in the HPLC profiles of the extracts. Most of the extracts presented inhibition rates higher than that of kojic acid as for the extract obtained after 6 days of fermentation in YES medium under stirring. Kojic acid was not the only metabolite responsible for the activity since some highly active extracts showed to possess low amounts of this compound, as determined by HPLC.

Bracarense, Adriana A.P.; Takahashi, Jacqueline A.

2014-01-01

359

The composition of the cell wall of Aspergillus niger  

PubMed Central

1. The cell-wall composition of Aspergillus niger has been investigated. Analysis shows the presence of six sugars, glucose, galactose, mannose, arabinose, glucosamine and galactosamine, all in the d-configuration, except that a small amount of l-galactose may be present. Sixteen common amino acids are also present. 2. The wall consists chiefly of neutral carbohydrate (73–83%) and hexosamine (9–13%), with smaller amounts of lipid (2–7%), protein (0·5–2·5%) and phosphorus (less than 0·1%). The acetyl content (3·0–3·4%) corresponds to 1·0mole/mole of hexosamine nitrogen. 3. A fractionation of the cell-wall complex was achieved, with or without a preliminary phenol extraction, by using n-sodium hydroxide. Though this caused some degradation, 30–60% of the wall could be solubilized (depending on the preparation). Analyses on several fractions suggest that fractionation procedures bring about some separation of components although not in a clear-cut fashion. 4. Cell-wall preparations were shown to yield a fraction having [?]D approx. +240° (in n-sodium hydroxide) and consisting largely of glucose. This was separated into two subfractions, one of which had [?]D+281° (in n-sodium hydroxide) and had properties resembling the polysaccharide nigeran; the other had [?]D +231° (in n-sodium hydroxide). It is suggested that nigeran is a cell-wall component.

Johnston, I. R.

1965-01-01

360

Lymphocyte sensitization to Aspergillus fumigatus in allergic bronchopulmonary aspergillosis.  

PubMed Central

Peripheral blood mononuclear cell (PBMC) proliferation induced by an extract of Aspergillus fumigatus (AF) was examined in patients with allergic bronchopulmonary aspergillosis (ABPA), all of whom had an immediate skin prick test reaction (SPT) and increased RAST binding to AF, and, for comparison, in individuals without immediate SPT reactivity or increased RAST binding to AF. The proliferative responses of PBMC from the ABPA patients were greater than those from the comparison donors. A substantial proportion of the comparison group, however, showed evidence of a specific immune response to AF, with AF-specific IgG measured by ELISA and specific lymphoproliferative responses. AF-responsive T cell lines and T cell clones were established from both ABPA patients and IgE-negative individuals. These clones, of helper/inducer (CD4+) phenotype, showed antigenic specificity and MHC restriction. The stimulating antigen was determined for four of six clones derived from a skin-prick-test-negative individual, and found to be of Mr 18 kD, possibly the major allergen, 'Ag 3'. ABPA patients showed a marked diminution of the proliferative response during disease exacerbation.

Walker, C A; Fitzharris, P; Longbottom, J L; Taylor, A J

1989-01-01

361

VelC positively controls sexual development in Aspergillus nidulans.  

PubMed

Fungal development and secondary metabolism is intimately associated via activities of the fungi-specific velvet family proteins including VeA, VosA, VelB and VelC. Among these, VelC has not been characterized in Aspergillus nidulans. In this study, we characterize the role of VelC in asexual and sexual development in A. nidulans. The velC mRNA specifically accumulates during the early phase of sexual development. The deletion of velC leads to increased number of conidia and reduced production of sexual fruiting bodies (cleistothecia). In the velC deletion mutant, mRNA levels of the brlA, abaA, wetA and vosA genes that control sequential activation of asexual sporulation increase. Overexpression of velC causes increased formation of cleistothecia. These results suggest that VelC functions as a positive regulator of sexual development. VelC is one of the five proteins that physically interact with VosA in yeast two-hybrid and GST pull down analyses. The ?velC ?vosA double mutant produced fewer cleistothecia and behaved similar to the ?vosA mutant, suggesting that VosA is epistatic to VelC in sexual development, and that VelC might mediate control of sex through interacting with VosA at specific life stages for sexual fruiting. PMID:24587098

Park, Hee-Soo; Nam, Tae-Young; Han, Kap-Hoon; Kim, Sun Chang; Yu, Jae-Hyuk

2014-01-01

362

Starch-binding domain shuffling in Aspergillus niger glucoamylase.  

PubMed

Aspergillus niger glucoamylase (GA) consists mainly of two forms, GAI [from the N-terminus, catalytic domain + linker + starch-binding domain (SBD)] and GAII (catalytic domain + linker). These domains were shuffled to make RGAI (SBD + linker + catalytic domain), RGAIDeltaL (SBD + catalytic domain) and RGAII (linker + catalytic domain), with domains defined by function rather than by tertiary structure. In addition, Paenibacillus macerans cyclomaltodextrin glucanotransferase SBD replaced the closely related A.niger GA SBD to give GAE. Soluble starch hydrolysis rates decreased as RGAII approximately GAII approximately GAI > RGAIDeltaL approximately RGAI approximately GAE. Insoluble starch hydrolysis rates were GAI > RGAIDeltaL > RGAI > GAE approximately RGAII > GAII, while insoluble starch-binding capacities were GAI > RGAI > RGAIDeltaL > RGAII > GAII > GAE. These results indicate that: (i) moving the SBD to the N-terminus or replacing the native SBD somewhat affects soluble starch hydrolysis; (ii) SBD location significantly affects insoluble starch binding and hydrolysis; (iii) insoluble starch hydrolysis is imperfectly correlated with its binding by the SBD; and (iv) placing the P.macerans cyclomaltodextrin glucanotransferase SBD at the end of a linker, instead of closely associated with the rest of the enzyme, severely reduces its ability to bind and hydrolyze insoluble starch. PMID:12915730

Cornett, Catherine A G; Fang, Tsuei-Yun; Reilly, Peter J; Ford, Clark

2003-07-01

363

SreA-mediated iron regulation in Aspergillus fumigatus  

PubMed Central

Aspergillus fumigatus, the most common airborne fungal pathogen of humans, employs two high-affinity iron uptake systems: iron uptake mediated by the extracellular siderophore triacetylfusarinine C and reductive iron assimilation. Furthermore, A. fumigatus utilizes two intracellular siderophores, ferricrocin and hydroxyferricrocin, to store iron. Siderophore biosynthesis, which is essential for virulence, is repressed by iron. Here we show that this control is mediated by the GATA factor SreA. During iron-replete conditions, SreA deficiency partially derepressed synthesis of triacetylfusarinine C and uptake of iron resulting in increased cellular accumulation of both iron and ferricrocin. Genome-wide DNA microarray analysis identified 49 genes that are repressed by iron in an SreA-dependent manner. This gene set, termed SreA regulon, includes all known genes involved in iron acquisition, putative novel siderophore biosynthetic genes, and also genes not directly linked to iron metabolism. SreA deficiency also caused upregulation of iron-dependent and antioxidative pathways, probably due to the increased iron content and iron-mediated oxidative stress. Consistently, the sreA disruption mutant displayed increased sensitivity to iron, menadion and phleomycin but retained wild-type virulence in a mouse model. As all detrimental effects of sreA disruption are restricted to iron-replete conditions these data underscore that A. fumigatus faces iron-depleted conditions during infection.

Schrettl, Markus; Kim, H Stanley; Eisendle, Martin; Kragl, Claudia; Nierman, William C; Heinekamp, Thorsten; Werner, Ernst R; Jacobsen, Ilse; Illmer, Paul; Yi, Hyojeong; Brakhage, Axel A; Haas, Hubertus

2008-01-01

364

Application of oxygen vectors to Aspergillus terreus cultivation.  

PubMed

Research was undertaken to examine the effects of adding an oxygen carrier (n-dodecane, n-tetradecane, or n-hexadecane) on lovastatin production by Aspergillus terreus in both shaking-flask and 5-l fermentor cultivations. In the shaking-flask cultivation, an addition of 2.5% (w/v) n-dodecane to the medium gave about a 1.4-fold increase (0.51 g/l) in lovastatin production. This improvement was related to morphological changes in the fungal cells, and resulted mainly from the formation of small, uniform, compact pellets of A. terreus. In contrast, in the 5-l fermentor cultivation, the lovastatin production was only one-ninth of that achieved without n-dodecane addition independent of the pellet density. This adverse effect of adding the oxygen carrier to the medium was attributed to an uncontrolled, high dissolved oxygen level (higher than 60%) which resulted in unfavorable morphological changes and the formation of star-like pellets. However, when this dosage of n-dodecane was added 24 h after the start of the 5-l fermentor cultivation, lovastatin production was further enhanced due to its foam suppressing activity in the fungal fermentation. PMID:16233333

Lai, Long-Shan T; Tsai, Tai-Her; Wang, Te Chi

2002-01-01

365

Modulation of antimicrobial metabolites production by the fungus Aspergillus parasiticus.  

PubMed

Biosynthesis of active secondary metabolites by fungi occurs as a specific response to the different growing environments. Changes in this environment alter the chemical and biological profiles leading to metabolites diversification and consequently to novel pharmacological applications. In this work, it was studied the influence of three parameters (fermentation length, medium composition and aeration) in the biosyntheses of antimicrobial metabolites by the fungus Aspergillus parasiticus in 10 distinct fermentation periods. Metabolism modulation in two culturing media, CYA and YES was evaluated by a 2(2) full factorial planning (ANOVA) and on a 2(3) factorial planning, role of aeration, medium composition and carbohydrate concentration were also evaluated. In overall, 120 different extracts were prepared, their HPLC profiles were obtained and the antimicrobial activity against A. flavus, C. albicans, E. coli and S. aureus of all extracts was evaluated by microdilution bioassay. Yield of kojic acid, a fine chemical produced by the fungus A. parasiticus was determined in all extracts. Statistical analyses pointed thirteen conditions able to modulate the production of bioactive metabolites by A. parasiticus. Effect of carbon source in metabolites diversification was significant as shown by the changes in the HPLC profiles of the extracts. Most of the extracts presented inhibition rates higher than that of kojic acid as for the extract obtained after 6 days of fermentation in YES medium under stirring. Kojic acid was not the only metabolite responsible for the activity since some highly active extracts showed to possess low amounts of this compound, as determined by HPLC. PMID:24948950

Bracarense, Adriana A P; Takahashi, Jacqueline A

2014-01-01

366

Genotypic and Phenotypic Versatility of Aspergillus flavus during Maize Exploitation  

PubMed Central

Aspergillus flavus is a cosmopolitan fungus able to respond to external stimuli and to shift both its trophic behaviour and the production of secondary metabolites, including that of the carcinogen aflatoxin (AF). To better understand the adaptability of this fungus, we examined genetic and phenotypic responses within the fungus when grown under four conditions that mimic different ecological niches ranging from saprophytic growth to parasitism. Global transcription changes were observed in both primary and secondary metabolism in response to these conditions, particularly in secondary metabolism where transcription of nearly half of the predicted secondary metabolite clusters changed in response to the trophic states of the fungus. The greatest transcriptional change was found between saprophytic and parasitic growth, which resulted in expression changes in over 800 genes in A. flavus. The fungus also responded to growth conditions, putatively by adaptive changes in conidia, resulting in differences in their ability to utilize carbon sources. We also examined tolerance of A. flavus to oxidative stress and found that growth and secondary metabolism were altered in a superoxide dismutase (sod) mutant and an alkyl-hydroperoxide reductase (ahp) mutant of A. flavus. Data presented in this study show a multifaceted response of A. flavus to its environment and suggest that oxidative stress and secondary metabolism are important in the ecology of this fungus, notably in its interaction with host plant and in relation to changes in its lifestyle (i.e. saprobic to pathogenic).

Reverberi, Massimo; Punelli, Marta; Scala, Valeria; Scarpari, Marzia; Uva, Paolo; Mentzen, Wieslawa I.; Dolezal, Andrea L.; Woloshuk, Charles; Pinzari, Flavia; Fabbri, Anna A.; Fanelli, Corrado; Payne, Gary A.

