Organic acid production by Aspergillus niger

DEFF Research Database (Denmark)

Jongh, Wian de

2006-01-01

. Specielt Aspergillus niger er interessant i forbindelse med produktion af organiske syrer, idet denne organisme tolerer lavt pH, kan give høje produktudbytter, og kan give høje produktiviteter som allerede illustreret i anvendelsen af denne organisme i produktionen af citronsyre. Disse faktorer gør A....... niger til en ideel kandidat for metabolic engineering, men anvendelsen af metabolic engineering til at udvikle en A. niger cellefabrik der producerer forskellige organiske syrer har været begrænset af vores kendskab til metabolismen og dens regulering i denne organisme. Formålet med dette Ph.D. stadium...... intracellulære metabolitter samt kontinuert fermentering af A. niger. Ved anvendelse af metabolic engieering lykkedes det at udvikle nogle stammer af A. niger der havde forbedret produktion af citrat. Mekanismerne bag de forbedrede produktiviteter blev undersøgt og resultaterne heraf er diskuteret i afhandlingen...

On the safety of Aspergillus niger - a review

DEFF Research Database (Denmark)

Schuster, E.; Dunn-Coleman, N.; Frisvad, Jens Christian

2002-01-01

Aspergillus niger is one of the most important microorganisms used in biotechnology. It has been in use already for many decades to produce extracellular (food) enzymes and citric acid. In fact, citric acid and many A. niger enzymes are considered GRAS by the United States Food and Drug...... retrieval reasons and there is a taxonomical consensus based on molecular data that the only other common species closely related to A. niger in the Aspergillus series Nigri is A. tubingensis. A. niger, like other filamentous fungi, should be treated carefully to avoid the formation of spore dust. However...... Administration. In addition, A. niger is used for biotransformations and waste treatment. In the last two decades, A. niger has been developed as an important transformation host to over-express food enzymes. Being pre-dated by older names, the name A. niger has been conserved for economical and information...

Aspergillus niger membrane-associated proteome analysis for the identification of glucose transporters.

Science.gov (United States)

Sloothaak, J; Odoni, D I; de Graaff, L H; Martins Dos Santos, V A P; Schaap, P J; Tamayo-Ramos, J A

2015-01-01

The development of biological processes that replace the existing petrochemical-based industry is one of the biggest challenges in biotechnology. Aspergillus niger is one of the main industrial producers of lignocellulolytic enzymes, which are used in the conversion of lignocellulosic feedstocks into fermentable sugars. Both the hydrolytic enzymes responsible for lignocellulose depolymerisation and the molecular mechanisms controlling their expression have been well described, but little is known about the transport systems for sugar uptake in A. niger. Understanding the transportome of A. niger is essential to achieve further improvements at strain and process design level. Therefore, this study aims to identify and classify A. niger sugar transporters, using newly developed tools for in silico and in vivo analysis of its membrane-associated proteome. In the present research work, a hidden Markov model (HMM), that shows a good performance in the identification and segmentation of functionally validated glucose transporters, was constructed. The model (HMMgluT) was used to analyse the A. niger membrane-associated proteome response to high and low glucose concentrations at a low pH. By combining the abundance patterns of the proteins found in the A. niger plasmalemma proteome with their HMMgluT scores, two new putative high-affinity glucose transporters, denoted MstG and MstH, were identified. MstG and MstH were functionally validated and biochemically characterised by heterologous expression in a S. cerevisiae glucose transport null mutant. They were shown to be a high-affinity glucose transporter (K m = 0.5 ± 0.04 mM) and a very high-affinity glucose transporter (K m = 0.06 ± 0.005 mM), respectively. This study, focusing for the first time on the membrane-associated proteome of the industrially relevant organism A. niger, shows the global response of the transportome to the availability of different glucose concentrations. Analysis of the A. niger

Identification of Genes Associated with Morphology in Aspergillus Niger by Using Suppression Subtractive Hybridization

Energy Technology Data Exchange (ETDEWEB)

Dai, Ziyu; Mao, Xingxue; Magnuson, Jon K.; Lasure, Linda L.

2004-04-01

The morphology of citric acid production strains of Aspergillus niger is sensitive to a variety of factors including the concentration of manganese (Mn2+). Upon increasing the Mn2+ concentration in A. niger (ATCC 11414) cultures to 14 ppb or higher, the morphology switches from pelleted to filamentous, accompanied by a rapid decline in citric acid production. Molecular mechanisms through which Mn2+ exerts effects on morphology and citric acid production in A. niger have not been well defined, but our use of suppression subtractive hybridization has identified 22 genes responsive to Mn2+. Fifteen genes were differentially expressed when A. niger was grown in media containing 1000 ppb Mn2+ (filamentous form) and seven genes in 10 ppb Mn2+ (pelleted form). Of the fifteen filamentous-associated genes, seven are novel and eight share 47-100% identity to genes from other organisms. Five of the pellet-associated genes are novel, and the other two genes encode a pepsin-type protease and polyubiquitin. All ten genes with deduced functions are either involved in amino acid metabolism/protein catabolism or cell regulatory processes. Northern-blot analysis showed that the transcripts of all 22 genes were rapidly enhanced or suppressed by Mn2+. Steady-state mRNA levels of six selected filamentous associated genes remained high during five days of culture in a filamentous state and low under pelleted growth conditions. The opposite behavior was observed for four selected pellet-associated genes. The full-length cDNA of the filamentous-associated clone, Brsa-25 was isolated. Antisense expression of Brsa-25 permitted pelleted growth and increased citrate production at higher concentrations of Mn2+ than could be tolerated by the parent strain. The results suggest the involvement of the newly isolated genes in regulation of A. niger morphology.

Recent Niger Delta shoreline response to Niger River hydrology: Conflict between forces of Nature and Humans

Science.gov (United States)

Dada, Olusegun A.; Li, Guangxue; Qiao, Lulu; Asiwaju-Bello, Yinusa Ayodele; Anifowose, Adeleye Yekini Biodun

2018-03-01

The Niger River Delta is a prolific hydrocarbon province and a mega-delta of economic and environmental relevance. To understand patterns of its recent shoreline evolution (1923-2013) in response to the Niger River hydrology, and establish the role played by forces of Nature and Human, available topographic and satellite remote sensing data, combined with hydro-climatic (rainfall and runoff) data were analyzed. Results indicate that the entire delta coastline dramatically receded: 82% of the >400 km-long coast retreated, during the period 1950-1987; and 69% between 2007 and 2012. Prior to 1950, there was a continuation of seaward advancement along 53-74% of the delta coast. The 1950-1987 shoreline recession coincided with occurrences of two major events in the Niger River basin; these are downward trends in hydro-climatic conditions (the great droughts of the 1970s-1980s), and dam construction on the Lower Niger River at Kainji (1964-1968). The 2007-2012 event corresponded with the extensive channel dredging during 2009-2012 in the Lower Niger River from the coastal town of Warri in the south to Baro in the north. Remarkably, the largest net shoreline advancement recorded in 74% of the entire delta area occurred within a year (2012-2013), which we link to increased sediment supply to the coast caused by the '2012' floods, adjudged the worst floods in the entire Niger River Basin in the last few decades. With both anthropogenic and environmental factors inducing delta evolution, only innovative river and coastal management can determine the fortune of the future coastal development of the Niger Delta.

Significance and occurrence of fumonisins from Aspergillus niger

DEFF Research Database (Denmark)

Mogensen, Jesper Mølgaard

Fumonisins is a well-studied group of mycotoxins, mainly produced in maize by Fusarium species. However with the recent discovery of a fumonisin production by Aspergillus niger, other food commodities are at risk, since A. niger is a ubiquitous contaminant of many food and feed products....... The objective of this thesis was to determine the significance and occurrence of fumonisins from Aspergillus niger in food, the frequency of fumonisin production in A. niger isolates, as well as studies of the effect of physiological factors affecting fumonisin production. Major findings in this context have...... been the ocumentation of the production of fumonisins in raisins and peanuts, and occurrence of A. niger derived fumonisins in retail wine and raisins. Physiological investigations have demonstrated that fumonisin production in A. niger occurs at temperatures between 20-37 °C. Three water activity...

[Progress in omics research of Aspergillus niger].

Science.gov (United States)

Sui, Yufei; Ouyang, Liming; Lu, Hongzhong; Zhuang, Yingping; Zhang, Siliang

2016-08-25

Aspergillus niger, as an important industrial fermentation strain, is widely applied in the production of organic acids and industrial enzymes. With the development of diverse omics technologies, the data of genome, transcriptome, proteome and metabolome of A. niger are increasing continuously, which declared the coming era of big data for the research in fermentation process of A. niger. The data analysis from single omics and the comparison of multi-omics, to the integrations of multi-omics based on the genome-scale metabolic network model largely extends the intensive and systematic understanding of the efficient production mechanism of A. niger. It also provides possibilities for the reasonable global optimization of strain performance by genetic modification and process regulation. We reviewed and summarized progress in omics research of A. niger, and proposed the development direction of omics research on this cell factory.

Regulation of the alpha-glucuronidase-encoding gene ( aguA) from Aspergillus niger.

Science.gov (United States)

de Vries, R P; van de Vondervoort, P J I; Hendriks, L; van de Belt, M; Visser, J

2002-09-01

The alpha-glucuronidase gene aguA from Aspergillus niger was cloned and characterised. Analysis of the promoter region of aguA revealed the presence of four putative binding sites for the major carbon catabolite repressor protein CREA and one putative binding site for the transcriptional activator XLNR. In addition, a sequence motif was detected which differed only in the last nucleotide from the XLNR consensus site. A construct in which part of the aguA coding region was deleted still resulted in production of a stable mRNA upon transformation of A. niger. The putative XLNR binding sites and two of the putative CREA binding sites were mutated individually in this construct and the effects on expression were examined in A. niger transformants. Northern analysis of the transformants revealed that the consensus XLNR site is not actually functional in the aguA promoter, whereas the sequence that diverges from the consensus at a single position is functional. This indicates that XLNR is also able to bind to the sequence GGCTAG, and the XLNR binding site consensus should therefore be changed to GGCTAR. Both CREA sites are functional, indicating that CREA has a strong influence on aguA expression. A detailed expression analysis of aguA in four genetic backgrounds revealed a second regulatory system involved in activation of aguA gene expression. This system responds to the presence of glucuronic and galacturonic acids, and is not dependent on XLNR.

The mutagenic effect of streptomyces and aspergillus niger with fast neutron irradiation

International Nuclear Information System (INIS)

Zhang Shengjun; Zhou Shuxin; Fang Xiaoming

1992-01-01

The authors describe the effect of irradiation on some Streptomyces and Aspergillus niger with fast neutron. The death rate(%), production rate(%, W/V), and heredities were determined and analysed. Particularly, five variant types of Strepto. griseous No.1 will be researched in depth

Niger

DEFF Research Database (Denmark)

Hahonou, Eric Komlavi

2015-01-01

The chapter provides knowledge about the role of non-state actors in security provision in Niger. It argues that it is of upmost importance to dig into the causes of ongoing armed conflicts and volatile situations. It points out the long-term decline of public service provision (including the role...

The Military Dimension of the Niger Delta Crisis: Increasing the Effectiveness of Security Forces Through Information Operations

Science.gov (United States)

2010-06-11

and over 250 ethnic groups, Nigeria is a mix of cultures , languages and interests. Nigeria got its name from the River Niger, the major river in the...largely Muslim Hausa/Fulani northern protectorate and the predominantly Christian Yoruba and Igbo southern protectorate (Gascoigne 2001). Nigeria gained...keen understanding of what he referred to as the demographic battlespace as well as ―the cultural intricacies that drive the Iraqi population‖ is

In Silico Analysis of Putative Sugar Transporter Genes in Aspergillus niger Using Phylogeny and Comparative Transcriptomics

Directory of Open Access Journals (Sweden)

Mao Peng

2018-05-01

Full Text Available Aspergillus niger is one of the most widely used fungi to study the conversion of the lignocellulosic feedstocks into fermentable sugars. Understanding the sugar uptake system of A. niger is essential to improve the efficiency of the process of fungal plant biomass degradation. In this study, we report a comprehensive characterization of the sugar transportome of A. niger by combining phylogenetic and comparative transcriptomic analyses. We identified 86 putative sugar transporter (ST genes based on a conserved protein domain search. All these candidates were then classified into nine subfamilies and their functional motifs and possible sugar-specificity were annotated according to phylogenetic analysis and literature mining. Furthermore, we comparatively analyzed the ST gene expression on a large set of fungal growth conditions including mono-, di- and polysaccharides, and mutants of transcriptional regulators. This revealed that transporter genes from the same phylogenetic clade displayed very diverse expression patterns and were regulated by different transcriptional factors. The genome-wide study of STs of A. niger provides new insights into the mechanisms underlying an extremely flexible metabolism and high nutritional versatility of A. niger and will facilitate further biochemical characterization and industrial applications of these candidate STs.

Acid Rain in Niger Delta Region: Implication on Water Resources ...

African Journals Online (AJOL)

This research focused on the effect of acid rain on the water quality of the Niger Delta region of Nigeria. Three hundred water samples were collected: 100 water samples from rain, 100 from open wells and 100 from rivers. The water samples were analysed using the paired t-test and multiple correlation analysis to ascertain ...

Stabilizing Niger

DEFF Research Database (Denmark)

Hahonou, Eric Komlavi

international intervention in Niger. Their main objective is to secure their own strategic, economic and political interests by strengthening the Nigerien authorities through direct intervention and capacity building activities. For western states reinforcing state security institutions and stabilizing elite...

Aspergillus Niger Genomics: Past, Present and into the Future

Energy Technology Data Exchange (ETDEWEB)

Baker, Scott E.

2006-09-01

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.

Transcriptional profiling of Aspergillus niger

OpenAIRE

Veen, van der, D.

2009-01-01

The industrially important fungus Aspergillus niger feeds naturally on decomposing plant material, of which a significant proportion is lipid. Examination of the A. niger genome sequence suggested that all proteins required for metabolic conversion of lipids are present, including 63 predicted lipases. In contrast to polysaccharide-degrading enzyme networks, not much is known about the signaling and regulatory processes that control lipase expression and activity in fungi. This project was ai...

The Aspergillus niger RmsA protein

Science.gov (United States)

Minkwitz, Susann; Schütze, Tabea; van den Hondel, Cees A.M.J.J; Ram, Arthur F.J

2010-01-01

Many cells and organisms go through polarized growth phases during their life. Cell polarization is achieved by local accumulation of signaling molecules which guide the cytoskeleton and vesicular trafficking to specific parts of the cell and thus ensure polarity establishment and maintenance. Polarization of signaling molecules is also fundamental for the lifestyle of filamentous fungi such as Aspergillus niger and essential for their morphogenesis, development and survival under environmental stress conditions. Considerable advances in our understanding on the protagonists and processes mediating polarized growth in filamentous fungi have been made over the past years. However, how the interplay of different signaling pathways is coordinated has yet to be determined. We found that the A. niger RmsA protein is central for the polarization of actin at the hyphal tip but also of vital importance for the metabolism, viability and stress resistance of A. niger. This suggests that RmsA could occupy an important position in the global network of pathways that balance growth, morphogenesis and survival of A. niger. PMID:20585521

A refined estimate of the malaria burden in Niger

Directory of Open Access Journals (Sweden)

Doudou Maimouna

2012-03-01

Full Text Available Abstract Background The health authorities of Niger have implemented several malaria prevention and control programmes in recent years. These interventions broadly follow WHO guidelines and international recommendations and are based on interventions that have proved successful in other parts of Africa. Most performance indicators are satisfactory but, paradoxically, despite the mobilization of considerable human and financial resources, the malaria-fighting programme in Niger seems to have stalled, as it has not yet yielded the expected significant decrease in malaria burden. Indeed, the number of malaria cases reported by the National Health Information System has actually increased by a factor of five over the last decade, from about 600,000 in 2000 to about 3,000,000 in 2010. One of the weaknesses of the national reporting system is that the recording of malaria cases is still based on a presumptive diagnosis approach, which overestimates malaria incidence. Methods An extensive nationwide survey was carried out to determine by microscopy and RDT testing, the proportion of febrile patients consulting at health facilities for suspected malaria actually suffering from the disease, as a means of assessing the magnitude of this problem and obtaining a better estimate of malaria morbidity in Niger. Results In total, 12,576 febrile patients were included in this study; 57% of the slides analysed were positive for the malaria parasite during the rainy season, when transmission rates are high, and 9% of the slides analysed were positive during the dry season, when transmission rates are lower. The replacement of microscopy methods by rapid diagnostic tests resulted in an even lower rate of confirmation, with only 42% of cases testing positive during the rainy season, and 4% during the dry season. Fever alone has a low predictive value, with a low specificity and sensitivity. These data highlight the absolute necessity of confirming all reported

Selection of tannase-producing Aspergillus niger strains Seleção de linhagens de Aspergillus niger produtoras de tanase

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Gustavo A.S. Pinto

2001-03-01

Full Text Available The aim of this work was to select strains of Aspergillus niger for tannase production. Growth of colonies in plates with tannic acid-containing medium indicated their ability to synthesize tannase. Tannase activity was also measured in solid-state fermentation. A. niger 11T25A5 was the best tannase producer (67.5 U.g-1/72 hours of fermentation.O objetivo deste trabalho foi selecionar linhagens de Aspergillus niger para síntese de tanase. O crescimento das colônias em meio contendo ácido tânico indicou capacidade de produção de tanase. A atividade enzimática foi determinada em fermentação semi-sólida. A. niger 11T25A5 foi o melhor produtor (67.5 U.g-1/72 horas de fermentação.

The Spread of Islam in the Niger and Senegal Valleys before the Rise of Almoravids

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Ahmed Elyas Hussein

2001-12-01

Full Text Available This study traces the early contacts of the middle and upper Niger and Senegal Rivers with the Muslims in the first five centuries after hijrah and shows the spread of Islam and the rise of states long before the emergence of Al-Moravids. It analyses the early Muslim expansion in the Western Sahara, the role of the Ibāḍiyyah in central Sahara and the efforts of the Sanhadja in the Western Sahara which resulted in the spread of Islam and rise of Islamic kingdoms in the Niger and the Senegal Valleys before the 5th centaury AH.

Physicochemical Properties Analysis and Secretome of Aspergillus niger in Fermented Rapeseed Meal.

Science.gov (United States)

Shi, Changyou; He, Jun; Yu, Jie; Yu, Bing; Mao, Xiangbing; Zheng, Ping; Huang, Zhiqing; Chen, Daiwen

2016-01-01

The nutrient digestibility and feeding value of rapeseed meal (RSM) for non-ruminant animals is poor due to the presence of anti-nutritional substances such as glucosinolate, phytic acid, crude fiber etc. In the present study, a solid state fermentation (SSF) using Aspergillus niger was carried out with the purpose of improving the nutritional quality of RSM. The chemical composition and physicochemical properties of RSM before and after fermentation were compared. To further understand possible mechanism of solid state fermentation, the composition of extracellular enzymes secreted by Aspergillus niger during fermentation was analysed using two-dimentional difference gel electrophoresis (2D-DIGE) combined with matrix assisted laser desorption ionization-time of flight-mass spectrometer (MALDI-TOF-MS). Results of the present study indicated that SSF had significant effects on chemical composition of RSM. The fermented rapeseed meal (FRSM) contained more crude protein (CP) and amino acid (AA) (except His) than unfermented RSM. Notably, the small peptide in FRSM was 2.26 time larger than that in unfermented RSM. Concentrations of anti-nutritional substrates in FRSM including neutral detergent fiber (NDF), glucosinolates, isothiocyanate, oxazolidithione, and phytic acid declined (P niger fermentation disrupted the surface structure, changed macromolecular organic compounds, and reduced the protein molecular weights of RSM substrate. Total proteins of raw RSM and FRSM were separated and 51 protein spots were selected for mass spectrometry according to 2D-DIGE map. In identified proteins, there were 15 extracellular hydrolases secreted by A. niger including glucoamylase, acid protease, beta-glucanase, arabinofuranosidase, xylanase, and phytase. Some antioxidant related enzymes also were identified. These findings suggested that A. niger is able to secrete many extracellular degradation enzymes (especially lignocellulosic hydrolyzing enzymes, acid proteases and phytase

Northern Marshall Islands Radiological Survey: a quality-control program for a radiochemical analyses

International Nuclear Information System (INIS)

Jennings, C.D.; Mount, M.E.

1983-08-01

More than 16,000 radiochemical analyses were performed on about 5400 samples of soils, vegetation, animals, fish, invertebrates, and water to establish amounts of 90 Sr, 137 Cs, 241 Am, and plutonium isotopes in the Northern Marshall Islands. Three laboratories were contracted by Lawrence Livermore National Laboratory to perform the radiochemical analyses: Environmental Analysis Laboratory (EAL), Richmond, California; Eberline Instrument Corporation (EIC), Albuquerque, New Mexico; and Laboratory of Radiation Ecology (LRE), University of Washington, Seattle, Washington. The analytical precision and accuracy were monitored by regularly including duplicate samples and natural matrix standards in each group of about 100 samples analyzed. Based on the duplicates and standards, over 83% of the radiochemical analyses in this survey were acceptable - 97% of the analyses by EAL, 45% of the analyses by EIC, and 98% of the analyses by LRE

Lysine aminopeptidase of Aspergillus niger

OpenAIRE

Basten, D.E.J.W.; Visser, J.; Schaap, P.J.

2001-01-01

Conserved regions within the M1 family of metallo-aminopeptidases have been used to clone a zinc aminopeptidase from the industrially used fungus Aspergillus niger. The derived amino acid sequence of ApsA is highly similar to two yeast zinc aminopeptidases, LAPI and AAPI (53.3 and 50.9␘verall similarity, respectively), two members of the M1 family of metallo-aminopeptidases. The encoding gene was successfully overexpressed in A. niger and the overexpressed product was purified and characteriz...

Assessment of Aspergillus niger biofilm growth kinetics in ...

African Journals Online (AJOL)

Jane

2011-10-12

Oct 12, 2011 ... other hand, A. niger biofilm growth followed a logistic model having higher maximal specific growth rate than ...... Growth estimation of Aspergillus oryzae cultured on ... Initial intracellular proteome profile of Aspergillus niger.

Proteomic analysis of the secretory response of Aspergillus niger to D-maltose and D-xylose

NARCIS (Netherlands)

Ferreira de Oliveira, J.M.P.; Passel, van M.W.J.; Schaap, P.J.; Graaff, de L.H.

2011-01-01

Fungi utilize polysaccharide substrates through extracellular digestion catalyzed by secreted enzymes. Thus far, protein secretion by the filamentous fungus Aspergillus niger has mainly been studied at the level of individual proteins and by genome and transcriptome analyses. To extend these

The Niger Delta

African Journals Online (AJOL)

AJL

2009-05-26

May 26, 2009 ... Available online at http://www.academicjournals.org/AJEST. ISSN 1996-0786 ... The Royal Niger Company--the chief instrument by ... burning within the image area. http://photojournal.jpl.nasa.gov/catalog/PIA03897. Figure 2 ...

Pêcheurs nomades du fleuve Niger

DEFF Research Database (Denmark)

Hahonou, Eric Komlavi

2017-01-01

Following Jean Rouch's travel on the Niger river and his first writings on the Sorkawa fishermen of Kebbi, the article documents the trajectory of a group of nomadic fishermen engaged in seasonal campaigns on the Niger river between Nigeria and Mali. The author retraces the evolution of fishermen...... in the process of sedentarisation of these fishermen. Sedentarisation goes hand in hand with impoverishment. Such trajectory is documented by a documentary movie, river Nomads (2016), starting point of a research at the crossroads of circular migrations and an anthropology of citizenship. This research agenda...

Biotransformation of Stypotriol triacetate by Aspergillus niger

Science.gov (United States)

Areche, Carlos; Vaca, Inmaculada; Labbe, Pamela; Soto-Delgado, Jorge; Astudillo, Luis; Silva, Mario; Rovirosa, Juana; San-Martin, Aurelio

2011-07-01

Biological transformation of the meroditerpenoid, stypotriol triacetate ( 1) by the fungi Aspergillus niger, Cunninghamella elegans, Gibberella fujikuroi and Mucor plumbeus was studied. The incubation of 1 with A. niger yielded the new compound 6',14-diacetoxy-stypol-4,5-dione ( 2) whose structure was established by 1H, 13C and 2D NMR and supported by DFT/GIAO.

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

Science.gov (United States)

2010-04-01

... cellulase derived from Aspergillus niger. Carbohydrase and cellulase enzyme preparation derived from Aspergillus niger may be safely used in food in accordance with the following prescribed conditions: (a) Aspergillus niger is classified as follows: Class, Deuteromycetes; order, Moniliales; family, Moniliaceae...

Fumonisins in Aspergillus niger: Industrial and food aspects

DEFF Research Database (Denmark)

Frisvad, Jens Christian; Nielsen, Kristian Fog; Mogensen, Jesper

Introduction: Fumonisins are toxic seconday metabolites from Fusarium verticillioides and other Fusaria, from Tolypocladium and Aspergillus niger 1,2. Being a generalist Aspergillus niger is the workhorse in a very large number of industrial applications, and is also a common contaminant in foods....... Fumonisin production by A. niger is depending on temperature and water activity, but is produced mostly on substrates with high maounts of sugar or salt 1,3,4. We wanted to find out whether industrial strains could produce fumonisins in worst case scenarios and if fumonisin production was only a feature...... ever used in biotechnology could produce fuminisins B2, B4 & B6. The strains could be subdivided into two clades (representing A. niger and the “phylospecies” A. awamori), and there were fumonisin producers in both clades. Ochratoxin A was also produced by strains in both clades, but only...

Pharmacognostical and phytochemical studies of Helleborus niger L root

Directory of Open Access Journals (Sweden)

V Kishor Kumar

2017-01-01

Full Text Available Background: Helleborus niger L (Ranunculaceae is used Ayurvedic and Unani systems and other herbal medicine systems. The roots of H. niger have a good medicinal value. Aims: To conduct a pharmacognostical and phytochemical study of H. niger. Materials and Methods: The pharmacognostical studies on roots including parameters such as taxonomical, macroscopic, microscopic characters, physico-chemical, ultra-violet analysis and phytochemical studies are established. Results: Macroscopically, the roots are brownish-black in colour, cylindrical in shape, feeble odour, slightly acrid taste with irregularly branched. Microscopically the root showed the presence of epidermis, air-chambers, fissure periderm, periderm, inner cortex, pith, phloem, xylem, vessels and xylem vessels. Microscopic examination of the powder showed the presence of parenchyma cells, parenchyma mass, periderm, cell inclusion, laticifer, lateral wall pith, perforation, xylem bundle and xylem elements. Ultra-violet and ordinary light analyses with different reagents were conducted to identify the drug in powder form. Physico-chemical evaluation established, Ash values - Total, acid insoluble, water soluble and sulphated ash values were 7.3%, 4.1%, 3.7% and 5.2%, respectively. Extractive values - Alcohol soluble, water soluble and ether soluble extractive values were 22.8%, 7.4% and 5.6%, respectively. Loss on drying was 3.3%. Preliminary phytochemical screening showed the presence of carbohydrate, glycoside, saponins, flavonoid, phytosterols, tannins and phenolic compounds. Conclusions: The results of the study can serve as a valuable resource of pharmacognostic and phytochemical information. This will serve as appropriate, standards for discovery of this plant material in future investigations and applications and also contribute towards establishing pharmacopoeial standards.

Novel Route for Agmatine Catabolism in Aspergillus niger Involves 4-Guanidinobutyrase.

Science.gov (United States)

Kumar, Sunil; Saragadam, Tejaswani; Punekar, Narayan S

2015-08-15

Agmatine, a significant polyamine in bacteria and plants, mostly arises from the decarboxylation of arginine. The functional importance of agmatine in fungi is poorly understood. The metabolism of agmatine and related guanidinium group-containing compounds in Aspergillus niger was explored through growth, metabolite, and enzyme studies. The fungus was able to metabolize and grow on l-arginine, agmatine, or 4-guanidinobutyrate as the sole nitrogen source. Whereas arginase defined the only route for arginine catabolism, biochemical and bioinformatics approaches suggested the absence of arginine decarboxylase in A. niger. Efficient utilization by the parent strain and also by its arginase knockout implied an arginase-independent catabolic route for agmatine. Urea and 4-guanidinobutyrate were detected in the spent medium during growth on agmatine. The agmatine-grown A. niger mycelia contained significant levels of amine oxidase, 4-guanidinobutyraldehyde dehydrogenase, 4-guanidinobutyrase (GBase), and succinic semialdehyde dehydrogenase, but no agmatinase activity was detected. Taken together, the results support a novel route for agmatine utilization in A. niger. The catabolism of agmatine by way of 4-guanidinobutyrate to 4-aminobutyrate into the Krebs cycle is the first report of such a pathway in any organism. A. niger GBase peptide fragments were identified by tandem mass spectrometry analysis. The corresponding open reading frame from the A. niger NCIM 565 genome was located and cloned. Subsequent expression of GBase in both Escherichia coli and A. niger along with its disruption in A. niger functionally defined the GBase locus (gbu) in the A. niger genome. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Selection of tannase-producing Aspergillus niger strains

OpenAIRE

Pinto,Gustavo A.S.; Leite,Selma G.F.; Terzi,Selma C.; Couri,Sonia

2001-01-01

The aim of this work was to select strains of Aspergillus niger for tannase production. Growth of colonies in plates with tannic acid-containing medium indicated their ability to synthesize tannase. Tannase activity was also measured in solid-state fermentation. A. niger 11T25A5 was the best tannase producer (67.5 U.g-1/72 hours of fermentation).

Conflict resolution among Niger delta communities: A historical ...

African Journals Online (AJOL)

Conflict related issues have assumed endemic proportion in the Niger Delta. A proper assessment of the critical factors in motion must take cognizance of their historical underpinnings. Peaceful co-existence, the hallmark of conflict resolution, can be feasible in the Niger Delta, through sustainable dialogue. These, among

Expression of human lymphotoxin alpha in Aspergillus niger

NARCIS (Netherlands)

Krasevec, N.; Hondel, C.A.M.J.J. van de; Komel, R.

2000-01-01

A gene-fusion expression strategy was applied for heterologous expression of human lymphotoxin alpha (LTα) in the Aspergillus niger AB1.13 protease-deficient strain. The LTα gene was fused with the A. niger glucoamylase GII-form as a carrier-gene, behind its transcription control and secretion

Physicochemical Properties Analysis and Secretome of Aspergillus niger in Fermented Rapeseed Meal.