2013-01-01

367

Biochemical and Molecular Characterization of Secreted ?-Xylosidase from Aspergillus niger*  

PubMed Central

?-Linked xylose is a major component of xyloglucans in the cell walls of higher plants. An ?-xylosidase (AxlA) was purified from a commercial enzyme preparation from Aspergillus niger, and the encoding gene was identified. The protein is a member of glycosyl hydrolase family 31. It was active on p-nitrophenyl-?-d-xyloside, isoprimeverose, xyloglucan heptasaccharide (XXXG), and tamarind xyloglucan. When expressed in Pichia pastoris, AxlA had activity comparable to the native enzyme on pNP?X and IP despite apparent hyperglycosylation. The pH optimum of AxlA was between 3.0 and 4.0. AxlA together with ?-glucosidase depolymerized xyloglucan heptasaccharide. A combination of AxlA, ?-glucosidase, xyloglucanase, and ?-galactosidase in the optimal proportions of 51:5:19:25 or 59:5:11:25 could completely depolymerize tamarind XG to free Glc or Xyl, respectively. To the best of our knowledge, this is the first characterization of a secreted microbial ?-xylosidase. Secreted ?-xylosidases appear to be rare in nature, being absent from other tested commercial enzyme mixtures and from the genomes of most filamentous fungi.

Scott-Craig, John S.; Borrusch, Melissa S.; Banerjee, Goutami; Harvey, Christopher M.; Walton, Jonathan D.

2011-01-01

368

Xylanolytic complex from Aspergillus giganteus: production and characterization.  

PubMed

An Aspergillus giganteus strain was isolated as an excellent producer of xylanase associated with low levels of cellulase. Optimal xylanase production was obtained in liquid Vogel medium containing xylan as carbon source, pH 6.5 to 7.0, at 25 degrees C and under shaking at 120 rpm during 84 h. Among the several carbon sources tested, higher xylanase production was verified in xylan, xylose, sugar-cane bagasse, wheat bran and corn cob cultures, respectively. Optimal conditions for activity determination were 50 degrees C and pH 6.0. The xylanolytic complex of A. giganteus showed low thermal stability with T(50) of 2 h, 13 min and 1 min when it was incubated at 40, 50 and 60 degrees C, respectively, and high stability from pH 4.5 to 10.5, with the best interval between 7.0 to 7.5. This broad range of stability in alkali pH indicates a potential applicability in some industrial processes, which require such condition. Xylanolytic activity of A. giganteus was totally inhibited by Hg(+2), Cu(+2) and SDS at 10 mM. The analysis of the products from the oat spelts xylan hydrolysis through thin-layer chromatography indicated endoxylanase activity, lack of debranching enzymes and beta-xylosidase activity in assay conditions. PMID:12872308

Coelho, Glauciane Danusa; Carmona, Eleonora Cano

2003-01-01

369

Control of amylase production and growth characteristics of Aspergillus ochraceus.  

PubMed

The growth and the extracellular amylase production by Aspergillus ochraceus were studied in a stationary culture medium. Maximum growth rate of this fungus was found after 5 days of incubation at 30 degrees C, but maximum amylase production was obtained after 2 days. The highest amylase production were attained with lactose, maltose, xylose and starch as carbon sources. The extracellular amylase production and mycelial growth were influenced by the concentration of starch. Other carbohydrates supported growth but did not induce amylase synthesis and glucose repressed it, indicating catabolite repression in this microorganism. The presence of both mechanisms of induction and repression suggests that at least these multiple forms of regulation are present in A. ochraceus. Of the nitrogen sources tested, casaminoacids, ammonium nitrate and sodium nitrate stimulated the highest yield of amylase. Optimal amylase production was obtained at pH 5.0, but enzyme activity was found only in the 4.0-6.0 pH range. These results were probably due to the inhibitory effect of NH4(+)-N in the culture medium. PMID:17061508

Nahas, Ely; Waldemarin, Mirela M

2002-01-01

370

Immunological Aspects of Candida and Aspergillus Systemic Fungal Infections  

PubMed Central

Patients with allogeneic stem cell transplantation (SCT) have a high risk of invasive fungal infections (IFIs) even after neutrophil regeneration. Immunological aspects might play a very important role in the IFI development in these patients. Some data are available supporting the identification of high-risk patients with IFI for example patients receiving stem cells from TLR4 haplotype S4 positive donors. Key defense mechanisms against IFI include the activation of neutrophils, the phagocytosis of germinating conidia by dendritic cells, and the fight of the cells of the innate immunity such as monocytes and natural killer cells against germlings and hyphae. Furthermore, immunosuppressive drugs interact with immune effector cells influencing the specific fungal immune defense and antimycotic drugs might interact with immune response. Based on the current knowledge on immunological mechanism in Aspergillus fumigatus, the first approaches of an immunotherapy using human T cells are in development. This might be an option for the future of aspergillosis patients having a poor prognosis with conventional treatment.

Mueller-Loebnitz, Christoph; Ostermann, Helmut; Franzke, Anke; Loeffler, Juergen; Uharek, Lutz; Topp, Max; Einsele, Hermann

2013-01-01

371

Aspergillus Enzymes Involved in Degradation of Plant Cell Wall Polysaccharides  

PubMed Central

Degradation of plant cell wall polysaccharides is of major importance in the food and feed, beverage, textile, and paper and pulp industries, as well as in several other industrial production processes. Enzymatic degradation of these polymers has received attention for many years and is becoming a more and more attractive alternative to chemical and mechanical processes. Over the past 15 years, much progress has been made in elucidating the structural characteristics of these polysaccharides and in characterizing the enzymes involved in their degradation and the genes of biotechnologically relevant microorganisms encoding these enzymes. The members of the fungal genus Aspergillus are commonly used for the production of polysaccharide-degrading enzymes. This genus produces a wide spectrum of cell wall-degrading enzymes, allowing not only complete degradation of the polysaccharides but also tailored modifications by using specific enzymes purified from these fungi. This review summarizes our current knowledge of the cell wall polysaccharide-degrading enzymes from aspergilli and the genes by which they are encoded.

de Vries, Ronald P.; Visser, Jaap

2001-01-01

372

Biocatalytic synthesis of butein and sulfuretin by Aspergillus alliaceus.  

PubMed

Aspergillus alliaceus UI315 was examined for its potential to catalyze biotransformation reactions of chalcones that mimic plant biosynthetic processes. 3-(4' '-Hydroxyphenyl)-1-(2',4'-dihydroxyphenyl)propenone (4,2',4'-trihydroxychalcone, isoliquiritigein) (1) was efficiently transformed to two major metabolites that were isolated chromatographically and identified by spectroscopic methods as 3-(3' ',4' '-dihydroxyphenyl)-1-(2',4'-dihydroxyphenyl)propenone (butein) (7) and 2-[(3,4-dihydroxyphenyl)methylene]-6-hydroxy-3(2H)benzofuranone (7,3',4'-trihydroxyaurone, sulfuretin) (10). Inhibition experiments suggested that initial C-3 hydroxylation of 1 to 7 was catalyzed by a cytochrome P450 enzyme system. A second A. alliaceus enzyme, partially purified and identified as a catechol oxidase, catalyzed the oxidation of the catechol butein (7) likely through an ortho-quinone (8) that cyclized to the aurone product 10. This work showed that A. alliaceus UI315 contains oxidative enzyme systems capable of converting phenolic chalcones such as 1 into aurones such as 10 in a process that mimics plant biosynthetic pathways. PMID:16787010

Sanchez-Gonzalez, Monica; Rosazza, John P N

2006-06-28

373

Aspergillus niger time to growth in dried tomatoes.  

PubMed

Individual and combined effects of aw and incorporation of selected concentrations of Mexican oregano essential oil on the time to growth (TTG) of Aspergillus niger intentionally inoculated into dried tomatoes were studied during storage at 25°C for 100 days. For aw 0.96, 1,000 ppm of Mexican oregano essential oil inhibited A. niger growth during 100 days, whereas 500 ppm were sufficient at aw 0.91 and 250 ppm for tomatoes with aw 0.78. A. niger growth was evident at different incubation times depending on tested tomato aw and concentration of essential oil; these data were utilized to model TTG. Regression analysis revealed good agreement between experimental and predicted data with a correlation coefficient higher than 0.98. Analysis of mold growth data through TTG models makes possible to include observations detected as no growth and can be utilized to predict mold time to growth for specific preservation factor combinations or to select preservation factor levels for an expected shelf-life based on A. niger growth. PMID:23587709

Gómez-Ramírez, C; Sosa-Morales, M E; Palou, E; López-Malo, A

2013-06-01

374

Regulation of Conidiation by Light in Aspergillus nidulans  

PubMed Central

Light regulates several aspects of the biology of many organisms, including the balance between asexual and sexual development in some fungi. To understand how light regulates fungal development at the molecular level we have used Aspergillus nidulans as a model. We have performed a genome-wide expression analysis that has allowed us to identify >400 genes upregulated and >100 genes downregulated by light in developmentally competent mycelium. Among the upregulated genes were genes required for the regulation of asexual development, one of the major biological responses to light in A. nidulans, which is a pathway controlled by the master regulatory gene brlA. The expression of brlA, like conidiation, is induced by light. A detailed analysis of brlA light regulation revealed increased expression after short exposures with a maximum after 60 min of light followed by photoadaptation with longer light exposures. In addition to brlA, genes flbA–C and fluG are also light regulated, and flbA–C are required for the correct light-dependent regulation of the upstream regulator fluG. We have found that light induction of brlA required the photoreceptor complex composed of a phytochrome FphA, and the white-collar homologs LreA and LreB, and the fluffy genes flbA–C. We propose that the activation of regulatory genes by light is the key event in the activation of asexual development by light in A. nidulans.

Ruger-Herreros, Carmen; Rodriguez-Romero, Julio; Fernandez-Barranco, Raul; Olmedo, Maria; Fischer, Reinhard; Corrochano, Luis M.; Canovas, David

2011-01-01

375

Novel cytosolic allergens of Aspergillus fumigatus identified from germinating conidia.  

PubMed

Aspergillus fumigatus is the common cause of allergic broncho-pulmonary aspergillosis (ABPA) and most of the allergens have been described from its secreted fraction. In the present investigation, germinating conidial cytosolic proteins of A. fumigatus were extracted from a 16 h culture. The proteome from this fraction was developed, and immuno-blots were generated using pooled ABPA patients' sera. Well separated Immunoglobulin-E (IgE) and Immunoglobulin-G (IgG) reactive spots were picked from corresponding 2DE gels and subjected to mass spectrometric analysis. As a result, 66 immuno-reactive proteins were identified from two geographically different strains (190/96 and DAYA) of A. fumigatus. Only 3 out of 66 proteins reacted with IgG, and the remaining 63 proteins were found to be IgE reactive. These 63 IgE-reactive cytosolic proteins from germinating conidia included 2 already known (Asp f12 and Asp f22) and 4 predicted allergens (Hsp88, Hsp70, malate dehydrogenase, and alcohol dehydrogenase) based on their homology with other known fungal allergens. In view of this, the panel of presently identified IgE-reactive novel proteins holds the potential of providing a basis for the wider diagnostic application in assay for allergic aspergillosis. We could demonstrate that recombinantly expressed proteins from this panel showed consistent reactivity with IgE of individual sera of ABPA patients. The recombinantly expressed proteins may also be useful in desensitization therapy of allergic disorders including ABPA. PMID:20828162

Singh, Bharat; Sharma, Gainda L; Oellerich, Michael; Kumar, Ram; Singh, Seema; Bhadoria, Dharam P; Katyal, Anju; Reichard, Utz; Asif, Abdul R

2010-11-01

376

Optimized bioprocess for production of fructofuranosidase by recombinant Aspergillus niger.  