Directory of Open Access Journals (Sweden)

Changyou Shi

Full Text Available The nutrient digestibility and feeding value of rapeseed meal (RSM for non-ruminant animals is poor due to the presence of anti-nutritional substances such as glucosinolate, phytic acid, crude fiber etc. In the present study, a solid state fermentation (SSF using Aspergillus niger was carried out with the purpose of improving the nutritional quality of RSM. The chemical composition and physicochemical properties of RSM before and after fermentation were compared. To further understand possible mechanism of solid state fermentation, the composition of extracellular enzymes secreted by Aspergillus niger during fermentation was analysed using two-dimentional difference gel electrophoresis (2D-DIGE combined with matrix assisted laser desorption ionization-time of flight-mass spectrometer (MALDI-TOF-MS. Results of the present study indicated that SSF had significant effects on chemical composition of RSM. The fermented rapeseed meal (FRSM contained more crude protein (CP and amino acid (AA (except His than unfermented RSM. Notably, the small peptide in FRSM was 2.26 time larger than that in unfermented RSM. Concentrations of anti-nutritional substrates in FRSM including neutral detergent fiber (NDF, glucosinolates, isothiocyanate, oxazolidithione, and phytic acid declined (P < 0.05 by 13.47, 43.07, 55.64, 44.68 and 86.09%, respectively, compared with unfermented RSM. A. niger fermentation disrupted the surface structure, changed macromolecular organic compounds, and reduced the protein molecular weights of RSM substrate. Total proteins of raw RSM and FRSM were separated and 51 protein spots were selected for mass spectrometry according to 2D-DIGE map. In identified proteins, there were 15 extracellular hydrolases secreted by A. niger including glucoamylase, acid protease, beta-glucanase, arabinofuranosidase, xylanase, and phytase. Some antioxidant related enzymes also were identified. These findings suggested that A. niger is able to secrete many

Corn stover-enhanced cellulase production by Aspergillus niger ...

African Journals Online (AJOL)

The production of extracellular cellulases by Aspergilus niger NRRL 567 on corn stover was studied in liquid state fermentation. In this study, three cellulases, exoglucanase (EXG), endoglucanase (EG) and β-glucosidase (BGL) were produced by A. niger NRRL 567. The optimal pH, temperature and incubation time for ...

Aspergillus niger: an unusual cause of invasive pulmonary aspergillosis

Science.gov (United States)

Person, A. K.; Chudgar, S. M.; Norton, B. L.; Tong, B. C.; Stout, J. E.

2010-01-01

Infections due to Aspergillus species cause significant morbidity and mortality. Most are attributed to Aspergillus fumigatus, followed by Aspergillus flavus and Aspergillus terreus. Aspergillus niger is a mould that is rarely reported as a cause of pneumonia. A 72-year-old female with chronic obstructive pulmonary disease and temporal arteritis being treated with steroids long term presented with haemoptysis and pleuritic chest pain. Chest radiography revealed areas of heterogeneous consolidation with cavitation in the right upper lobe of the lung. Induced bacterial sputum cultures, and acid-fast smears and cultures were negative. Fungal sputum cultures grew A. niger. The patient clinically improved on a combination therapy of empiric antibacterials and voriconazole, followed by voriconazole monotherapy. After 4 weeks of voriconazole therapy, however, repeat chest computed tomography scanning showed a significant progression of the infection and near-complete necrosis of the right upper lobe of the lung. Serum voriconazole levels were low–normal (1.0 μg ml−1, normal range for the assay 0.5–6.0 μg ml−1). A. niger was again recovered from bronchoalveolar lavage specimens. A right upper lobectomy was performed, and lung tissue cultures grew A. niger. Furthermore, the lung histopathology showed acute and organizing pneumonia, fungal hyphae and oxalate crystallosis, confirming the diagnosis of invasive A. niger infection. A. niger, unlike A. fumigatus and A. flavus, is less commonly considered a cause of invasive aspergillosis (IA). The finding of calcium oxalate crystals in histopathology specimens is classic for A. niger infection and can be helpful in making a diagnosis even in the absence of conidia. Therapeutic drug monitoring may be useful in optimizing the treatment of IA given the wide variations in the oral bioavailability of voriconazole. PMID:20299503

Contribution of arginase to manganese metabolism of Aspergillus niger.

Science.gov (United States)

Keni, Sarita; Punekar, Narayan S

2016-02-01

Aspects of manganese metabolism during normal and acidogenic growth of Aspergillus niger were explored. Arginase from this fungus was a Mn[II]-enzyme. The contribution of the arginase protein towards A. niger manganese metabolism was investigated using arginase knockout (D-42) and arginase over-expressing (ΔXCA-29) strains of A. niger NCIM 565. The Mn[II] contents of various mycelial fractions were found in the order: D-42 strain niger mycelia harvested from acidogenic growth media contain substantially less Mn[II] as compared to those from normal growth media. Nevertheless, acidogenic mycelia harbor considerable Mn[II] levels and a functional arginase. Altered levels of mycelial arginase protein did not significantly influence citric acid production. The relevance of arginase to cellular Mn[II] pool and homeostasis was evaluated and the results suggest that arginase regulation could occur via manganese availability.

Oil and Security in Nigeria: The Niger Delta Crisis | Owolabi | Africa ...

African Journals Online (AJOL)

This paper examines oil and security in Nigeria, with special reference to the crisis-ravaged Niger Delta. Its focus on the Niger Delta and its festering crisis stems from that region's critical importance to Nigeria. As the nation's treasure base, the Niger Delta provides over 80 percent of government revenues, 95 percent of ...

Genetic relationships among strains of the Aspergillus niger aggregate

DEFF Research Database (Denmark)

Ferracin, L.M.; Frisvad, Jens Christian; Taniwaki, M.H.

2009-01-01

We analyzed the genetic relationships between 51 fungal isolates previously identified as A. niger aggregate, obtained from dried fruit samples from worldwide origin and 7 A. tubingensis obtained from Brazilian coffee beans samples. Greater fungal diversity was found in black sultanas. Aspergillus...... niger sensu stricto was the most prevalent species. It was found in all fruit substrates of all geographical origins. Based on Random Amplification of Polymorphic DNA (RAPD) and beta-tubulin sequences data two groups of A. niger were found. In spite of the small number of isolates from Group IV...

Aspergillus niger endocarditis in an immunocompetent patient: an unusual course

Science.gov (United States)

Kreiss, Y.; Vered, Z.; Keller, N.; Kochva, I.; Sidi, Y.; Gur, H.

2000-01-01

Aspergillus is an opportunistic nosocomial fungus generally associated with a high mortality rate. A niger has been rarely associated with infection, and most cases have occurred in patients who have recently undergone heart surgery or in immunocompromised patients. We present a case of an immunocompetent patient with A niger endocarditis which illustrates the difficulties in diagnosis and the possible insidious course of fungal endocarditis.


Keywords: endocarditis; Aspergillus niger; transoesophageal echocardiography PMID:10644391

Secretome analysis of Trichoderma reesei and Aspergillus niger cultivated by submerged and sequential fermentation processes: Enzyme production for sugarcane bagasse hydrolysis.

Science.gov (United States)

Florencio, Camila; Cunha, Fernanda M; Badino, Alberto C; Farinas, Cristiane S; Ximenes, Eduardo; Ladisch, Michael R

2016-08-01

Cellulases and hemicellulases from Trichoderma reesei and Aspergillus niger have been shown to be powerful enzymes for biomass conversion to sugars, but the production costs are still relatively high for commercial application. The choice of an effective microbial cultivation process employed for enzyme production is important, since it may affect titers and the profile of protein secretion. We used proteomic analysis to characterize the secretome of T. reesei and A. niger cultivated in submerged and sequential fermentation processes. The information gained was key to understand differences in hydrolysis of steam exploded sugarcane bagasse for enzyme cocktails obtained from two different cultivation processes. The sequential process for cultivating A. niger gave xylanase and β-glucosidase activities 3- and 8-fold higher, respectively, than corresponding activities from the submerged process. A greater protein diversity of critical cellulolytic and hemicellulolytic enzymes were also observed through secretome analyses. These results helped to explain the 3-fold higher yield for hydrolysis of non-washed pretreated bagasse when combined T. reesei and A. niger enzyme extracts from sequential fermentation were used in place of enzymes obtained from submerged fermentation. An enzyme loading of 0.7 FPU cellulase activity/g glucan was surprisingly effective when compared to the 5-15 times more enzyme loadings commonly reported for other cellulose hydrolysis studies. Analyses showed that more than 80% consisted of proteins other than cellulases whose role is important to the hydrolysis of a lignocellulose substrate. Our work combined proteomic analyses and enzymology studies to show that sequential and submerged cultivation methods differently influence both titers and secretion profile of key enzymes required for the hydrolysis of sugarcane bagasse. The higher diversity of feruloyl esterases, xylanases and other auxiliary hemicellulolytic enzymes observed in the enzyme

Partially purified polygalacturonase from Aspergillus niger (SA6 ...

African Journals Online (AJOL)

Polygalacturonase (PG) was isolated from Aspergillus niger (A. niger) (SA6), partially purified and characterized. The PG showed two bands on SDS-PAGE suggesting an “endo and exo PG with apparent molecular weights of 35 and 40 KDa, respectively. It was purified 9-fold with a yield of 0.18% and specific activity of 246 ...

IDRC in Niger

International Development Research Centre (IDRC) Digital Library (Canada)

IDRC has supported research in. Niger since 1974. This support has been sporadic in the absence of democratic stability in the country. It has nonetheless enabled researchers to develop ways to counter deforestation and test varieties of cereal and legume crops that can resist drought conditions. Research on the effects of ...

Post-genomic insights into the plant polysaccharide degradation potential of Aspergillus nidulans and comparison to Aspergillus niger and Aspergillus oryzae

DEFF Research Database (Denmark)

Coutinho, Pedro M.; Andersen, Mikael Rørdam; Kolenova, Katarina

2009-01-01

The plant polysaccharide degradative potential of Aspergillus nidulans was analysed in detail and compared to that of Aspergillus niger and Aspergillus oryzae using a combination of bioinformatics, physiology and transcriptomics. Manual verification indicated that 28.4% of the A. nidulans ORFs...... between the Aspergilli in the presence Of putative regulatory sequences in the promoters of the ORFs Of this Study and correlation of the presence Of putative XlnR binding sites to induction by xylose was detected for A. niger. These data demonstrate differences at genome content, Substrate specificity...

Transcriptome analysis of Aspergillus niger grown on sugarcane bagasse

Directory of Open Access Journals (Sweden)

Goldman Gustavo H

2011-10-01

Full Text Available Abstract Background Considering that the costs of cellulases and hemicellulases contribute substantially to the price of bioethanol, new studies aimed at understanding and improving cellulase efficiency and productivity are of paramount importance. Aspergillus niger has been shown to produce a wide spectrum of polysaccharide hydrolytic enzymes. To understand how to improve enzymatic cocktails that can hydrolyze pretreated sugarcane bagasse, we used a genomics approach to investigate which genes and pathways are transcriptionally modulated during growth of A. niger on steam-exploded sugarcane bagasse (SEB. Results Herein we report the main cellulase- and hemicellulase-encoding genes with increased expression during growth on SEB. We also sought to determine whether the mRNA accumulation of several SEB-induced genes encoding putative transporters is induced by xylose and dependent on glucose. We identified 18 (58% of A. niger predicted cellulases and 21 (58% of A. niger predicted hemicellulases cellulase- and hemicellulase-encoding genes, respectively, that were highly expressed during growth on SEB. Conclusions Degradation of sugarcane bagasse requires production of many different enzymes which are regulated by the type and complexity of the available substrate. Our presently reported work opens new possibilities for understanding sugarcane biomass saccharification by A. niger hydrolases and for the construction of more efficient enzymatic cocktails for second-generation bioethanol.

Transcriptome analysis of Aspergillus niger grown on sugarcane bagasse

Science.gov (United States)

2011-01-01

Background Considering that the costs of cellulases and hemicellulases contribute substantially to the price of bioethanol, new studies aimed at understanding and improving cellulase efficiency and productivity are of paramount importance. Aspergillus niger has been shown to produce a wide spectrum of polysaccharide hydrolytic enzymes. To understand how to improve enzymatic cocktails that can hydrolyze pretreated sugarcane bagasse, we used a genomics approach to investigate which genes and pathways are transcriptionally modulated during growth of A. niger on steam-exploded sugarcane bagasse (SEB). Results Herein we report the main cellulase- and hemicellulase-encoding genes with increased expression during growth on SEB. We also sought to determine whether the mRNA accumulation of several SEB-induced genes encoding putative transporters is induced by xylose and dependent on glucose. We identified 18 (58% of A. niger predicted cellulases) and 21 (58% of A. niger predicted hemicellulases) cellulase- and hemicellulase-encoding genes, respectively, that were highly expressed during growth on SEB. Conclusions Degradation of sugarcane bagasse requires production of many different enzymes which are regulated by the type and complexity of the available substrate. Our presently reported work opens new possibilities for understanding sugarcane biomass saccharification by A. niger hydrolases and for the construction of more efficient enzymatic cocktails for second-generation bioethanol. PMID:22008461

Biosorption of uranium with Aspergillus niger

International Nuclear Information System (INIS)

Yakubu, N.A.; Dudeney, A.W.L.

1986-01-01

This paper considers interactions of uranium with the microfilamentous fungus Aspergillus niger grown as pellets 4 mm in diameter for column application. Adsorption and desorption isotherms, a range of physical measurements, and a derived mechanistic model, indicated that a simple ion exchange process predominates in which uranyl cations reversibly replace protons on the amino acid groups of proteins and glycoproteins within the cell wall structure. Under the conditions employed uranium adsorbed onto A. niger (CMI 296409) some fourteen times more efficiently at pH 4 than onto the ion exchange resin IRA-400, and was readily desorbed at pH 1. The fungus had inferior selectivity and wet volume/dry weight ratio. Uranium was adsorbed semi-continuously by heat-killed A. niger pellets fluidised in a compartmentalised column. When operated with an intermittent countercurrent flow of the biomass, uranium concentrations of 100 g/m 3 and 5 g/m 3 at pH 4 could be reduced to less than 10 g/m 3 and 1 g/m 3 , respectively. (author)

AKTIVITAS ANTIFUNGI FRAKSI ETILASETAT AKAR SINGAWALANG (PETIVERIA ALLIACEA L. TERHADAP ASPERGILLUS NIGER

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Niken Indriyanti

2015-06-01

Full Text Available Aspergillus niger is a mold that can infect respiratory tract in certain condition. Azoles are used to solve this infection. Drug development on antifungal drugs still continued, one of the resorce is from plant. A plant that widely studied as antifungi is singawalang (Petiveria alliacea L.. Activity of ethanol extract and fraction of singawalang roots on Aspergillus niger tested by microdilution broth method appropriate to Clinical and Laboratory Standard Institute (CLSI standard. Microdilution test results showed that Singawalang roots extract has antifungal activity against Aspergillus niger with Minimum Inhibition Concentration (MIC 32 μg/mL and Minimum Fungicidal Concentration (MFC 1048 μg/mL. Fraction that has high activity against Aspergillus niger was ethylacetate fraction of Singawalang roots with MIC 128 µg/ml dan MFC 512 μg/mL. The higher activity of the extract than the fraction was predicted as the impact of multiple compounds that have synergic activity. The growth profile of Aspergillus niger showed unconstant result and tends to descend. However, further research needed to ensure this effect.   Keywords:    antifungal, microdilution, singawalang (Petiveria alliacea L., Aspergillus niger      ABSTRAK   Aspergillus niger merupakan kapang penginfeksi saluran pernafasan pada kondisi tertentu. Obat-obat golongan azol biasa digunakan untuk mengatasi infeksi ini. Pengembangan obat antifungi saat ini terus dilakukan, termasuk dari tanaman. Salah satu tanaman yang telah banyak diteliti memiliki efek antifungi adalah tanaman singawalang (Petiveria alliacea L.. Pengujian dilakukan dengan Broth Microdilution sesuai standar Clinical and Laboratory Standard Institute (CLSI. Ekstrak akar singawalang menghambat pertumbuhan Aspergillus niger dan memiliki KHM 32 ppm dan KFM 1048 ppm. Hasil dan Fraksi Ekstrak Akar Singawalang Terhadap Aspergillus niger pada fraksi etilasetat ekstrak etanol akar singawalang adalah Konsentrasi Hambat

Homosexuality amongst migrant oil workers in the Niger Delta ...

African Journals Online (AJOL)

Aims: To determine the prevalence of homosexuality among migrant oil workers in Niger Delta. Methods: A prospective questionnaire – based study was conducted among migrant oil workers in the Niger Delta region of Nigeria. The design was to determine the prevalence of homosexuality in the workers in oil workers.

Molecular and Chemical Characterization of the Biosynthesis of the 6-MSA-Derived Meroterpenoid Yanuthone D in Aspergillus niger

DEFF Research Database (Denmark)

Holm, Dorte Koefoed; Petersen, Lene Maj; Klitgaard, Andreas

2014-01-01

Secondary metabolites in filamentous fungi constitute a rich source of bioactive molecules. We have deduced the genetic and biosynthetic pathway of the antibiotic yanuthone D from Aspergillus niger. Our analyses show that yanuthone D is a meroterpenoid derived from the polyketide 6-methylsalicylic...

screening and improvement of local isolates of aspergillus niger

African Journals Online (AJOL)

DR. AMINU

ABSTRACT. The study involved the screening of fourteen isolates of Aspergillus niger for citric acid production from glucose. The study was aimed at screening and improving local strains of Aspergillus niger with potential for citric acid production. All the isolates screened produced varying amounts of citric acid, the highest ...

Expression of Lactate Dehydrogenase in Aspergillus niger for L-Lactic Acid Production

Science.gov (United States)

Dave, Khyati K.; Punekar, Narayan S.

2015-01-01

Different engineered organisms have been used to produce L-lactate. Poor yields of lactate at low pH and expensive downstream processing remain as bottlenecks. Aspergillus niger is a prolific citrate producer and a remarkably acid tolerant fungus. Neither a functional lactate dehydrogenase (LDH) from nor lactate production by A. niger is reported. Its genome was also investigated for the presence of a functional ldh. The endogenous A. niger citrate synthase promoter relevant to A. niger acidogenic metabolism was employed to drive constitutive expression of mouse lactate dehydrogenase (mldhA). An appraisal of different branches of the A. niger pyruvate node guided the choice of mldhA for heterologous expression. A high copy number transformant C12 strain, displaying highest LDH specific activity, was analyzed under different growth conditions. The C12 strain produced 7.7 g/l of extracellular L-lactate from 60 g/l of glucose, in non-neutralizing minimal media. Significantly, lactate and citrate accumulated under two different growth conditions. Already an established acidogenic platform, A. niger now promises to be a valuable host for lactate production. PMID:26683313

Analysis of functional xylanases in xylan degradation by Aspergillus niger E-1 and characterization of the GH family 10 xylanase XynVII.

Science.gov (United States)

Takahashi, Yui; Kawabata, Hiroaki; Murakami, Shuichiro

2013-01-01

Xylanases produced by Aspergillus niger are industrially important and many types of xylanases have been reported. Individual xylanases have been well studied for their enzymatic properties, gene cloning, and heterologous expression. However, less attention has been paid to the relationship between xylanase genes carried on the A. niger genome and xylanases produced by A. niger strains. Therefore, we examined xylanase genes encoded on the genome of A. niger E-1 and xylanases produced in culture. Seven putative xylanase genes, xynI-VII (named in ascending order of the molecular masses of the deduced amino acid sequences), were amplified from the strain E-1 genome using primers designed from the genome sequence of A. niger CBS 513.88 by PCR and phylogenetically classified into three clusters. Additionally, culture supernatant analysis by DE52 anion-exchange column chromatography revealed that this strain produced three xylanases, XynII, XynIII, and XynVII, which were identified by N-terminal amino acid sequencing and MALDI-TOF-MS analyses, in culture when gown in 0.5% xylan medium supplemented with 50 mM succinate. Furthermore, XynVII, the only GH family 10 xylanase in A. niger E-1, was purified and characterized. The purified enzyme showed a single band with a molecular mass of 35 kDa by SDS-PAGE. The highest activity of purified XynVII was observed at 55°C and pH 5.5. The enzyme was stable in the broad pH range of 3-10 and up to 60°C and was resistant to most metal ions and modifying regents. XynVII showed high specificity against beechwood xylan with K m and V max values of 2.8 mg mL(-1) and 127 μmol min(-1)mg(-1), respectively. TLC and MALDI-TOF-MS analyses showed that the final hydrolyzed products of the enzyme from beechwood xylan were xylose, xylobiose, and xylotriose substituted with a 4-o-metylglucuronic acid residue.

Trade and inter-group relations in the lower Niger 1830-1960 | Ali ...

African Journals Online (AJOL)

This study focuses on trade and intergroup relations in the Lower Niger in the period 1830-1960. Trade constitutes an integral aspect of communal relationship in the Lower Niger region from 1830 to 1960. The objective of the study is to show how the people of the Lower Niger related with each other in trade and other ...

The Economic Dimensions of the Niger Delta Ethnic Conflicts (Pp ...

African Journals Online (AJOL)

User

1970, the price of international oil stepped upwards following the Middle. Eastern Yom Kippur .... Over the years, the pleas of the Niger Delta people for accommodation are ignored or .... In a labour surplus region like the Niger Delta, budget.

western niger delta, nigeria

African Journals Online (AJOL)

HP

2015-07-21

Jul 21, 2015 ... River Niger catchment being along the corridors of mangrove and forest region might be responsible for the persistence in the occurrence of mangrove and rain forest pollen Zonocostites ramonae and Retitricolporites irregularis, Canthium spp. throughout the stratigraphic column of the well. REFERENCES.

The Aspergillus niger growth on the treated concrete substrate using variable antifungals

Science.gov (United States)

Parjo, U. K.; Sunar, N. M.; Leman, A. M.; Gani, P.; Embong, Z.; Tajudin, S. A. A.

2016-11-01

The aim of this study was to evaluate the Aspergillus niger (A. niger) growth on substrates after incorporates with different compounds of antifungals which is normally used in food industry. The antifungals named as potassium sorbate (PS), calcium benzoate (CB) and zinc salicylate (ZS) were applied on concrete substrate covered with different wall finishing such as acrylic paint (AP), glycerol based paint (GBP), thin wallpaper (THIN) and thick wallpaper (THICK). The concrete substrate were inoculated with spore suspension, incubated at selected temperature (30oC) and relative humidity (90%)in plant growth chamber. The observations were done from the Day 3 until Day 27. The results showed that the growth of the A. niger for concrete treated by PS for AP, GBP, THIN, and THICK were 64%, 32%, 11% and 100%, respectively. Meanwhile for CB, the growth of A. niger on AP, GBP, THIN, and THICK were 100%, 12%, 41%, and 13%, respectively. Similarly, treated concrete by ZS revealed that the growth of A. niger on the same substrate cover were 33%, 47%, 40%, and 39%, respectively. The results obtained in this study provide a valuable knowledge on the abilities of antifungals to remediate A. niger that inoculated on the concrete substrate. Consequently, this study proved that the PS covering with THIN more efficiency compares CB and ZS to prevent A. niger growth.

Phosphate solubilizing ability of two Arctic Aspergillus niger strains

Directory of Open Access Journals (Sweden)

Shiv Mohan Singh,

2011-06-01

Full Text Available Many filamentous fungi were isolated from the soils of Ny-Ålesund, Spitsbergen, Svalbard, and were screened in vitro for their phosphate solubilizing ability. Two strains of Aspergillus niger showed good tricalcium phosphate (TCP solubilizing ability in Pikovskaya's medium. The TCP solubilization index was calculated at varying levels of pH and temperatures. The ability of Aspergillus niger strain-1 to solubilize and release inorganic-P was 285 µg ml–1, while Aspergillus niger strain-2 solubilized 262 µg ml–1 from 0.5% TCP after seven days. This is the first report of TCP solubilization by Arctic strains that may serve as very good phosphate solubilizers in the form of biofertilizer.

Reconstruction of the central carbon metabolism of Aspergillus niger

DEFF Research Database (Denmark)

David, Helga; Åkesson, Mats Fredrik; Nielsen, Jens

2003-01-01

The topology of central carbon metabolism of Aspergillus niger was identified and the metabolic network reconstructed, by integrating genomic, biochemical and physiological information available for this microorganism and other related fungi. The reconstructed network may serve as a valuable...... of metabolic fluxes using metabolite balancing. This framework was employed to perform an in silico characterisation of the phenotypic behaviour of A. niger grown on different carbon sources. The effects on growth of single reaction deletions were assessed and essential biochemical reactions were identified...... for different carbon sources. Furthermore, application of the stoichiometric model for assessing the metabolic capabilities of A. niger to produce metabolites was evaluated by using succinate production as a case study....

Expression of the Aspergillus terreus itaconic acid biosynthesis cluster in Aspergillus niger.

Science.gov (United States)

van der Straat, Laura; Vernooij, Marloes; Lammers, Marieke; van den Berg, Willy; Schonewille, Tom; Cordewener, Jan; van der Meer, Ingrid; Koops, Andries; de Graaff, Leo H

2014-01-17

Aspergillus terreus is a natural producer of itaconic acid and is currently used to produce itaconic acid on an industrial scale. The metabolic process for itaconic acid biosynthesis is very similar to the production of citric acid in Aspergillus niger. However, a key enzyme in A. niger, cis-aconitate decarboxylase, is missing. The introduction of the A. terreus cadA gene in A. niger exploits the high level of citric acid production (over 200 g per liter) and theoretically can lead to production levels of over 135 g per liter of itaconic acid in A. niger. Given the potential for higher production levels in A. niger, production of itaconic acid in this host was investigated. Expression of Aspergillus terreus cis-aconitate decarboxylase in Aspergillus niger resulted in the production of a low concentration (0.05 g/L) of itaconic acid. Overexpression of codon-optimized genes for cis-aconitate decarboxylase, a mitochondrial transporter and a plasma membrane transporter in an oxaloacetate hydrolase and glucose oxidase deficient A. niger strain led to highly increased yields and itaconic acid production titers. At these higher production titers, the effect of the mitochondrial and plasma membrane transporters was much more pronounced, with levels being 5-8 times higher than previously described. Itaconic acid can be produced in A. niger by the introduction of the A. terreus cis-aconitate decarboxylase encoding cadA gene. This results in a low itaconic acid production level, which can be increased by codon-optimization of the cadA gene for A. niger. A second crucial requirement for efficient production of itaconic acid is the expression of the A. terreus mttA gene, encoding a putative mitochondrial transporter. Expression of this transporter results in a twenty-fold increase in the secretion of itaconic acid. Expression of the A. terreus itaconic acid cluster consisting of the cadA gene, the mttA gene and the mfsA gene results in A. niger strains that produce over

Dousing the tension in the Niger delta through administrative agency

African Journals Online (AJOL)

Dousing the tension in the Niger delta through administrative agency: A programme evaluation of Niger delta development commission as an intervention regime. ... the study concludes that because of systemic constraints arising from the hegemonic interests of the dominant coalitions in the Nigerian Social formation, ...

Identification of thermostable β-xylosidase activities produced by Aspergillus brasiliensis and Aspergillus niger

DEFF Research Database (Denmark)

Pedersen, Mads; Lauritzen, Henrik Klitgaard; Frisvad, Jens Christian

2007-01-01

Twenty Aspergillus strains were evaluated for production of extracellular cellulolytic and xylanolytic activities. Aspergillus brasiliensis, A. niger and A. japonicus produced the highest xylanase activities with the A. brasiliensis and A. niger strains producing thermostable beta......-xylosidases. The beta-xylosidase activities of the A. brasiliensis and A. niger strains had similar temperature and pH optima at 75 degrees C and pH 5 and retained 62% and 99%, respectively, of these activities over 1 h at 60 degrees C. At 75 degrees C, these values were 38 and 44%, respectively. Whereas A. niger...

Biominerlization and possible endosulfan degradation pathway adapted by Aspergillus niger.

Science.gov (United States)

Bhalerao, Tejomyee S

2013-11-28

Endosulfan is a chlorinated pesticide; its persistence in the environment and toxic effects on biota are demanding its removal. This study aims at improving the tolerance of the previously isolated fungus Aspergillus niger (A. niger) ARIFCC 1053 to endosulfan. Released chloride, dehalogenase activity, and released proteins were estimated along with analysis of endosulfan degradation and pathway identification. The culture could tolerate 1,000 mg/ml of technical grade endosulfan. Complete disappearance of endosulfan was seen after 168 h of incubation. The degradation study could easily be correlated with increase in released chlorides, dehalogenase activity and protein released. Comparative infrared spectral analysis suggested that the molecule of endosulfan was degraded efficiently by A. niger ARIFCC 1053. Obtained mass ion values by GC-MS suggested a hypothetical pathway during endosulfan degradation by A. niger ARIFCC 1053. All these results provide a basis for the development of bioremediation strategies to remediate the pollutant under study in the environment.

Post-genomic insights into the plant polysaccharide degradation potential of Aspergillus nidulans and comparison to Aspergillus niger and Aspergillus oryzae

NARCIS (Netherlands)

Coutinho, Pedro M; Andersen, Mikael R; Kolenova, Katarina; vanKuyk, Patricia A; Benoit, Isabelle; Gruben, Birgit S; Trejo-Aguilar, Blanca; Visser, Hans; van Solingen, Piet; Pakula, Tiina; Seiboth, Bernard; Battaglia, Evy; Aguilar-Osorio, Guillermo; de Jong, Jan F; Ohm, Robin A; Aguilar, Mariana; Henrissat, Bernard; Nielsen, Jens; Stålbrand, Henrik; de Vries, Ronald P

The plant polysaccharide degradative potential of Aspergillus nidulans was analysed in detail and compared to that of Aspergillus niger and Aspergillus oryzae using a combination of bioinformatics, physiology and transcriptomics. Manual verification indicated that 28.4% of the A. nidulans ORFs

The molecular and genetic basis of conidial pigmentation in Aspergillus niger

DEFF Research Database (Denmark)

Jørgensen, Thomas R.; Park, Joohae; Arentshorst, Mark

2011-01-01

A characteristic hallmark of Aspergillus niger is the formation of black conidiospores. We have identified four loci involved in spore pigmentation of A. niger by using a combined genomic and classical complementation approach. First, we characterized a newly isolated color mutant, colA, which......-γ-pyrone subclass of polyketides were specifically dependent on fwnA, and funalenone on fwnA, olvA and brnA. Thus, secondary metabolite profiling of the color mutants revealed a close relationship between polyketide synthesis and conidial pigmentation in A. niger....

Organic acid production in Aspergillus niger and other filamentous fungi

NARCIS (Netherlands)

Odoni, Dorett I.

2017-01-01

The aim of the thesis was to increase the understanding of organic acid production in Aspergillus niger and other filamentous fungi, with the ultimate purpose to improve A. niger as biotechnological production host.

In Chapter 1, the use of microbial

Lead immobilization by geological fluorapatite and fungus Aspergillus niger.

Science.gov (United States)

Li, Zhen; Wang, Fuwei; Bai, Tongshuo; Tao, Jinjin; Guo, Jieyun; Yang, Mengying; Wang, Shimei; Hu, Shuijin

2016-12-15

Phosphate solubilizing fungi have high ability to secrete organic acids. In this study, fungus Aspergillus niger and geological fluorapatite were applied in lead remediation in aqueous solution. Formation and morphology of the lead minerals, e.g., pyromorphite and lead oxalate, were investigated by SEM, XRD, and ATR-IR. The total quantity of organic acids reached the maximum at the sixth day, which improved the concentration of soluble P up to ∼370mg/L from ∼0.4mg/L. The organic acids, especially the oxalic acid, enhance the solubility of fluorapatite significantly. The stable fluoropyromorphite [Pb 5 (PO 4 ) 3 F] is precipitated with the elevated solubility of fluorapatite in the acidic environment. Furthermore, A. niger grows normally with the presence of lead cations. It is shown that >99% lead cations can be removed from the solution. However, immobilization caused by the precipitation of lead oxalate cannot be ignored if the fungus A. niger was cultured in the Pb solution. This study elucidates the mechanisms of lead immobilization by FAp and A. niger, and sheds its perspective in lead remediation, especially for high Pb concentration solution. Copyright © 2016 Elsevier B.V. All rights reserved.