PubMed

A comprehensive approach of bioprocess design at various levels was used to optimize microbial production of extracellular fructofuranosidase, important as biocatalyst to derive fructooligosaccharides with broad application in food or pharmaceutical industry. For production, the recombinant strain Aspergillus niger SKAn1015 was used, which expresses the fructofuranosidase encoding gene suc1 under control of a strong constitutive promoter. In a first screening towards an optimized medium, glucose, nitrate, Fe(2+), and Mn(2+) were identified as beneficial for production. A minimal medium with optimized concentration of these key nutrients, obtained by central composite design experiments and quadratic modelling, provided a threefold increased fructofuranosidase activity in the culture supernatant (400 U/mL) as compared to the originally described medium. Utilizing the optimized medium, the process was then transferred from shake flask into a fed-batch-operated bioreactor. Hereby, the intended addition of talc microparticles allowed engineering the morphology of A. niger into a highly active mycelial form, which strongly boosted production. Fructofuranosidase production was highly specific as confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis. The secreted enzyme activity of 2,800 U/mL, corresponding to about 3 g/L of fructofuranosidase, achieved by the microparticle-enhanced fed-batch process, is tenfold higher than that of any other process reported so far, so that the presented bioprocess strategy appears as a milestone towards future industrial fructofuranosidase production. PMID:20502893

Driouch, Habib; Roth, Andreas; Dersch, Petra; Wittmann, Christoph

2010-08-01

377

Studies on sulfhydryl groups of Aspergillus niger amine oxidase.  

PubMed

Amino acid analysis of the amine oxidase of Aspergillus niger (monoamine:O2 oxidoreductase (deaminating), EC 1.4.3.4) showed a composition similar to that of bovine plasma enzyme. One molecule of enzyme contained 25 Cys residues. It was shown that 9 to 11 residues of Cys were titrated to be SH groups. The amine oxidase reaction was markedly inhibited by metal ions (Cu2+, Hg2+, Ag+). The enzyme was inactivated with SH reagents (phenyl mercuric acetate, Cl-HgBzO-) and the extent of this inactivation was dependent on the time of incubation with SH reagents. Also, the Cl-HgBzO- -inactivated enzyme was reactivated with cysteine and this reactivation was biphasic with the time of incubation. The Cl-HgBzO--inactivated amine oxidase was compared with the native enzyme in their reactivity with phenylhydrazine and their spectral properties. The results showed that the Cl-HgBzO--inactivated enzyme had lower reactivity with phenylhydrazine than the native enzyme and had higher absorbance values than the native enzyme around 400 nm wavelengths. PMID:1174546

Suzuki, H; Ogura, Y; Yamada, H; Arima, K

1975-09-22

378

Some factors affecting tannase production by Aspergillus niger Van Tieghem  

PubMed Central

One variable at a time procedure was used to evaluate the effect of qualitative variables on the production of tannase from Aspergillus niger Van Tieghem. These variables including: fermentation technique, agitation condition, tannins source, adding carbohydrates incorporation with tannic acid, nitrogen source type and divalent cations. Submerged fermentation under intermittent shaking gave the highest total tannase activity. Maximum extracellular tannase activity (305 units/50 mL) was attained in medium containing tannic acid as tannins source and sodium nitrate as nitrogen source at 30 °C for 96 h. All added carbohydrates showed significant adverse effects on the production of tannase. All tested divalent cations significantly decreased tannase production. Moreover, split plot design was carried out to study the effect of fermentation temperature and fermentation time on tannase production. The results indicated maximum tannase production (312.7 units/50 mL) at 35 °C for 96 h. In other words, increasing fermentation temperature from 30 °C to 35 °C resulted in increasing tannase production.

Aboubakr, Hamada A.; El-Sahn, Malak A.; El-Banna, Amr A.

2013-01-01

379

Characterization of nonochratoxigenic strains of Aspergillus carbonarius from grapes.  

PubMed

Aspergillus carbonarius is the main responsible source of ochratoxin A (OTA) in food commodities such as wine, grapes or dried vine fruits from main viticultural regions worldwide. Besides, OTA production is a very consistent property of this species and for this reason atoxigenic isolates of A. carbonarius are very rarely found in natural environments. In the present study, for the first time, three nonochratoxigenic wild strains of A. carbonarius have been discovered, unambiguously identified, characterized in deep and compared to ochratoxigenic strains of the same species. In addition, polyketide synthase (pks) genes suggested to be involved in OTA biosynthesis were also screened in these strains. The identification of the strains was confirmed by ITS-5.8S rRNA, ?-tubulin and calmodulin gene sequencing. The three atoxigenic strains did not produce OTA in a conducive culture medium at any of the temperatures and times of incubation tested. Five ketosynthase domains from pks genes previously described in A. carbonarius were detected both in ochratoxigenic and in nonochratoxigenic strains. Atoxigenic strains of A. carbonarius could be useful as biotechnological agents to be used in food industry and as biological agents for control of OTA production in vineyards and other crops. PMID:24010591

Cabańes, F J; Bragulat, M R; Castellá, G

2013-12-01

380

Identification of the Predominant Volatile Compounds Produced by Aspergillus flavus  

PubMed Central

A culture of Aspergillus flavus grown on moistened wheat meal was homogenized with a blendor, and the resulting slurry was vacuum-distilled at 5 mm of Hg and 35 C. The aqueous distillate was collected in traps cooled to -10 to -80 C. The culture volatiles were extracted from the distillate with CH2Cl2, and, after removal of the bulk of the solvent, the concentrated volatiles were examined by packed-column gas chromatography. Nineteen peaks were observed, and coupled gas chromatography-mass spectrometry was employed to identify the larger components. The compounds identified were: 3-methyl-butanol, 3-octanone, 3-octanol, 1-octen-3-ol, 1-octanol, and cis-2-octen-1-ol. The two octenols were the predominant compounds, and sufficient sample was trapped from the gas chromatograph for infrared analyses; this confirmed the mass spectral identifications and permitted the assignment of the cis designation to 2-octen-1-ol. Both oct-1-en-3-ol and cis-2-octen-1-ol are thought to be responsible for the characteristic musty-fungal odor of certain fungi; the latter compound may be a useful chemical index of fungal growth.

Kaminski, E.; Libbey, L. M.; Stawicki, S.; Wasowicz, E.

1972-01-01

381

Light represses conidiation in koji mold Aspergillus oryzae.  

PubMed

In the filamentous fungus Aspergillus oryzae, there has been no report on photoreaction. Here we investigated the effect of light in A. oryzae and found that conidiation was repressed by white light. This reaction is contrary to that of other Aspergilli, which show abundant conidiation under light. Moreover, red light also caused reduced conidiation. Genome sequencing of A. oryzae indicated the existence of homologs of some light-related genes in other filamentous fungi. To approach the molecular mechanism of this photoresponse, the effect of red light on the expression level of several genes putatively responsible for conidiation or photoperception, i.e., brlA, a gene known to be required for conidiation, AofphA, the putative homolog of the A. nidulans phytochrome gene fphA, and AoveA, the putative homolog of the negative regulator gene in conidiation in A. nidulans, was examined. These three genes showed no significant response to red light at the transcriptional level. The results indicate that A. oryzae perceives and responds to red light in a manner independent of the transcriptional regulation of these genes. PMID:17690479

Hatakeyama, Riko; Nakahama, Tomoyuki; Higuchi, Yujiro; Kitamoto, Katsuhiko

2007-08-01

382

Analysis of a novel calcium auxotrophy in Aspergillus nidulans  

PubMed Central

In Aspergillus nidulans a combination of null mutations in halA, encoding a protein kinase, and sltA, encoding a zinc-finger transcription factor having no yeast homologues, results in an elevated calcium requirement (‘calcium auxotrophy’) without impairing net calcium uptake. sltA? (±halA?) mutations result in hypertrophy of the vacuolar system. In halA?sltA? (and sltA?) strains, transcript levels for pmcA and pmcB, encoding vacuolar Ca2+-ATPase homologues, are highly elevated, suggesting a regulatory relationship between vacuolar membrane area and certain vacuolar membrane ATPase levels. Deletion of both pmcA and pmcB strongly suppresses the ‘calcium auxotrophy’. Therefore the ‘calcium auxotrophy’ possibly results from excessive vacuolar calcium sequestration, causing cytosolic calcium deprivation. Null mutations in nhaA, homologous to Saccharomyces cerevisiaeNHA1, encoding a plasma membrane Na+/H+ antiporter effluxing Na+ and K+, and a non-null mutation in trkB, homologous to S. cerevisiaeTRK1, encoding a plasma membrane high affinity K+ transporter, also suppress the calcium auxotrophy.

Findon, Helen; Calcagno-Pizarelli, Ana-Maria; Martinez, Jose L.; Spielvogel, Anja; Markina-Inarrairaegui, Ane; Indrakumar, Tanya; Ramos, Jose; Penalva, Miguel A.; Espeso, Eduardo A.; Arst, Herbert N.

2010-01-01

383

Septum-directed secretion in the filamentous fungus Aspergillus oryzae.  

PubMed

Although exocytosis in fungal cells takes place at hyphal tips, there also seems a line of circumstantial evidence suggesting the occurrence of exocytosis at other sites of cells, such as septa. To investigate whether exocytosis takes place at fungal septa, we monitored dynamics of EGFP-fused ?-amylase (AmyB-EGFP), the representative secretory enzyme of the filamentous fungus Aspergillus oryzae. We found that AmyB-EGFP accumulates in Spitzenkörper at hyphal tips as well as septal periplasm between the plasma membrane and cell walls. The septal accumulation of AmyB-EGFP was a rapid process, and required microtubules but not F-actin. Thus, this process is independent of exocytosis at hyphal tips that requires both microtubules and F-actin. In addition, fluorescence recovery after photobleaching (FRAP) analysis of EGFP-fused AoSnc1 revealed that secretory vesicles constitutively fuse with the septal plasma membrane. These results demonstrated that exocytosis takes place at septa in addition to hyphal tips. Analysis of two plasma membrane transporters, AoUapC and AoGap1, revealed that they preferentially accumulate at septa and the lateral plasma membrane with no clear accumulation at apical Spitzenkörper, suggesting that non-tip directed exocytosis is important for delivery of these proteins. PMID:21564341

Hayakawa, Yugo; Ishikawa, Eri; Shoji, Jun-Ya; Nakano, Hiroyuki; Kitamoto, Katsuhiko

2011-07-01

384

An insight into the curdione biotransformation pathway by Aspergillus niger.  

PubMed

Curdione (1), a sesquiterpene with a germacrane skeleton from rhizomes of Curcuma wenyujin, has attracted attention due to its important pharmacological properties. Herein, we investigated the chemo-biotransformation of curdione (1) systematically using Aspergillus niger AS 3.739. Regio- and stereoselective hydroxylation of curdione with filamentous fungus A. niger AS 3.739 led to seven metabolites including four new compounds 3?-hydroxycurcumalactone, 2?-hydroxycurcumalactone, (10S)-9,10-dihydroxy-curcumalactone and (10R)-9,10-dihydroxy-curcumalactone. Their structures were determined by spectroscopic techniques including two-dimensional NMR and TOF-MS (Time of Flight Mass Spectrometry). Based upon the analysis of biological and chemical conversions of curdione, a tentative metabolic pathway via chemo-bio cascade reactions is proposed in A. niger system, which provides an insight into the corresponding metabolism of curdione in animal systems. In addition, experiments with selected monooxygenase inhibitors suggest that cytochrome P450 monooxygenase played a crucial role in the hydroxylation of curdione. PMID:24456521

Chen, Yinan; Zhang, Lang; Qin, Bin; Zhang, Xin; Jia, Xian; Wang, Xiaoying; Jin, Danni; You, Song

2014-01-01

385

Anti-inflammatory drimane sesquiterpene lactones from an Aspergillus species.  

PubMed

IFN-? inducible protein 10 (IP-10, CXCL10) is a 10 kDa chemokine, which is secreted from various cell types after exposure to pro-inflammatory stimuli. This chemokine is a ligand for the CXCR3 receptor and regulates immune responses by activating and recruiting leukocytes such as T cells, eosinophils, monocytes, and NK cells to sites of inflammation. Altered expression of CXCL10 has been associated with chronic inflammatory and infectious diseases and therefore CXCL10 represents a promising target for the development of new anti-inflammatory drugs. In a search for inhibitors of CXCL10 promoter activity, three structurally related drimane sesquiterpene lactones (compounds 1-3) were isolated from fermentations of an Aspergillus species. Compounds 1 and 2 inhibited the IFN-?/TNF-?/IL-1? induced CXCL10 promoter activity in transiently transfected human DLD-1 colon carcinoma cells in a dose-dependent manner with IC50 values of 12.4 ?M for 1 and 55 ?M for 2, whereas 3 was devoid of any biological activity. Moreover, compounds 1 and 2 reduced CXCL10 mRNA levels and synthesis in IFN-?/TNF-?/IL-1? stimulated DLD-1 cells. PMID:24792812

Felix, Silke; Sandjo, Louis P; Opatz, Till; Erkel, Gerhard

2014-06-01

386

Isolation and toxigenicity of Aspergillus fumigatus from moldy silage.  