Assessing Niger-Delta Wetland Resources: A Case-Study of Mangrove Ecosystem

Science.gov (United States)

Anwan, R. H.; Ndimele, P. E.; Whenu, O. O.; Anetekhai, M. A.; Essien-Ibok, M. A.; Erondu, E. S.

2016-02-01

The Niger Delta is located in the Atlantic coast of Southern Nigeria and is the world's second largest delta with a coastline of about 450km. The Niger Delta region occupies a surface area of about 112,110km2, representing about 12% of Nigeria's total surface area. The Delta's environment can be broken down into four ecological zones: coastal barrier islands, mangrove swamp forests, freshwater swamps, and lowland rainforests. The mangrove swamps of Niger Delta, which is the largest delta in Africa constitute the dominant wetland ecosystem in the Niger Delta region and covers an area of about 1,900km2. Mangroves constitute important nurseries for fishes, crustaceans, sponges, algae and other invertebrates, and also acts as a sink, retaining pollutants from contaminated tidal water. The Niger Delta mangrove together with the creeks and rivers are a major source of food and livelihood for about 30 million people, which represents more than 17% of Nigeria's population. Other ecosystem services provided by this unique environment are flood control, ground water re-fill, reservoir of biodiversity, fuel wood, cultural values etc. This ecosystem also plays important role in climate change mitigation because of its high blue carbon sequestration potential. This is particularly important because of continuous gas flaring in Niger Delta from petroleum operations, which releases carbon dioxide among other gases into the atmosphere. This wetland is potentially a good site for ecotourism and also qualifies to be a world heritage site and Ramsar site if proper steps are taken. The benefits derivable from this fragile ecosystem are under severe threat by anthropogenic stressors. These include the installation of pipelines and seismic exploration by oil companies, crude oil pollution, deforestation, urbanization etc. This paper discusses the extent of depletion and loss of mangrove ecosystem in the Niger Delta region and the value of its goods and services.

Biosorption of radionuclide Americium-241 by A. niger spore and hyphae

International Nuclear Information System (INIS)

Yang Yuanyou; Liu Ning; Jin Jiannan; Hua Xinfeng; Zhang Taiming; Luo Shunzhong; Sun Qiling

2002-01-01

The biosorption of radionuclide 241 Am from solution was studied by a. niger spore and hyphae, and the effects of the operational conditions on the treatment were investigated. The results showed the treatment by A. niger spore and hyphae were very efficient. An average of 96% of the total 241 Am was removed from 241 Am solutions of 5.6-111 MBq/L (C 0 ), with adsorption capacities (W) of 7.2-142.4 MBq/g biomass, 5.2-106.5 MBq/g, respectively. The biosorption equilibrium was achieved within 1 h and the optimum pH value ranged 3-0.1 mol/L HNO 3 and 3-2 for spore and hyphae of A. niger, respectively. No significant effects on 241 Am biosorption were observed at 15 degree C-45 degree C, or challenged with containing Au 3+ or Ag + , even 2000 times above 241 Am amount. the index relationship between concentrations and adsorption capacities of 241 Am indicated that the 241 Am biosorption by A. niger spore and hyphae obey to Freundlich adsorption equation. The adsorption behavior of A. niger spore and hyphae were basically coincident

Niger Delta Crisis and Security Implications for the Nation State ...

African Journals Online (AJOL)

The Niger Delta is the nation's treasure base, the Niger Delta provides over 80 percent of government revenue, 95 percent of export receipts, and 90 percent of ... The government should tackle the fundamental issue of basic necessities – provision of good motorable roads, pipe borne water, electricity, good hospitals, good ...

Estimation of Thermal Conductivity in the North- Western Niger Delta ...

African Journals Online (AJOL)

Thermal conductivity estimates are computed from nineteen petroleum wells in the north-western Niger Delta, Nigeria, using a geometric mean model. Sonic and gamma-ray logs were digitised and used in the estimation of in situ conductivity. The Niger Delta is composed of three major diachronous lithostratigraphic units of ...

Caribbean piracy and youth restiveness in Niger delta: A ...

African Journals Online (AJOL)

Our aim in this paper is to make a comparative analysis of Caribbean piracy and youth restiveness in Niger Delta of Nigeria. It will not be out of place to carry out such an analysis having seen, heard or read of the ongoing chaos, insecurity in the. Niger Delta Zone in Nigeria. We have to look at the past to find out such similar

A novel pig feed formulation containing Aspergillus niger CSA35 ...

African Journals Online (AJOL)

This study investigated the effects of Aspergillus niger CSA35 pretreated-cassava (Manihot esculenta Crantz) peel feed (CPFG) on the body weight gain and some selected biochemical parameters of pigs. Cassava peels treated with biomass of A. niger CSA35 for a period of three weeks to initiate enzymatic digestion of ...

Women of Niger Delta

African Journals Online (AJOL)

Religion Dept

The Indispensability of Women in Conflict Resolution in the Niger Delta ... The situation leads to a shift in gender roles with a dramatic increase in the number of women .... organization is to work in partnership with the Nigerian Government and the .... that “women are the impartial arbitrators in family or clan disputes or.

Cellobiohydrolase B of Aspergillus niger over-expressed in Pichia pastoris stimulates hydrolysis of oil palm empty fruit bunches.

Science.gov (United States)

Woon, James Sy-Keen; Mackeen, Mukram M; Illias, Rosli M; Mahadi, Nor M; Broughton, William J; Murad, Abdul Munir Abdul; Abu Bakar, Farah Diba

2017-01-01

Aspergillus niger , along with many other lignocellulolytic fungi, has been widely used as a commercial workhorse for cellulase production. A fungal cellulase system generally includes three major classes of enzymes i.e., β-glucosidases, endoglucanases and cellobiohydrolases. Cellobiohydrolases (CBH) are vital to the degradation of crystalline cellulose present in lignocellulosic biomass. However, A. niger naturally secretes low levels of CBH. Hence, recombinant production of A. niger CBH is desirable to increase CBH production yield and also to allow biochemical characterisation of the recombinant CBH from A. niger . In this study, the gene encoding a cellobiohydrolase B ( cbh B) from A. niger ATCC 10574 was cloned and expressed in the methylotrophic yeast Pichia pastoris X-33. The recombinant CBHB was purified and characterised to study its biochemical and kinetic characteristics. To evaluate the potential of CBHB in assisting biomass conversion, CBHB was supplemented into a commercial cellulase preparation (Cellic ® CTec2) and was used to hydrolyse oil palm empty fruit bunch (OPEFB), one of the most abundant lignocellulosic waste from the palm oil industry. To attain maximum saccharification, enzyme loadings were optimised by response surface methodology and the optimum point was validated experimentally. Hydrolysed OPEFB samples were analysed using attenuated total reflectance FTIR spectroscopy (ATR-FTIR) to screen for any compositional changes upon enzymatic treatment. Recombinant CBHB was over-expressed as a hyperglycosylated protein attached to N -glycans. CBHB was enzymatically active towards soluble substrates such as 4-methylumbelliferyl-β-D-cellobioside (MUC), p -nitrophenyl-cellobioside ( p NPC) and p -nitrophenyl-cellobiotrioside ( p NPG3) but was not active towards crystalline substrates like Avicel ® and Sigmacell cellulose. Characterisation of purified CBHB using MUC as the model substrate revealed that optimum catalysis occurred at 50 °C and

Single cell transcriptomics of neighboring hyphae of Aspergillus niger

Science.gov (United States)

2011-01-01

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. PMID:21816052

Aspergillus niger is a superior expression host for the production of bioactive fungal cyclodepsipeptides.

Science.gov (United States)

Boecker, Simon; Grätz, Stefan; Kerwat, Dennis; Adam, Lutz; Schirmer, David; Richter, Lennart; Schütze, Tabea; Petras, Daniel; Süssmuth, Roderich D; Meyer, Vera

2018-01-01

Fungal cyclodepsipeptides (CDPs) are non-ribosomally synthesized peptides produced by a variety of filamentous fungi and are of interest to the pharmaceutical industry due to their anticancer, antimicrobial and anthelmintic bioactivities. However, both chemical synthesis and isolation of CDPs from their natural producers are limited due to high costs and comparatively low yields. These challenges might be overcome by heterologous expression of the respective CDP-synthesizing genes in a suitable fungal host. The well-established industrial fungus Aspergillus niger was recently genetically reprogrammed to overproduce the cyclodepsipeptide enniatin B in g/L scale, suggesting that it can generally serve as a high production strain for natural products such as CDPs. In this study, we thus aimed to determine whether other CDPs such as beauvericin and bassianolide can be produced with high titres in A. niger , and whether the generated expression strains can be used to synthesize new-to-nature CDP derivatives. The beauvericin and bassianolide synthetases were expressed under control of the tuneable Tet-on promoter, and titres of about 350-600 mg/L for bassianolide and beauvericin were achieved when using optimized feeding conditions, respectively. These are the highest concentrations ever reported for both compounds, whether isolated from natural or heterologous expression systems. We also show that the newly established Tet-on based expression strains can be used to produce new-to-nature beauvericin derivatives by precursor directed biosynthesis, including the compounds 12-hydroxyvalerate-beauvericin and bromo-beauvericin. By feeding deuterated variants of one of the necessary precursors (d-hydroxyisovalerate), we were able to purify deuterated analogues of beauvericin and bassianolide from the respective A. niger expression strains. These deuterated compounds could potentially be used as internal standards in stable isotope dilution analyses to evaluate and quantify

HisB as novel selection marker for gene targeting approaches in Aspergillus niger.

Science.gov (United States)

Fiedler, Markus R M; Gensheimer, Tarek; Kubisch, Christin; Meyer, Vera

2017-03-08

For Aspergillus niger, a broad set of auxotrophic and dominant resistance markers is available. However, only few offer targeted modification of a gene of interest into or at a genomic locus of choice, which hampers functional genomics studies. We thus aimed to extend the available set by generating a histidine auxotrophic strain with a characterized hisB locus for targeted gene integration and deletion in A. niger. A histidine-auxotrophic strain was established via disruption of the A. niger hisB gene by using the counterselectable pyrG marker. After curing, a hisB - , pyrG - strain was obtained, which served as recipient strain for further studies. We show here that both hisB orthologs from A. nidulans and A. niger can be used to reestablish histidine prototrophy in this recipient strain. Whereas the hisB gene from A. nidulans was suitable for efficient gene targeting at different loci in A. niger, the hisB gene from A. niger allowed efficient integration of a Tet-on driven luciferase reporter construct at the endogenous non-functional hisB locus. Subsequent analysis of the luciferase activity revealed that the hisB locus is tight under non-inducing conditions and allows even higher luciferase expression levels compared to the pyrG integration locus. Taken together, we provide here an alternative selection marker for A. niger, hisB, which allows efficient homologous integration rates as well as high expression levels which compare favorably to the well-established pyrG selection marker.

The Niger Delta Amnesty Program

Directory of Open Access Journals (Sweden)

Benjamin A. Okonofua

2016-06-01

Full Text Available The armed conflict between militias and government forces in Nigeria’s Niger Delta region has spanned for more than two decades, defying all solutions. A disarmament, demobilization, and reintegration (DDR program was established in August 2015 in effort to end the violence and has remained in place. It is a radically different approach from past approaches that displayed zero tolerance to all political challenges to oil production or the allocation of oil profits. The approach appeared to be immediately successful in that it forced a ceasefire, engaged militants in planned programs to rehabilitate and reintegrate them into civilian society, and opened up the oil wells (many of which had been shut due to the crisis with the effect of increasing government revenue, which depends 85% on oil exports. Yet, few studies have attempted to understand the dynamics within the country that are responsible for the design and implementation of this broad policy shift or to understand whether and how the current initiative is able to end the conflict and institute peace beyond the short term. This study, therefore, is important because it provides a critical perspective that anticipates and explains emerging issues with the Niger Delta Amnesty Program, which have implications for DDR adaptation and implementation all over the world. Ultimately, the research demonstrates how the DDR program both transforms the Niger Delta conflict and becomes embroiled in intense contestations not only about the mechanism for transforming the targeted population but also whether and how the program incorporates women who are being deprioritized by the program.

Electrochemical monitoring of citric acid production by Aspergillus niger

International Nuclear Information System (INIS)

Kutyła-Olesiuk, Anna; Wawrzyniak, Urszula E.; Ciosek, Patrycja; Wróblewski, Wojciech

2014-01-01

Highlights: • Citric acid fermentation process (production) by Aspergillus niger. • Qualitative/quantitative monitoring of standard culture and culture infected with yeast. • Electronic tongue based on potentiometric and voltammetric sensors. • Evaluation of the progress and the correctness of the fermentation process. • The highest classification abilities of the hybrid electronic tongue. - Abstract: Hybrid electronic tongue was developed for the monitoring of citric acid production by Aspergillus niger. The system based on various potentiometric/voltammetric sensors and appropriate chemometric techniques provided correct qualitative and quantitative classification of the samples collected during standard Aspergillus niger culture and culture infected with yeast. The performance of the proposed approach was compared with the monitoring of the fermentation process carried out using classical methods. The results obtained proved, that the designed hybrid electronic tongue was able to evaluate the progress and correctness of the fermentation process

Electrochemical monitoring of citric acid production by Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Kutyła-Olesiuk, Anna; Wawrzyniak, Urszula E.; Ciosek, Patrycja; Wróblewski, Wojciech, E-mail: wuwu@ch.pw.edu.pl

2014-05-01

Highlights: • Citric acid fermentation process (production) by Aspergillus niger. • Qualitative/quantitative monitoring of standard culture and culture infected with yeast. • Electronic tongue based on potentiometric and voltammetric sensors. • Evaluation of the progress and the correctness of the fermentation process. • The highest classification abilities of the hybrid electronic tongue. - Abstract: Hybrid electronic tongue was developed for the monitoring of citric acid production by Aspergillus niger. The system based on various potentiometric/voltammetric sensors and appropriate chemometric techniques provided correct qualitative and quantitative classification of the samples collected during standard Aspergillus niger culture and culture infected with yeast. The performance of the proposed approach was compared with the monitoring of the fermentation process carried out using classical methods. The results obtained proved, that the designed hybrid electronic tongue was able to evaluate the progress and correctness of the fermentation process.

D-Galactose uptake is nonfunctional in the conidiospores of Aspergillus niger

NARCIS (Netherlands)

Fekete, E.; de Vries, R.P.; Seiboth, B.; vanKuyk, P.A.; Sandor, E.; Metz, B.; Kubicek, C.P.; Karaffa, L.

2012-01-01

The majority of black Aspergilli (Aspergillus section Nigri), including Aspergillus niger, as well as many other Ascomycetes fail to germinate on d-galactose as a sole carbon source. Here, we provide evidence that the ability of A. niger to transport d-galactose is growth stage dependent, being

Cytosolic streaming in vegetative mycelium and aerial structures of aspergillus niger

NARCIS (Netherlands)

Bleichrodt, R.; Vinck, A.; Krijgsheld, P.; van Leeuwen, M.R.; Dijksterhuis, J.; Wösten, H.A.B.

2013-01-01

Aspergillus niger forms aerial hyphae and conidiophores after a period of vegetative growth. The hyphae within the mycelium of A. niger are divided by septa. The central pore in these septa allows for cytoplasmic streaming. Here, we studied inter- and intra-compartmental streaming of the reporter

Development of ferry service on the lower Niger, 1901-1960 | Ali ...

African Journals Online (AJOL)

The paper demonstrates colonial government efforts in developing water transportation on the Lower Niger River by maintaining vessels as vehicles of transportation from the beginning of the twentieth century. Government departments were set up at various times to oversee activities of users of the River Niger.

Proteomic Analysis of the Secretory Response of Aspergillus niger to D-Maltose and D-Xylose

OpenAIRE

Ferreira de Oliveira, José Miguel P.; van Passel, Mark W. J.; Schaap, Peter J.; de Graaff, Leo H.

2011-01-01

Fungi utilize polysaccharide substrates through extracellular digestion catalyzed by secreted enzymes. Thus far, protein secretion by the filamentous fungus Aspergillus niger has mainly been studied at the level of individual proteins and by genome and transcriptome analyses. To extend these studies, a complementary proteomics approach was applied with the aim to investigate the changes in secretome and microsomal protein composition resulting from a shift to a high level secretion condition....

Creating the next steps to care: Maternal heath, improvisation, and Fulani women in Niamey, Niger.

Science.gov (United States)

Burgess, Sarah

2016-12-01

On paper, Niger's maternal healthcare system is extensively outlined by policies which assure access to certain services and create hierarchical referral chains. In practice it remains intensely improvisational: actors in the system must frequently make up the next steps to giving and receiving care, often outside the existing policies and procedures. Although population health in Niger has improved since the recently enacted gratuité des soins policy (which guarantees free access to certain material and child health services), care on the ground is still dictated by difficult circumstances and scarce resources. Health workers often lack the required medications and supplies; nevertheless, they must find ways to deliver services. Patients seeking maternal health services are frequently dissatisfied with the care they receive and so move forward of their own volition, by negotiating with health workers or by looking for services elsewhere. This research builds on recent scholarly work on improvisation, and asks us to further look at the ways that improvisation can be informed by the identity of the actors. Examining case studies of women from the Fulani ethnic group illustrates how particular cultural differences can inform improvisation. Analysing improvisation can also have policy implications; identifying typical points of departure from the official maternal health care system can reveal points where Niger can bolster its commitment to a universally high quality of care.

Climatology of the northern hemisphere stratosphere derived from Berlin analyses. Pt. 1. Monthly means

International Nuclear Information System (INIS)

Pawson, S.; Labitzke, K.; Lenschow, R.; Naujokat, B.; Rajewski, B.; Wiesner, M.; Wohlfart, R.C.

1993-01-01

This work presents a climatology of the northern hemisphere lower and middle stratosphere derived from daily radiosonde observations subjectively analysed in the Stratospheric Research Group of the 'Meteorologisches Institut der Freien Universitaet Berlin'. Previous climatologies from these data were presented by Labitzke (1972), van Loon et al. (1972), and by Labitzke and Goretzki (1982). Although some more recent climatological fields have been presented in several works by members of the group, no complete atlas has been compiled for some time. The work is intended to serve as a reference for people interested in the stratosphere and, particularly, the climate analysis and modelling communities, which require contemporary analyses of the available data in order to interpret their products. In this first part of the climatological atlas, monthly mean data are presented. (orig./KW)

Climatology of the northern hemisphere stratosphere derived from Berlin analyses. Pt. 1. Monthly means

Energy Technology Data Exchange (ETDEWEB)

Pawson, S; Labitzke, K; Lenschow, R; Naujokat, B; Rajewski, B; Wiesner, M; Wohlfart, R C

1933-01-01

This work presents a climatology of the northern hemisphere lower and middle stratosphere derived from daily radiosonde observations subjectively analysed in the Stratospheric Research Group of the 'Meteorologisches Institut der Freien Universitaet Berlin'. Previous climatologies from these data were presented by Labitzke (1972), van Loon et al. (1972), and by Labitzke and Goretzki (1982). Although some more recent climatological fields have been presented in several works by members of the group, no complete atlas has been compiled for some time. The work is intended to serve as a reference for people interested in the stratosphere and, particularly, the climate analysis and modelling communities, which require contemporary analyses of the available data in order to interpret their products. In this first part of the climatological atlas, monthly mean data are presented. (orig./KW)

Production of Fumonisin B-2 and B-4 by Aspergillus niger on Grapes and Raisins

DEFF Research Database (Denmark)

Mogensen, Jesper Mølgaard; Frisvad, Jens Christian; Thrane, Ulf

2010-01-01

The recent discovery of fumonisin production in Aspergillus niger, raises concerns about the presence of these mycotoxins in grapes and raisins as well as other commodities where A. niger is a frequent contaminant. Here we investigate the potential production of fumonisins in A. niger cultured...... on grapes and raisins. Sixty-six A. niger, 4 A. tubingensis, and 16 A. acidus strains isolated from raisins were tested for fumonisin production on laboratory media. Neither A. tubingensis nor A. acidus strains produced fumonisins, but 77% of A. niger strains did. None of the strains produced ochratoxin A....... Ten selected fumonisin producing A. niger strains were further able to produce fumonisin B2 and fumonisin B4 on grapes in the range 171−7841 μg fumonisin B2/kg and 14−1157 μg fumonisin B4/kg. Four selected strains were able to produce fumonisin B2 (5−6476 μg/kg) and fumonisin B4 (12−672 μg...

Characteristics of exo- polygalacturonase produced by irradiated Aspergillus niger and Trichoderma viride spores

International Nuclear Information System (INIS)

Youssef, B.M.; Swailam, H.M.; Gomaa, N.M.; EL-Mehallawy, A.A.

2010-01-01

Out of 69 fungal isolates from nine pectin rich fresh fruit wastes-showed pectinolytic activity, two were the powerful and best. They were identified as Aspergillus niger and Trichoderma viride. Gamma irradiation of the spore suspensions of these two isolates (0- 3 kGy) stimulated the exo-polygalacturonase (PG) production. Treatment with 0.25 kGy and 0.25-0.50 kGy was found to be the best doses for inducing PG activity produced from T. viride and Asp. niger respectively . The enzyme characteristics were also studied. The optimum temperature of T. viride enzyme reaction was 5 C compared with 45 degree C for Asp. niger enzyme extract.The optimum incubation time of T. viride enzyme reaction was 70-80 min which greater than that of Asp. niger namely 60 min.The results of enzyme reaction ph revealed that the best PG activity was observed at ph 5.0 for the extract of the two fungal isolates. The stability of the enzyme was affected markedly by each of incubation temp., incubation period and ph value .A. niger and T. viride crude extract enzymes were stimulated with Mn 2+ while Zn 2+ and Ca 2+ were inhibitors. The best volume of crude enzyme extract was 3.00 ml in case of T. viride while in case of A. niger was 2.00 ml. T. viride enzyme extract showed its highest enzyme activity with substrate concentration 1.5 % while that of A. niger was found to be 3.0%.

The infrared spectral transmittance of Aspergillus niger spore aggregated particle swarm

Science.gov (United States)

Zhao, Xinying; Hu, Yihua; Gu, Youlin; Li, Le

2015-10-01

Microorganism aggregated particle swarm, which is quite an important composition of complex media environment, can be developed as a new kind of infrared functional materials. Current researches mainly focus on the optical properties of single microorganism particle. As for the swarm, especially the microorganism aggregated particle swarm, a more accurate simulation model should be proposed to calculate its extinction effect. At the same time, certain parameters deserve to be discussed, which helps to better develop the microorganism aggregated particle swarm as a new kind of infrared functional materials. In this paper, take Aspergillus Niger spore as an example. On the one hand, a new calculation model is established. Firstly, the cluster-cluster aggregation (CCA) model is used to simulate the structure of Aspergillus Niger spore aggregated particle. Secondly, the single scattering extinction parameters for Aspergillus Niger spore aggregated particle are calculated by using the discrete dipole approximation (DDA) method. Thirdly, the transmittance of Aspergillus Niger spore aggregated particle swarm is simulated by using Monte Carlo method. On the other hand, based on the model proposed above, what influences can wavelength causes has been studied, including the spectral distribution of scattering intensity of Aspergillus Niger spore aggregated particle and the infrared spectral transmittance of the aggregated particle swarm within the range of 8-14μm incident infrared wavelengths. Numerical results indicate that the scattering intensity of Aspergillus Niger spore aggregated particle reduces with the increase of incident wavelengths at each scattering angle. Scattering energy mainly concentrates on the scattering angle between 0-40°, forward scattering has an obvious effect. In addition, the infrared transmittance of Aspergillus Niger spore aggregated particle swarm goes up with the increase of incident wavelengths. However, some turning points of the trend are

Heterologous expression of trametes versicolor laccase in pichia pastoris and aspergillus niger

CSIR Research Space (South Africa)

Bohlin, C

2006-09-01

Full Text Available primarily for screening purposes. With A. niger, high levels of laccase (2700 U/L) were produced using a min- imal medium containing sucrose and yeast extract. Recombinant laccase from A. niger harboring the lcc2 cDNA was purified to homogeneity...). Methods Microbial Strains and Recombinant DNA The lcc1 and lcc2 cDNA genes from T. (Coriolus, Polyporus) versicolor (9–11) were used in the construction of plasmids for expression of laccases in P. pastoris and A. niger. For the expression in P...

Physiological characterisation of acuB deletion in Aspergillus niger

DEFF Research Database (Denmark)

Meijer, Susan Lisette; De Jongh, Willem Adriaan; Olsson, Lisbeth

2009-01-01

The acuB gene of Aspergillus niger is an ortholog of facB in Aspergillus nidulans. Under carbon-repression conditions, facB is repressed, thereby preventing acetate metabolism when the repressing carbon source is present. Even though facB is reported to be repressed directly by CreA, it is believed...... that a basal level of FacB activity exists under glucose-repressive conditions. In the present study, the effect of deletion of acuB on the physiology of A. niger was assessed. Differences in organic acid and acetate production, enzyme activities and extracellular amino and non-amino organic acid production...... were determined under glucose-repressing and -derepressing conditions. Furthermore, consumption of alternative carbon sources (e.g. xylose, citrate, lactate and succinate) was investigated. It was shown that AcuB has pleiotropic effects on the physiology of A. niger. The results indicate that metabolic...

Fumonisin and Ochratoxin Production in Industrial Aspergillus niger Strains

DEFF Research Database (Denmark)

Frisvad, Jens Christian; Larsen, Thomas Ostenfeld; Thrane, Ulf

2011-01-01

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 (B(2), B(4), and B(6)) 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...

Fumonisin and Ochratoxin Production in Industrial Aspergillus niger Strains

Science.gov (United States)

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

2011-01-01

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. PMID:21853139

The Effect of Tallow As Lipase Inducer on Total of Aspergillus Niger, Lipolitic Activity and Lipase Yield

Directory of Open Access Journals (Sweden)

Manik Eirry Sawitri

2012-02-01

Full Text Available The objectives of this research was to determined of tallow addition with different concentration as lipase Aspergillus niger inducer to total of A. niger, lipolitic activity and lipase yield. The result showed that tallow addition as inducer in the lipase A. niger production gave no significant effect on total of A. niger (5.3 x 107 – 1.7 x 108 cfu/gram in the medium. Tallow addition gave a highly significant effect on lipolytic activity and yield of lipase A. niger. Lipolytic activity ranged between 32.0354 – 53.1197 U/mg protein, while the yield of lipase was 6.6418–7.8941 µg/ml. The conclusion of this research was the addition of tallow for 8% as the lipase inducer of A. niger on lipase production was  more effective to obtain the optimal result. Keywords : Tallow, lipase, inducer, Aspergillus niger

Antimicrobial activity and agricultural properties of bitter melon (Momordica charantia L.) grown in northern parts of Turkey: a case study for adaptation.

Science.gov (United States)

Yaldız, Gülsüm; Sekeroglu, Nazım; Kulak, Muhittin; Demirkol, Gürkan

2015-01-01

This study was designed to determine the adaptation capability of bitter melon (Momordica charantia L.), which is widely grown in tropical and subtropical climates, in northern parts of Turkey. In this study, plant height, number of fruits, fruit length, fruit width, number of seeds and fruit weight of bitter melon grown in field conditions were determined. The antimicrobial effect of the ethanol extract of fruit and seeds against Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Salmonella typhi, Aspergillus niger and Candida albicans microorganisms was tested in vitro by the disc diffusion method. In conclusion, plant height (260 cm), number of fruits (16 per  plant), number of seeds (30.2  per fruit), fruit width (3.8 cm), fruit length (10.6 cm) and fruit weight (117.28 g fruit(- 1)) were determined; fruits were found to have antimicrobial activity against A. niger; oil and seeds were found to have antimicrobial activity against A. niger and E. coli.

Toolkit for visualization of the cellular structure and organelles in Aspergillus niger.

Science.gov (United States)

Buren, Emiel B J Ten; Karrenbelt, Michiel A P; Lingemann, Marit; Chordia, Shreyans; Deng, Ying; Hu, JingJing; Verest, Johanna M; Wu, Vincen; Gonzalez, Teresita J Bello; Heck, Ruben G A van; Odoni, Dorett I; Schonewille, Tom; Straat, Laura van der; Graaff, Leo H de; Passel, Mark W J van

2014-12-19

Aspergillus niger is a filamentous fungus that is extensively used in industrial fermentations for protein expression and the production of organic acids. Inherent biosynthetic capabilities, such as the capacity to secrete these biomolecules in high amounts, make A. niger an attractive production host. Although A. niger is renowned for this ability, the knowledge of the molecular components that underlie its production capacity, intercellular trafficking processes and secretion mechanisms is far from complete. Here, we introduce a standardized set of tools, consisting of an N-terminal GFP-actin fusion and codon optimized eforRed chromoprotein. Expression of the GFP-actin construct facilitates visualization of the actin filaments of the cytoskeleton, whereas expression of the chromoprotein construct results in a clearly distinguishable red phenotype. These experimentally validated constructs constitute the first set of standardized A. niger biomarkers, which can be used to study morphology, intercellular trafficking, and secretion phenomena.

Cellobiohydrolase B of Aspergillus niger over-expressed in Pichia pastoris stimulates hydrolysis of oil palm empty fruit bunches

Directory of Open Access Journals (Sweden)

James Sy-Keen Woon

2017-10-01

Full Text Available Background Aspergillus niger, along with many other lignocellulolytic fungi, has been widely used as a commercial workhorse for cellulase production. A fungal cellulase system generally includes three major classes of enzymes i.e., β-glucosidases, endoglucanases and cellobiohydrolases. Cellobiohydrolases (CBH are vital to the degradation of crystalline cellulose present in lignocellulosic biomass. However, A. niger naturally secretes low levels of CBH. Hence, recombinant production of A. niger CBH is desirable to increase CBH production yield and also to allow biochemical characterisation of the recombinant CBH from A. niger. Methods In this study, the gene encoding a cellobiohydrolase B (cbhB from A. niger ATCC 10574 was cloned and expressed in the methylotrophic yeast Pichia pastoris X-33. The recombinant CBHB was purified and characterised to study its biochemical and kinetic characteristics. To evaluate the potential of CBHB in assisting biomass conversion, CBHB was supplemented into a commercial cellulase preparation (Cellic® CTec2 and was used to hydrolyse oil palm empty fruit bunch (OPEFB, one of the most abundant lignocellulosic waste from the palm oil industry. To attain maximum saccharification, enzyme loadings were optimised by response surface methodology and the optimum point was validated experimentally. Hydrolysed OPEFB samples were analysed using attenuated total reflectance FTIR spectroscopy (ATR-FTIR to screen for any compositional changes upon enzymatic treatment. Results Recombinant CBHB was over-expressed as a hyperglycosylated protein attached to N-glycans. CBHB was enzymatically active towards soluble substrates such as 4-methylumbelliferyl-β-D-cellobioside (MUC, p-nitrophenyl-cellobioside (pNPC and p-nitrophenyl-cellobiotrioside (pNPG3 but was not active towards crystalline substrates like Avicel® and Sigmacell cellulose. Characterisation of purified CBHB using MUC as the model substrate revealed that optimum

NUTRIENT COMPOSITION OF NIGER SEED (GUIZOTIA ...