PubMed

Thirty-nine silage samples were collected from various silos on Terceira Island in the Azores. Samples were examined for the presence of total fungi, and isolates of Aspergillus fumigatus were analyzed for their ability to produce fumitremorgens B and C, fumigaclavines B and C, and gliotoxin. Thirty-four silage samples (87%) were contaminated with fungi, and A. fumigatus was isolated from 27 samples (69%). Samples that were taken from the surface of silos had significantly higher populations of both total fungi and A. fumigatus than did samples taken from the middle of silos. Analysis of 27 A. fumigatus isolates (one representing each positive sample) showed that 59.3% produced fumitremorgen B; 33.3% produced fumitremorgen C; 29.6% produced fumigaclavine B; 7.4% produced fumigaclavine C; and 11.1% produced gliotoxin. Fifty-two percent of the isolates produced multiple toxins, and 25.9% did not produce any of these toxins. Gliotoxin and fumigaclavine C were always produced in combination with other toxins. Because of the demonstrated potential of these A. fumigatus isolates to produce mycotoxins, it is important to properly construct and manage silos to prevent their contamination with A. fumigatus. PMID:12733634

dos Santos, Valentina Melo; Dorner, Joe W; Carreira, Fátima

2003-01-01

387

Molecular characterization of StcI esterase from Aspergillus nidulans.  

PubMed

Aspergillus nidulans produces StcI esterase, which is involved in the biosynthesis of sterigmatocystin, a precursor of aflatoxins. Previous reports of this esterase in A. nidulans suggest that it is composed of 286 amino acid residues with a theoretical molecular mass of 31 kDa. Various conditions were evaluated to determine the optimal expression conditions for StcI; the highest level was observed when A. nidulans was cultured in solid oat media. Various esterases were expressed differentially according to the culture media used. However, specific antibodies designed to detect StcI reacted with a protein with an unexpected molecular mass of 35 kDa in cell extracts from all expression conditions. Analysis of the gene sequence and already reported expressed sequence tags indicated the presence of an additional 29-amino-acid N-terminal region of StcI, which is not a signal peptide and which has not been previously reported. We also detected the presence of this additional N-terminal region using reverse-transcriptase polymerase chain reaction. The complete protein (NStcI) was cloned and successfully expressed in Pichia pastoris. PMID:19440704

Peńa-Montes, Carolina; Lange, Stefan; Flores, Idalia; Castro-Ochoa, Denise; Schmid, Rolf; Cruz-García, Felipe; Farrés, Amelia

2009-10-01

388

Population balance modeling of the conidial aggregation of Aspergillus niger.  

PubMed

Numerous biotechnological production processes are based on the submerse cultivation of filamentous fungi. Process design, however, is often hampered by the complex growth pattern of these organisms. In the morphologic development of coagulating filamentous fungi, like Aspergillus niger, conidial aggregation is the first step of filamentous morphogenesis. For a proper description of this phenomenon it is necessary to characterize conidial populations. Kinetic studies performed with an in-line particle size analyzer suggested that two distinct aggregation steps have to be considered. The first step of conidial aggregation starts immediately after inoculation. Both the rate constants of formation and disintegration of aggregates have been determined by measuring the concentration of conidia at the beginning of the cultivation and the concentration of particles at steady state during the first hours of cultivation. In contrast to the first aggregation step, where the collision of conidia is presumed to be responsible for the process, the second aggregation step is thought to be initiated by germination of conidia. Growing hyphae provide additional surface for the attachment of non- germinated conidia, which leads to a strong decrease in particle concentration. The specific hyphal length growth rate and the ratio of particle concentration to the growing adhesion hyphal surface are decisive matters of the second aggregation step. Both aggregation steps can be described by population dynamics and simulated using the program package PARSIVAL (PARticle SIze eVALution) for the treatment of general particle population balances. PMID:17625790

Lin, P-J; Grimm, L H; Wulkow, M; Hempel, D C; Krull, R

2008-02-01

389

A molecular and bioinformatic study on the ochratoxin A (OTA)-producing Aspergillus affinis (section Circumdati).  

PubMed

Aspergillus affinis (section Circumdati) is a novel ochratoxin A (OTA)-producing species found in submerged riparian decomposing leaves. However, very little is known about its role on the breakdown of plant debris and its ability to degrade carbohydrate polymers. Moreover, its OTA biosynthetic pathway has not yet been explored. In the present paper, we investigated the gene encoding the extracellular alpha-amylase (amyAa) of A. affinis within the evolution of the Aspergillus lineages in relation to the possible use of this enzyme in starch processing. The novel amyAa, despite being related to branches of the Aspergillus species of the sections Terrei and Flavi, formed a distinct phylogenetic branch, which may be of outstanding importance from a biotechnological point of view. Moreover, we identified the polyketide synthase gene (pks) putatively required for the first step of OTA biosynthesis in A. affinis. This otapks was examined in relation to a limited number of orthologous genes available from Aspergillus species of the sections Circumdati and Nigri. Our study highlights the importance of otapks as target genes in the treatment of ochratoxigenic Aspergillus species on a more comprehensive evolutionary basis. PMID:24668272

Davolos, Domenico; Pietrangeli, Biancamaria

2014-05-01

390

The biodiversity of Aspergillus section Flavi in brazil nuts: from rainforest to consumer.  

PubMed

A total of 288 brazil nut samples (173 kernel and 115 shell) from the Amazon rainforest region and Săo Paulo State, Brazil were collected at different stages of brazil nut production. Samples were analysed for: percentages of aflatoxigenic fungal species and potential for aflatoxin production and presence of aflatoxins. Aspergillus nomius was the most common species found (1235 isolates) which amounted to 30% of the total species with potential to produce aflatoxins. This species is of concern since 100% of all isolates produced aflatoxins B(1), B(2), G(1) and G(2). Aspergillus flavus was almost equally common (1212 isolates) although only 46% produced aflatoxins under laboratory conditions, and only aflatoxins B(1) and B(2). Low number of other species with the potential to produce aflatoxins was isolated: Aspergillus arachidicola and Aspergillus bombycis produced B and G aflatoxins whilst Aspergillus pseudotamarii produced only aflatoxin B(1). The total aflatoxin levels found in samples taken from the rainforests was 0.7 ?g/kg, from processing plants before and after sorting 8.0 and 0.1 ?g/kg respectively, from street markets in the Amazon region 6.3 ?g/kg and from supermarkets in Săo Paulo State 0.2 ?g/kg. Processing, which included manual or mechanical sorting and drying at 60°C for 30 to 36 h, eliminated on average more than 98% of total aflatoxins. These results showed that sorting is a very effective way to decrease aflatoxin content in brazil nuts. PMID:23290234

Calderari, Thaiane O; Iamanaka, Beatriz T; Frisvad, Jens C; Pitt, John I; Sartori, Daniele; Pereira, Jose Luiz; Fungaro, Maria Helena P; Taniwaki, Marta H

2013-01-01

391

PCR detection of DNA specific for Aspergillus species in serum of patients with invasive aspergillosis.  

PubMed Central

We investigated the possible presence of DNA specific for Aspergillus species in serum samples of patients with invasive aspergillosis (IA) by the nested PCR method. Fourteen strains of fungi including 5 strains of Aspergillus species and 10 strains of common bacteria were used for examination of specificity and sensitivity of the nested PCR. Two sets of oligonucleotide primers were derived from the sequence of the variable regions V7 to V9 of the 18S rRNA genes of Aspergillus fumigatus. The specific fragment was amplified from five strains of Aspergillus species in the single and nested PCR but not from other microorganisms. Target DNA was detected by the nested PCR with as little as 50 fg of the extracted DNA of A. fumigatus. We investigated the detection of DNA specific for Aspergillus species in serum samples of a murine model of aspergillosis and 20 patients with IA. The specific fragment was detected by the nested PCR in 71% of serum samples of infected mice and 70% of serum samples of patients with IA, while galactomannan antigen was detected in 43 and 60% of samples, respectively. The high sensitivity and specificity of the nested PCR indicate that the assay can provide early diagnosis with sufficient accuracy to be clinically useful for immunocompromised patients with IA.

Yamakami, Y; Hashimoto, A; Tokimatsu, I; Nasu, M

1996-01-01

392

Toward systems metabolic engineering of Aspergillus and Pichia species for the production of chemicals and biofuels.  

PubMed

Recently genome sequence data have become available for Aspergillus and Pichia species of industrial interest. This has stimulated the use of systems biology approaches for large-scale analysis of the molecular and metabolic responses of Aspergillus and Pichia under defined conditions, which has resulted in much new biological information. Case-specific contextualization of this information has been performed using comparative and functional genomic tools. Genomics data are also the basis for constructing genome-scale metabolic models, and these models have helped in the contextualization of knowledge on the fundamental biology of Aspergillus and Pichia species. Furthermore, with the availability of these models, the engineering of Aspergillus and Pichia is moving from traditional approaches, such as random mutagenesis, to a systems metabolic engineering approach. Here we review the recent trends in systems biology of Aspergillus and Pichia species, highlighting the relevance of these developments for systems metabolic engineering of these organisms for the production of hydrolytic enzymes, biofuels and chemicals from biomass. PMID:23576362

Caspeta, Luis; Nielsen, Jens

2013-05-01

393

Spatial and Temporal Patterns of Aspergillus flavus Strain Composition and Propagule Density in Yuma County, Arizona, Soils  

Microsoft Academic Search

Orum, T. V., Bigelow, D. M., Nelson, M. R., Howell, D. R., and Cotty, P. J. 1997. Spatial and temporal patterns of Aspergillus flavus strain composition and propagule density in Yuma County, Arizona, soils. Plant Dis. 81:911-916. Aspergillus flavus isolates from Arizona can be divided into S and L strains on the basis of scle- rotial morphology. These genetically distinct

Thomas V. Orum; Donna M. Bigelow; Merritt R. Nelson; Donald R. Howell; Peter J. Cotty

1997-01-01

394

Ecophysiology of ochratoxigenic Aspergillus ochraceus and Penicillium verrucosum isolates. Predictive models for fungal spoilage prevention – a review  

Microsoft Academic Search

Ochratoxin A (OTA) is a secondary metabolite produced by several species of Aspergillus and Penicillium; among them Aspergillus ochraceus and Penicillium verrucosum are two ochratoxigenic species capable of growing in different climates and thus contamination of food crops with OTA can occur worldwide. OTA can be found in a wide range of foods such as cereals, coffee, cocoa, spices, beer,

E. Pardo; S. Marín; A. J. Ramos; V. Sanchis

2006-01-01

395

Aspergillus fumigatus rasA and rasB regulate the timing and morphology of asexual development  

Microsoft Academic Search

Expression of rasA plays an important role in conidial germination in Aspergillus nidulans. Conidial germination is required to initiate both infection and asexual development in the opportunistic pathogen Aspergillus fumigatus. Therefore, we sought to determine the requirements for Ras proteins in conidial germination and asexual development of A. fumigatus. A second homolog, rasB, has been identified that characterizes a new

Jarrod R. Fortwendel; John C. Panepinto; Amy E. Seitz; David S. Askew; Judith C. Rhodes

2004-01-01

396

Scaling study for SP100 reactor technology  

Microsoft Academic Search

Several ways were explored of extending SP-100 reactor technology to higher power levels. One approach was to use the reference SP-100 pin design and increase the fuel pin length and the number of fuel pins as needed to provide higher capability. The impact on scaling of a modified and advanced SP-100 reactor technology was also explored. Finally, the effect of

A. C. Marshall; B. McKissock; OH Cleveland

1989-01-01

397

Incidence of fumonisin B(2) production by Aspergillus niger in Portuguese wine regions.  