African Journals Online (AJOL)

B. S. Chandravanshi

fiber. Niger oil has a fatty acid composition typical for seed oils of the .... system using external calibration curve after optimizing the parameters in to .... physical and chemical properties of the soil, application of natural (manure) and artificial.

The identity of the enigmatic "Black Shrew" (Sorex niger Ord, 1815)

Science.gov (United States)

Woodman, Neal

2013-01-01

The scientific name Sorex niger Ord, 1815 (Mammalia, Soricidae) was originally applied to a North American species that George Ord called the “Black Shrew.” The origin of the name “Black Shrew,” however, was obscure, and Samuel Rhoads subsequently wrote that the species represented by this name could not be determined. The names Sorex niger Ord and Black Shrew have since been mostly forgotten. Two of Ord's contemporaries, however, noted that Ord's use of these names probably alluded to Benjamin Smith Barton's Black Shrew, whose discovery near Philadelphia was announced by Barton in 1806. Examination of two unpublished illustrations of the Black Shrew made by Barton indicates that the animal depicted is Blarina brevicauda (Say, 1822). Had the connection between Ord's and Barton's names been made more clearly, one of the most common mammals in eastern North America would bear a different scientific name today. This connection also would have affected the validity of Sorex niger Horsfield, 1851. While Sorex niger Ord remains a nomen nudum, the animal it referenced can now be identified.

Empowering Women in West African Markets. Case Studies from Kano, Katsina (Nigeria) and Maradi (Niger)

DEFF Research Database (Denmark)

Hoffmann, Leena; Melly, Paul; Walther, Olivier

contributes to a better understanding and assessment of the links between gender and the functioning of markets and value chains under relatively stable (non-emergency; non-crisis) conditions. Such an understanding can support the World Food Programme (WFP), whose recent studies examine the gender dynamics......The aim of this study is to provide grassroots understanding of the market conditions faced by women farmers and traders in two culturally similar yet administratively different areas: the Kano-Katsina region in northern Nigeria and the Maradi region in southern Niger. The comparative analysis...... dispersed throughout this report provides an overall picture of context specific gender barriers that limit women’s participation in the sub-regional agricultural and livestock economy and in agricultural markets and value chains along the economic corridor that connects Kano, Katsina and Maradi. This study...

Screening of mutant strains producing phytase from A. niger by 60Co γ-ray irradiation

International Nuclear Information System (INIS)

Yang Pingping; Wang Yan; Tao Wenyi

2004-01-01

60 Co γ-ray was used to irradiate Aspergillus niger 447-92 for screening the mutant strain of producing phytase, and the effects of mutation induction were determined and analyzed. A mutant strain A. niger 496-1 with high level of phytase was selected, the phytase properties of A. niger 496-1 were analyzed

The effects of types of media on uranium leaching using metabolite of Aspergillus niger

International Nuclear Information System (INIS)

Li Guangyue; Ding Dexin; Wang Yongdong; Hu Nan

2012-01-01

To investigate the influences of different media to uranium leaching applying with metabolite of Aspergillus niger, PSA and glucose-steepwater medium were used for the culture of Aspergillus niger, and the metabolite of Aspergillus niger with different pH value produced in the diverse culture temperature were obtained which was applied on the tests of uranium leaching as leaching agent. The test results show that the maximum leaching rate is 83.05% when the leaching agent is the metabolite of Aspergillus niger produced by PSA, as for the glucose- steepwater medium, the maximum leaching rate is 68.20%. The pH value of the metabolite of Aspergillus niger of the two kinds of media has a significant effect on the leaching rate. When PSA is adopted, the best leaching rate appears at the pH value of metabolite ranging from 2.0 to 2.5, and as for the glucose-steepwater medium, the pH value is below 2.1. (authors)

An Over-View of Niger Delta Indigenous Religion | Tasie | Lwati: A ...

African Journals Online (AJOL)

This essay is an outline and interpretation of Niger Delta indigenous religion. It examines the structure of the indigenous religion and points out that as heterogeneous and diverse as the people of Niger Delta are, so also is the indigenous religion of the people. Thus, an ethnic group may emphasize a belief system or an ...

Nitrile biotransformation by Aspergillus niger

Czech Academy of Sciences Publication Activity Database

Šnajdrová, Radka; Kristová, Veronika; Crestia, D.; Nikolaou, K.; Kuzma, Marek; Lemaire, M.; Gallienne, E.; Bolte, J.; Bezouška, K.; Křen, Vladimír; Martínková, Ludmila

2004-01-01

Roč. 29, - (2004), s. 227-232 ISSN 1381-1177 R&D Projects: GA MŠk OC D25.002; GA AV ČR IAA4020213 Institutional research plan: CEZ:AV0Z5020903 Keywords : aspergillus niger * nitrile-converting enzymes * nitrile hydratase Subject RIV: EE - Microbiology, Virology Impact factor: 1.547, year: 2004

Metabolic control analysis of Aspergillus niger L-arabinose catabolism

DEFF Research Database (Denmark)

de Groot, M.J.L.; Prathumpai, Wai; Visser, J.

2005-01-01

A mathematical model of the L-arabinose/D-xylose catabolic pathway of Aspergillus niger was constructed based on the kinetic properties of the enzymes. For this purpose L-arabinose reductase, L-arabitol dehydrogenase and D-xylose reductase were purified using dye-affinity chromatography...... aiming at either flux or metabolite level optimization of the L-arabinose catabolic pathway of A. niger. Faster L-arabinose utilization may enhance utilization of readily available organic waste containing hemicelluloses to be converted into industrially interesting metabolites or valuable enzymes...

Quantitative iTRAQ secretome analysis of aspergillus niger reveals novel hydrolytic enzymes

NARCIS (Netherlands)

Adav, S.S.; Li, A.A.; Manavalan, A.; Punt, P.; Sze, S.K.

2010-01-01

The natural lifestyle of Aspergillus niger made them more effective secretors of hydrolytic proteins and becomes critical when this species were exploited as hosts for the commercial secretion of heterologous proteins. The protein secretion profile of A. niger and its mutant at different pH was

FluG affects secretion in colonies of Aspergillus niger.

Science.gov (United States)

Wang, Fengfeng; Krijgsheld, Pauline; Hulsman, Marc; de Bekker, Charissa; Müller, Wally H; Reinders, Marcel; de Vries, Ronald P; Wösten, Han A B

2015-01-01

Colonies of Aspergillus niger are characterized by zonal heterogeneity in growth, sporulation, gene expression and secretion. For instance, the glucoamylase gene glaA is more highly expressed at the periphery of colonies when compared to the center. As a consequence, its encoded protein GlaA is mainly secreted at the outer part of the colony. Here, multiple copies of amyR were introduced in A. niger. Most transformants over-expressing this regulatory gene of amylolytic genes still displayed heterogeneous glaA expression and GlaA secretion. However, heterogeneity was abolished in transformant UU-A001.13 by expressing glaA and secreting GlaA throughout the mycelium. Sequencing the genome of UU-A001.13 revealed that transformation had been accompanied by deletion of part of the fluG gene and disrupting its 3' end by integration of a transformation vector. Inactivation of fluG in the wild-type background of A. niger also resulted in breakdown of starch under the whole colony. Asexual development of the ∆fluG strain was not affected, unlike what was previously shown in Aspergillus nidulans. Genes encoding proteins with a signal sequence for secretion, including part of the amylolytic genes, were more often downregulated in the central zone of maltose-grown ∆fluG colonies and upregulated in the intermediate part and periphery when compared to the wild-type. Together, these data indicate that FluG of A. niger is a repressor of secretion.

Niger institute focuses on financial accountability | IDRC ...

International Development Research Centre (IDRC) Digital Library (Canada)

2016-04-28

Apr 28, 2016 ... Niger institute focuses on financial accountability ... on renewing outdated financial management systems that impeded effective management and reporting on its activities. ... Canada-Africa grants spur novel ideas, networks.

Analcite formation in the Agades Region (Niger); Les formations a analcime de la Region d'Agades (Republique du Niger)

Energy Technology Data Exchange (ETDEWEB)

NONE

1966-06-01

A study based mainly upon field mapping and drill cores examination, followed by a laboratory survey allows us to support a genetic hypothesis upon the formation of analcime in the 'Continental intercalaire' of Agades (Niger). Analcime could be generated from an early diagenesis of argillaceous sediments influenced by high soda content fossil waters inside confined continental sedimentary basins. (authors) [French] Une etude axee essentiellement sur des leves de terrain et des carottes de sondages, suivie d'une etude en laboratoire, permet d'avancer une hypothese genetique sur les formations a analcime du Continental Intercalaire d'AGADES (Niger). L'analcime resulterait d'une diagenese precoce de sediments argileux, sous l'influence d'eaux connees riches en soude, dans des bassins sedimentaires continentaux confines.

AMNESTY IN THE NIGER DELTA: VERTICAL MOVEMENT ...

African Journals Online (AJOL)

OLAWUYI

federal government, the Niger Delta communities claim that they are entitled to ... instability, macroeconomic challenges, inconsistent policy regimes to ..... continues they cannot threaten the stability of the country nor affect its continued.

Electron spin resonance (ESR) studies on irradiated cocoa beans and niger seeds

International Nuclear Information System (INIS)

Mangaonkar, S.R.; Natarajan, V.; Sastry, M.D.; Desai, S.R.P.; Kulkarni, P.R.

1997-01-01

Electron spin resonance (ESR) spectra of irradiated (10kGy) and unirradiated cocoa beans and niger seeds have been compared. Unirradiated cocoa beans failed to give any ESR signal, whereas after irradiation (10kGy) an ESR signal at g = 2.0042 was observed. However, ESR signals are given by both irradiated and unirradiated niger seeds. The intensity of signal was found to be dose-dependent up to 10kGy for both seeds. The signals were stable up to 180 days in both cases. The results indicate the possibility of using ESR for distinguishing between irradiated and unirradiated cocoa beans but not for niger seeds

Areva in Niger

International Nuclear Information System (INIS)

2005-02-01

Niger is the second poorest country in the world but it has natural resources underground in the form of uranium ores deposits. This uranium is currently mined by two companies incorporated under Nigerian law: Somair and Cominak, operated by the principal shareholder Areva (through its subsidiary Cogema). After a presentation of Somair and Cominak key figures, this document details the working conditions and radiological protection, the environmentally friendly operations, the production traceability, the local economic development, the strengthening of the health care system and the development of the infrastructure. (A.L.B.)

Coupled hydrologic and hydraulic modeling of Upper Niger River Basin

Science.gov (United States)

Fleischmann, Ayan; Siqueira, Vinícius; Paris, Adrien; Collischonn, Walter; Paiva, Rodrigo; Gossett, Marielle; Pontes, Paulo; Calmant, Stephane; Biancamaria, Sylvain; Crétaux, Jean-François; Tanimoune, Bachir

2017-04-01

The Upper Niger Basin is located in Western Africa, flowing from Guinea Highlands towards the Sahel region. In this area lies the seasonally inundated Niger Inland Delta, which supports important environmental services such as habitats for wildlife, climate and flood regulation, as well as large fishery and agricultural areas. In this study, we present the application of MGB-IPH large scale hydrologic and hydrodynamic model for the Upper Niger Basin, totaling c.a. 650,000 km2 and set up until the city of Niamey in Niger. The model couples hydrological vertical balance and runoff generation with hydrodynamic flood wave propagation, by allowing infiltration from floodplains into soil column as well as representing backwater effects and floodplain storage throughout flat areas such as the Inland Delta. The model is forced with TRMM 3B42 daily precipitation and Climate Research Unit (CRU) climatology for the period 2000-2010, and was calibrated against in-situ discharge gauges and validated with in-situ water level, remotely sensed estimations of flooded areas (classification of MODIS imagery) and satellite altimetry (JASON-2 mission). Model results show good predictions for calibrated daily discharge and validated water level and altimetry at stations both upstream and downstream of the delta (Nash-Sutcliffe Efficiency>0.7 for all stations), as well as for flooded areas within the delta region (ENS=0.5; r2=0.8), allowing a good representation of flooding dynamics basinwide and simulation of flooding behavior of both perennial (e.g., Niger main stem) and ephemeral rivers (e.g., Niger Red Flood tributaries in Sahel). Coupling between hydrology and hydrodynamic processes indicates an important feedback between floodplain and soil water storage that allows high evapotranspiration rates even after the flood passage around the inner delta area. Also, representation of water retention in floodplain channels and distributaries in the inner delta (e.g., Diaka river

Nigeria. Petroleum, pollution and poverty in the Niger Delta

International Nuclear Information System (INIS)

2009-06-01

The oil industry has operated in the Niger Delta in Nigeria for more than half a century - bringing almost no benefit to the people living there. Instead, widespread and unchecked human rights violations have pushed many people deeper into poverty and deprivation, fuelled conflict and led to a pervasive sense of powerlessness and frustration. This multidimensional crisis is driven by many factors - abuses committed by the security forces and militant groups, extensive pollution of land and water, corruption, serious corporate bad practice and government neglect. Nigeria: Petroleum, pollution and poverty in the Niger Delta focuses on one dimension of the crisis: the impact of pollution and environmental damage caused by the oil industry on the human rights of those living in the Niger Delta. Many people in the oil-producing areas of the delta rely on fisheries, subsistence agriculture and associated processing industries for their livelihood. Decades of pollution and environmental damage have resulted in violations of the right to an adequate standard of living - including food and water - violations of the right to gain a living through work, and violations of the right to health. The report examines who is responsible for this situation in a context where multinational oil companies have been operating for decades. It highlights how companies take advantage of the weak regulatory systems that characterize many poor countries, and how the poorest people are often the most vulnerable to exploitation. The people of the Niger Delta have seen their human rights undermined by oil companies that their government can not - or will not - hold to account. They have been systematically denied access to information about how oil exploration and production will affect them, and are repeatedly denied access to justice. The Niger Delta provides a stark case study of the lack of accountability of a government to the people, and of multinational companies' almost total lack of

Real-time PCR-based method for rapid detection of Aspergillus niger and Aspergillus welwitschiae isolated from coffee.

Science.gov (United States)

von Hertwig, Aline Morgan; Sant'Ana, Anderson S; Sartori, Daniele; da Silva, Josué José; Nascimento, Maristela S; Iamanaka, Beatriz Thie; Pelegrinelli Fungaro, Maria Helena; Taniwaki, Marta Hiromi

2018-05-01

Some species from Aspergillus section Nigri are morphologically very similar and altogether have been called A. niger aggregate. Although the species included in this group are morphologically very similar, they differ in their ability to produce mycotoxins and other metabolites and their taxonomical status has evolved continuously. Among them, A. niger and A. welwitschiae are ochratoxin A and fumonisin B 2 producers and their detection and/or identification is of crucial importance for food safety. The aim of this study was the development of a real-time PCR-based method for simultaneous discrimination of A. niger and A. welwitschiae from other species of the A. niger aggregate isolated from coffee beans. One primer pair and a hybridization probe specific for detection of A. niger and A. welwitschiae strains were designed based on the BenA gene sequences, and used in a Real-time PCR assay for the rapid discrimination between both these species from all others of the A. niger aggregate. The Real-time PCR assay was shown to be 100% efficient in discriminating the 73 isolates of A. niger/A. welwitschiae from the other A. niger aggregate species analyzed as a negative control. This result testifies to the use of this technique as a good tool in the rapid detection of these important toxigenic species. Copyright © 2018 Elsevier B.V. All rights reserved.

Evaluation of Antimicrobial Activity of Glucose Oxidase from Aspergillus niger EBL-A and Penicillium notatum

Directory of Open Access Journals (Sweden)

Muhammad Anjum Zia

2013-12-01

Full Text Available This work aimed to study the production and purification of glucose oxidase by Aspergillus niger and Penicillium notatum using corn steep liquor as the substrate and evaluate its antimicrobial activity for use in pharmaceutical and food industries. The enzyme was purified by ammonium sulfate precipitation (60-85%, DEAE-cellulose ion exchange and Sephadex G-200 size exclusion chromatography. The crude enzyme extracts of A. niger and P. notatum showed 2.32 and 5.53 U mg-1 specific activities, respectively, which after desalting was 15.52 and 12.05 U mg-1, and after ion exchange and gel filtration chromatography was 29.09 - 62 and 25.72 - 59.37 U mg-1 for A. niger and P. notatum, respectively. The antimicrobial activity was determined by disc diffusion method against selected microbial strains where glucose oxidase from A. niger showed anti-bacterial activity, while no fungicidal effects were shown by both A. niger and P. notatum glucose oxidases.

Advances in citric acid fermentation by Aspergillus niger: biochemical aspects, membrane transport and modeling.

Science.gov (United States)

Papagianni, Maria

2007-01-01

Citric acid is regarded as a metabolite of energy metabolism, of which the concentration will rise to appreciable amounts only under conditions of substantive metabolic imbalances. Citric acid fermentation conditions were established during the 1930s and 1940s, when the effects of various medium components were evaluated. The biochemical mechanism by which Aspergillus niger accumulates citric acid has continued to attract interest even though its commercial production by fermentation has been established for decades. Although extensive basic biochemical research has been carried out with A. niger, the understanding of the events relevant for citric acid accumulation is not completely understood. This review is focused on citric acid fermentation by A. niger. Emphasis is given to aspects of fermentation biochemistry, membrane transport in A. niger and modeling of the production process.

Cloning and Genomic Organization of a Rhamnogalacturonase Gene from Locally Isolated Strain of Aspergillus niger.

Science.gov (United States)

Damak, Naourez; Abdeljalil, Salma; Taeib, Noomen Hadj; Gargouri, Ali

2015-08-01

The rhg gene encoding a rhamnogalacturonase was isolated from the novel strain A1 of Aspergillus niger. It consists of an ORF of 1.505 kb encoding a putative protein of 446 amino acids with a predicted molecular mass of 47 kDa, belonging to the family 28 of glycosyl hydrolases. The nature and position of amino acids comprising the active site as well as the three-dimensional structure were well conserved between the A. niger CTM10548 and fungal rhamnogalacturonases. The coding region of the rhg gene is interrupted by three short introns of 56 (introns 1 and 3) and 52 (intron 2) bp in length. The comparison of the peptide sequence with A. niger rhg sequences revealed that the A1 rhg should be an endo-rhamnogalacturonases, more homologous to rhg A than rhg B A. niger known enzymes. The comparison of rhg nucleotide sequence from A. niger A1 with rhg A from A. niger shows several base changes. Most of these changes (59 %) are located at the third base of codons suggesting maintaining the same enzyme function. We used the rhamnogalacturonase A from Aspergillus aculeatus as a template to build a structural model of rhg A1 that adopted a right-handed parallel β-helix.

Analytical and computational approaches to define the Aspergillus niger secretome

Energy Technology Data Exchange (ETDEWEB)

Tsang, Adrian; Butler, Gregory D.; Powlowski, Justin; Panisko, Ellen A.; Baker, Scott E.

2009-03-01

We used computational and mass spectrometric approaches to characterize the Aspergillus niger secretome. The 11,200 gene models predicted in the genome of A. niger strain ATCC 1015 were the data source for the analysis. Depending on the computational methods used, 691 to 881 proteins were predicted to be secreted proteins. We cultured A. niger in six different media and analyzed the extracellular proteins produced using mass spectrometry. A total of 222 proteins were identified, with 39 proteins expressed under all six conditions and 74 proteins expressed under only one condition. The secreted proteins identified by mass spectrometry were used to guide the correction of about 20 gene models. Additional analysis focused on extracellular enzymes of interest for biomass processing. Of the 63 glycoside hydrolases predicted to be capable of hydrolyzing cellulose, hemicellulose or pectin, 94% of the exo-acting enzymes and only 18% of the endo-acting enzymes were experimentally detected.

Sorption of 241Am by Aspergillus niger spore and hyphae

International Nuclear Information System (INIS)

Yuanyou Yang; Ning Liu; Jiali Liao; Jiannan Jin; Shunzhong Luo; Taiming Zhang; Pengji Zhao

2004-01-01

Biosorption of 241 Am by a fungus A. niger, including the spore and hyphae, was investigated. The preliminary results showed that the adsorption of 241 Am by the microorganism was efficient. More than 96% of the total 241 Am could be removed from 241 Am solutions of 5.6-111 MBq/l (C 0 ) by spore and hyphae of A. niger, with adsorbed 241 Am metal (Q) of 7.2-142.4 MBq/g biomass, and 5.2-106.5 MBq/g, respectively. The biosorption equilibrium was achieved within 1 hour and the optimum pH range was pH 1-3. No obvious effects on 241 Am adsorption by the fungus were observed at 10-45 deg C, or in solutions containing Au 3+ or Ag + , even 2000 times above the 241 Am concentration. The 241 Am biosorption by the fungus obeys the Freundlich adsorption equation. There was no significant difference between the adsorption behavior of A. niger spore and hyphae. (author)

Production and Purification of Peroxidase from Aspergillus niger.

Directory of Open Access Journals (Sweden)

Mohammed A. Jebor

2017-02-01

Full Text Available This study was conducted in the laboratories of Biology Department, College of Science, which deals with isolation and purification of peroxidase and optimization of process parameters to achieve maximum yield of peroxidase by Aspergillus niger. Solid-state fermentation of Aspergillus niger was carried out for enhanced production of peroxidase using hydrogen peroxide as the substrate of enzyme maximum activity of the enzyme was achieved under optimum growth conditions. The optimum conditions were the isolated of Aspergillus niger from soil and growth in synthetic medium, it gave high titer of peroxidase activity, the fructose as carbon source, peptone as nitrogen source, after 12 days of incubation, incubation temperature 25 °C and pH = 6.5. Peroxidase purified in four purification steps; precipitation with 70% saturation of ammonium sulfate, step of dialysis, the third by ion exchange chromatography using DEAE-Cellulose and fourth by gel filtration throughout Sephadex G-100. The specific activity of the purified enzyme was 150U/mg with 7.75 folds. The peroxidase was shown to have molecular weight of 40kDa in SDS-PAGA and about 40kDa in gel filtration.The optimum pH and temperature for peroxidase activity 7 and 35 C0 respectively.

Characterisation of Aspergillus niger prolyl aminopeptidase

NARCIS (Netherlands)

Basten, E.J.W.; Moers, A.P.H.A.; Ooyen, van A.J.J.; Schaap, P.J.

2005-01-01

We have cloned a gene (papA) that encodes a prolyl aminopeptidase from Aspergillus niger. Homologous genes are present in the genomes of the Eurotiales A. nidulans, A. fumigatus and Talaromyces emersonii, but the gene is not present in the genome of the yeast Saccharomyces cerevisiae. Cell extracts

Isolation, Optimization, and Investigation of Production of Linoleic Acid in Aspergillus niger

Directory of Open Access Journals (Sweden)

Noushin Shafiei

2016-08-01

Full Text Available Background and Objectives: Microorganisms that are capable of accumulating lipid up to 20% of their biomass are called oleaginous microorganisms. In this study, optimization in lipid and linolenic acid production was investigated in Aspergillus niger as an oleaginous filamentous fungi. Methods: In this study, at first different strains of filamentous fungi were isolated, and after staining of the isolates with Sudan Black, their oil was extracted using chloroform/methanol. Then, the isolates with oil/dry biomass ratio of more than 20% were considered as oleaginous filamentous fungi. After microscopic examination, the identified isolate was optimized in terms of oil production. Finally, the amount of linolenic acid was evaluated using gas chromatography. Results: At first, 20 filamentous fungi isolates were isolated. According to the results of Sudan Black staining, lipid inclusions were observed in all the fungal isolates. The amount of oil produced in all isolates, showed that the percentage of oil production in isolates 4, 5, and 16, was more than 20%. In microscopic examination, the isolate 5 was Aspergillus niger. The best pH, temperature, time, and carbon source for oil production by Aspergillus niger was 4.5, 30°C, 96 hours, and fructose, respectively. The amount of linolenic acid in Aspergillus niger was reported 22.4% using gas chromatography.   Conclusion: The results of this study revealed that Aspergillus niger is an appropriate filamentous fungi for linolenic acid production.   

Mapping palaeolakes in the Ténéré Desert of northeastern Niger using space-borne data for groundwater potential

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Molina, Gloria; Gaber, Ahmed; El-Baz, Farouk

2017-12-01

Groundwater resources in arid lands are crucial for supporting life. Thus, delineation of low land areas, where surface runoff accumulated during pluvial periods assists in groundwater explorations. Therefore, the drainage patterns in northeastern Niger using various sources of DEMs of optical (ASTER) and radar (SRTM) satellite data were extracted. These data reveal three palaeolakes in the Ténéré Desert. In addition, the DEMs together with the optical and radar satellite data were used to define a major watershed measuring 634,000 km2. This watershed may have led to the formation of one major palaeolake as an ancestor of the three palaeolakes. The latter extend to 11,514 km2, 17,571 km2 and 18,453 km2. The optical and radar satellites images show that the boundaries of these three lakes have been modified by extensive longitudinal and transverse sand dunes of considerable thickness. These dunes accumulated during a much later arid episode in geologic time, probably during the late Quaternary. Prior to that, the former marshlands received water from the Tibesti Mountains of northern Chad, the Ahaggar Plateau of southeastern Algeria and the Air Mountain of northern Niger. The drainage patterns clearly show the pathway of water down to the ground level. The longest drainage line is emanating from the Ahaggar Plateau and extends south west for 837 km. The water overflow of the southernmost lake led to the formation of another distinct drainage line, leading to the southwestern edge of the ancestral Megalake Chad. This drainage line begins in the vicinity of the town of Fachi and extends southward through the town of Dillia as a single tributary, and is here named the Dillia Palaeoriver. These observations, which are based on the study of satellite data require geophysical fieldwork to ascertain the interpretations, and evaluate the potential for groundwater accumulation in the region.

Clinical profile of parkinson's disease: Experience of niger

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Hamid Assadeck

2018-01-01

Full Text Available Background: Parkinson's disease (PD is a chronic neurodegenerative pathology with unknown etiology. It is characterized clinically by the classic triad that associated tremors, bradykinesia, and rigidity. In Niger, there are no data on PD. Aims: We aimed to provide the demographic and clinical profile of PD in patients from Niger to create a database on PD in Niger. Patients and Methods: We conducted a retrospective study at the Neurology Outpatient Clinic of the Hôpital National de Niamey (HNN, Niger over a period of 4.42 years from February 2009 to July 2013 collecting all cases of PD. The demographic and clinical features of all patients were collected and analyzed. Results: During the period of the study, 1695 patients consulted at the Neurology Outpatient Clinic of the HNN, among which 76 patients (4.48% had secondary parkinsonism and 25 patients (1.47% had features compatible with PD. Only patients with PD were included in this study. The mean age at onset of symptoms was 58 years (range: 42–74 years. The male sex was predominant (60% with a sex ratio of 1.5. The mean time interval from the onset of symptoms to diagnosis of PD was 1.8 years (range: 1–5 years. The tremor was the most common symptom (84%. Bradykinesia represented 64% of the symptoms and rigidity 20%. At the time of the diagnosis of PD, 8 patients (32% were in Stage I of the classification of Hoehn and Yahr, 16 patients (64% in Stage II, and 1 patient (4% in Stage III. The levodopa/carbidopa combination was the most used antiparkinsonian drug in our patients (88%. The mean time of follow-up of the patients was 2.5 years (range: 1–4.42 years. During the course of the disease, 9 patients (36% were in Stage II of the classification of Hoehn and Yahr, 13 patients (52% in Stage III, and 3 patients (12% in Stage IV. Conclusion: Our study provides demographic and clinical data of PD in patients from Niger and shows that the hospital frequency of this disease is low (1

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger.

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Amaike Campen, Saori; Lynn, Jed; Sibert, Stephanie J; Srikrishnan, Sneha; Phatale, Pallavi; Feldman, Taya; Guenther, Joel M; Hiras, Jennifer; Tran, Yvette Thuy An; Singer, Steven W; Adams, Paul D; Sale, Kenneth L; Simmons, Blake A; Baker, Scott E; Magnuson, Jon K; Gladden, John M

2017-01-01

Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme production host before they could be considered a viable alternative to current commercial cellulases. Aspergillus niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. niger and Escherichia coli. This comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. niger is equivalent, suggesting that A. niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry.

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Amaike Campen, Saori; Lynn, Jed; Sibert, Stephanie J.; Srikrishnan, Sneha; Phatale, Pallavi; Feldman, Taya; Guenther, Joel M.; Hiras, Jennifer; Tran, Yvette Thuy An; Singer, Steven W.; Adams, Paul D.; Sale, Kenneth L.; Simmons, Blake A.; Baker, Scott E.; Magnuson, Jon K.; Gladden, John M.; Croft, Anna Kristina

2017-12-27

Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme production host before they could be considered a viable alternative to current commercial cellulases. Aspergillus niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. niger and Escherichia coli. This comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. niger is equivalent, suggesting that A. niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry.

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger

Science.gov (United States)

Lynn, Jed; Sibert, Stephanie J.; Srikrishnan, Sneha; Phatale, Pallavi; Feldman, Taya; Guenther, Joel M.; Hiras, Jennifer; Tran, Yvette Thuy An; Singer, Steven W.; Adams, Paul D.; Sale, Kenneth L.; Simmons, Blake A.; Baker, Scott E.; Magnuson, Jon K.; Gladden, John M.

2017-01-01

Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme production host before they could be considered a viable alternative to current commercial cellulases. Aspergillus niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. niger and Escherichia coli. This comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. niger is equivalent, suggesting that A. niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry. PMID:29281693

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger.

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Saori Amaike Campen

Full Text Available Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme production host before they could be considered a viable alternative to current commercial cellulases. Aspergillus niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. niger and Escherichia coli. This comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. niger is equivalent, suggesting that A. niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry.

Identification and functional analysis of two Golgi-localized UDP-galactofuranose transporters with overlapping functions in Aspergillus niger.

Science.gov (United States)

Park, Joohae; Tefsen, Boris; Heemskerk, Marc J; Lagendijk, Ellen L; van den Hondel, Cees A M J J; van Die, Irma; Ram, Arthur F J

2015-11-02

Galactofuranose (Galf)-containing glycoconjugates are present in numerous microbes, including filamentous fungi where they are important for morphology, virulence and maintaining cell wall integrity. The incorporation of Galf-residues into galactomannan, galactomannoproteins and glycolipids is carried out by Golgi-localized Galf transferases. The nucleotide sugar donor used by these transferases (UDP-Galf) is produced in the cytoplasm and has to be transported to the lumen of the Golgi by a dedicated nucleotide sugar transporter. Based on homology with recently identified UDP-Galf-transporters in A. fumigatus and A. nidulans, two putative UDP-Galf-transporters in A. niger were found. Their function and localization was determined by gene deletions and GFP-tagging studies, respectively. The two putative UDP-Galf-transporters in A. niger are homologous to each other and are predicted to contain eleven transmembrane domains (UgtA) or ten transmembrane domains (UgtB) due to a reduced length of the C-terminal part of the UgtB protein. The presence of two putative UDP-Galf-transporters in the genome was not unique for A. niger. From the twenty Aspergillus species analysed, nine species contained two additional putative UDP-Galf-transporters. Three of the nine species were outside the Aspergillus section nigri, indication an early duplication of UDP-Galf-transporters and subsequent loss of the UgtB copy in several aspergilli. Deletion analysis of the single and double mutants in A. niger indicated that the two putative UDP-Galf-transporters (named UgtA and UgtB) have a redundant function in UDP-Galf-transport as only the double mutant displayed a Galf-negative phenotype. The Galf-negative phenotype of the double mutant could be complemented by expressing either CFP-UgtA or CFP-UgtB fusion proteins from their endogenous promoters, indicating that both CFP-tagged proteins are functional. Both Ugt proteins co-localize with each other as well as with the GDP

PENAMBAHAN MIKROBA, Aspergillus niger DALAM BUNGKIL KELAPA SAWIT SEBAGAI BAHAN BAKU PAKAN UNTUK PEMBESARAN IKAN KERAPU MACAN

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Neltje Nobertine Palinggi

2008-12-01

Full Text Available Penelitian ini dilakukan untuk mendapatkan informasi tentang pengaruh dosis Aspergillus niger dalam bungkil kelapa sawit sebagai bahan pakan pada pembesaran ikan kerapu macan. Ikan uji yang digunakan berukuran bobot rata-rata 23,15±0,23 g; ditebar dalam keramba jaring apung ukuran 1 m x 1 m x 2 m, dengan kepadatan 16 ekor/keramba. Perlakuan yang diuji adalah penambahan Aspergillus niger sebanyak 2, 4, 8, 16 g/kg bungkil kelapa sawit dan kontrol. Masing-masing perlakuan diulang tiga kali dan disain adalah rancangan acak lengkap. Selama pemeliharaan, ikan diberi pakan uji dua kali sehari (pagi dan sore secara satiasi selama 20 minggu. Hasil penelitian menunjukkan bahwa penambahan 8 g Aspergillus niger/kg bungkil kelapa sawit memberikan pertambahan bobot dan laju spesifik lebih tinggi daripada kontrol (P0,05, namun nilainya nyata lebih tinggi (P0.05 among those of the juveniles fed on the diets with 2, 4, 16 g of A. niger/kg palm oil cake. Although the feed efficiency, protein efficiency ratio and protein retention of juveniles fed on the diet with 8 g A. niger/kg palm oil cake were not significantly different (P>0.05 from those of the juveniles fed on the diets with 2 and 4 g of A. niger/kg palm oil cake, those of juveniles the fed diet with 8 g of A. niger/kg palm oil cake were significantly higher (P<0.05 than those of the juveniles fed the diet with 16 g A. niger/kg palm oil cake. The best of growth rate of tiger grouper juveniles occurred at the dosage of 7.8—8.2 g A. niger/kg palm oil cake.

Heterologous and endogenous U6 snRNA promoters enable CRISPR/Cas9 mediated genome editing in Aspergillus niger.

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Zheng, Xiaomei; Zheng, Ping; Sun, Jibin; Kun, Zhang; Ma, Yanhe

2018-01-01

U6 promoters have been used for single guide RNA (sgRNA) transcription in the clustered regularly interspaced short palindromic repeats/CRISPR-associated protein (CRISPR/Cas9) genome editing system. However, no available U6 promoters have been identified in Aspergillus niger, which is an important industrial platform for organic acid and protein production. Two CRISPR/Cas9 systems established in A. niger have recourse to the RNA polymerase II promoter or in vitro transcription for sgRNA synthesis, but these approaches generally increase cloning efforts and genetic manipulation. The validation of functional RNA polymerase II promoters is therefore an urgent need for A. niger . Here, we developed a novel CRISPR/Cas9 system in A. niger for sgRNA expression, based on one endogenous U6 promoter and two heterologous U6 promoters. The three tested U6 promoters enabled sgRNA transcription and the disruption of the polyketide synthase albA gene in A. niger . Furthermore, this system enabled highly efficient gene insertion at the targeted genome loci in A. niger using donor DNAs with homologous arms as short as 40-bp. This study demonstrated that both heterologous and endogenous U6 promoters were functional for sgRNA expression in A. niger . Based on this result, a novel and simple CRISPR/Cas9 toolbox was established in A. niger, that will benefit future gene functional analysis and genome editing.

Genomic analysis of the aconidial and high-performance protein producer, industrially relevant Aspergillus niger SH2 strain.

Science.gov (United States)

Yin, Chao; Wang, Bin; He, Pan; Lin, Ying; Pan, Li

2014-05-15

Aspergillus niger is usually regarded as a beneficial species widely used in biotechnological industry. Obtaining the genome sequence of the widely used aconidial A. niger SH2 strain is of great importance to understand its unusual production capability. In this study we assembled a high-quality genome sequence of A. niger SH2 with approximately 11,517 ORFs. Relatively high proportion of genes enriched for protein expression related FunCat items verify its efficient capacity in protein production. Furthermore, genome-wide comparative analysis between A. niger SH2 and CBS513.88 reveals insights into unique properties of A. niger SH2. A. niger SH2 lacks the gene related with the initiation of asexual sporulation (PrpA), leading to its distinct aconidial phenotype. Frame shift mutations and non-synonymous SNPs in genes of cell wall integrity signaling, β-1,3-glucan synthesis and chitin synthesis influence its cell wall development which is important for its hyphal fragmentation during industrial high-efficiency protein production. Copyright © 2014 Elsevier B.V. All rights reserved.

Novel pathway of NAD metabolism in Aspergillus niger

International Nuclear Information System (INIS)

Kuwahara, Masaaki

1977-01-01

New steps of NAD metabolism were shown in Aspergillus niger. Radioactive nicotinic acid and nicotinamide were incorporated into nicotinamide ribose diphosphate ribose (NAmRDPR), which had been isolated from the culture filtrate. The enzyme preparation of the mold degraded NAmRDPR to form nicotinamide mononucleotide and nicotinic acid under the neutral and alkaline conditions. In the acid extracts of the mycelia grown on the radioactive precursors, high level of radioactivity was detected on NAD. The experimental results showed that the Preiss-Handler pathway and the NAD cycling system function in the NAD biosynthesis in A. niger. A part of the radioactive precursors was also incorporated into nicotinic acid ribonucleoside, which was thought to be formed from nicotinic acid mononucleotide. (auth.)

Production of extremophilic bacterial cellulase enzymes in aspergillus niger.

Energy Technology Data Exchange (ETDEWEB)

Gladden, John Michael

2013-09-01

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.

Aspergillus niger causing tracheobronchitis and invasive pulmonary aspergillosis in a lung transplant recipient: case report Aspergillus niger causando traqueobronquite e aspergilose pulmonar invasiva em transplantado de pulmão: relato de caso

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Melissa Orzechowski Xavier

2008-04-01

Full Text Available A case of invasive aspergillosis caused by Aspergillus niger in a lung transplant recipient is described. The patient presented hyperglycemia starting postoperatively, with other complications such as cytomegalovirus infection. The associated predisposing factors and other implications are discussed. Aspergillus niger seems to be a fungal species of low virulence that requires the presence of a severely immunosuppressed host to cause invasive disease.Descreve-se um caso de aspergilose invasiva causada por Aspergillus niger em um paciente transplantado de pulmão com quadros hiperglicêmicos desde o pós-operatório e outras complicações como infecção por citomegalovírus. Os fatores predisponentes associados e outras implicações são discutidos. Aspergillus niger parece ser uma espécie fúngica de baixa virulência, necessitando a presença de um hospedeiro gravemente imunodeprimido para causar doença invasiva.

Corporate and state responses to anti-oil protests in the Niger Delta

Energy Technology Data Exchange (ETDEWEB)

Frynas, J.G. [Coventry University (United Kingdom). International Business at Coventry Business School

2001-07-01

Conflicts between oil companies and village communities in the Niger Delta have lasted for several decades, but during the 1990s they escalated further and received international media coverage. Much of it focused on the anti-Shell protests by the Movement for the Survival of the Ogoni People (MOSOP) which led to Shell's withdrawal from the Ogoni area in 1993. Notwithstanding the political changes following General Abacha's death in June 1998, the conflicts are continuing. While the intensity of the Ogoni protests decreased from 1995 onwards, other ethnic and political groups across the Niger Delta began to disrupt oil activities. This article critically examines the response of the Nigerian state and the oil companies to the anti-oil protests in the Delta. The investigation focuses on three generic strategies: concessions by the state and oil companies to protesters, such as the creation of development projects; the use of public relations in dealing with the Niger Delta crisis; and the use of violence by the state and the oil companies against anti-oil protesters. The analysis suggests that the state and corporate response to the Niger Delta crisis has so far been inadequate in the sense that it fails to satisfy the demands of the local people. Judging from past experience, unless there are structural changes within Nigeria's institutional framework, which would allow for a more effective use of the country's oil wealth for the benefit of the oil-producing areas, conflicts in the Niger Delta are likely to continue. (author)

Evidence for a cytoplasmic pathway of oxalate biosynthesis in Aspergillus niger

International Nuclear Information System (INIS)

Kubicek, C.P.; Schreferl-Kunar, G.; Woehrer, W.; Roehr, M.

1988-01-01

Oxalate accumulation of up to 8 g/liter was induced in Aspergillus niger by shifting the pH from 6 to 8. This required the presence of P/sub i/ and a nitrogen source and was inhibited by the protein synthesis inhibitor cycloheximide. Exogenously added 14 CO 2 was not incorporated into oxalate, but was incorporated into acetate and malate, thus indicating the biosynthesis of oxalate by hydrolytic cleavage of oxaloacetate. Inhibition of mitochondrial citrate metabolism by fluorocitrate did not significantly decrease the oxalate yield. The putative enzyme that was responsible for this oxaloacetate hydrolase (EC 3.7.1.1), which was induced de novo during the pH shift. Subcellular fractionation of oxalic acid-forming mycelia of A. niger showed that this enzyme is located in the cytoplasm of A. niger. The results are consistent with a cytoplasmic pathway of oxalate formation which does not involve the tricarboxylic acid cycle

Short tandem repeat (STR based genetic diversity and relationship of indigenous Niger cattle

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M. Grema

2017-11-01

Full Text Available The diversity of cattle in Niger is predominantly represented by three indigenous breeds: Zebu Arabe, Zebu Bororo and Kuri. This study aimed at characterizing the genetic diversity and relationship of Niger cattle breeds using short tandem repeat (STR marker variations. A total of 105 cattle from all three breeds were genotyped at 27 STR loci. High levels of allelic and gene diversity were observed with an overall mean of 8.7 and 0.724 respectively. The mean inbreeding estimate within breeds was found to be moderate with 0.024, 0.043 and 0.044 in Zebu Arabe, Zebu Bororo and Kuri cattle respectively. The global F statistics showed low genetic differentiation among Niger cattle with about 2.6 % of total variation being attributed to between-breed differences. Neighbor-joining tree derived from pairwise allele sharing distance revealed Zebu Arabe and Kuri clustering together while Zebu Bororo appeared to be relatively distinct from the other two breeds. High levels of admixture were evident from the distribution of pairwise inter-individual allele sharing distances that showed individuals across populations being more related than individuals within populations. Individuals were assigned to their respective source populations based on STR genotypes, and the percent correct assignment of Zebu Bororo (87.5 to 93.8 % was consistently higher than Zebu Arabe (59.3 to 70.4 % and Kuri (80.0 to 83.3 % cattle. The qualitative and quantitative tests for mutation drift equilibrium revealed absence of genetic bottleneck events in Niger cattle in the recent past. High genetic diversity and poor genetic structure among indigenous cattle breeds of Niger might be due to historic zebu–taurine admixture and ongoing breeding practices in the region. The results of the present study are expected to help in formulating effective strategies for conservation and genetic improvement of indigenous Niger cattle breeds.

Energies and media nr 34. Disaster in Japan. How uranium mines are also useful to Niger; Energies et medias no. 34. Catastrophe au Japon. Comment les mines d'uranium servent aussi le Niger

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-03-15

After a brief article on the disaster which occurred in Japan (tsunami, nuclear accident in Fukushima, problems faced in Fukushima), this issue addresses the developments induced by the exploitation of uranium mines in Niger: local personnel employment and training, creation of new towns for the personnel, construction of hospitals and roads. The article also addresses the revenues of Niger related to these mines, and the health issue related to mine exploitations (training of authorities in Niger, personnel in charge of radiation protection, personnel and population radioprotection, process residues, water contamination, health monitoring)

Prospecting for the incidence of genes involved in ochratoxin and fumonisin biosynthesis in Brazilian strains of Aspergillus niger and Aspergillus welwitschiae.

Science.gov (United States)

Massi, Fernanda Pelisson; Sartori, Daniele; de Souza Ferranti, Larissa; Iamanaka, Beatriz Thie; Taniwaki, Marta Hiromi; Vieira, Maria Lucia Carneiro; Fungaro, Maria Helena Pelegrinelli

2016-03-16

Aspergillus niger "aggregate" is an informal taxonomic rank that represents a group of species from the section Nigri. Among A. niger "aggregate" species Aspergillus niger sensu stricto and its cryptic species Aspergillus welwitschiae (=Aspergillus awamori sensu Perrone) are proven as ochratoxin A and fumonisin B2 producing species. A. niger has been frequently found in tropical and subtropical foods. A. welwitschiae is a new species, which was recently dismembered from the A. niger taxon. These species are morphologically very similar and molecular data are indispensable for their identification. A total of 175 Brazilian isolates previously identified as A. niger collected from dried fruits, Brazil nuts, coffee beans, grapes, cocoa and onions were investigated in this study. Based on partial calmodulin gene sequences about one-half of our isolates were identified as A. welwitschiae. This new species was the predominant species in onions analyzed in Brazil. A. niger and A. welwitschiae differ in their ability to produce ochratoxin A and fumonisin B2. Among A. niger isolates, approximately 32% were OTA producers, but in contrast only 1% of the A. welwitschiae isolates revealed the ability to produce ochratoxin A. Regarding fumonisin B2 production, there was a higher frequency of FB2 producing isolates in A. niger (74%) compared to A. welwitschiae (34%). Because not all A. niger and A. welwitschiae strains produce ochratoxin A and fumonisin B2, in this study a multiplex PCR was developed for detecting the presence of essential genes involved in ochratoxin (polyketide synthase and radHflavin-dependent halogenase) and fumonisin (α-oxoamine synthase) biosynthesis in the genome of A. niger and A. welwitschiae isolates. The frequency of strains harboring the mycotoxin genes was markedly different between A. niger and A. welwitschiae. All OTA producing isolates of A. niger and A. welwitschiae showed in their genome the pks and radH genes, and 95.2% of the nonproducing

Simultaneous amyloglucosidase and exo-polygalacturonase production by Aspergillus niger using solid-state fermentation

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Jorge Alberto Vieira Costa

2007-09-01

Full Text Available Amyloglucosidase (AMG and exo-polygalacturonase (exo-PG were simultaneously produced by two different strains of Aspergillus niger in solid-state fermentation (SSF using defatted rice-bran as substrate. The effect of Aspergillus niger strain (t0005/007-2 and/or CCT 3312, inoculum type (spore suspension or fermented bran and addition of inducers (pectin and/or starch to the culture media was studied using a 3² x 2¹ factorial experimental design. The production of AMG and exo-PG was significantly affected by fungal strain and inoculum type but inducers had no effect. The maximum yields obtained were 1310 U/g dm for AMG using a spore suspension of A. niger CCT 3312 and 50.2 U/g dm for exo-PG production, using A. niger t0005/007-2 and fermented bran as inoculum. The yields obtained represented acceptable values in comparison with data available in the literature and indicated that defatted rice-bran was a good nutrient source.As enzimas amiloglicosidase (AMG e exo-poligalacturonase (exo-PG foram produzidas simultaneamente por duas cepas de Aspergillus niger, através de fermentação em estado sólido usando farelo de arroz desengordurado como substrato. Foram avaliados os efeitos da cepa de Aspergillus niger, tipo de inóculo e adição de indutores no meio de cultura, utilizando-se um planejamento experimental fracionário 3² x 2¹. O máximo rendimento obtido foi 1310 U/g ms para a produção de AMG e 50,2 U/g ms para a exo-PG. Comparando-se estes resultados com dados da literatura pode-se dizer que os rendimentos obtidos foram aceitáveis e indicam que o farelo de arroz desengordurado é uma boa fonte de nutrientes. A produção de AMG e exo-PG foi significativamente afetada pelas variáveis cepa de A. niger e tipo de inóculo, enquanto a variável indutor não apresentou influência significativa na produção destas enzimas.

Invasive Aspergillus niger complex infections in a Belgian tertiary care hospital.

Science.gov (United States)

Vermeulen, E; Maertens, J; Meersseman, P; Saegeman, V; Dupont, L; Lagrou, K

2014-05-01

The incidence of invasive infections caused by the Aspergillus niger species complex was 0.043 cases/10 000 patient-days in a Belgian university hospital (2005-2011). Molecular typing was performed on six available A. niger complex isolates involved in invasive disease from 2010 to 2011, revealing A. tubingensis, which has higher triazole minimal inhibitory concentrations, in five out of six cases. © 2013 The Authors Clinical Microbiology and Infection © 2013 European Society of Clinical Microbiology and Infectious Diseases.

Elucidation of the biosynthesis of meroterpenoid yanuthone D in Aspergillus Niger

DEFF Research Database (Denmark)

Holm, Dorte Koefoed; Petersen, Lene Maj; Klitgaard, Andreas

2012-01-01

We have elucidated the mode of biosynthesis of the meroterpenoid compound Yanuthone D in Aspergillus niger. We have successfully deleted all cluster genes, and identified a number of intermediates. Structures of the intermediates were solved using a combined approach comprising classical 1D- and 2D......-NMR and tandem mass spectrometry (MS/MS). In this study we have confirmed that Yanuthone D is of meroterpenoid origin, and we have identified an unexpected precursor, which has not before been reported for Aspergillus niger....

Structural and functional annotation of citrate synthase from Aspergillus niger ANJ-120.

Science.gov (United States)

Mustafa, Ghulam; Arif, Rawaba; Bukhari, Shazia Anwer; Ali, Muhammad; Sharif, Sumaira; Atta, Asia

2018-03-01

Citrate synthase (CS) is involved in citric acid biosynthesis which is a well-established metabolic pathway. The condensation of acetyl-CoA with oxaloacetate is catalyzed by CS. Citric acid (CA) has a number of applications in pharmaceutical industry. CA in combination with bicarbonates is used as an effervescent in the preparations of tablets and powders. It has also been used as an anticoagulant and acidulant to form mild astringent. In current study, detailed structural and functional analyses of CS protein were carried out using various bioinformatics tools. Structural modeling was also done by building 3D model of CS from Aspergillus niger ANJ-120 using Modeller 9.16 software. The 3D Model was then evaluated using different online approaches. Furthermore, superimposition of query and template structures, Root Mean Squared Deviation and visualization of generated model were done through UCSF Chimera 1.5.3. Even though various roles of CS protein were already known and verified experimentally, here we presented a structural analysis of CS protein. The structural investigation of CS protein will be helpful for protein engineering strategies and understanding the interactions among proteins. Due to large number of applications, the production of citric acid by A. niger and its bioinformatics studies will offer substantial improvement in commercial scale intensification of this useful product.

Environmental Law and Underdevelopment in the Niger Delta ...

African Journals Online (AJOL)

Environmental Law and Underdevelopment in the Niger Delta Region of Nigeria. ... is composed of many ecosystems of great economic and social importance, ... producing companies contribute to the degradation of the environment which in ...

Effect of different polyphenol sources on the efficiency of ellagic acid release by Aspergillus niger.

Science.gov (United States)

Sepúlveda, Leonardo; de la Cruz, Reynaldo; Buenrostro, José Juan; Ascacio-Valdés, Juan Alberto; Aguilera-Carbó, Antonio Francisco; Prado, Arely; Rodríguez-Herrera, Raúl; Aguilar, Cristóbal Noé

2016-01-01

Fungal hydrolysis of ellagitannins produces hexahydroxydiphenic acid, which is considered an intermediate molecule in ellagic acid release. Ellagic acid has important and desirable beneficial health properties. The aim of this work was to identify the effect of different sources of ellagitannins on the efficiency of ellagic acid release by Aspergillus niger. Three strains of A. niger (GH1, PSH and HT4) were assessed for ellagic acid release from different polyphenol sources: cranberry, creosote bush, and pomegranate used as substrate. Polyurethane foam was used as support for solid-state culture in column reactors. Ellagitannase activity was measured for each of the treatments. Ellagic acid was quantified by high performance liquid chromatography. When pomegranate polyphenols were used, a maximum value of ellagic acid (350.21 mg/g) was reached with A. niger HT4 in solid-state culture. The highest amount of ellagitannase (5176.81 U/l) was obtained at 8h of culture when cranberry polyphenols and strain A. niger PSH were used. Results demonstrated the effect of different polyphenol sources and A. niger strains on ellagic acid release. It was observed that the best source for releasing ellagic acid was pomegranate polyphenols and A. niger HT4 strain, which has the ability to degrade these compounds for obtaining a potent bioactive molecule such as ellagic acid. Copyright © 2015 Asociación Argentina de Microbiología. Publicado por Elsevier España, S.L.U. All rights reserved.

Salmonella biofilm formation on Aspergillus niger involves cellulose--chitin interactions.

Directory of Open Access Journals (Sweden)

Maria T Brandl

Full Text Available Salmonella cycles between host and nonhost environments, where it can become an active member of complex microbial communities. The role of fungi in the environmental adaptation of enteric pathogens remains relatively unexplored. We have discovered that S. enterica Typhimurium rapidly attaches to and forms biofilms on the hyphae of the common fungus, Aspergillus niger. Several Salmonella enterica serovars displayed a similar interaction, whereas other bacterial species were unable to bind to the fungus. Bacterial attachment to chitin, a major constituent of fungal cell walls, mirrored this specificity. Pre-incubation of S. Typhimurium with N-acetylglucosamine, the monomeric component of chitin, reduced binding to chitin beads by as much as 727-fold and inhibited attachment to A. niger hyphae considerably. A cellulose-deficient mutant of S. Typhimurium failed to attach to chitin beads and to the fungus. Complementation of this mutant with the cellulose operon restored binding to chitin beads to 79% of that of the parental strain and allowed for attachment and biofilm formation on A. niger, indicating that cellulose is involved in bacterial attachment to the fungus via the chitin component of its cell wall. In contrast to cellulose, S. Typhimurium curli fimbriae were not required for attachment and biofilm development on the hyphae but were critical for its stability. Our results suggest that cellulose-chitin interactions are required for the production of mixed Salmonella-A. niger biofilms, and support the hypothesis that encounters with chitinaceous alternate hosts may contribute to the ecological success of human pathogens.

Production and qualification of transglucosidase from Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Benson, C.P.; Kelly, C.T.; Fogarty, W.M.

1982-08-01

The production of transglucosidase by Aspergillus niger was examined in batch culture with thin-layer chromatography (t.l.c.). Corn steep liquor was used as the nitrogen source and the activities obtained with four different carbon sources were examiend both qualitatively and quantitatively. Prompted by the non-quantitative nature of the t.l.c. assay technique, a quantiative transglucosidase assay procedure was developed subsequently. This was based on the hydrolysis of alpha-methyl-D-glucoside which was shown to be unaffected not only by amyloglucosidase of A. niger but also by that from a number of other organisms. The glucose released was measured by the glucose oxidase-peroxidase reagent, thus providing a rapid and reliable quantitative assay procedure for determining transglucosidase in the presence of amyloglucosidase. (Refs. 30).

The situation in the Niger Delta; La situation dans le delta du Niger

Energy Technology Data Exchange (ETDEWEB)

Vitalis, E

2007-07-15

An energy issue for the United States and a political challenge for Europe, Nigeria is experiencing growing instability and is on the verge of civil war; the ecosystem and the population of the Niger Delta are the main victims. The State, corrupt, is powerless to contain the rising violence and redistribute the proceeds of oil sales. It is high time for oil-consuming countries, starting with the United States, to concern themselves with stabilizing the region. Europe must contribute to the lasting development of this country. (author)

The effects of agitation and aeration on the production of gluconic acid by Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Dronawat, S.N.; Svihla, C.K.; Hanley, T.R. [Univ. of Louisville, KY (United States)

1995-12-31

The effects of agitation and aeration in the production of gluconic acid by Aspergillus niger from a glucose medium were investigated. Experiments were conducted at aeration rates of 5.0 and 10.0 L/min. Four different agitation speeds were investigated for each aeration rate. Gluconic acid concentration and biomass concentration were analyzed, and the rate of consumption of substrate by A. niger was noted. The main purpose of this work was to find the optimal conditions of agitation and aeration for the growth of A. niger and production of gluconic acid in submerged culture in a batch fermentor at a bench-top scale. The oxygen-transfer rates at different agitation and aeration rates were calculated. The gluconic acid concentration and rate of growth of A. niger increased with increase in the agitation and aeration rates.

Remote sensing experiment in West Africa. [drought effects on desert agriculture and vegetation in Niger

Science.gov (United States)

Macleod, N. H.

1974-01-01

There are substantial needs of the Sahelien Zone to detail the state of regional agricultural resources in the face of a sixth year of serious drought conditions. While most of the work has been done in the Republic of Niger, the principles which have emerged from the analysis seem to be applicable to much of the Sahel. The discussion relates to quite specific rehabilitation and development initiations under consideration in Niger which are based in part upon direct analysis of ERTS imagery of the country, in part on field surveys and on discussions with Nigerian officials and technicians. Again, because the entire Sahelien Zone (including Niger) has large zones of similar ecologic characteristics, modificiations of the approaches suggested for Niger are applicable to the solution of rehabilitation of the desert, the savannah and the woodlands of West Africa in general.

Evidence for a cytoplasmic pathway of oxalate biosynthesis in Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Kubicek, C.P.; Schreferl-Kunar, G.; Woehrer, W.; Roehr, M.

1988-03-01

Oxalate accumulation of up to 8 g/liter was induced in Aspergillus niger by shifting the pH from 6 to 8. This required the presence of P/sub i/ and a nitrogen source and was inhibited by the protein synthesis inhibitor cycloheximide. Exogenously added /sup 14/CO/sub 2/ was not incorporated into oxalate, but was incorporated into acetate and malate, thus indicating the biosynthesis of oxalate by hydrolytic cleavage of oxaloacetate. Inhibition of mitochondrial citrate metabolism by fluorocitrate did not significantly decrease the oxalate yield. The putative enzyme that was responsible for this oxaloacetate hydrolase (EC 3.7.1.1), which was induced de novo during the pH shift. Subcellular fractionation of oxalic acid-forming mycelia of A. niger showed that this enzyme is located in the cytoplasm of A. niger. The results are consistent with a cytoplasmic pathway of oxalate formation which does not involve the tricarboxylic acid cycle.

Corporate Social Responsibility: Case Study of Community Expectations and the Administrative Systems, Niger Delta

Science.gov (United States)

Ogula, David

2012-01-01

Poor community-company relations in the Niger Delta have drawn attention to the practice of corporate social responsibility (CSR) in the region. Since the 1960s, transnational oil corporations operating in the Niger Delta have adopted various CSR strategies, yet community-company relations remain adversarial. This article examines community…

Genome sequencing and analysis of the versatile cell factory Aspergillus niger CBS 513.88

NARCIS (Netherlands)

Pel, Herman J.; de Winde, Johannes H.; Archer, David B.; Dyer, Paul S.; Hofmann, Gerald; Schaap, Peter J.; Turner, Geoffrey; Albang, Richard; Albermann, Kaj; Andersen, Mikael R.; Bendtsen, Jannick D.; Benen, Jacques A. E.; van den Berg, Marco; Breestraat, Stefaan; Caddick, Mark X.; Contreras, Roland; Cornell, Michael; Coutinho, Pedro M.; Danchin, Etienne G. J.; Debets, Alfons J. M.; Dekker, Peter; van Dijck, Piet W. M.; van Dijk, Alard; Dijkhuizen, Lubbert; Driessen, Arnold J. M.; d'Enfert, Christophe; Geysens, Steven; Groot, Gert S. P.; de Groot, Piet W. J.; Guillemette, Thomas; Henrissat, Bernard; Herweijer, Marga; van den Hombergh, Johannes P. T. W.; van den Hondel, Cees A. M. J. J.; van der Heijden, Rene T. J. M.; van der Kaaij, Rachel M.; Klis, Frans M.; Kools, Harrie J.; Kubicek, Christian P.; van Kuyk, Patricia A.; Lauber, Juergen; Lu, Xin; van der Maarel, Marc J. E. C.; Meulenberg, Rogier; Menke, Hildegard; Mortimer, Martin A.; Nielsen, Jens; Oliver, Stephen G.; Olsthoorn, Maurien; Pal, Karoly; van Peij, Noel N. M. E.; Ram, Arthur F. J.; Rinas, Ursula; Roubos, Johannes A.; Sagt, Cees M. J.; Schmoll, Monika; Sun, Jibin; Ussery, David; Varga, Janos; Vervecken, Wouter; de Vondervoort, Peter J. J. van; Wedler, Holger; Wosten, Han A. B.; Zeng, An-Ping; van Ooyen, Albert J. J.; Visser, Jaap; Stam, Hein; Enfert, Christophe d’; Lauber, Jürgen; Goosen, Coenie; de Vries, Ronald P.

The filamentous fungus Aspergillus niger is widely exploited by the fermentation industry for the production of enzymes and organic acids, particularly citric acid. We sequenced the 33.9-megabase genome of A. niger CBS 513.88, the ancestor of currently used enzyme production strains. A high level of

Equilibrium unfolding of A. niger RNase: pH dependence of chemical and thermal denaturation.

Science.gov (United States)

Kumar, Gundampati Ravi; Sharma, Anurag; Kumari, Moni; Jagannadham, Medicherla V; Debnath, Mira

2011-08-01

Equilibrium unfolding of A. niger RNase with chemical denaturants, for example GuHCl and urea, and thermal unfolding have been studied as a function of pH using fluorescence, far-UV, near-UV, and absorbance spectroscopy. Because of their ability to affect electrostatic interactions, pH and chemical denaturants have a marked effect on the stability, structure, and function of many globular proteins. ANS binding studies have been conducted to enable understanding of the folding mechanism of the protein in the presence of the denaturants. Spectroscopic studies by absorbance, fluorescence, and circular dichroism and use of K2D software revealed that the enzyme has α + β type secondary structure with approximately 29% α-helix, 24% β-sheet, and 47% random coil. Under neutral conditions the enzyme is stable in urea whereas GuHCl-induced equilibrium unfolding was cooperative. A. niger RNase has little ANS binding even under neutral conditions. Multiple intermediates were populated during the pH-induced unfolding of A. niger RNase. Urea and temperature-induced unfolding of A. niger RNase into the molten globule-like state is non-cooperative, in contrast to the cooperativity seen with the native protein, suggesting the presence of two parts/domains, in the molecular structure of A. niger RNase, with different stability that unfolds in steps. Interestingly, the GuHCl-induced unfolding of the A state (molten globule state) of A. niger RNase is unique, because a low concentration of denaturant not only induces structural change but also facilitates transition from one molten globule like state (A(MG1)) into another (I(MG2)).