PubMed

Fumonisin B(2) (FB(2)) was recently found to be produced by Aspergillus niger . When grape-derived products were subsequently analyzed, FB(2) contamination was found in raisins, must, and wine. This study evaluated 681 strains of black aspergilli species isolated from Portuguese wine grapes for FB(2) production when grown on Czapek yeast agar. FB(2) was not detected in Aspergillus carbonarius (n = 75) or Aspergillus ibericus (n = 9) strains, but it was detected in 176 (29%) of the strains belonging to A. niger aggregate (n = 597). The amount of FB(2) produced by these strains ranged from 0.003 to 6.0 mg/kg with a mean of 0.66 mg/kg. The Alentejo region had the lowest percentage (10%) of fumonisinogenic strains, whereas the Douro region had the highest percentage of fumonisinogenic strains (38%). Only 10 strains were found to produce FB(2) and ochratoxin A simultaneously. PMID:21668017

Abrunhosa, Luis; Calado, Thalita; Venancio, Armando

2011-07-13

398

Reliable and simple detection of ochratoxin and fumonisin production in black Aspergillus.  

PubMed

To date, edible fungi such as black Aspergillus (Aspergillus niger aggregates) have been considered as safe. However, it has recently been reported that some strains have a mycotoxin biosynthetic capability, and this capability must be evaluated to determine the safety of edible fungi. In this study, we assessed the ability of mycotoxin production in A. niger aggregates isolated from various Korean foods using multiplex PCR and high-performance liquid chromatography (HPLC) analyses. Multiplex PCR and HPLC analyses of 32 A. niger aggregates showed that ochratoxin and fumonisin were produced only by strains exhibiting positive PCR patterns with ochratoxin and fumonisin biosynthesis genes. However, several strains did not produce mycotoxins, even though they contained mycotoxin biosynthesis genes. Using multiplex PCR pattern and HPLC analyses, we selected Aspergillus strains that do not produce mycotoxins, which will contribute to the development of safer fermented foods. PMID:24680080

Kim, Nam Yeun; Lee, Inhyung; Ji, Geun Eog

2014-04-01

399

Requirement of LaeA for secondary metabolism and sclerotial production in Aspergillus flavus.  

PubMed

The nuclear regulator LaeA has been shown to govern production of multiple secondary metabolites in Aspergillus nidulans and Aspergillus fumigatus. Herein we examine the role of this protein in Aspergillus flavus. Similarly as in other Aspergilli, LaeA had a major effect on A. flavus secondary metabolism where DeltalaeA and over-expression laeA (OE::laeA) strains yielded opposite phenotypes resulting in decreased (increased) secondary metabolite production. The two mutant strains also exhibited striking morphological phenotypes in the loss (increase) of sclerotial production in comparison to wildtype. Growth on seed was marked by decreased (increased) conidial and aflatoxin production of the respective mutants; this was accompanied by decreased lipase activity in DeltalaeA, an enzymatic process correlated with seed maceration. Transcriptional examination of the mutants showed LaeA negatively regulates expression of its recently identified nuclear partner VeA, another global regulator of A. flavus secondary metabolites and sclerotia. PMID:18667168

Kale, Shubha P; Milde, Lane; Trapp, Marisa K; Frisvad, Jens C; Keller, Nancy P; Bok, Jin Woo

2008-10-01

400

Successful surgical intervention in an unusual case of Aspergillus endocarditis with acute myeloid leukemia.  

PubMed

Endocarditis due to Aspergillus infection is a rare complication in patients with hematological malignancies. Here, we present a case of aspergillus endocarditis in a patient with acute myeloid leukemia (AML) successfully treated with antifungal therapy and surgical treatment. The patient was a 51 years old male, a known case of AML who was admitted to our medical center for evacuating his valvular vegetations and repairing his atrial septal defect. He underwent an open heart surgery to relinquish his thromboses and also received an antifungal regimen. The patient tolerated the procedure well and eight months after his surgery, the patient remains asymptomatic. Successful treatment of this severe case of aspergillus endocarditis justifies a multidisciplinary method to be as a safe and effective approach to manage these patients. PMID:23945898

Ansari Aval, Zahra; Mirhosseini, Seyed Mohsen; Fakhri, Mohammad; Mozaffary, Amirhossein; Adimi Naghan, Parisa; Behzadnia, Neda; Ahmadi, Zargham-Hossein

2013-01-01

401

Aspergillus in a cervico-vaginal smear of an adult postmenopausal female: An unusual case  

PubMed Central

There are several case reports documenting opportunistic fungal infection in the female genital tract, withr Aspergillus spp being a rarely reported causative organism. We hereby report a case of Aspergillus infection in a 48 year-old, postmenopausal female with carcinoma of the cervix. She presented with features of pelvic inflammatory disease, and an initial routine cervico-vaginal smear revealed severe inflammation along with fungal bodies. The features were consistent with the presence of Aspergillus spp, while the background epithelial cells were negative for intraepithelial malignancy. She was offered therapy for pelvic inflammatory disease. A repeat Papanicolaou smear after two weeks was negative for intraepithelial organisms, but showed the evidence of a high-grade squamous intraepithelial lesion, with biopsy confirming squamous cell carcinoma.

Deb, Prabal; Srivastava, Anurag

2009-01-01

402

A comparative study of carotenoids of Aschersonia aleyroides and Aspergillus giganteus.  

PubMed

The orange-red sporodochium of Aschersonia aleyroides contains six caortenes with beta-carotene (87%) as the major pigment. In old cultures there is a decrease in total carotenoids, the disappearance of two trans-carotenes and the appearance of two cis-carotenes. In the case of Aspergillus giganteus and its mutant A. giganteus mut. alba the major carotene is also beta-carotene (80%) with six other carotenoids, including possibly the acid pigment aspserxanthin. Until now this latter pigment has only been detected in Aspergillus and therefore it can be regarded as a criterion to discriminate between Apergillus and other fungi. Aschersonia and Aspergillus seem not to be closely related on the basis of pigment patterns, which is in agreement with distinct morphological differences. PMID:554534

van Eijk, G W; Mummery, R S; Roeymans, H J; Valadon, L R

1979-01-01

403

Current section and species complex concepts in Aspergillus: recommendations for routine daily practice.  

PubMed

The identification of fungi by molecular techniques has generated important changes in fungal taxonomy. The use of molecular tools in taxonomic studies has led to the description of some cryptic species that were placed into a complex of morphologically similar organisms and were subsequently misidentified. There are still limited data available on the prevalence of cryptic species of Aspergillus in the clinical setting, although some studies report 10-14% of the total number of Aspergillus species. In addition, the main concern about the emergence of Aspergillus cryptic species is that they can be more resistant to antifungal agents. The rise in the incidence of fungal infections and the changing landscape of epidemiology, together with the description of new pathogens and their different susceptibility profiles, make the identification by molecular methods and/or antifungal susceptibility testing the best options available for the correct management of these infections. PMID:23230833

Alastruey-Izquierdo, Ana; Mellado, Emilia; Cuenca-Estrella, Manuel

2012-12-01

404

Identification and cloning of a second phytase gene (phyB) from Aspergillus niger (ficuum).  

PubMed

An Aspergillus niger (ficuum) genomic DNA lambda EMBL3 library was probed with a 354-bp DNA fragment obtained by polymerase chain reaction of A. niger DNA with oligonucleotides based on partial amino acid sequence of a pH 2.5 optimum acid phosphatase. A clone containing a 1605 bp segment (phyB) encoding the 479 amino acid enzyme was isolated and found to contain four exons. Global alignment revealed 23.5% homology to Aspergillus niger phytase (PhyA); four regions of extensive homology were identified. Some of these regions may contain catalytic sites for phosphatase function. PMID:7916610

Ehrlich, K C; Montalbano, B G; Mullaney, E J; Dischinger, H C; Ullah, A H

1993-08-31

405

Calcium oxalate crystal deposition in a patient with Aspergilloma due to Aspergillus niger  

PubMed Central

Discrimination between aspergilloma and chronic necrotizing pulmonary aspergillosis (CNPA) based on radiological findings can difficult. We describe a patient with aspergilloma and organizing pneumonia that was possibly caused by Aspergillus niger infection and radiologically mimicked CNPA. A postmortem histological analysis showed diffuse alveolar damage that had originated in peri-cavitary lung parenchyma. Calcium oxalate or Aspergillus niger was located inside, but not outside the cavity in the right upper lobe. Calcium oxalate or other unknown hyphal bioactive components might provoke severe lung inflammation not only adjacent to the cavity, but also on the contralateral side.

Oda, Miku; Wakayama, Megumi; Shibuya, Kazutoshi; Ogawa, Yukari; Inui, Toshiya; Yokoyama, Emi; Inoue, Manami; Shimoyamada, Hiroaki; Fujiwara, Masachika; Ota, Tomohiro; Takizawa, Hajime; Goto, Hajime

2013-01-01

406

Toxigenic Aspergillus flavus and aflatoxins in Sri Lankan medicinal plant material.  

PubMed

The fungal flora of 6 Asian medicinal plants, Aerva lanata (Linn.) Juss. Alyssicarpus vaginalis D.C., Tribulus terrestris Linn. Adhatoda vasica Nees., Centella asciatica (L.) Urb., Cardiospermum halicacabum Linn. was determined. After surface disinfection Aspergillus spp. were most frequently observed. Aspergillus flavus, isolated from Alyssicarpus vaginalis and Aerva lanata produced aflatoxins in culture. Aflatoxin B1 was also detected in a sample of Aerra lanata at a level of 0.5 micrograms/g. Plant material destined for medicinal use should be stored carefully prior to its use to prevent growth of naturally occurring toxigenic mold fungi. PMID:1906136

Abeywickrama, K; Bean, G A

1991-03-01

407

Antifungal macrodiolide from Streptomyces sp.  

PubMed Central

Aerobic fermentation cultures of Streptomyces sp. produced an antifungal macrodiolide. This new antibiotic consists of two units of homononactic acid linked to form a cyclic diester. An unknown polypeptide was also isolated in trace quantities. The antibiotic with polypeptide complex showed high levels of antifungal activity compared with that of the macrodiolide alone. The macrodiolide also showed a stimulatory effect on some species of fungi. The production, purification, and characterization of these compounds are reported.

Jois, H R; Sarkar, A; Gurusiddaiah, S

1986-01-01

408

Pseudonocardia cypriaca sp. nov., Pseudonocardia salamisensis sp. nov., Pseudonocardia hierapolitana sp. nov. and Pseudonocardia kujensis sp. nov., isolated from soil.  

PubMed

The taxonomic positions of four novel actinomycetes isolated from soil samples, designated KT2142T, PM2084T, K236T and A4038T, were established by using a polyphasic approach. The organisms had chemical and morphological features that were consistent with their classification in the genus Pseudonocardia. Whole-cell hydrolysates of the four strains contained meso-diaminopimelic acid and arabinose and galactose as the diagnostic sugars (cell-wall type IV). Their predominant menaquinone was found to be MK-8(H4). The major fatty acid was iso-C16:0. 16S rRNA gene sequence data supported the classification of the isolates in the genus Pseudonocardia and showed that they formed four distinct branches within the genus. DNA-DNA relatedness studies between the isolates and their phylogenetic neighbours showed that they belonged to distinct genomic species. The four isolates were readily distinguished from one another and from the type strains of species classified in the genus Pseudonocardia based on a combination of phenotypic and genotypic properties. In conclusion, it is proposed that the four isolates be classified in four novel species of the genus Pseudonocardia, for which the names Pseudonocardia cypriaca sp. nov. (type strain KT2142T=KCTC 29067T=DSM 45511T=NRRL B-24882T), Pseudonocardia hierapolitana sp. nov. (type strain PM2084T=KCTC 29068T=DSM 45671T=NRRL B-24879T), Pseudonocardia salamisensis sp. nov. (type strain K236T=KCTC 29100T=DSM 45717T) and Pseudonocardia kujensis sp. nov. (type strain A4038T=KCTC 29062T=DSM 45670T=NRRL B-24890T) are proposed. PMID:24523445

Sahin, Nevzat; Veyisoglu, Aysel; Tatar, Demet; Spröer, Cathrin; Cetin, Demet; Guven, Kiymet; Klenk, Hans-Peter

2014-05-01

409

Homologue expression of a ?-xylosidase from native Aspergillus niger.  