Biological leaching of heavy metals from a contaminated soil by Aspergillus niger

International Nuclear Information System (INIS)

Ren Wanxia; Li Peijun; Geng Yong; Li Xiaojun

2009-01-01

Bioleaching of heavy metals from a contaminated soil in an industrial area using metabolites, mainly weak organic acids, produced by a fungus Aspergillus niger was investigated. Batch experiments were performed to compare the leaching efficiencies of one-step and two-step processes and to determine the transformation of heavy metal chemical forms during the bioleaching process. After the one or two-step processes, the metal removals were compared using analysis of variance (ANOVA) and least-significance difference (LSD). A. niger exhibits a good potential in generating a variety of organic acids effective for metal solubilisation. Results showed that after the one-step process, maximum removals of 56%, 100%, 30% and 19% were achieved for copper, cadmium, lead and zinc, respectively. After the two-step process, highest removals of 97.5% Cu, 88.2% Cd, 26% Pb, and 14.5% Zn were obtained. Results of sequential extraction showed that organic acids produced by A. niger were effective in removing the exchangeable, carbonate, and Fe/Mn oxide fractions of Cu, Cd, Pb and Zn; and after both processes the metals remaining in the soil were mainly bound in stable fractions. Such a treatment procedure indicated that leaching of heavy metals from contaminated soil using A. niger has the potential for use in remediation of contaminated soils.

Biological leaching of heavy metals from a contaminated soil by Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Ren Wanxia, E-mail: ren_laura@163.com [Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Li Peijun, E-mail: lipeijun@iae.ac.cn [Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Geng Yong; Li Xiaojun [Institute of Applied Ecology, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

2009-08-15

Bioleaching of heavy metals from a contaminated soil in an industrial area using metabolites, mainly weak organic acids, produced by a fungus Aspergillus niger was investigated. Batch experiments were performed to compare the leaching efficiencies of one-step and two-step processes and to determine the transformation of heavy metal chemical forms during the bioleaching process. After the one or two-step processes, the metal removals were compared using analysis of variance (ANOVA) and least-significance difference (LSD). A. niger exhibits a good potential in generating a variety of organic acids effective for metal solubilisation. Results showed that after the one-step process, maximum removals of 56%, 100%, 30% and 19% were achieved for copper, cadmium, lead and zinc, respectively. After the two-step process, highest removals of 97.5% Cu, 88.2% Cd, 26% Pb, and 14.5% Zn were obtained. Results of sequential extraction showed that organic acids produced by A. niger were effective in removing the exchangeable, carbonate, and Fe/Mn oxide fractions of Cu, Cd, Pb and Zn; and after both processes the metals remaining in the soil were mainly bound in stable fractions. Such a treatment procedure indicated that leaching of heavy metals from contaminated soil using A. niger has the potential for use in remediation of contaminated soils.

Productive mutants of niger

International Nuclear Information System (INIS)

Misra, R.C.

2001-01-01

Seeds of six niger (Guizotia abyssinica Cass.) varieties ('GA-10', 'ONS-8', 'IGP-72', 'N-71', 'NB-9' and 'UN-4') were treated with 0.5, 0.75 and 1% ethyl methanesulphonate. After four generations of selection, 29 mutant lines were developed and those were evaluated from 1990-92 during Kharif (July to October) and Rabi (December to March) seasons. Average plant characteristics and yield data of four high yielding mutants along with 'IGP-76' (National Check), GA-10 (Zonal Check) and 'Semiliguda Local' (Local Check) are presented

Bioluminescent hydrocarbonclastic bacteria of the Niger Delta ...

African Journals Online (AJOL)

Utilization of three petroleum hydrocarbons (Mobil SAE 40 Engine Oil, Diesel and Bonny light Crude Oil) by four bioluminescent bacteria (Vibrio harveyi, V. fisheri, Photobacterium leiognathi and P. Phosphoreum isolated from the Bonny estuary in the Niger Delta, Nigeria was investigated. Microbial utilization was monitored ...

Pectinolytic complex production by Aspergillus niger URM 4645 ...

African Journals Online (AJOL)

-PG), pectin lyase (PL), and pectin methylesterase (PE), produced by Aspergillus niger URM 4645, were studied in solid state fermentation (SSF) using yellow passion fruit peels as substrate. The effect of substrate amount, initial moisture ...

Germination of Aspergillus niger conidia

OpenAIRE

Hayer, Kimran

2014-01-01

Aspergillus niger is a black-spored filamentous fungus that forms asexual spores called conidospores (‘conidia’). Germination of conidia, leading to the formation of hyphae, is initiated by conidial swelling and mobilisation of endogenous carbon and energy stores, followed by polarisation and emergence of a hyphal germ tube. These morphological and biochemical changes which define the model of germination have been studied with the aim of understanding how conidia sense and utilise different...

Regulatory processes in Aspergillus niger

OpenAIRE

Poulsen, Lars; Thykær, Jette; Eliasson Lantz, Anna

2012-01-01

Filamentous fungi are extensively used in the fermentation industry for synthesis of numerous products. One of the most important, is the fungus Aspergillus niger, used industrially for production of organic acids, and homologous as well as heterologous enzymes. This fungus has numerous of advantages, including tolerance for low pH, which is important for acid production. Furthermore, it has the capability of metabolizing a wide variety of carbon sources, possesses an exceptional efficient pr...

Effect of temperature and water activity on the production of fumonisins by Aspergillus niger and different Fusarium species

Science.gov (United States)

2009-01-01

Background Fumonisins are economically important mycotoxins which until recently were considered to originate from only a few Fusarium species. However recently a putative fumonisin gene cluster was discovered in two different Aspergillus niger strains followed by detection of an actual fumonisin B2 (FB2) production in four strains of this biotechnologically important workhorse. Results In the present study, a screening of 5 A. niger strains and 25 assumed fumonisin producing Fusarium strains from 6 species, showed that all 5 A. niger strains produced FB2 and 23 of 25 Fusarium produced fumonisin B1 and other isoforms (fumonisin B2 and B3). Five A. niger and five Fusarium spp. were incubated at six different temperatures from 15-42°C on Czapek Yeast Agar +5% salt or Potato Dextrose Agar. A. niger had the highest production of FB2 at 25-30°C whereas Fusarium spp. had the maximal production of FB1 and FB2 at 20-25°C. Addition of 2.5-5% NaCl, or 10-20% sucrose increased the FB2 production of A. niger, whereas addition of glycerol reduced FB2 production. All three water activity lowering solutes reduced the fumonisin production of the Fusarium species. Conclusion The present study shows that the regulation of fumonisin production is very different in A. niger and Fusarium, and that food and feeds preserved by addition of sugar or salts may be good substrates for fumonisin B2 production by A. niger. PMID:20043849

Effect of temperature and water activity on the production of fumonisins by Aspergillus niger and different Fusarium species

Directory of Open Access Journals (Sweden)

Frisvad Jens C

2009-12-01

Full Text Available Abstract Background Fumonisins are economically important mycotoxins which until recently were considered to originate from only a few Fusarium species. However recently a putative fumonisin gene cluster was discovered in two different Aspergillus niger strains followed by detection of an actual fumonisin B2 (FB2 production in four strains of this biotechnologically important workhorse. Results In the present study, a screening of 5 A. niger strains and 25 assumed fumonisin producing Fusarium strains from 6 species, showed that all 5 A. niger strains produced FB2 and 23 of 25 Fusarium produced fumonisin B1 and other isoforms (fumonisin B2 and B3. Five A. niger and five Fusarium spp. were incubated at six different temperatures from 15-42°C on Czapek Yeast Agar +5% salt or Potato Dextrose Agar. A. niger had the highest production of FB2 at 25-30°C whereas Fusarium spp. had the maximal production of FB1 and FB2 at 20-25°C. Addition of 2.5-5% NaCl, or 10-20% sucrose increased the FB2 production of A. niger, whereas addition of glycerol reduced FB2 production. All three water activity lowering solutes reduced the fumonisin production of the Fusarium species. Conclusion The present study shows that the regulation of fumonisin production is very different in A. niger and Fusarium, and that food and feeds preserved by addition of sugar or salts may be good substrates for fumonisin B2 production by A. niger.

Sedimentology and ichnology of Neogene Coastal Swamp deposits in the Niger Delta Basin, Nigeria

Directory of Open Access Journals (Sweden)

Ezeh Sunny C.

2016-09-01

Full Text Available Often analyses of depositional environments from sparse data result in poor interpretation, especially in multipartite depositional settings such as the Niger Delta. For instance, differentiating channel sandstones, heteroliths and mudstones within proximal environments from those of distal facies is difficult if interpretations rely solely on well log signatures. Therefore, in order to achieve an effective and efficient interpretation of the depositional conditions of a given unit, integrated tools must be applied such as matching core descriptions with wireline log signature. In the present paper cores of three wells from the Coastal Swamp depositional belt of the Niger Delta are examined in order to achieve full understanding of the depositional environments. The well sections comprise cross-bedded sandstones, heteroliths (coastal and lower shoreface and mudstones that were laid down in wave, river and tidal processes. Interpretations were made from each data set comprising gamma ray logs, described sedimentological cores showing sedimentary features and ichnological characteristics; these were integrated to define the depositional settings. Some portions from one of the well sections reveal a blocky gamma ray well log signature instead of a coarsening-upward trend that characterises a shoreface setting while in other wells the signatures for heteroliths at some sections are bell blocky in shaped rather than serrated. Besides, heteroliths and mudstones within the proximal facies and those of distal facies were difficult to distinguish solely on well log signatures. However, interpretation based on sedimentology and ichnology of cores from these facies was used to correct these inconsistencies. It follows that depositional environment interpretation (especially in multifarious depositional environments such as the Niger Delta should ideally be made together with other raw data for accuracy and those based solely on well log signatures should

Intra and extracellular nuclease production by Aspergillus niger and Aspergillus nidulans

Directory of Open Access Journals (Sweden)

Ferreira Adlane V. B.

1998-01-01

Full Text Available Intra and extracellular nuclease production by strains of Aspergillus niger and Aspergillus nidulans was estimated using a modified DNAse test agar and cell-free extract assays. Differences in the production of nucleases by A. niger and A. nidulans were observed. These observations suggest that the DNAse test agar can be helpful for a quick screening for some types of nucleases in filamentous fungi. The assays using cell-free extracts can also be useful for initial characterization of other types of nucleases.

Functional expression of amine oxidase from Aspergillus niger (AO-I) in Saccharomyces cerevisiae.

Science.gov (United States)

Kolaríková, Katerina; Galuszka, Petr; Sedlárová, Iva; Sebela, Marek; Frébort, Ivo

2009-01-01

The aim of this work was to prepare recombinant amine oxidase from Aspergillus niger after overexpressing in yeast. The yeast expression vector pDR197 that includes a constitutive PMA1 promoter was used for the expression in Saccharomyces cerevisiae. Recombinant amine oxidase was extracted from the growth medium of the yeast, purified to homogeneity and identified by activity assay and MALDI-TOF peptide mass fingerprinting. Similarity search in the newly published A. niger genome identified six genes coding for copper amine oxidase, two of them corresponding to the previously described enzymes AO-I a methylamine oxidase and three other genes coding for FAD amine oxidases. Thus, A. niger possesses an enormous metabolic gear to grow on amine compounds and thus support its saprophytic lifestyle.

The opposite roles of agdA and glaA on citric acid production in Aspergillus niger.

Science.gov (United States)

Wang, Lu; Cao, Zhanglei; Hou, Li; Yin, Liuhua; Wang, Dawei; Gao, Qiang; Wu, Zhenqiang; Wang, Depei

2016-07-01

Citric acid is produced by an industrial-scale process of fermentation using Aspergillus niger as a microbial cell factory. However, citric acid production was hindered by the non-fermentable isomaltose and insufficient saccharification ability in A. niger when liquefied corn starch was used as a raw material. In this study, A. niger TNA 101ΔagdA was constructed by deletion of the α-glucosidase-encoding agdA gene in A. niger CGMCC 10142 genome using Agrobacterium tumefaciens-mediated transformation. The transformants A. niger OG 1, OG 17, and OG 31 then underwent overexpression of glucoamylase in A. niger TNA 101ΔagdA. The results showed that the α-glucosidase activity of TNA 101ΔagdA was decreased by 62.5 % compared with CGMCC 10142, and isomaltose was almost undetectable in the fermentation broth. The glucoamylase activity of the transformants OG 1 and OG 17 increased by 34.5 and 16.89 % compared with that of TNA 101ΔagdA, respectively. In addition, for the recombinants TNA 101ΔagdA, OG 1 and OG 17, there were no apparent defects in the growth development. Consequently, in comparison with CGMCC 10142, TNA 101ΔagdA and OG 1 decreased the residual reducing sugar by 52.95 and 88.24 %, respectively, and correspondingly increased citric acid production at the end of fermentation by 8.68 and 16.87 %. Citric acid production was further improved by decreasing the non-fermentable residual sugar and increasing utilization rate of corn starch material in A. niger. Besides, the successive saccharification and citric acid fermentation processes were successfully integrated into one step.

Glucoamylase biosynthesis by cells of Aspergillus niger C sub 58-III immobilized in sintered glass and pumice stones

Energy Technology Data Exchange (ETDEWEB)

Fiedurek, J.; Lobarzewski, J. (Uniwersytet Marii Curie-Sklodowskiej, Lublin (Poland). Inst. Mikrobiologii i Biochemii)

1990-09-01

A simple method of A. niger C{sub 58-III} cell immobilization is described. This strain produces extracellular glucoamylase. According to the proposed method A. niger spores were first immobilized by adsorption in sintered glass Rasching rings (RR) or pumice stones (PS). Growing out from spores, A. niger cells produced extracellular glucoamylase. This technique facilitates the culture growth in a filamentous spongy structure of the supports with a continuous accumulation of biomass. After every 24 h it was possible to obtain culture liquid rich in glucoamylase. This procedure can be repeated 30 times using the same sample of immobilized A. niger culture without any loss of glucoamylase activity in the liquid medium. In a 96 h period immobilized A. niger cells produced 300 units . ml{sup -1} whereas a shake culture of this fungus produced only 186 units . ml{sup -1}. (orig.).

Bioremediation of Synthetic and Industrial Effluents by Aspergillus niger Isolated from Contaminated Soil Following a Sequential Strategy.

Science.gov (United States)

Gulzar, Tahsin; Huma, Tayyaba; Jalal, Fatima; Iqbal, Sarosh; Abrar, Shazia; Kiran, Shumaila; Nosheen, Sofia; Hussain, Waqar; Rafique, Muhammad Asim

2017-12-16

The present study aimed to assess and compare the ability to remediate synthetic textile and industrial wastewaters by Fenton treatment, a biological system and sequential treatments using Aspergillus niger ( A. niger ). All studied treatments were found to be effective in decolorization of the effluents under study. Fenton treatment followed by A. niger showed excellent potential for the maximum decolorization of the synthetic and industrial effluents under study. The effectiveness of sequential treatment was evaluated by water quality parameters such as total organic carbon (TOC), Biological Oxygen Demand (BOD5) and Chemical Oxygen Demand (COD) before and after each treatment. The results indicated that A. niger is an effective candidate for detoxification of textile wastewaters.

Bioremediation of Synthetic and Industrial Effluents by Aspergillus niger Isolated from Contaminated Soil Following a Sequential Strategy

Directory of Open Access Journals (Sweden)

Tahsin Gulzar

2017-12-01

Full Text Available The present study aimed to assess and compare the ability to remediate synthetic textile and industrial wastewaters by Fenton treatment, a biological system and sequential treatments using Aspergillus niger (A. niger. All studied treatments were found to be effective in decolorization of the effluents under study. Fenton treatment followed by A. niger showed excellent potential for the maximum decolorization of the synthetic and industrial effluents under study. The effectiveness of sequential treatment was evaluated by water quality parameters such as total organic carbon (TOC, Biological Oxygen Demand (BOD5 and Chemical Oxygen Demand (COD before and after each treatment. The results indicated that A. niger is an effective candidate for detoxification of textile wastewaters.

Combinatorial control of gene expression in Aspergillus niger grown on sugar beet pectin.

Science.gov (United States)

Kowalczyk, Joanna E; Lubbers, Ronnie J M; Peng, Mao; Battaglia, Evy; Visser, Jaap; de Vries, Ronald P

2017-09-27

Aspergillus niger produces an arsenal of extracellular enzymes that allow synergistic degradation of plant biomass found in its environment. Pectin is a heteropolymer abundantly present in the primary cell wall of plants. The complex structure of pectin requires multiple enzymes to act together. Production of pectinolytic enzymes in A. niger is highly regulated, which allows flexible and efficient capture of nutrients. So far, three transcriptional activators have been linked to regulation of pectin degradation in A. niger. The L-rhamnose-responsive regulator RhaR controls the production of enzymes that degrade rhamnogalacturonan-I. The L-arabinose-responsive regulator AraR controls the production of enzymes that decompose the arabinan and arabinogalactan side chains of rhamnogalacturonan-II. The D-galacturonic acid-responsive regulator GaaR controls the production of enzymes that act on the polygalacturonic acid backbone of pectin. This project aims to better understand how RhaR, AraR and GaaR co-regulate pectin degradation. For that reason, we constructed single, double and triple disruptant strains of these regulators and analyzed their growth phenotype and pectinolytic gene expression in A. niger grown on sugar beet pectin.

An onion farmer with a case of hypersensitivity pneumonitis caused by Aspergillus niger.

Science.gov (United States)

Sakamoto, Tomohiro; Yamasaki, Akira; Funaki, Yoshihiro; Harada, Tomoya; Okazaki, Ryota; Hasegawa, Yasuyuki; Sueda, Yuriko; Fukushima, Takehito; Morita, Masahito; Yamamoto, Akihiro; Kodani, Masahiro; Shimizu, Eiji

2018-01-01

A 62-year old man was admitted to our hospital with a 2-week complaint of a dry cough, general fatigue, and dyspnea on effort. He has been an onion farmer for several years and developed these symptoms after cleaning up onion peels with air compressors. A chest roentgenogram and computed tomography showed a ground glass shadow in the bilateral upper lung field. Cellular analysis of the bronchoalveolar lavage fluid showed elevated total cell numbers and lymphocytes. Transbronchial lung biopsies revealed a non-caseating granuloma with both epithelioid cells and Langhans giant cells. After the admission, these symptoms and radiological findings gradually improved without any treatment. Then, a returning-home provocation test was positive only when he worked cleaning up onion peels with air compressors. A. niger was cultured from his workplace and black mold from the onion peels. The precipitation antibody and the antigen were both positive for Aspergillus . Therefore, we diagnosed this case as hypersensitivity pneumonitis caused by inhalation of A. niger . Although hypersensitivity pneumonia caused by A. niger is rare, physicians should aware the possibility of this condition in farmers because A niger is ubiquitously present in several vegetables and fruits.

VeA of Aspergillus niger increases spore dispersing capacity by impacting conidiophore architecture.

Science.gov (United States)

Wang, Fengfeng; Dijksterhuis, Jan; Wyatt, Timon; Wösten, Han A B; Bleichrodt, Robert-Jan

2015-01-01

Aspergillus species are highly abundant fungi worldwide. Their conidia are among the most dominant fungal spores in the air. Conidia are formed in chains on the vesicle of the asexual reproductive structure called the conidiophore. Here, it is shown that the velvet protein VeA of Aspergillus niger maximizes the diameter of the vesicle and the spore chain length. The length and width of the conidiophore stalk and vesicle were reduced nearly twofold in a ΔveA strain. The latter implies a fourfold reduced surface area to develop chains of spores. Over and above this, the conidial chain length was approximately fivefold reduced. The calculated 20-fold reduction in formation of conidia by ΔveA fits the 8- to 17-fold decrease in counted spore numbers. Notably, morphology of the ΔveA conidiophores of A. niger was very similar to that of wild-type Aspergillus sydowii. This suggests that VeA is key in conidiophore architecture diversity in the fungal kingdom. The finding that biomass formation of the A. niger ΔveA strain was reduced twofold shows that VeA not only impacts dispersion capacity but also colonization capacity of A. niger.

Gene deletion of cytosolic ATP: citrate lyase leads to altered organic acid production in Aspergillus niger

DEFF Research Database (Denmark)

Meijer, Susan Lisette; Nielsen, Michael Lynge; Olsson, Lisbeth

2009-01-01

With the availability of the genome sequence of the filamentous fungus Aspergillus niger, the use of targeted genetic modifications has become feasible. This, together with the fact that A. niger is well established industrially, makes this fungus an attractive micro-organism for creating a cell...... factory platform for production of chemicals. Using molecular biology techniques, this study focused on metabolic engineering of A. niger to manipulate its organic acid production in the direction of succinic acid. The gene target for complete gene deletion was cytosolic ATP: citrate lyase (acl), which...... the acl gene. Additionally, the total amount of organic acids produced in the deletion strain was significantly increased. Genome-scale stoichiometric metabolic model predictions can be used for identifying gene targets. Deletion of the acl led to increased succinic acid production by A. niger....

Floods in the Niger basin - analysis and attribution

Science.gov (United States)

Aich, V.; Koné, B.; Hattermann, F. F.; Müller, E. N.

2014-08-01

This study addresses the increasing flood risk in the Niger basin and assesses the damages that arise from flooding. Statistics from three different sources (EM-DAT, Darthmouth Flood Observatory, NatCat Munich RE) on people affected by floods show positive trends for the entire basin beginning in the 1980s. An assessment of four subregions across the Niger basin indicates even exponential trends for the Sahelian and Sudanian regions. These positive trends for flooding damage match up to a time series of annual maximum discharge (AMAX): the strongest trends in AMAX are detected in the Sahelian and Sudanian regions, where the population is also increasing the fastest and vulnerability generally appears to be very high. The joint effect of these three factors can possibly explain the exponential increase in people affected by floods in these subregions. In a second step, the changes in AMAX are attributed to changes in precipitation and land use via a data-based approach within a hypothesis-testing framework. Analysis of rainfall, heavy precipitation and the runoff coefficient shows a coherent picture of a return to wet conditions in the basin, which we identify as the main driver of the increase in AMAX in the Niger basin. The analysis of flashiness (using the Richards-Baker Index) and the focus on the "Sahel Paradox" of the Sahelian region reveal an additional influence of land-use change, but it seems minor compared to the increase in precipitation.

In Vitro Efficacy of Continuous Mild High Temperature on the Biofilm Formation of Aspergillus Niger.

Science.gov (United States)

Zeng, Rong; Tong, Jian Bo; Liu, Yu Zhen; Chen, Qing; Lin, Tong; Li, Min; Lü, Gui Xia

2017-12-20

Objective To investigate whether continuous mild high temperature (increased temperature without causing significant damage to host cells) can inhibit the biofilm formation of Aspergillus niger (A.niger) and its vitality.Methods A.niger biofilms were formed on a coverslip in 24-well tissue culture plate and were checked at the time points 4,8,10,16,24,48 and 72 hours.Confocal laser scanning microscopy (CLSM) was used to image and quantify A.niger biofilm formation under three different continuous mild high temperatures at 37℃,39℃,and 41℃.Furthermore,2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay was used to quantify the dynamic growth of A.niger biofilm under the above conditions.Results Compared with the culture condition 37℃,CLSM analysis at 39℃ or 41℃ showed that higher temperature induced later germination at 4 hours (t=8.603,P=0.047;t=14.550,P=0.008),poorer hyphal elongation at 8 hours(t=35.118,P=0.039;t=63.450,P=0.006),poorer polar growth,and reduced biofilm thickness from 10 to 24 hours.The XTT assay showed that higher temperature (39℃ or 41℃) lead to lower vitality at 10 hours,higher vitality at 16 hours,but finally lower vitality from 24 to 72 hours (t=24.262,P=0.038;t=7.556,P=0.031).Conclusion Continuous mild high temperature may have a negative regulatory effect on biofilm formation of A.niger and its vitality.

Nutrient enrichment of pineapple waste using Aspergillus niger and ...

African Journals Online (AJOL)

Nutrient enrichment of pineapple waste using Aspergillus niger and Trichoderma viride by solid state fermentation. Evans Otieno Omwango, Eliud Nyaga Mwaniki Njagi, George Owino Orinda, Ruth Nduta Wanjau ...

Review of secondary metabolites and mycotoxins from the Aspergillus niger group

DEFF Research Database (Denmark)

Nielsen, Kristian Fog; Mogensen, Jesper Mølgaard; Johansen, Maria

2009-01-01

(excluding A. aculeatus and its close relatives) from which currently 145 different secondary metabolites have been isolated and/or detected. From a human and animal safety point of view, the mycotoxins ochratoxin A (from A. carbonarius and less frequently A. niger) and fumonisin B2 (from A. niger......) are currently the most problematic compounds. Especially in foods and feeds such as coffee, nuts, dried fruits, and grape-based products where fumonisin-producing fusaria are not a problem, fumonisins pose a risk. Moreover, compounds such as malformins, naptho-γ-pyrones, and bicoumarins (kotanins) call...

Genome sequencing and analysis of the versatile cell factory Aspergillus niger CBS 513.88

DEFF Research Database (Denmark)

Pel, Herman J.; de Winde, Johannes H.; Archer, David B.

2007-01-01

The filamentous fungus Aspergillus niger is widely exploited by the fermentation industry for the production of enzymes and organic acids, particularly citric acid. We sequenced the 33.9-megabase genome of A. niger CBS 513.88, the ancestor of currently used enzyme production strains. A high level...... clusters for fumonisin and ochratoxin A synthesis....

Putative Aspergillus niger-induced oxalate nephrosis in sheep : clinical communication

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C.J. Botha

2009-05-01

Full Text Available A sheep farmer provided a maize-based brewer's grain (mieliemaroek and bales of Eragrostis curvula hay to ewes and their lambs, kept on zero-grazing in pens. The 'mieliemaroek' was visibly mouldy. After 14 days in the feedlot, clinical signs, including generalised weakness, ataxia of the hind limbs, tremors and recumbency, were noticed. Six ewes died within a period of 7 days. A post mortem examination was performed on 1 ewe. The carcass appeared to be cachectic with mild effusions into the body cavities; mild lung congestion and pallor of the kidneys were observed. Microscopical evaluation revealed nephrosis and birefringent oxalate crystals in the renal tubules when viewed under polarised light. A provisional diagnosis of oxalate nephrosis with subsequent kidney failure was made. Amongst other fungi, Aspergillus niger was isolated from 'mieliemaroek' samples submitted for fungal culture and identification. As A. niger is known to synthesise oxalates, a qualitative screen to detect oxalic acid in the mieliemaroek and purified A. niger isolates was performed using high-performance liquid chromatography (HPLC. Oxalic acid was detected, which supported a diagnosis of soluble oxalate-induced nephropathy.

Examining Nutritional Adequacy and Dietary Diversity Among Women in Niger.

Science.gov (United States)

Cisse-Egbuonye, Nafissatou; Ishdorj, Ariun; McKyer, E L J; Mkuu, Rahma

2017-06-01

Objective The purpose of this study was to examine the nutritional adequacy and dietary composition among women residing in Zinder and Maradi of Niger, and the factors that affect the variety of their dietary intake. Methods Data from 3360 women of ages 15-49 were used in the analysis. The variable of interest was the Women Dietary Diversity Score (WDDS), which is the simple sum of scores of the 9 categorized food groups, ranging from 0 to 9. Lower values for WDDS indicate nutritionally inadequate dietary diversity. Analysis included descriptive, Mann-Whitney U test and linear regression. Results The majority of the participants were residing in the Maradi Region (56.7%) and were living in households with both male and female adults (94.9%). The mean WDDS was 3.5 in Zinder compared to 2.5 in Maradi (p Hunger Scale (HHS) had a negative and significant effect on WDDS. Conclusion Niger has one of the highest concentrations of malnutrition in the world. In 2012, approximately 2.5 million Nigeriens were affected by malnutrition. Our study results reinforce the importance to conduct more studies that examine the nutritional intake of women in Niger.

Substrate water availability and seed water content on niger germination

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Carla Regina Baptista Gordin

2015-09-01

Full Text Available Niger is an oleaginous species whose cultivation has been spreading, but there is not much information on the adverse conditions during its seedling establishment. This study aimed at evaluating the effects of substrate water availability and seed water content on niger germination. Seeds were moistened using the humid atmosphere method for 0; 24; 48; and 72 hours, obtaining the water contents of 7.0 %, 12.8 %, 16.8 % and 32.2 %. Then, they were sown in substrate moistened with PEG 6000 solutions with different osmotic potentials: 0.0 MPa (control, -0.1 MPa, -0.2 MPa, -0.3 MPa and -0.4 MPa. A completely randomized design, in a 4 x 5 factorial scheme (water content x osmotic potential, with four replications of 50 seeds, was used. First count and germination percentage, germination speed index and mean time, shoot and root length and seedlings dry weight were evaluated. The reduction in the substrate osmotic potential decreases the niger seed germination and seedling growth, regardless of water content, but with a higher evidence in seed water contents below 32.2 % and 12.8 %, respectively.

Gurya cutting and female genital fistulas in Niger: ten cases.

Science.gov (United States)

Ouedraogo, Itengre; McConley, Regina; Payne, Christopher; Heller, Alison; Wall, L Lewis

2018-03-01

The objective was to determine the contribution of female genital cutting to genital fistula formation in Niger from the case records of a specialist fistula hospital. A retrospective review was undertaken of the records of 360 patients seen at the Danja Fistula Center, Danja, Niger, between March 2014 and September 2016. Pertinent clinical and socio-demographic data were abstracted from the cases identified. A total of 10 fistulas resulting from gurya cutting was obtained: 9 cases of urethral loss and 1 rectovaginal fistula. In none of the cases was genital cutting performed for obstructed labor or as part of ritual coming-of-age ceremonies, but all cutting procedures were considered "therapeutic" within the local cultural context as treatment for dyspareunia, lack of interest in or unwillingness to engage in sexual intercourse, or female behavior that was deemed to be culturally inappropriate by the male spouse, parents, or in-laws. Clinical cure (fistula closed and the patient continent) was obtained in all 10 cases, although 3 women required more than one operation. Gurya cutting is an uncommon, but preventable, cause of genital fistulas in Niger. The socio-cultural context which gives rise to gurya cutting is explored in some detail.

The Niger Delta Avengers, Autonomous Ethnic Clans and Common ...

African Journals Online (AJOL)

Nneka Umera-Okeke

therefore investigated the sudden emergence of Niger Delta Avengers ... hardship, deprivations and environmental degradation occasioned by oil pipeline .... analysis of coded materials of the library such as books, magazines, journals,.

New insight into the disinfection mechanism of Fusarium monoliforme and Aspergillus niger by TiO2 photocatalyst under low intensity UVA light.