PubMed

Xylan constitutes the second most abundant source of renewable organic carbon on earth and is located in the cell walls of hardwood and softwood plants in the form of hemicellulose. Based on its availability, there is a growing interest in production of xylanolytic enzymes for industrial applications. ?-1,4-xylan xylosidase (EC 3.2.1.37) hydrolyses from the nonreducing end of xylooligosaccharides arising from endo-1,4-?-xylanase activity. This work reports the partial characterization of a purified ?-xylosidase from the native strain Aspergillus niger GS1 expressed by means of a fungal system. A gene encoding ?-xylosidase, xlnD, was successfully cloned from a native A. niger GS1 strain. The recombinant enzyme was expressed in A. niger AB4.1 under control of A. nidulans gpdA promoter and trpC terminator. ?-xylosidase was purified by affinity chromatography, with an apparent molecular weight of 90 kDa, and showed a maximum activity of 4,280 U mg protein(-1) at 70°C, pH 3.6. Half-life was 74 min at 70°C, activation energy was 58.9 kJ mol(-1), and at 50°C optimum stability was shown at pH 4.0-5.0. ?-xylosidase kept residual activity >83% in the presence of dithiothreitol (DTT), ?-mercaptoethanol, sodium dodecyl sulfate (SDS), ethylenediaminetetraacetate (EDTA), and Zn(2+). Production of a hemicellulolytic free xylosidase showed some advantages in applications, such as animal feed, enzymatic synthesis, and the fruit-juice industry where the presence of certain compounds, high temperatures, and acid media is unavoidable in the juice-making process. PMID:21116681

Amaro-Reyes, A; García-Almendárez, B E; Vázquez-Mandujano, D G; Amaya-Llano, S; Castańo-Tostado, E; Guevara-González, R G; Loera, O; Regalado, C

2011-09-01

410

How Peroxisomes Affect Aflatoxin Biosynthesis in Aspergillus Flavus  

PubMed Central

In filamentous fungi, peroxisomes are crucial for the primary metabolism and play a pivotal role in the formation of some secondary metabolites. Further, peroxisomes are important site for fatty acids ?-oxidation, the formation of reactive oxygen species and for their scavenging through a complex of antioxidant activities. Oxidative stress is involved in different metabolic events in all organisms and it occurs during oxidative processes within the cell, including peroxisomal ?-oxidation of fatty acids. In Aspergillus flavus, an unbalance towards an hyper-oxidant status into the cell is a prerequisite for the onset of aflatoxin biosynthesis. In our preliminary results, the use of bezafibrate, inducer of both peroxisomal ?-oxidation and peroxisome proliferation in mammals, significantly enhanced the expression of pex11 and foxA and stimulated aflatoxin synthesis in A. flavus. This suggests the existence of a correlation among peroxisome proliferation, fatty acids ?-oxidation and aflatoxin biosynthesis. To investigate this correlation, A. flavus was transformed with a vector containing P33, a gene from Cymbidium ringspot virus able to induce peroxisome proliferation, under the control of the promoter of the Cu,Zn-sod gene of A. flavus. This transcriptional control closely relates the onset of the antioxidant response to ROS increase, with the proliferation of peroxisomes in A. flavus. The AfP33 transformant strain show an up-regulation of lipid metabolism and an higher content of both intracellular ROS and some oxylipins. The combined presence of a higher amount of substrates (fatty acids-derived), an hyper-oxidant cell environment and of hormone-like signals (oxylipins) enhances the synthesis of aflatoxins in the AfP33 strain. The results obtained demonstrated a close link between peroxisome metabolism and aflatoxin synthesis.

Reverberi, Massimo; Punelli, Marta; Smith, Carrie A.; Zjalic, Slaven; Scarpari, Marzia; Scala, Valeria; Cardinali, Giorgia; Aspite, Nicaela; Pinzari, Flavia; Payne, Gary A.; Fabbri, Anna A.; Fanelli, Corrado

2012-01-01

411

The Proteomic Signature of Aspergillus fumigatus During Early Development*  

PubMed Central

Aspergillus fumigatus is a saprophytic fungus that causes a range of diseases in humans including invasive aspergillosis. All forms of disease begin with the inhalation of conidia, which germinate and develop. Four stages of early development were evaluated using the gel free system of isobaric tagging for relative and absolute quantitation to determine the full proteomic profile of the pathogen. A total of 461 proteins were identified at 0, 4, 8, and 16 h and fold changes for each were established. Ten proteins including the hydrophobin rodlet protein RodA and a protein involved in melanin synthesis Abr2 were found to decrease relative to conidia. To generate a more comprehensive view of early development, a whole genome microarray analysis was performed comparing conidia to 8 and 16 h of growth. A total of 1871 genes were found to change significantly at 8 h with 1001 genes up-regulated and 870 down-regulated. At 16 h, 1235 genes changed significantly with 855 up-regulated and 380 down-regulated. When a comparison between the proteomics and microarray data was performed at 8 h, a total of 22 proteins with significant changes also had corresponding genes that changed significantly. When the same comparison was performed at 16 h, 12 protein and gene combinations were found. This study, the most comprehensive to date, provides insights into early pathways activated during growth and development of A. fumigatus. It reveals a pathogen that is gearing up for rapid growth by building translation machinery, generating ATP, and is very much committed to aerobic metabolism.

Cagas, Steven E.; Jain, Mohit Raja; Li, Hong; Perlin, David S.

2011-01-01

412

Serum stimulates growth of and proteinase secretion by Aspergillus fumigatus.  

PubMed

Serum contains iron-binding proteins, which inhibit the growth of most pathogenic microorganisms, including fungi. The purpose of this research was to investigate the effect of serum on growth of the opportunistic fungal pathogen Aspergillus fumigatus. Supplementing minimal essential medium (MEM) with up to 80% human serum or up to 80% fetal bovine serum (FBS) stimulated growth and increased the amount of A. fumigatus dry biomass approximately fourfold. In addition, a 100-fold increase in proteinase secretion, as measured by azocasein hydrolysis, was observed when 10% human serum or 10% FBS was added to MEM. The fungal proteinases secreted in serum-containing media were shown to degrade (3)H-labeled basal lamina proteins. The factor in serum that stimulated proteinase secretion was larger than 10 kDa and was 85% inactivated when the serum was heated for 30 min at 66 degrees C. The proportions of proteinases of each catalytic class secreted by A. fumigatus in the presence of serum were different from the proportions secreted in media containing single proteins. Proteinase secretion did not result from increased protein concentration in the medium per se because bovine serum albumin (BSA) at a concentration equivalent to the concentration of serum produced only 20% of the proteinase activity per milligram (dry weight) that was produced by FBS. Addition of BSA plus 100 microM FeCl(3) to MEM resulted in the same level of growth as addition of serum, indicating that a combination of nutritional factors in serum may stimulate growth. However, the level of proteinase secretion was still only 30% of the level observed with FBS. These data indicate that serum does not inhibit the growth of A. fumigatus and that the nutrients in serum result in high levels of proteinase secretion, potentially increasing the invasiveness of this species. PMID:11748159

Gifford, Anna H T; Klippenstein, Jodine R; Moore, Margo M

2002-01-01

413

Invasive Aspergillus infections in hospitalized patients with chronic lung disease  

PubMed Central

Background Although invasive pulmonary aspergillosis (IPA) is more prevalent in immunocompromised patients, critical care clinicians need to be aware of the occurrence of IPA in the nontraditional host, such as a patient with chronic lung disease. The purpose of this study was to describe the IPA patient with chronic lung disease and compare the data with that of immunocompromised patients. Methods The records of 351 patients with Aspergillus were evaluated in this single-center, retrospective study for evidence and outcomes of IPA. The outcomes of 57 patients with chronic lung disease and 56 immunocompromised patients were compared. Patients with chronic lung disease were defined by one of the following descriptive terms: emphysema, asthma, idiopathic lung disease, bronchitis, bronchiectasis, sarcoid, or pulmonary leukostasis. Results Baseline demographics were similar between the two groups. Patients with chronic lung disease were primarily defined by emphysema (61%) and asthma (18%), and immunocompromised patients primarily had malignancies (27%) and bone marrow transplants (14%). A higher proportion of patients with chronic lung disease had a diagnosis of IPA by bronchoalveolar lavage versus the immunocompromised group (P < 0.03). The major risk factors for IPA were found to be steroid use in the chronic lung disease group and neutropenia and prior surgical procedures in the immunocompromised group. Overall, 53% and 69% of chronic lung disease and immunocompromised patients were cured (P = 0.14); 55% of chronic lung patients and 47% of immunocompromised patients survived one month (P = 0.75). Conclusion Nontraditional patients with IPA, such as those with chronic lung disease, have outcomes and mortality similar to that in the more traditional immunocompromised population.

Wessolossky, Mireya; Welch, Verna L; Sen, Ajanta; Babu, Tara M; Luke, David R

2013-01-01

414

Eosinophil deficiency compromises lung defense against Aspergillus fumigatus.  

PubMed

Exposure to the mold Aspergillus fumigatus may result in allergic bronchopulmonary aspergillosis, chronic necrotizing pulmonary aspergillosis, or invasive aspergillosis (IA), depending on the host's immune status. Neutrophil deficiency is the predominant risk factor for the development of IA, the most life-threatening condition associated with A. fumigatus exposure. Here we demonstrate that in addition to neutrophils, eosinophils are an important contributor to the clearance of A. fumigatus from the lung. Acute A. fumigatus challenge in normal mice induced the recruitment of CD11b+ Siglec F+ Ly-6G(lo) Ly-6C(neg) CCR3+ eosinophils to the lungs, which was accompanied by an increase in lung Epx (eosinophil peroxidase) mRNA levels. Mice deficient in the transcription factor dblGATA1, which exhibit a selective deficiency in eosinophils, demonstrated impaired A. fumigatus clearance and evidence of germinating organisms in the lung. Higher burden correlated with lower mRNA expression of Epx (eosinophil peroxidase) and Prg2 (major basic protein) as well as lower interleukin 1? (IL-1?), IL-6, IL-17A, granulocyte colony-stimulating factor (G-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and CXCL1 levels. However, examination of lung inflammatory cell populations failed to demonstrate defects in monocyte/macrophage, dendritic cell, or neutrophil recruitment in dblGATA1-deficient mice, suggesting that the absence of eosinophils in dlbGATA1-deficient mice was the sole cause of impaired lung clearance. We show that eosinophils generated from bone marrow have potent killing activity against A. fumigtaus in vitro, which does not require cell contact and can be recapitulated by eosinophil whole-cell lysates. Collectively, our data support a role for eosinophils in the lung response after A. fumigatus exposure. PMID:24379296

Lilly, Lauren M; Scopel, Michaella; Nelson, Michael P; Burg, Ashley R; Dunaway, Chad W; Steele, Chad

2014-03-01

415

Physiological characterization of ATP-citrate lyase in Aspergillus niger.  

PubMed

Acetyl-CoA, an important molecule in cellular metabolism, is generated in multiple subcellular compartments and mainly used for energy production, biosynthesis of a diverse set of molecules, and protein acetylation. In eukaryotes, cytosolic acetyl-CoA is derived mainly from the conversion of citrate and CoA by ATP-citrate lyase. Here, we describe the targeted deletions of acl1 and acl2, two tandem divergently transcribed genes encoding subunits of ATP-citrate lyase in Aspergillus niger. We show that loss of acl1 or/and acl2 results in a significant decrease of acetyl-CoA and citric acid levels in these mutants, concomitant with diminished vegetative growth, decreased pigmentation, reduced asexual conidiogenesis, and delayed conidial germination. Exogenous addition of acetate repaired the defects of acl-deficient strains in growth and conidial germination but not pigmentation and conidiogenesis. We demonstrate that both Acl1 and Acl2 subunits are required to form a functional ATP-citrate lyase in A. niger. First, deletion of acl1 or/and acl2 resulted in similar defects in growth and development. Second, enzyme activity assays revealed that loss of either acl1 or acl2 gene resulted in loss of ATP-citrate lyase activity. Third, in vitro enzyme assays using bacterially expressed 6His-tagged Acl protein revealed that only the complex of Acl1 and Acl2 showed ATP-citrate lyase activity, no enzyme activities were detected with the individual protein. Fourth, EGFP-Acl1 and mCherry-Acl2 proteins were co-localized in the cytosol. Thus, acl1 and acl2 coordinately modulate the cytoplasmic acetyl-CoA levels to regulate growth, development, and citric acid synthesis in A. niger. PMID:24566752

Chen, Hong; He, Xihong; Geng, Hongran; Liu, Hao

2014-04-01

416

Cell cycle regulation in Aspergillus by two protein kinases.  

PubMed Central

Great progress has recently been made in our understanding of the regulation of the eukaryotic cell cycle, and the central role of cyclin-dependent kinases is now clear. In Aspergillus nidulans it has been established that a second class of cell-cycle-regulated protein kinases, typified by NIMA (encoded by the nimA gene), is also required for cell cycle progression into mitosis. Indeed, both p34cdc2/cyclin B and NIMA have to be correctly activated before mitosis can be initiated in this species, and p34cdc2/cyclin B plays a role in the mitosis-specific activation of NIMA. In addition, both kinases have to be proteolytically destroyed before mitosis can be completed. NIMA-related kinases may also regulate the cell cycle in other eukaryotes, as expression of NIMA can promote mitotic events in yeast, frog or human cells. Moreover, dominant-negative versions of NIMA can adversely affect the progression of human cells into mitosis, as they do in A. nidulans. The ability of NIMA to influence mitotic regulation in human and frog cells strongly suggests the existence of a NIMA pathway of mitotic regulation in higher eukaryotes. A growing number of NIMA-related kinases have been isolated from organisms ranging from fungi to humans, and some of these kinases are also cell-cycle-regulated. How NIMA-related kinases and cyclin-dependent kinases act in concert to promote cell cycle transitions is just beginning to be understood. This understanding is the key to a full knowledge of cell cycle regulation.

Osmani, S A; Ye, X S

1996-01-01

417

Calcineurin Controls Growth, Morphology, and Pathogenicity in Aspergillus fumigatus  

PubMed Central

Calcineurin is implicated in a myriad of human diseases as well as homeostasis and virulence in several major human pathogenic microorganisms. The fungus Aspergillus fumigatus is a leading cause of infectious death in the rapidly expanding immunocompromised patient population. Current antifungal treatments for invasive aspergillosis are often ineffective, and novel therapeutic approaches are urgently needed. We demonstrate that a mutant of A. fumigatus lacking the calcineurin A (cnaA) catalytic subunit exhibited defective hyphal morphology related to apical extension and polarized growth, which resulted in drastically decreased filamentation. The ?cnaA mutant lacked the extensive lattice of invading hyphae seen with the wild-type and complemented strains. Sporulation was also affected in the ?cnaA mutant, including morphological conidial defects with the absence of surface rodlets and the added presence of disjunctors creating long conidial chains. Infection with the ?cnaA mutant in several distinct animal models with different types of immunosuppression and inoculum delivery led to a profound attenuation of pathogenicity compared to infection with the wild-type and complemented strains. Lung tissue from animals infected with the ?cnaA mutant showed a complete absence of hyphae, in contrast to tissue from animals infected with the wild-type and complemented strains. Quantitative fungal burden and pulmonary infarct scoring confirmed these findings. Our results support the clinical observation that substantially decreasing fungal growth can prevent disease establishment and decrease mortality. Our findings reveal that calcineurin appears to play a globally conserved role in the virulence of several pathogenic fungi and yet plays specialized roles in each and can be an excellent target for therapeutic intervention.

Steinbach, William J.; Cramer, Robert A.; Perfect, B. Zachary; Asfaw, Yohannes G.; Sauer, Theodor C.; Najvar, Laura K.; Kirkpatrick, William R.; Patterson, Thomas F.; Benjamin, Daniel K.; Heitman, Joseph; Perfect, John R.

2006-01-01

418

Serum Stimulates Growth of and Proteinase Secretion by Aspergillus fumigatus  

PubMed Central

Serum contains iron-binding proteins, which inhibit the growth of most pathogenic microorganisms, including fungi. The purpose of this research was to investigate the effect of serum on growth of the opportunistic fungal pathogen Aspergillus fumigatus. Supplementing minimal essential medium (MEM) with up to 80% human serum or up to 80% fetal bovine serum (FBS) stimulated growth and increased the amount of A. fumigatus dry biomass approximately fourfold. In addition, a 100-fold increase in proteinase secretion, as measured by azocasein hydrolysis, was observed when 10% human serum or 10% FBS was added to MEM. The fungal proteinases secreted in serum-containing media were shown to degrade 3H-labeled basal lamina proteins. The factor in serum that stimulated proteinase secretion was larger than 10 kDa and was 85% inactivated when the serum was heated for 30 min at 66°C. The proportions of proteinases of each catalytic class secreted by A. fumigatus in the presence of serum were different from the proportions secreted in media containing single proteins. Proteinase secretion did not result from increased protein concentration in the medium per se because bovine serum albumin (BSA) at a concentration equivalent to the concentration of serum produced only 20% of the proteinase activity per milligram (dry weight) that was produced by FBS. Addition of BSA plus 100 ?M FeCl3 to MEM resulted in the same level of growth as addition of serum, indicating that a combination of nutritional factors in serum may stimulate growth. However, the level of proteinase secretion was still only 30% of the level observed with FBS. These data indicate that serum does not inhibit the growth of A. fumigatus and that the nutrients in serum result in high levels of proteinase secretion, potentially increasing the invasiveness of this species.

Gifford, Anna H. T.; Klippenstein, Jodine R.; Moore, Margo M.

2002-01-01

419

Peroxisomes are involved in biotin biosynthesis in Aspergillus and Arabidopsis.  

PubMed

Among the eukaryotes only plants and a number of fungi are able to synthesize biotin. Although initial events leading to the biosynthesis of biotin remain largely unknown, the final steps are known to occur in the mitochondria. Here we deleted the Aopex5 and Aopex7 genes encoding the receptors for peroxisomal targeting signals PTS1 and PTS2, respectively, in the filamentous fungus Aspergillus oryzae. In addition to exhibiting defects in the peroxisomal targeting of either PTS1 or PTS2 proteins, the deletion strains also displayed growth defects on minimal medium containing oleic acid as the sole carbon source. Unexpectedly, these peroxisomal transport-deficient strains also exhibited growth defects on minimal medium containing glucose as the sole carbon source that were remediated by the addition of biotin and its precursors, including 7-keto-8-aminopelargonic acid (KAPA). Genome database searches in fungi and plants revealed that BioF protein/KAPA synthase, one of the biotin biosynthetic enzymes, has a PTS1 sequence at the C terminus. Fungal ?bioF strains expressing the fungal and plant BioF proteins lacking PTS1 still exhibited growth defects in the absence of biotin, indicating that peroxisomal targeting of KAPA synthase is crucial for the biotin biosynthesis. Furthermore, in the plant Arabidopsis thaliana, AtBioF localized to the peroxisomes through recognition of its PTS1 sequence, suggesting involvement of peroxisomes in biotin biosynthesis in plants. Taken together we demonstrate a novel role for peroxisomes in biotin biosynthesis and suggest the presence of as yet unidentified peroxisomal proteins that function in the earlier steps of biotin biosynthesis. PMID:21730067

Tanabe, Yasuko; Maruyama, Jun-ichi; Yamaoka, Shohei; Yahagi, Daiki; Matsuo, Ichiro; Tsutsumi, Nobuhiro; Kitamoto, Katsuhiko

2011-09-01

420

Arabinase gene expression in Aspergillus niger: indications for coordinated regulation.  

PubMed

Aspergillus niger secretes three glycosylated glycosyl hydrolases which are involved in degradation of the plant cell wall polysaccharide L-arabinan: alpha-L-arabinofuranosidases (ABF) A and B, and endo-1,5-alpha-L-arabinase (ABN) A. The nucleotide sequence of the previously cloned gene encoding ABF A (abfA) from A. niger was determined. The coding region contains seven introns. Mature ABF A comprises 603 amino acids with a molecular mass of 65.4 kDa as deduced from the nucleotide sequence. The secreted enzyme is N-glycosylated. The primary structures of the three A. niger arabinases characterized lack similarity. Regulation of arabinase expression upon induction by sugar beet pulp and by L-arabitol was studied as a function of time. This was done in wild-type A. niger as well as in transformants carrying multiple copies of either one of the ABF-encoding genes. Each arabinase gene responded differently upon a mycelial transfer to L-arabitol-containing medium. Extra copies of abfA or abfB led to a decreased expression level of ABN A, though the repression elicited by abfB is stronger and more persistent than that effected by abfA. Multiple copies of both abf genes influence expression of the other ABF similarly, but to a far less pronounced degree than they affect ABN A synthesis. Four putative promoter elements, shared by all three arabinase genes, could be involved in coordination of L-arabinan degradation by A. niger. PMID:8000538

Flipphi, M J; Visser, J; van der Veen, P; de Graaff, L H

1994-10-01

421

The proteomic signature of Aspergillus fumigatus during early development.  

PubMed

Aspergillus fumigatus is a saprophytic fungus that causes a range of diseases in humans including invasive aspergillosis. All forms of disease begin with the inhalation of conidia, which germinate and develop. Four stages of early development were evaluated using the gel free system of isobaric tagging for relative and absolute quantitation to determine the full proteomic profile of the pathogen. A total of 461 proteins were identified at 0, 4, 8, and 16 h and fold changes for each were established. Ten proteins including the hydrophobin rodlet protein RodA and a protein involved in melanin synthesis Abr2 were found to decrease relative to conidia. To generate a more comprehensive view of early development, a whole genome microarray analysis was performed comparing conidia to 8 and 16 h of growth. A total of 1871 genes were found to change significantly at 8 h with 1001 genes up-regulated and 870 down-regulated. At 16 h, 1235 genes changed significantly with 855 up-regulated and 380 down-regulated. When a comparison between the proteomics and microarray data was performed at 8 h, a total of 22 proteins with significant changes also had corresponding genes that changed significantly. When the same comparison was performed at 16 h, 12 protein and gene combinations were found. This study, the most comprehensive to date, provides insights into early pathways activated during growth and development of A. fumigatus. It reveals a pathogen that is gearing up for rapid growth by building translation machinery, generating ATP, and is very much committed to aerobic metabolism. PMID:21825280

Cagas, Steven E; Jain, Mohit Raja; Li, Hong; Perlin, David S

2011-11-01

422

Eisosome Organization in the Filamentous AscomyceteAspergillus nidulans?†  

PubMed Central

Eisosomes are subcortical organelles implicated in endocytosis and have hitherto been described only in Saccharomyces cerevisiae. They comprise two homologue proteins, Pil1 and Lsp1, which colocalize with the transmembrane protein Sur7. These proteins are universally conserved in the ascomycetes. We identify in Aspergillus nidulans (and in all members of the subphylum Pezizomycotina) two homologues of Pil1/Lsp1, PilA and PilB, originating from a duplication independent from that extant in the subphylum Saccharomycotina. In the aspergilli there are several Sur7-like proteins in each species, including one strict Sur7 orthologue (SurG in A. nidulans). In A. nidulans conidiospores, but not in hyphae, the three proteins colocalize at the cell cortex and form tightly packed punctate structures that appear different from the clearly distinct eisosome patches observed in S. cerevisiae. These structures are assembled late during the maturation of conidia. In mycelia, punctate structures are present, but they are composed only of PilA, while PilB is diffused in the cytoplasm and SurG is located in vacuoles and endosomes. Deletion of each of the genes does not lead to any obvious growth phenotype, except for moderate resistance to itraconazole. We could not find any obvious association between mycelial (PilA) eisosome-like structures and endocytosis. PilA and SurG are necessary for conidial eisosome organization in ways that differ from those for their S. cerevisiae homologues. These data illustrate that conservation of eisosomal proteins within the ascomycetes is accompanied by a striking functional divergence.

Vangelatos, Ioannis; Roumelioti, Katerina; Gournas, Christos; Suarez, Teresa; Scazzocchio, Claudio; Sophianopoulou, Vicky

2010-01-01

423

How peroxisomes affect aflatoxin biosynthesis in Aspergillus flavus.  