Science.gov (United States)

Pokhum, Chonlada; Viboonratanasri, Duangamon; Chawengkijwanich, Chamorn

2017-11-01

Titanium dioxide (TiO 2) photocatalytic reaction has great potential for the disinfection of harmful pathogens. However, the disinfection mechanisms of TiO 2 photocatalysis are not yet well-known for fungi and protozoa. In this work, the photocatalytic disinfection mechanism of Fusarium monoliforme and Aspergillus niger under low intensity UVA light (365nm, niger was more sensitive to UVA-light. Serious destructions of cell membrane and cellular organelles were shown in A. niger exposed to UVA-light only and photocatalytic treatments. However, morphological change in A. niger cell wall was only observed in photocatalytic treatment. Changes to the outermost melanin like layer and cell wall of A. niger spore due to photocatalytic treatment were greatly apparent while the intracellular organelles of A. niger spore were not affected. Therefore, regrowth of A. niger on agar plate was expected from the germination of A. niger spore in the subsequent dark. These observations give a better understanding of the photocatalytic disinfection mechanism toward fungi. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of the role of the Aspergillus niger aminolevulinic acid synthase (hemA) gene illustrates the difference between regulation of yeast and fungal haem- and sirohaem-dependent pathways

NARCIS (Netherlands)

Franken, A.C.; Christien Lokman, B.; Ram, A.F.; Hondel, C.A. van den; Weert, S. de; Punt, P.J.

2012-01-01

To increase knowledge on haem biosynthesis in filamentous fungi like Aspergillus niger, pathway-specific gene expression in response to haem and haem intermediates was analysed. This analysis showed that iron, 5′-aminolevulinic acid (ALA) and possibly haem control haem biosynthesis mostly via

Analysis of the role of the A. niger aminolevulinic acid synthase (hemA) gene illustrates the difference between regulation of yeast and fungal heme and siroheme dependent pathways

NARCIS (Netherlands)

A.F. Ram; C.A. van den Hondel; Christien Lokman; P.J. Punt; S. de Weert; A. Franken

2012-01-01

To increase knowledge on haem biosynthesis in filamentous fungi like Aspergillus niger, pathway-specific gene expression in response to haem and haem intermediates was analysed. This analysis showed that iron, 5'-aminolevulinic acid (ALA) and possibly haem control haem biosynthesis mostly via

CONFLICT RESOLUTION THROUGH DIALOGUE IN THE NIGER ...

African Journals Online (AJOL)

imitch

sea are Rivers forcados, marking the Western boundary of Bayelsa State, and St. ... sandy, porous and salty soil, too much rainfall, agricultural land .... media reports that the leaders of the Niger Delta have rejected Alhaji Ibrahim Gambari as the government ... continues to flow to enrich other people across the country …

Identification and characterization of starch and inulin modifying network of Aspergillus niger by functional genomics

NARCIS (Netherlands)

Yuan, Xiao-Lian

2008-01-01

Aspergillus niger produces a wide variety of carbohydrate hydrolytic enzymes which have potential applications in the baking, starch, textile, food and feed industries. The goal of this thesis is to unravel the molecular mechanisms of starch and inulin modifying network of A. niger, in order to

The Niger Delta: State Repression and Violence Nexus

African Journals Online (AJOL)

crosdel emuedo

2005-02-19

Feb 19, 2005 ... This explains its concern only with unimpeded access to crude oil at very cheap ... The people of the Niger Delta on the other hand, places premium on the concept of human ... going amnesty, over 123 hostages were taken.

Simultaneous Production of Amyloglucosidase and Exo-Polygalacturonase by Aspergillus niger in a Rotating Drum Reactor.

Science.gov (United States)

Colla, Eliane; Santos, Lucielen Oliveira; Deamici, Kricelle; Magagnin, Glênio; Vendruscolo, Mauricio; Costa, Jorge Alberto Vieira

2017-02-01

Simultaneous production of amyloglucosidase (AMG) and exo-polygalacturonase (exo-PG) was carried out by Aspergillus niger in substrate of defatted rice bran in a rotating drum bioreactor (RDB) and studied by a 3 1  × 2 2 factorial experimental design. Variables under study were A. niger strains (A. niger NRRL 3122 and A. niger t0005/007-2), types of inoculum (spore suspension and fermented bran), and types of inducer (starch, pectin, and a mix of both). Solid-state fermentation process (SSF) was conducted at 30 °C under 60-vvm aeration for 96 h in a pilot scale. Production of AMG and exo-PG was significantly affected by the fungal strain and the type of inoculum, but inducers did not trigger any significant effect, an evidence of the fact that these enzymes are constitutive. The maximum activity of exo-PG was 84 U g dm -1 whereas the maximum yield of AMG was 886.25 U g dm -1 .

A Transcriptome Meta-Analysis Proposes Novel Biological Roles for the Antifungal Protein AnAFP in Aspergillus niger.

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Norman Paege

Full Text Available Understanding the genetic, molecular and evolutionary basis of cysteine-stabilized antifungal proteins (AFPs from fungi is important for understanding whether their function is mainly defensive or associated with fungal growth and development. In the current study, a transcriptome meta-analysis of the Aspergillus niger γ-core protein AnAFP was performed to explore co-expressed genes and pathways, based on independent expression profiling microarrays covering 155 distinct cultivation conditions. This analysis uncovered that anafp displays a highly coordinated temporal and spatial transcriptional profile which is concomitant with key nutritional and developmental processes. Its expression profile coincides with early starvation response and parallels with genes involved in nutrient mobilization and autophagy. Using fluorescence- and luciferase reporter strains we demonstrated that the anafp promoter is active in highly vacuolated compartments and foraging hyphal cells during carbon starvation with CreA and FlbA, but not BrlA, as most likely regulators of anafp. A co-expression network analysis supported by luciferase-based reporter assays uncovered that anafp expression is embedded in several cellular processes including allorecognition, osmotic and oxidative stress survival, development, secondary metabolism and autophagy, and predicted StuA and VelC as additional regulators. The transcriptomic resources available for A. niger provide unparalleled resources to investigate the function of proteins. Our work illustrates how transcriptomic meta-analyses can lead to hypotheses regarding protein function and predict a role for AnAFP during slow growth, allorecognition, asexual development and nutrient recycling of A. niger and propose that it interacts with the autophagic machinery to enable these processes.

A Transcriptome Meta-Analysis Proposes Novel Biological Roles for the Antifungal Protein AnAFP in Aspergillus niger.

Science.gov (United States)

Paege, Norman; Jung, Sascha; Schäpe, Paul; Müller-Hagen, Dirk; Ouedraogo, Jean-Paul; Heiderich, Caroline; Jedamzick, Johanna; Nitsche, Benjamin M; van den Hondel, Cees A; Ram, Arthur F; Meyer, Vera

2016-01-01

Understanding the genetic, molecular and evolutionary basis of cysteine-stabilized antifungal proteins (AFPs) from fungi is important for understanding whether their function is mainly defensive or associated with fungal growth and development. In the current study, a transcriptome meta-analysis of the Aspergillus niger γ-core protein AnAFP was performed to explore co-expressed genes and pathways, based on independent expression profiling microarrays covering 155 distinct cultivation conditions. This analysis uncovered that anafp displays a highly coordinated temporal and spatial transcriptional profile which is concomitant with key nutritional and developmental processes. Its expression profile coincides with early starvation response and parallels with genes involved in nutrient mobilization and autophagy. Using fluorescence- and luciferase reporter strains we demonstrated that the anafp promoter is active in highly vacuolated compartments and foraging hyphal cells during carbon starvation with CreA and FlbA, but not BrlA, as most likely regulators of anafp. A co-expression network analysis supported by luciferase-based reporter assays uncovered that anafp expression is embedded in several cellular processes including allorecognition, osmotic and oxidative stress survival, development, secondary metabolism and autophagy, and predicted StuA and VelC as additional regulators. The transcriptomic resources available for A. niger provide unparalleled resources to investigate the function of proteins. Our work illustrates how transcriptomic meta-analyses can lead to hypotheses regarding protein function and predict a role for AnAFP during slow growth, allorecognition, asexual development and nutrient recycling of A. niger and propose that it interacts with the autophagic machinery to enable these processes.

Quantitative iTRAQ secretome analysis of Aspergillus niger reveals novel hydrolytic enzymes.

Science.gov (United States)

Adav, Sunil S; Li, An A; Manavalan, Arulmani; Punt, Peter; Sze, Siu Kwan

2010-08-06

The natural lifestyle of Aspergillus niger made them more effective secretors of hydrolytic proteins and becomes critical when this species were exploited as hosts for the commercial secretion of heterologous proteins. The protein secretion profile of A. niger and its mutant at different pH was explored using iTRAQ-based quantitative proteomics approach coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS). This study characterized 102 highly confident unique proteins in the secretome with zero false discovery rate based on decoy strategy. The iTRAQ technique identified and relatively quantified many hydrolyzing enzymes such as cellulases, hemicellulases, glycoside hydrolases, proteases, peroxidases, and protein translocating transporter proteins during fermentation. The enzymes have potential application in lignocellulosic biomass hydrolysis for biofuel production, for example, the cellulolytic and hemicellulolytic enzymes glucan 1,4-alpha-glucosidase, alpha-glucosidase C, endoglucanase, alpha l-arabinofuranosidase, beta-mannosidase, glycosyl hydrolase; proteases such as tripeptidyl-peptidase, aspergillopepsin, and other enzymes including cytochrome c oxidase, cytochrome c oxidase, glucose oxidase were highly expressed in A. niger and its mutant secretion. In addition, specific enzyme production can be stimulated by controlling pH of the culture medium. Our results showed comprehensive unique secretory protein profile of A. niger, its regulation at different pH, and the potential application of iTRAQ-based quantitative proteomics for the microbial secretome analysis.

Estresse salino na germinação de sementes e desenvolvimento de plântulas de niger (Guizotia abyssinica (L.f. Cass. Salt stress on seeds germination and seedlings development of niger (Guizotia abyssinica (L.f. Cass.

Directory of Open Access Journals (Sweden)

Carla Regina Baptista Gordin

2012-12-01

Full Text Available O processo de salinização dos solos e das águas subterrâneas e superficiais é um dos mais importantes problemas de degradação ambiental. O niger é uma herbácea anual com potencial para a produção de biodiesel, cujo comportamento em condições salinas ainda é desconhecido. Dessa forma, objetivou-se avaliar a germinação de sementes e crescimento de plântulas de niger submetidos a diferentes sais e concentrações. Os tratamentos utilizados corresponderam a três sais: cloreto de potássio (KCl, cloreto de cálcio (CaCl2 e cloreto de sódio (NaCl, associados a quatro potenciais osmóticos (-0,3; -0,6; -0,9 e -1,2 MPa. As sementes de niger semeadas diretamente sobre substrato umedecido com água destilada constituíram o controle. O efeito da salinidade na germinação das sementes foi avaliado pela porcentagem, tempo médio e índice de velocidade. As plântulas foram analisadas quanto ao comprimento da parte aérea e raiz e massas fresca e seca de plântulas inteiras. O delineamento estatístico adotado foi o inteiramente casualizado, constituindo-se de um fatorial 3x5 (sais x potenciais osmóticos com quatro repetições de 50 sementes cada. As sementes de niger são sensíveis a salinidade. A exposição ao NaCl, KCl e CaCl2 a partir do potencial osmótico de -0,3 MPa reduz o poder germinativo e o crescimento de plântulas. Os sais inibem a germinação de sementes do niger no potencial de -1,2 MPa.The soil, and subterranean and superficial water saltiness process is one of the most important environment degradation problems. Niger is an annual herbaceous with biodiesel production potential, which seeds behavior is unknown in saline conditions. In this way, this work aimed to evaluate the niger seeds germination and initial seedlings growth submitted to different salt solutions. The treatments used constituted of three types of salts: NaCl, KCl and CaCl2 at four osmotic potentials (-0.3; -0.6; -0.9 e -1.2 MPa. The niger seeds

Comparative genomics of citric-acid-producing Aspergillus niger ATCC 1015 versus enzyme-producing CBS 513.88

DEFF Research Database (Denmark)

Andersen, Mikael Rørdam; Salazar, Margarita Pena; Schaap, Peter J.

2011-01-01

The filamentous fungus Aspergillus niger exhibits great diversity in its phenotype. It is found globally, both as marine and terrestrial strains, produces both organic acids and hydrolytic enzymes in high amounts, and some isolates exhibit pathogenicity. Although the genome of an industrial enzyme......-producing A. niger strain (CBS 513.88) has already been sequenced, the versatility and diversity of this species compel additional exploration. We therefore undertook whole-genome sequencing of the acidogenic A. niger wild-type strain (ATCC 1015) and produced a genome sequence of very high quality. Only 15...

Comparative genomics and transcriptome analysis of Aspergillus niger and metabolic engineering for citrate production

Science.gov (United States)

Yin, Xian; Shin, Hyun-dong; Li, Jianghua; Du, Guocheng; Liu, Long; Chen, Jian

2017-01-01

Despite a long and successful history of citrate production in Aspergillus niger, the molecular mechanism of citrate accumulation is only partially understood. In this study, we used comparative genomics and transcriptome analysis of citrate-producing strains—namely, A. niger H915-1 (citrate titer: 157 g L−1), A1 (117 g L−1), and L2 (76 g L−1)—to gain a genome-wide view of the mechanism of citrate accumulation. Compared with A. niger A1 and L2, A. niger H915-1 contained 92 mutated genes, including a succinate-semialdehyde dehydrogenase in the γ-aminobutyric acid shunt pathway and an aconitase family protein involved in citrate synthesis. Furthermore, transcriptome analysis of A. niger H915-1 revealed that the transcription levels of 479 genes changed between the cell growth stage (6 h) and the citrate synthesis stage (12 h, 24 h, 36 h, and 48 h). In the glycolysis pathway, triosephosphate isomerase was up-regulated, whereas pyruvate kinase was down-regulated. Two cytosol ATP-citrate lyases, which take part in the cycle of citrate synthesis, were up-regulated, and may coordinate with the alternative oxidases in the alternative respiratory pathway for energy balance. Finally, deletion of the oxaloacetate acetylhydrolase gene in H915-1 eliminated oxalate formation but neither influence on pH decrease nor difference in citrate production were observed. PMID:28106122

Germination of Aspergillus niger conidia is triggered by nitrogen compounds related to L-amino acids.

Science.gov (United States)

Hayer, Kimran; Stratford, Malcolm; Archer, David B

2014-10-01

Conidial germination is fundamentally important to the growth and dissemination of most fungi. It has been previously shown (K. Hayer, M. Stratford, and D. B. Archer, Appl. Environ. Microbiol. 79:6924-6931, 2013, http://dx.doi.org/10.1128/AEM.02061-13), using sugar analogs, that germination is a 2-stage process involving triggering of germination and then nutrient uptake for hyphal outgrowth. In the present study, we tested this 2-stage germination process using a series of nitrogen-containing compounds for the ability to trigger the breaking of dormancy of Aspergillus niger conidia and then to support the formation of hyphae by acting as nitrogen sources. Triggering and germination were also compared between A. niger and Aspergillus nidulans using 2-deoxy-D-glucose (trigger), D-galactose (nontrigger in A. niger but trigger in A. nidulans), and an N source (required in A. niger but not in A. nidulans). Although most of the nitrogen compounds studied served as nitrogen sources for growth, only some nitrogen compounds could trigger germination of A. niger conidia, and all were related to L-amino acids. Using L-amino acid analogs without either the amine or the carboxylic acid group revealed that both the amine and carboxylic acid groups were essential for an L-amino acid to serve as a trigger molecule. Generally, conidia were able to sense and recognize nitrogen compounds that fitted into a specific size range. There was no evidence of uptake of either triggering or nontriggering compounds over the first 90 min of A. niger conidial germination, suggesting that the germination trigger sensors are not located within the spore. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Gluconate formation and polyol metabolism in Aspergillus niger

NARCIS (Netherlands)

Witteveen, C.F.B.

1993-01-01

The capacity of A.niger to accumulate metabolites is remarkable. Under all conditions polyols accumulate in the cell and when mycelium in later developmental stages is considered, depending on the carbon source, aeration and external pH, polyols

Lipids of marine origin: the rudderfish (Centrolophus niger)

CSIR Research Space (South Africa)

De Koning, AJ

2006-01-01

Full Text Available Muscle of rudderfish (centrolophus niger), or black ruff, a rare mesopelagic fish caught in the South Atlantic, was found to contain 19.3% total lipids. The major part of the lipids (~70%) was unusual in not yielding glycerol but non...

Effect of temperature and water activity on the production of fumonisins by Aspergillus niger and different Fusarium species

DEFF Research Database (Denmark)

Mogensen, Jesper Mølgaard; Nielsen, Kristian Fog; Samson, Robert A.

2009-01-01

Background Fumonisins are economically important mycotoxins which until recently were considered to originate from only a few Fusarium species. However recently a putative fumonisin gene cluster was discovered in two different Aspergillus niger strains followed by detection of an actual fumonisin B......2 (FB2) production in four strains of this biotechnologically important workhorse. Results In the present study, a screening of 5 A. niger strains and 25 assumed fumonisin producing Fusarium strains from 6 species, showed that all 5 A. niger strains produced FB2 and 23 of 25 Fusarium produced...... fumonisin B1 and other isoforms (fumonisin B2 and B3). Five A. niger and five Fusarium spp. were incubated at six different temperatures from 15-42°C on Czapek Yeast Agar +5% salt or Potato Dextrose Agar. A. niger had the highest production of FB2 at 25-30°C whereas Fusarium spp. had the maximal production...

Assessing transportation and road conditions in niger state, nigeria ...

African Journals Online (AJOL)

Assessing transportation and road conditions in niger state, nigeria using geoinformatics, with focus on impact of climate ... Also the impacts of climate change on transportation were highlighted. ... EMAIL FULL TEXT EMAIL FULL TEXT

Hyphal heterogeneity in Aspergillus niger

OpenAIRE

de Bekker, A.M.

2011-01-01

Mycelial fungi use hyphae to colonize substrates. These hyphae secrete enzymes that convert complex polymers into breakdown products that can be taken up to serve as nutrients. Using GFP as a reporter it has been shown that exploring hyphae of Aspergillus niger are heterogenic with respect to expression of the glucoamylase gene glaA; some hyphae strongly express the glucoamylase gene glaA, while others express it lowly. This was a surprising finding considering the fact that all hyphae were e...

Surface Modified Long Period Fiber Grating Sensor for Rapid Detection of Aspergillus Niger Fungal Spores

Science.gov (United States)

Gambhir, Monika; Gupta, Shilpi; John, Priya; Mahakud, Ramakanta; Kumar, Jitendra; Prakash, Om

2018-03-01

We present development of a compact and label-free sensor based on the surface modification of copper vapor laser fabricated long period fiber gratings for detection of airborne Aspergillus niger (A. niger) fungal spores. Surface of sensors were functionalized with monoclonal glucose oxidases IgG1 for target-specific covalent binding. In process of functionalization and binding of 103 cfu/ml of pathogenic A. niger fungal spores, notable shorter wave transition in resonance wavelength from 1562.93 nm to 1555.97 nm, and significant reduction in peak loss from 61.72 dB to 57.48 dB were recorded. The implementation was cost effective and yielded instantaneous results.

GRACE Detected Rise of Groundwater in the Sahelian Niger River Basin

Science.gov (United States)

Werth, S.; White, D.; Bliss, D. W.

2017-12-01

West African regions along the Niger River experience climate and land cover changes that affect hydrological processes and therewith the distribution of fresh water resources (WR). This study provides an investigation of long-term changes in terrestrial water storages (TWS) of the Niger River basin and its subregions by analyzing a decade of satellite gravity data from the Gravity Recovery and Climate Experiment (GRACE) mission. The location of large trends in TWS maps of differently processed GRACE solutions points to rising groundwater stocks. Soil moisture data from a global land surface model allow separating the effect of significantly increasing amount of WR from that of TWS variations. Surface water variations from a global water storage model validated with observations from altimetry data were applied to estimate the groundwater component in WR. For the whole Niger, a rise in groundwater stocks is estimated to be 93 ± 61 km3 between January 2003 and December 2013. A careful analysis of uncertainties in all data sets supports the significance of the groundwater rise. Our results confirm previous observations of rising water tables, indicating that effects of land cover changes on groundwater storage are relevant on basin scales. Areas with rising water storage are stocking a comfortable backup to mitigate possible future droughts and to deliver water to remote areas. This has implications for Niger water management strategies. Increasing groundwater recharges may be accompanied by reduction in water quality. This study helps to inform authority's decision to mitigate its negative impacts on local communities.

Fungal bioleaching of WPCBs using Aspergillus niger: Observation, optimization and kinetics.

Science.gov (United States)

Faraji, Fariborz; Golmohammadzadeh, Rabeeh; Rashchi, Fereshteh; Alimardani, Navid

2018-07-01

In this study, Aspergillus niger (A. niger) as an environmentally friendly agent for fungal bioleaching of waste printed circuit boards (WPCBs) was employed. D-optimal response surface methodology (RSM) was utilized for optimization of the bioleaching parameters including bioleaching method (one step, two step and spent medium) and pulp densities (0.5 g L -1 to 20 g L -1 ) to maximize the recovery of Zn, Ni and Cu from WPCBs. According to the high performance liquid chromatography analysis, citric, oxalic, malic and gluconic acids were the most abundant organic acids produced by A.niger in 21 days experiments. Maximum recoveries of 98.57% of Zn, 43.95% of Ni and 64.03% of Cu were achieved based on acidolysis and complexolysis dissolution mechanisms of organic acids. Based on the kinetic studies, the rate controlling mechanism for Zn dissolution at one step approach was found to be diffusion through liquid film, while it was found to be mixed control for both two step and spent medium. Furthermore, rate of Cu dissolution which is controlled by diffusion in one step and two step approaches, detected to be controlled by chemical reaction at spent medium. It was shown that for Ni, the rate is controlled by chemical reaction for all the methods studied. Eventually, it was understood that A. niger is capable of leaching 100% of Zn, 80.39% of Ni and 85.88% of Cu in 30 days. Copyright © 2018 Elsevier Ltd. All rights reserved.

Cytosolic streaming in vegetative mycelium and aerial structures of Aspergillus niger.

Science.gov (United States)

Bleichrodt, R; Vinck, A; Krijgsheld, P; van Leeuwen, M R; Dijksterhuis, J; Wösten, H A B

2013-03-15

Aspergillus niger forms aerial hyphae and conidiophores after a period of vegetative growth. The hyphae within the mycelium of A. niger are divided by septa. The central pore in these septa allows for cytoplasmic streaming. Here, we studied inter- and intra-compartmental streaming of the reporter protein GFP in A. niger. Expression of the gene encoding nuclear targeted GFP from the gpdA or glaA promoter resulted in strong fluorescence of nuclei within the vegetative hyphae and weak fluorescence in nuclei within the aerial structures. These data and nuclear run on experiments showed that gpdA and glaA are higher expressed in the vegetative mycelium when compared to aerial hyphae, conidiophores and conidia. Notably, gpdA or glaA driven expression of the gene encoding cytosolic GFP resulted in strongly fluorescent vegetative hyphae and aerial structures. Apparently, GFP streams from vegetative hyphae into aerial structures. This was confirmed by monitoring fluorescence of photo-activatable GFP (PA-GFP). In contrast, PA-GFP did not stream from aerial structures to vegetative hyphae. Streaming of PA-GFP within vegetative hyphae or within aerial structures of A. niger occurred at a rate of 10-15 μm s(-1). Taken together, these results not only show that GFP streams from the vegetative mycelium to aerial structures but it also indicates that its encoding RNA is not streaming. Absence of RNA streaming would explain why distinct RNA profiles were found in aerial structures and the vegetative mycelium by nuclear run on analysis and micro-array analysis.

Genetic and phenotypic diversity of naturally isolated wild strains of Aspergillus niger with hyper glucose oxidase production

Directory of Open Access Journals (Sweden)

MAHMOUD EL-HARIRI

2015-12-01

Full Text Available Glucose oxidase (GOx is the basic stone for many of biological industry worldwide. The improvement of GOx production basically depends on selection of hyper producer strain of Aspergillus niger. Selective isolation and screening for natural hyper producer strains of A. niger and sequence analysis of the GOD gene, which is responsible for production of the enzyme, are very effective approaches to investigate the naturally modified strains of A. niger with hyper productive capacity of GOx enzyme. The aims of the current study were selective isolation of naturally hyper GOx producing strains of A. niger and evaluation of their GOx activities under optimized parameters in the laboratory. Five wild Egyptian isolates of A. niger were screened for GOx and catalase activity using two types of modified basal liquid media. The GOx activity was evaluated by high throughout liquid phase system. The isolates showed a variable activity for GOx production ranged from 0 to 28.7 U.ml-1. One isolate coded Strain 7 was negative GOx producer on Vogel's broth medium in comparison to other isolates, while its GOx activity on Cazpek Dox was considered as positive (7.28 U.ml-1. It was concluded that GOx production is affected by three controllable factors – the basal media components, time of incubation, and the strain with its adaption to the media components‎. Also, the catalase activity was tested and it was produced with a different degree of variability, which may be reflected on GOx stability. GOD genes of these wild variant of A. niger were cloned and sequenced to determine intraspecies diversity of GOD between the wild variants. The comparison of isolated wild variants to other reference hyper GOx producer strains of A. niger was performed to determine if the GOD sequence analysis of these strains can be distinguished based on their GOx activity. This is the first report for isolation and detection of naturally A. niger hyper GOx-producer strains with

Nutritive Value of Fermented Water Hyacinth (Eichornia crassipes Leaf with Aspergillus niger in Tegal Duck

Directory of Open Access Journals (Sweden)

I Mangisah

2010-05-01

Full Text Available Two steps of experiment were conducted to evaluate the proximate composition and nutritive value of fermented water hyacinth leaf (WHL with Aspergillus niger in Tegal duck. Twenty two heads of eight-week Tegal ducks with an average body weight of 1202.55 + 111.14 g were used in this experiment. There were two treatments namely: non-fermented (NFWH and fermented with Aspergillus niger (FWHAN. Each treatment was replicated 10 times. Data gathered were analyzed using t-student test. The proximate composition between NFWH and FWHAN showed an increase in crude protein/CP (11.44 vs 16.09% and ash (12.76 vs 22.37% but a decrease in crude fiber/CF (21.51 vs 16.62% and nitrogen free extract/NFE (53.20 vs 43.59%. The nutritive value of diet for eight-week Tegal ducks showed that fermentation of WHL with Aspergillus niger significantly increased CP digestibility, true metabolizable energy (TME and nitrogen retention (NR, but not for CF digestibility. It could be concluded that fermentation of WHL with Aspergillus niger increases the nutrient quality and the nutritive value of diet for eight-week Tegal ducks in term of CP digestibility, TME and NR. (Animal Production 12(2: 100-104 (2010Key Words: water hyacinth leaf, fermentation, Aspergillus niger, biological value, Tegal ducks

Pattern of Complicated Unsafe Abortions in Niger Delta University ...

African Journals Online (AJOL)

Alasia Datonye

of cases of complicated unsafe abortion managed at the. Niger Delta University ... previous termination of pregnancy and 87.3% of the patients had ... and outcome were obtained. ... life-threatening complications, post- abortion family planning.

The correlation between mannanase and cellulase activities towards fibre content of palm oil sludge fermented with Aspergillus niger

Directory of Open Access Journals (Sweden)

T. Purwadaria

1998-12-01

Full Text Available Enzyme (mannanase and cellulase activities and fibre (hemicellulose, cellulose and lignin contents were determined during the fermentation course of palm oil sludge with Aspergillus niger TL (wild type and A. niger ES I (an asporogenous mutant. The analyses were carried out at the incubation time of 3 and 4 days of aerobic fennentation and at 2 days of anaerobic fermentation afterward. The correlations between mamlanase activity with hemicellulose content and cellulose activity with cellulose content were calculated by linear regression . The activities of matutanase and cellulase are increasing during the aerobic fennentation, while in the anaerobic fennentation the enzyme activities are decreasing due to instability of the enzymes. The enzyme activities of ESI are higher than the TL. The regression coefficient is highly significant for correlation between mamlanase and hemicellulose content of fermented product by ESI (r = 0.83; P0 .05 . Marutanase and cellulase activities were also detected after the fermented product dried at 60°C which indicated the enzymes are quite stable .

Exploiting proteomic data for genome annotation and gene model validation in Aspergillus niger

OpenAIRE

Wright, James C.; Sugden, Deana; Francis-McIntyre, Sue; Riba Garcia, Isabel; Gaskell, Simon J.; Grigoriev, Igor V.; Baker, Scott E.; Beynon, Robert J.; Hubbard, Simon J.

2009-01-01

Abstract Background Proteomic data is a potentially rich, but arguably unexploited, data source for genome annotation. Peptide identifications from tandem mass spectrometry provide prima facie evidence for gene predictions and can discriminate over a set of candidate gene models. Here we apply this to the recently sequenced Aspergillus niger fungal genome from the Joint Genome Institutes (JGI) and another predicted protein set from another A.niger sequence. Tandem mass spectra (MS/MS) were ac...

cellulase and pectinase production potentials of aspergillus niger

African Journals Online (AJOL)

Prof Oyeleke

Production of pectinase and cellulase by Aspergillus niger from corn cob was examined. ... organism was screened for enzymatic activity using Carboxyl Methyl ... preparation of denim fabrics in textile industries, ... exploitation of cellulase is its high cost of production ... catabolite repression influence economics of cellulase.

Phonology and Morphology of Mambay (Niger-Congo, Adamawa)

NARCIS (Netherlands)

Anonby, Erik John

2008-01-01

Mambay is an Adamawa (Niger-Congo) language spoken by 15,000 people in Chad and Cameroon. The study opens with historical and linguistic background. A phonological inventory of the language is then presented and distribution patterns are examined. Some striking phenomena include a profoundly

Characterization of the Aspergillus niger prtT, a unique regulator of extracellular protease encoding genes

NARCIS (Netherlands)

Punt, P.J.; Schuren, F.H.J.; Lehmbeck, J.; Christensen, T.; Hjort, C.; Hondel, C.A.M.J.J. van den

2008-01-01

Expression of several Aspergillus niger genes encoding major secreted, but not vacuolar, protease genes including the major acid protease gene pepA, was shown to be affected in the previously isolated A. niger protease mutant, AB1.13 [Mattern, I.E., van Noort, J.M., van den Berg, P., Archer, D.A.,

Aye-aye population genomic analyses highlight an important center of endemism in northern Madagascar.

Science.gov (United States)

Perry, George H; Louis, Edward E; Ratan, Aakrosh; Bedoya-Reina, Oscar C; Burhans, Richard C; Lei, Runhua; Johnson, Steig E; Schuster, Stephan C; Miller, Webb

2013-04-09

We performed a population genomics study of the aye-aye, a highly specialized nocturnal lemur from Madagascar. Aye-ayes have low population densities and extensive range requirements that could make this flagship species particularly susceptible to extinction. Therefore, knowledge of genetic diversity and differentiation among aye-aye populations is critical for conservation planning. Such information may also advance our general understanding of Malagasy biogeography, as aye-ayes have the largest species distribution of any lemur. We generated and analyzed whole-genome sequence data for 12 aye-ayes from three regions of Madagascar (North, West, and East). We found that the North population is genetically distinct, with strong differentiation from other aye-ayes over relatively short geographic distances. For comparison, the average FST value between the North and East aye-aye populations--separated by only 248 km--is over 2.1-times greater than that observed between human Africans and Europeans. This finding is consistent with prior watershed- and climate-based hypotheses of a center of endemism in northern Madagascar. Taken together, these results suggest a strong and long-term biogeographical barrier to gene flow. Thus, the specific attention that should be directed toward preserving large, contiguous aye-aye habitats in northern Madagascar may also benefit the conservation of other distinct taxonomic units. To help facilitate future ecological- and conservation-motivated population genomic analyses by noncomputational biologists, the analytical toolkit used in this study is available on the Galaxy Web site.