PubMed

In filamentous fungi, peroxisomes are crucial for the primary metabolism and play a pivotal role in the formation of some secondary metabolites. Further, peroxisomes are important site for fatty acids ?-oxidation, the formation of reactive oxygen species and for their scavenging through a complex of antioxidant activities. Oxidative stress is involved in different metabolic events in all organisms and it occurs during oxidative processes within the cell, including peroxisomal ?-oxidation of fatty acids. In Aspergillus flavus, an unbalance towards an hyper-oxidant status into the cell is a prerequisite for the onset of aflatoxin biosynthesis. In our preliminary results, the use of bezafibrate, inducer of both peroxisomal ?-oxidation and peroxisome proliferation in mammals, significantly enhanced the expression of pex11 and foxA and stimulated aflatoxin synthesis in A. flavus. This suggests the existence of a correlation among peroxisome proliferation, fatty acids ?-oxidation and aflatoxin biosynthesis. To investigate this correlation, A. flavus was transformed with a vector containing P33, a gene from Cymbidium ringspot virus able to induce peroxisome proliferation, under the control of the promoter of the Cu,Zn-sod gene of A. flavus. This transcriptional control closely relates the onset of the antioxidant response to ROS increase, with the proliferation of peroxisomes in A. flavus. The AfP33 transformant strain show an up-regulation of lipid metabolism and an higher content of both intracellular ROS and some oxylipins. The combined presence of a higher amount of substrates (fatty acids-derived), an hyper-oxidant cell environment and of hormone-like signals (oxylipins) enhances the synthesis of aflatoxins in the AfP33 strain. The results obtained demonstrated a close link between peroxisome metabolism and aflatoxin synthesis. PMID:23094106

Reverberi, Massimo; Punelli, Marta; Smith, Carrie A; Zjalic, Slaven; Scarpari, Marzia; Scala, Valeria; Cardinali, Giorgia; Aspite, Nicaela; Pinzari, Flavia; Payne, Gary A; Fabbri, Anna A; Fanelli, Corrado

2012-01-01

424

Characterization of a recombinant ?-glucuronidase from Aspergillus fumigatus.  

PubMed

The degradation of xylan requires the action of glycanases and esterases which hydrolyse, in a synergistic fashion, the main chain and the different substituents which decorate its structure. Among the xylanolytic enzymes acting on side-chains are the ?-glucuronidases (AguA) (E.C. 3.2.1.139) which release methyl glucuronic acid residues. These are the least studies among the xylanolytic enzymes. In this work, the gene and cDNA of an ?-glucuronidase from a newly isolated strain of Aspergillus fumigatus have been sequenced, and the gene has been expressed in Pichia pastoris. The gene is 2523 bp long, has no introns and codes for a protein of 840 amino acid residues including a putative signal peptide of 19 residues. The mature protein has a calculated molecular weight of 91,725 and shows 99 % identity with a putative ?-glucuronidase from A. fumigatus A1163. The recombinant enzyme was expressed with a histidine tag and was purified to near homogeneity with a nickel nitriloacetic acid (Ni-NTA) column. The purified enzyme has a molecular weight near 100,000. It is inactive using birchwood glucuronoxylan as substrate. Activity is observed in the presence of xylooligosaccharides generated from this substrate by a family 10 endoxylanase and when a mixture of aldouronic acids are used as substrates. If, instead, family 11 endoxylanase is used to generate oligosaccharides, no activity is detected, indicating a different specificity in the cleavage of xylan by family 10 and 11 endoxylanases. Enzyme activity is optimal at 37 °C and pH 4.5-5. The enzyme binds cellulose, thus it likely possesses a carbohydrate binding module. Based on its properties and sequence similarities the catalytic module of the newly described ?-glucuronidase can be classified in family 67 of the glycosyl hydrolases. The recombinant enzyme may be useful for biotechnological applications of ?-glucuronidases. PMID:23719223

Rosa, Lorena; Ravanal, María Cristina; Mardones, Wladimir; Eyzaguirre, Jaime

2013-05-01

425

Peroxisomes Are Involved in Biotin Biosynthesis in Aspergillus and Arabidopsis*  

PubMed Central

Among the eukaryotes only plants and a number of fungi are able to synthesize biotin. Although initial events leading to the biosynthesis of biotin remain largely unknown, the final steps are known to occur in the mitochondria. Here we deleted the Aopex5 and Aopex7 genes encoding the receptors for peroxisomal targeting signals PTS1 and PTS2, respectively, in the filamentous fungus Aspergillus oryzae. In addition to exhibiting defects in the peroxisomal targeting of either PTS1 or PTS2 proteins, the deletion strains also displayed growth defects on minimal medium containing oleic acid as the sole carbon source. Unexpectedly, these peroxisomal transport-deficient strains also exhibited growth defects on minimal medium containing glucose as the sole carbon source that were remediated by the addition of biotin and its precursors, including 7-keto-8-aminopelargonic acid (KAPA). Genome database searches in fungi and plants revealed that BioF protein/KAPA synthase, one of the biotin biosynthetic enzymes, has a PTS1 sequence at the C terminus. Fungal ?bioF strains expressing the fungal and plant BioF proteins lacking PTS1 still exhibited growth defects in the absence of biotin, indicating that peroxisomal targeting of KAPA synthase is crucial for the biotin biosynthesis. Furthermore, in the plant Arabidopsis thaliana, AtBioF localized to the peroxisomes through recognition of its PTS1 sequence, suggesting involvement of peroxisomes in biotin biosynthesis in plants. Taken together we demonstrate a novel role for peroxisomes in biotin biosynthesis and suggest the presence of as yet unidentified peroxisomal proteins that function in the earlier steps of biotin biosynthesis.

Tanabe, Yasuko; Maruyama, Jun-ichi; Yamaoka, Shohei; Yahagi, Daiki; Matsuo, Ichiro; Tsutsumi, Nobuhiro; Kitamoto, Katsuhiko

2011-01-01

426

Vacuolar membrane dynamics in the filamentous fungus Aspergillus oryzae.  

PubMed

Vacuoles in filamentous fungi are highly pleomorphic and some of them, e.g., tubular vacuoles, are implicated in intra- and intercellular transport. In this report, we isolated Aovam3, the homologue of the Saccharomyces cerevisiae VAM3 gene that encodes the vacuolar syntaxin, from Aspergillus oryzae. In yeast complementation analyses, the expression of Aovam3 restored the phenotypes of both Deltavam3 and Deltapep12 mutants, suggesting that AoVam3p is likely the vacuolar and/or endosomal syntaxin in A. oryzae. FM4-64 [N-(3-triethylammoniumpropyl)-4-(p-diethylaminophenyl-hexatrienyl)pyridinium dibromide] and CMAC (7-amino-4-chloromethylcoumarin) staining confirmed that the fusion protein of enhanced green fluorescent protein (EGFP) with AoVam3p (EGFP-AoVam3p) localized on the membrane of the pleomorphic vacuolar networks, including large spherical vacuoles, tubular vacuoles, and putative late endosomes/prevacuolar compartments. EGFP-AoVam3p-expressing strains allowed us to observe the dynamics of vacuoles with high resolutions, and moreover, led to the discovery of several new aspects of fungal vacuoles, which have not been discovered so far with conventional staining methods, during different developmental stages. In old hyphae, EGFP fluorescence was present in the entire lumen of large vacuoles, which occupied most of the cell, indicating that degradation of cytosolic materials had occurred in such hyphae via an autophagic process. In hyphae that were not in contact with nutrients, such as aerial hyphae and hyphae that grew on a glass surface, vacuoles were composed of small punctate structures and tubular elements that often formed reticulum-like networks. These observations imply the presence of so-far-unrecognized roles of vacuoles in the development of filamentous fungi. PMID:16467481

Shoji, Jun-ya; Arioka, Manabu; Kitamoto, Katsuhiko

2006-02-01

427

Isolation and characterization of Aspergillus oryzae vacuolar protein sorting mutants.  

PubMed

The vacuolar protein sorting (vps) system in the filamentous fungus Aspergillus oryzae, which has unique cell polarity and the ability to secrete large amounts of proteins, was evaluated by using mutants that missort vacuolar proteins into the medium. Vacuolar carboxypeptidase Y (CPY) fused with enhanced green fluorescent protein (EGFP) was used as a vacuolar marker. Twenty dfc (dim EGFP fluorescence in conidia) mutants with reduced intracellular EGFP fluorescence in conidia were isolated by fluorescence-activated cell sorting from approximately 20,000 UV-treated conidia. Similarly, 22 hfm (hyper-EGFP fluorescence released into the medium) mutants with increased extracellular EGFP fluorescence were isolated by using a fluorescence microplate reader from approximately 20,000 UV-treated conidia. The dfc and hfm mutant phenotypes were pH dependent, and missorting of CPY-EGFP could vary by 10- to 40-fold depending on the ambient pH. At pH 5.5, the dfc-14 and hfm-4 mutants had an abnormal hyphal morphology that is consistent with fragmentation of vacuoles and defects in cell polarity. In contrast, the hyphal and vacuolar morphology of the dfc-14 and hfm-4 mutants was normal at pH 8.0, although CPY-EGFP accumulated in perivacuolar dot-like structures similar to the class E compartments in Saccharomyces cerevisiae vps mutants. In hfm-21, CPY-EGFP localized at the Spitzenkörper when the mutant was grown at pH 8.0 but not in vacuoles, suggesting that hfm-21 may transport CPY-EGFP via a novel pathway that involves the Spitzenkörper. Correlations between vacuolar protein sorting, pH response, and cell polarity are reported for the first time for filamentous fungi. PMID:16085884

Ohneda, Mamoru; Arioka, Manabu; Kitamoto, Katsuhiko

2005-08-01

428

Breeding of starch-utilizing and itaconic-acid-producing koji molds by interspecific protoplast fusion between Aspergillus terreus and Aspergillus usamii  

Microsoft Academic Search

Interspecific protoplast fusion between?Aspergillus terreus, an itaconic acid producer, and A.?usamii, a glucoamylase producer, was done to breed new koji molds producing itaconic acid from starch. Protoplast fusion between auxotrophic mutant strains by poly(ethylene glycol) treatment\\u000a produced prototrophic fusants with a fusion frequency of 10?5?10?4. The stabilities of some fusants obtained were confirmed by successive subcultures. Conidial analyses of DNA

K. Kirimura; T. Sato; N. Nakanishi; M. Terada; S. Usami

1997-01-01

429

Aspergillus parasiticus communities associated with sugarcane in the Rio Grande Valley of Texas: implications of global transport and host association within Aspergillus section Flavi.  

PubMed

In the Rio Grande Valley of Texas (RGV), values of maize and cottonseed crops are significantly reduced by aflatoxin contamination. Aflatoxin contamination of susceptible crops is the product of communities of aflatoxin producers and the average aflatoxin-producing potentials of these communities influence aflatoxin contamination risk. Cropping pattern influences community composition and, thereby, the epidemiology of aflatoxin contamination. In 2004, Aspergillus parasiticus was isolated from two fields previously cropped to sugarcane but not from 23 fields without recent history of sugarcane cultivation. In 2004 and 2005, A. parasiticus composed 18 to 36% of Aspergillus section Flavi resident in agricultural soils within sugarcane-producing counties. A. parasiticus was not detected in counties that do not produce sugarcane. Aspergillus section Flavi soil communities within sugarcane-producing counties differed significantly dependent on sugarcane cropping history. Fields cropped to sugarcane within the previous 5 years had greater quantities of A. parasiticus (mean = 16 CFU/g) than fields not cropped to sugarcane (mean = 0.1 CFU/g). The percentage of Aspergillus section Flavi composed of A. parasiticus increased to 65% under continuous sugarcane cultivation and remained high the first season of rotation out of sugarcane. Section Flavi communities in fields rotated to non-sugarcane crops for 3 to 5 years were composed of <5% A. parasiticus, and fields with no sugarcane history averaged only 0.2% A. parasiticus. The section Flavi community infecting RGV sugarcane stems ranged from 95% A. parasiticus in billets prepared for commercial planting to 52% A. parasiticus in hand-collected sugarcane stems. Vegetative compatibility assays and multilocus phylogenies verified that aflatoxin contamination of raw sugar was previously attributed to similar A. parasiticus in Japan. Association of closely related A. parasiticus genotypes with sugarcane produced in Japan and RGV, frequent infection of billets by these genotypes, and the ephemeral nature of A. parasiticus in RGV soils suggests global transport with sugarcane planting material. PMID:24224872

Garber, N P; Cotty, P J

2014-05-01

430

Pantoea rodasii sp. nov., Pantoea rwandensis sp. nov. and Pantoea wallisii sp. nov., isolated from Eucalyptus.  

PubMed

Several Gram-negative-staining, facultatively anaerobic bacterial isolates were obtained from Eucalyptus seedlings showing symptoms of bacterial blight and dieback in Colombia, Rwanda and South Africa. Partial 16S rRNA gene sequencing, together with partial gyrB sequencing, placed the