Ordinance No. 87-015, Economic and Social Development Plan of Niger, 1987-1991, 30 April 1987.

Science.gov (United States)

1987-01-01

This document contains major provisions of the Economic and Social Development Plan of Niger (1987-91) and Niger's 1987 Ordinance No. 87-16 containing the National Charter. The development plan notes the problems attendant upon Niger's population growth and calls for voluntary, not coercive, measures to manage population growth. A program of action is outlined that involves a reduction in mortality and morbidity, an emphasis on family planning programs, demographic research and education, and provision of population information. The reprinted portions of Niger's National Charter define national unity; call for improvement in the status and education of women; and guarantee freedom of movement and of residence as well as the right to education and to health. Specific actions sought include making basic education obligatory, improving literacy, protecting health by increasing life expectancy and improving quality of life, protecting the family, protecting the handicapped and the aged, and providing sex education for young people. The foundation of the population policy of Niger will be to improve living conditions and the health of the people. Efforts will be made to allow women to master the appropriate technologies to lighten the burden of their domestic work and free them for training activities. Specific actions are delineated to protect agricultural resources, reduce desertification, improve housing conditions, and address urbanization.

Community participation and environmental decision-making in the Niger Delta

International Nuclear Information System (INIS)

Adomokai, Rosemary; Sheate, William R.

2004-01-01

The participation of communities in the process of environmental decision-making in Nigeria and the Niger Delta region in particular is a relatively new process. There are many practical problems ranging from financial support, methods used and the willingness of identified stakeholders to participate. This paper seeks to highlight recent developments in community participation and environmental decision-making in the Niger Delta, using the EIA Decree of 1992 as a reference point. The EIA Decree of 1992 is the only legislation that refers to participation of the communities when environmental decisions are being made. The study reported here aimed to examine differences and similarities between the identified stakeholders interviewed in the research, in order to highlight areas of improvement that will encourage positive changes to the process and foster better relations between the stakeholders. The paper provides a brief background to community participation in the Niger Delta region and reports on the research approach adopted. Interviews with stakeholders in the EIA process were undertaken to provide a better understanding of public participation in practice under the EIA Decree. While participation was found to be now firmly on the agenda, there is still much to do to engender greater awareness of EIA and the potential benefits participation can hold

Chronic necrotising pneumonia caused by Aspergillus niger.

Science.gov (United States)

Wiggins, J; Clark, T J; Corrin, B

1989-01-01

A woman with asthma developed chronic necrotising semi-invasive pneumonia due to mixed Aspergillus niger and Candida albicans infection; though not severely immunosuppressed, she may have been predisposed by long term oral corticosteroid and recurrent oral antibiotic treatment. The diagnosis should be considered in patients with chronic airflow limitation who develop cavitating pneumonia. Images PMID:2763249

Assessment of the pectinolytic network of Aspergillus niger by functional genomics : insights from the transcriptome

NARCIS (Netherlands)

Martens-Uzunova, E.S.

2008-01-01

More than a century ago, in 1889, A. Fernbach presented a detailed report about the invertase of Aspergillus niger in the third edition of “Annales De L'institut Pasteur”. Since then, many of the enzymes secreted by A. niger have found a broad range of applications, and today they are produced on an

BIOSORPSI DAN REDUKSI KROM LIMBAH PENYAMAKAN KULIT DENGAN BIOMASSA Fusarium sp DAN Aspergillus niger (Biosorpstion and Reduction of Chromium Bearing Tannery Wastewater Using The Biomass of Fusarium Sp. and Aspergillus niger

Directory of Open Access Journals (Sweden)

Suharjono Triatmojo

2001-08-01

Full Text Available ABSTRAK Tujuan penelitian ini ialah untuk membuktikan bahwa biomassa Fusarium sp dapat mereduksi Cr(VI, dan biomassa Aspergillus niger dapat digunakan untuk mengambil ion krom dari larutan. Fusarium.sp ditumbuhkan pada media cair kentang dekftosa cair, ditambah K2Cr2O7 atau sludge limbah penyamakan kulit. Selanjutnya diamati perubahan warnanya, bila terjadi perubahan warna dan oranye ke ungu atau tak berwarna maka telah terjadi reduksi krom valensi VI menjadi krom valensi Ill. Aspergillus niger ditumbuhkan pada media Potato dectrose agar (PDA padat, dipindahkan ke media cair yang bensi bakto pepton, bakto dektrose dan srukronutrien. Produksi biomassa dilakukan pada labu erlenmeyer; setelah 5 hari dipanen dan dibuat bubuk. Bubuk ini digunakan untuk mengambil krom dari larutan. Hasil penelitian menunjukkan bahwa biomassa Fusarium sp dapat digunakan untuk mengambil krom dan larutan yang.mengandung KrCrrO, atau sludge limbah penyamakan kulit. Waktu inkubasi yang lebih lama meningkatkan absorbsi krom oleh biomassa Fascrium sp. Fusarium sp mampu mereduksi Cr(VI menjadi Cr(Iii. Biomassa Aspergillus niger dapat digunakan untuk mengambil krom dari larutan. Hasil terbaik diperoleh pada konsentrasi awal 100 mg/I, pada pH 2,0, berat biomassa 0,1 g, dan waktu kontak 12 jam, yaitu 96,23% untuk Cr(II| dan96,3 % untuk Cr(VI. Fusarium sp. dan A. niger dapat digunakan sebagai bioremediator dalam penanganan limbah penyamakan kulit secara biologi.   ABSTRACT The objectives of this research was to study the biosorption and reduction of chromium bearing tannery wastewater using biomass of Fusarium sp and Aspergillus niger. Fusarium sp was used to investigate bioaccumulation and reduction of chromium in K2 Cr2O7 solution and solution containing sludge of leather tanning waste, and aspergillus niger was used to investigate biosorption of Cr(III and Cr(VI in solution. Fusarium sp was grown on sterilized potato extrose liquid medium, added with K2Cr2O7solution or sludge

Actual Uranium Exploration and Mining Activities in Niger

International Nuclear Information System (INIS)

Kache, Mamane

2014-01-01

Conclusion: Since the Fukushima nuclear power plant accident in 2011, many mining companies are not interested in uranium. It leads to the decrease in uranium spot price and the delay of IMOURAREN Project. Only, 47 exploration licenses for 12 mining companies are now valid in Niger.

Growth and hydrolase profiles can be used as characteristics to distinguish Aspergillus niger and other black aspergilli

Science.gov (United States)

Meijer, M.; Houbraken, J.A.M.P.; Dalhuijsen, S.; Samson, R.A.; de Vries, R.P.

2011-01-01

Wild type Aspergillus niger isolates from different biotopes from all over the world were compared to each other and to the type strains of other black Aspergillus species with respect to growth and extracellular enzyme profiles. The origin of the A. niger isolate did not result in differences in growth profile with respect to monomeric or polymeric carbon sources. Differences were observed in the growth rate of the A. niger isolates, but these were observed on all carbon sources and not specific for a particular carbon source. In contrast, carbon source specific differences were observed between the different species. Aspergillus brasiliensis is the only species able to grow on D-galactose, and A. aculeatus had significantly better growth on Locus Bean gum than the other species. Only small differences were found in the extracellular enzyme profile of the A. niger isolates during growth on wheat bran, while large differences were observed in the profiles of the different black aspergilli. In addition, differences were observed in temperature profiles between the black Aspergillus species, but not between the A. niger isolates, demonstrating no isolate-specific adaptations to the environment. These data indicate that the local environment does not result in stable adaptations of A. niger with respect to growth profile or enzyme production, but that the potential is maintained irrespective of the environmental parameters. It also demonstrates that growth, extracellular protein and temperature profiles can be used for species identification within the group of black aspergilli. PMID:21892240

Comparison of survivability of Staphylococcus aureus and spores of Aspergillus niger on commonly used floor materials.

Science.gov (United States)

Gupta, Mridula; Bisesi, Michael; Lee, Jiyoung

2017-07-01

The survivability of Staphylococcus aureus and spores of Aspergillus niger was compared on 5 common floor materials. Floor materials were inoculated with a known concentration of S aureus and spores of A niger on day 0. Their survivability was measured on days, 2, 7, 14, and 28 by bulk rinsate method and enumerated using culture-based method. The difference in change of S aureus levels was statistically significant for all tested days (P niger spores were undetected on residential broadloom carpet and rubber-backed commercial carpet after day 2 but survived on VCT, PT, and wood until day 28. Floor materials with hard and smooth surfaces, such as VCT and PT, can allow survival of S aureus and A niger for up to 4 weeks. It may imply that floor materials can play a major role in preserving microbial contaminants in the built environment. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Effect of gamma irradiation on aspergillus niger for enhanced production of glucose oxidase

International Nuclear Information System (INIS)

Zia, M.A.; Rasul, S.

2012-01-01

Developing countries have a high prevalence of diabetes and their populations are suffering from associated adverse factors. Such a frequency requires more effective diagnosis, mostly achieved by glucose diagnostic kits. Although high priced kits are available in market but local production of such kits can be highly cost effective and may confer the decline in incidence of the disease. Glucose oxidase is the key enzyme for the determination of glucose in such analytical tools. Enhanced production of glucose oxidase was performed by mutagenesis of Aspergillus niger by gamma irradiation. A dose of 80 krad was found as optimum for derivation of positive mutant strains. Following the screening by triton X-100 and 2-deoxy-D-glucose, the selected strains A. niger G-80-A, A. niger G-80-B and A. niger G-80-C showed 27.5, 23.20 and 20.55 UmL/sub -1/ glucose oxidase activity in enzyme diffusion zone test; which is much higher to parental strain (7.5 UmL/sup -1/). A. niger G-80-A was subjected to submerged fermentation and obtained highest yields after 36 h, at CSL 2%, pH 6.5, 30 degree C, KH/sub 2/PO/sub 4/ 0.8% and urea 0.3%. Partial purification by ammonium sulfate resulted in 175 UmL/sup -1/ of glucose oxidase activity after dialysis. Kinetic parameters like optimum pH, temperature, K/sub m/ and V/sub max/ were found to be 6.0 (180 +- 2 UmL/sup -1/), 30 degree C (185 +- 0.5 UmL/sup -1/), 5.26 mM and 400 U mL/sup -1/, respectively. Active inhibition of the enzyme by increasing concentration of PLP in reaction mixture confirmed the presence of functional lysyl residue on the active site of enzyme. (author)

DEEP HANGING WALL TRAPS-THE REMAINING PROMISSING TARGETS FOR OIL EXPLORATION IN THE NIGER DELTA

International Nuclear Information System (INIS)

Oton, S.W

2004-01-01

It is well known that the most dominant types of Hydrocarbon types found in the petroliferous Niger Delta are the classical rollover anticlinical traps 'I of oil exploration in the delta, these easy-to-find rollover structures are getting exhausted. They are most numerous at shallow depths in the younger delta front sedimentary sequence. Generally, during this primary oil exploration stage, oil and gas exploration have been concentrated in the shallow depths where they are easy to reach, easy to explore and easy to produce. This means that the present and future exploration campaigns in the Niger Delta should be directed towards other types of hydrocarbon trapping mechanisms that have been mapped in the delta. Many exploration models have been used and oil has been found in at least nine types of traps in the Niger Delta. The contrary (or anitithetic) fault model was used at the close of the last century. This model is so called because the controlling antithetic fault has a regional dip contrary to the structure-building growth fault with which it is associated. These faults, which are widespread in the Niger Delta, are easy to map especially on the Petro geological model. In this period, several promising hydrocarbon accumulations trapped against antithetic faults were discovered and tested. These hydrocarbon targets also seem fully explored and exhausted now. Recently, from modern high resolution 2-D and 3-D seismic data a lot of good prospects have been mapped and drilled in the deep horizon. In the last few years, a lot of unexplored oil have been discovered and tested in the deep horizons. They are mostly in hanging wall traps, at depth below 4,000 meters. This shows that most of the remaining undiscovered hydrocarbons in the Niger Delta may well be in these deep hanging wall traps between 4,000 and close to 5,600 meters. A definite search for deep-seated hanging wall traps is therefore recommended in a bid to find more new reservoirs and thereby increase the

Transcriptomic comparison of Aspergillus niger growing on two different sugars reveals coordinated regulation of the secretory pathway

DEFF Research Database (Denmark)

Jørgensen, Thomas R; Goosen, Theo; Hondel, Cees A M J J van den

2009-01-01

BACKGROUND: The filamentous fungus, Aspergillus niger, responds to nutrient availability by modulating secretion of various substrate degrading hydrolases. This ability has made it an important organism in industrial production of secreted glycoproteins. The recent publication of the A. niger...... the physiology and transcriptome of A. niger growing at the same specific growth rate (0.16 h(-1)) on xylose or maltose in carbon-limited chemostat cultures. Transcription profiles were obtained using Affymetrix GeneChip analysis of six replicate cultures for each of the two growth-limiting carbon sources...

Morphological and genetic analyses of the first record of the Niger Hind, Cephalopholis nigri (Perciformes: Serranidae, in the Mediterranean Sea and of the African Hind, Cephalopholis taeniops, in Malta

Directory of Open Access Journals (Sweden)

Noel Vella

2016-11-01

Full Text Available Abstract Background Non-native marine species, including tropical eastern Atlantic fish species are on the increase in Malta, with shipping activities being the main vector for the movement of these alien species from the Atlantic into the Mediterranean Sea. This calls for cooperation and collaboration between various sea-users and researchers to ensure continuous monitoring of coastal biodiversity. Methods Research methods involving local fishermen cooperation in monitoring efforts to identify and track populations of alien species in the Central Mediterranean has led to new records for the genus Cephalopholis (Perciformes: Serranidae in Malta. Morphological characteristics, meristic counts and mitochondrial DNA sequences from specimens of both species sampled from Maltese waters were analysed to confirm their species identify accurately, essential for tracking their respective population expansions in the Mediterranean. Results and conclusion Results from this study have led to confirmation of the first record of the Niger Hind, Cephalopholis nigri (Günther, 1859, in the Mediterranean Sea and of the establishment of the African Hind, Cephalopholis taeniops (Valenciennes, 1828 in Maltese waters.

Influence of the mycelium growth conditions on the production of amylolytic, proteolytic and pectinolytic enzymes by Aspergillus niger C

Energy Technology Data Exchange (ETDEWEB)

Fiedurek, J.; Ilczuk, Z.; Lobarzewski, J. (Uniwersytet Marii Curie-Sklodowskiej, Lublin (Poland). Inst. Mikrobiologii i Biochemii)

1989-01-01

Various nitrogen and carbon sources, as well as natural products, were examined as inducers of the production of amylases, proteases and pectinases by A. niger C. A. niger C grown on wheat bran extract medium provided culture supernatants with the highest enzymatic activities. Some culture conditions, e.g. pH, medium temperature and time period of cultivation, were optimalized to improve the growth and enzyme biosynthesis by A. niger C. (orig.).

Traditional wrestling in Niger: between state voluntarism and ...

African Journals Online (AJOL)

Traditional wrestling occupies pride of place in Niger, compared to other sports and cultural activities. Interest in traditional wrestling is widespread among Nigériens from all walks of life: young men, adults, senior citizens, young women, mature women, adult men, handicapped persons, prisoners, peasant farmers, civil ...

Mantle electrical conductivity profile of Niger delta region

Indian Academy of Sciences (India)

The mantle electrical conductivity-depth profile of the Niger delta region in Nigeria has been determined using solar quiet day ionospheric current (Sq).The magnetometer data obtained in 2010 from geomagnetic stations installed in Lagos by magnetic dataset (MAGDAS) in 2008 and data from magnetometers installed in ...

Niger River Discharge and the Connection to the West African Monsoon Over the Last 25 kyr

Science.gov (United States)

Patten, J.; Marcantonio, F.; Slowey, N. C.; Schmidt, M. W.; Parker, A. O.; Thomas, D. J.

2016-12-01

The intensity of the West African monsoon is directly tied to the shifting of the Inter-Tropical Convergence Zone and global-scale climate variability. As the West African monsoon varies through time, it affects the precipitation that occurs within the Niger River basin and the Niger River's discharge into the eastern equatorial Atlantic Ocean. The accumulation of marine sediments on the continental slope offshore of the Niger Delta reflects these processes. We seek to better understand how related environmental processes have varied as climate and sea level changed during the latter part of the last glacial-interglacial cycle. Here we present results from our ongoing investigation of sediments collected offshore of the Niger Delta that reflect such changes. The concentrations of 230Th, 232Th, and 234U in the sediments have been measured and combined with ages from radiocarbon dates and planktonic foraminiferal δ18O stratigraphies to estimate how the rate of sediment accumulation has varied through time. This record is considered together with measurements of sediment CaCO3 content and grain-size distribution to better understand the relative importance of environmental processes that control the flux of sediments and thorium to the seafloor - scavenging by particles settling through the water column versus the transport of sediments downslope by turbidity flows. We present xs230Th-derived 232Th fluxes that we suggest approximate the amount of fine-grained detrital material delivered from the Niger River to our sites. We anticipate that the importance of these competing processes will vary as climate/sea-level change influences the flux of sediments from the Niger River and the transport of these sediments to the slope.

Deprivation and Resistance: Environmental Crisis, Political Action, and Conflict Resolution in the Niger Delta since the 1980s

Directory of Open Access Journals (Sweden)

David Aworawo

2013-05-01

Full Text Available The interlocking relationship between environmental degradation, poverty,and violent conflict has been a prominent theme contained within the literature on sustainable development and conflict resolution since the midtwentieth century. While some analysts have argued that violence has not been limited to the poor and deprived, many have concluded from various studies that the devastation of the environment, poverty, and conflict are inextricably intertwined. This article examines this theme by analyzing the pattern of violence and nature of conflict resolution in the oil-producing enclave of the Niger Delta in the past three decades. A report of the United Nations Environment Programme on parts of the Niger Delta published in August 2011 reveals that the area is one of the most intensely polluted in the world. The report confirms the conclusion of several other earlier reports on the Niger Delta, which state that activities relating to the exploitation of oil and gas have led to intense environmental pollution and extreme poverty and that those conditions have spawned violence. The article is exploratory and analytical. It draws from diverse sources, including government records and reports of intergovernmental and non-governmental organizations as well as oral information gathered by the author from fieldwork conducted across the Niger Delta between 2007 and 2012, to explore the nature of the Niger Delta crisis from the 1980s until the present. The article argues that environmental degradation is central to the Niger Delta crisis, as it has hampered rural economic activities and posed a threat to human security. The article concludes that the effective tackling of the environmental crisis in the Niger Delta would surely reduce poverty and violence in the area.

Analcite formation in the Agades Region (Niger)

International Nuclear Information System (INIS)

1966-06-01

A study based mainly upon field mapping and drill cores examination, followed by a laboratory survey allows us to support a genetic hypothesis upon the formation of analcime in the 'Continental intercalaire' of Agades (Niger). Analcime could be generated from an early diagenesis of argillaceous sediments influenced by high soda content fossil waters inside confined continental sedimentary basins. (authors) [fr

Oil, migration, and the political economy of HIV/AIDS prevention in Nigeria's Niger Delta.

Science.gov (United States)

Udoh, Isidore A

2013-01-01

In most of sub-Saharan Africa, HIV/AIDS is driven by endemic structural problems such as unemployment, poverty, forced migration, sexual exploitation, and concurrent sexual partnerships. In the Niger Delta of Nigeria, the epidemic is exacerbated by recurring regional conflict and negative environmental externalities resulting from 50 years of oil exploration. This article seeks to identify and analyze potential barriers to HIV/AIDS prevention and treatment from oil pollution and other environmental stressors in Nigeria's Niger Delta. We develop a conceptual framework to understand how oil politics and economic systems affect HIV risks in Nigeria. We then evaluate evidence of how environmental exposures can amplify risks. Using 10 semi-structured interviews, with 85 focus group participants, we test the argument that HIV transmission in the Niger Delta is related to a manipulative "divide and rule" power dynamic that characterizes multinational oil companies' role in shaping conflict contours in oil communities. Oil exploration destroys livelihoods, institutions, and values and forces impoverished and illiterate girls and women to migrate or be trafficked to urban centers as child laborers and sex workers. The elevated HIV/AIDS risk in the Niger Delta brings into focus the political economy of resource extraction, globalization, and indigenous, minority rights and struggles.

What are Pregnant Women in a Rural Niger Delta Community's ...

African Journals Online (AJOL)

Erah

Buchanan House, Glasgow Caledonian University Email: Caroline. ... exploratory qualitative study was carried out to identify pregnant women in a rural Niger Delta community's perceptions of ..... sometimes you stay for the whole day.

Quantifying the exposure of humans and the environment to oil pollution in the Niger Delta using advanced geostatistical techniques.

Science.gov (United States)

Obida, Christopher B; Alan Blackburn, G; Duncan Whyatt, J; Semple, Kirk T

2018-02-01

The Niger Delta is one of the largest oil producing regions of the world. Large numbers and volumes of oil spills have been reported in this region. What has not been quantified is the putative exposure of humans and/or the environment to this hydrocarbon pollution. In this novel study, advanced geostatistical techniques were applied to an extensive database of oil spill incidents from 2007 to 2015. The aims were to (i) identify and analyse spill hotspots along the oil pipeline network and (ii) estimate the exposure of the hydrocarbon pollution to the human population and the environment within the Niger Delta. Over the study period almost 90millionlitres of oil were released. Approximately 29% of the human population living in proximity to the pipeline network has been potentially exposed to oil contamination, of which 565,000 people live within high or very high spill intensity sectors. Over 1000km 2 of land has been contaminated by oil pollution, with broadleaved forest, mangroves and agricultural land the most heavily impacted land cover types. Proximity to the coast, roads and cities are the strongest spatial factors contributing to spill occurrence, which largely determine the accessibility of sites for pipeline sabotage and oil theft. Overall, the findings demonstrate the high levels of environmental and human exposure to hydrocarbon pollutants in the Niger Delta. These results provide evidence with which to spatially target interventions to reduce future spill incidents and mitigate the impacts of previous spills on human communities and ecosystem health. Copyright © 2017 Elsevier Ltd. All rights reserved.

Enhanced citrate production through gene insertion in Aspergillus niger

DEFF Research Database (Denmark)

Jongh, Wian de; Nielsen, Jens

2007-01-01

The effect of inserting genes involved in the reductive branch of the tricarboxylic acid (TCA) cycle on citrate production by Aspergillus niger was evaluated. Several different genes were inserted individually and in combination, i.e. malate dehydrogenase (mdh2) from Saccharomyces cerevisiae, two...

Improving cellulase production by Aspergillus niger using adaptive evolution

NARCIS (Netherlands)

Patyshakuliyeva, Aleksandrina; Arentshorst, Mark; Allijn, Iris E; Ram, Arthur F J; de Vries, Ronald P; Gelber, Isabelle Benoit

OBJECTIVES: To evaluate the potential of adaptive evolution as a tool in generating strains with an improved production of plant biomass degrading enzymes. RESULTS: An Aspergillus niger cellulase mutant was obtained by adaptive evolution. Physiological properties of this mutant revealed a five times

Recombinant bacterial hemoglobin alters metabolism of Aspergillus niger

DEFF Research Database (Denmark)

Hofmann, Gerald; Diano, Audrey; Nielsen, Jens

2009-01-01

, 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...

Expression-based clustering of CAZyme-encoding genes of Aspergillus niger.

Science.gov (United States)

Gruben, Birgit S; Mäkelä, Miia R; Kowalczyk, Joanna E; Zhou, Miaomiao; Benoit-Gelber, Isabelle; De Vries, Ronald P

2017-11-23

The Aspergillus niger genome contains a large repertoire of genes encoding carbohydrate active enzymes (CAZymes) that are targeted to plant polysaccharide degradation enabling A. niger to grow on a wide range of plant biomass substrates. Which genes need to be activated in certain environmental conditions depends on the composition of the available substrate. Previous studies have demonstrated the involvement of a number of transcriptional regulators in plant biomass degradation and have identified sets of target genes for each regulator. In this study, a broad transcriptional analysis was performed of the A. niger genes encoding (putative) plant polysaccharide degrading enzymes. Microarray data focusing on the initial response of A. niger to the presence of plant biomass related carbon sources were analyzed of a wild-type strain N402 that was grown on a large range of carbon sources and of the regulatory mutant strains ΔxlnR, ΔaraR, ΔamyR, ΔrhaR and ΔgalX that were grown on their specific inducing compounds. The cluster analysis of the expression data revealed several groups of co-regulated genes, which goes beyond the traditionally described co-regulated gene sets. Additional putative target genes of the selected regulators were identified, based on their expression profile. Notably, in several cases the expression profile puts questions on the function assignment of uncharacterized genes that was based on homology searches, highlighting the need for more extensive biochemical studies into the substrate specificity of enzymes encoded by these non-characterized genes. The data also revealed sets of genes that were upregulated in the regulatory mutants, suggesting interaction between the regulatory systems and a therefore even more complex overall regulatory network than has been reported so far. Expression profiling on a large number of substrates provides better insight in the complex regulatory systems that drive the conversion of plant biomass by fungi. In

Reduction of Aspergillus niger Virulence in Apple Fruits by Deletion of the Catalase Gene cpeB.

Science.gov (United States)

Zhang, Meng-Ke; Tang, Jun; Huang, Zhong-Qin; Hu, Kang-Di; Li, Yan-Hong; Han, Zhuo; Chen, Xiao-Yan; Hu, Lan-Ying; Yao, Gai-Fang; Zhang, Hua

2018-05-30

Aspergillus niger, a common saprophytic fungus, causes rot in many fruits. We studied the role of a putative catalase-peroxidase-encoding gene, cpeB, in oxidative stress and virulence in fruit. The cpeB gene was deleted in A. niger by homologous recombination, and the Δ cpeB mutant showed decreased CAT activity compared with that of the wild type. The cpeB gene deletion caused increased sensitivity to H 2 O 2 stress, and spore germination was significantly reduced; in addition, the reactive-oxygen-species (ROS) metabolites superoxide anions (·O 2 - ), hydrogen peroxide (H 2 O 2 ), and malondialdehyde (MDA) accumulated in the Δ cpeB mutant during H 2 O 2 stress. Furthermore, ROS metabolism in A. niger infected apples was determined, and our results showed that the Δ cpeB mutant induced an attenuated response in apple fruit during the fruit-pathogen interaction; the cpeB gene deletion significantly reduced the development of lesions, suggesting that the cpeB gene in A. niger is essential for full virulence in apples.

[Hygiene, safety and occupational medicine in Niger].

Science.gov (United States)

Moussa, F; Sékou, H

1997-01-01

The laws and rules governing hygiene, safety and medicine in the workplace in Niger were evaluated in this study. We used labour administration, health service and Social Security Department reports to review each type of professional activity and the risks associated with it. This enabled us to make recommendations to the authorities and to the organizations representing employers and staff, concerning the prevention of risks at work.

The GlaA signal peptide substantially increases the expression and secretion of α-galactosidase in Aspergillus niger.

Science.gov (United States)

Xu, Yue; Wang, Yan-Hui; Liu, Tian-Qi; Zhang, Hui; Zhang, He; Li, Jie

2018-03-31

α-Galactosidases are widely used in many fields. It is necessary to improve the production of enzymes through microbiological processes. The aim of this study was to construct recombinant Aspergillus niger strains with high α-galactosidase production. Two recombinant A. niger strains were constructed: AB and AGB. The recombinant AB strain contained the α-galactosidase aglB gene from A. niger with its native AglB signal peptide regulated by the glucoamylase promoter. In the AGB recombinant strain, the AglB signal peptide was replaced with the glucoamylase (GlaA) signal peptide. The extracellular maximum α-galactosidase activity of the AGB strain was 215.7 U/ml and that of the AB strain was 9.8 U/mL. The optimal conditions for α-galactosidase were pH 3.5 and 35 °C. The GlaA signal peptide substantially increased the yield of secreted α-galactosidase in A. niger. This recombinant strain holds great potential for industrial applications.

Control of Aspergillus niger with garlic, onion and leek extracts

African Journals Online (AJOL)

Administrator

2007-02-19

Feb 19, 2007 ... Key words: Aspergillus niger, garlic, onion, leek, antifungal activity. ..... Antimicrobial activity of essential oil extracts of various onions (Allium cepa) ... activity of oregano and thyme essential oils applied as fumigants against.

stabilization of dredged spoils for pavement construction in the niger

African Journals Online (AJOL)

Dr. Tse

Natural soils underlying the East-West road are mainly clay and silt of poor quality ... on the dredged soils included particle size distribution, compaction and California ... KEYWORDS: Stabilization, dredge spoil, pavement, Niger Delta, cement.

ITS2 barcoding DNA region combined with high resolution melting (HRM) analysis of Hyoscyami Semen, the mature seed of Hyoscyamus niger.

Science.gov (United States)

Xiong, Chao; Hu, Zhi-Gang; Tu, Yuan; Liu, He-Gang; Wang, Ping; Zhao, Ming-Ming; SHIi, Yu-Hua; Wu, Lan; Sun, Wei; Chen, Shi-Lin

2016-12-01

Hyoscyami Semen, the mature dried seed of Hyoscyamus niger L., has long been used as a traditional Chinese medicine to treat human diseases. Hyoscyami Semen is found in local markets in China. In markets, sellers and buyers commonly inadvertently mix the seeds of H. niger with the seeds of related species such as Hygrophila salicifolia (Vahl) Nees, Astragalus complanatus R. Br., Cuscuta australis R. Br., Cuscuta chinensis Lam., and Impatiens balsamina L. because of their similar morphologies or similar names. Thus, developing a reliable method for discriminating H. niger seeds from its adulterants is necessary to reduce confusion and ensure the safe use of Hyoscyami Semen. The present study was designed to evaluate the efficiency of high-resolution melting analysis combined with DNA barcoding (Bar-HRM) with internal transcribed spacer 2 to discriminate H. niger. Our results show that Bar-HRM successfully identified the adulterants and detected the proportion of H. niger DNA extract within an admixture. In particular, HRM detected H. niger DNA extract in A. complanatus DNA extract at concentrations as low as 1%. In conclusion, the Bar-HRM method developed in the present study for authenticating H. niger is rapid and cost-effective. It can be used in the future to guarantee the purity of Hyoscyami Semen for the clinical use. Copyright © 2016 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

Risk assessment of fungal spoilage: A case study of Aspergillus niger on yogurt.

Science.gov (United States)

Gougouli, Maria; Koutsoumanis, Konstantinos P

2017-08-01

A quantitative risk assessment model of yogurt spoilage by Aspergillus niger was developed based on a stochastic modeling approach for mycelium growth by taking into account the important sources of variability such as time-temperature conditions during the different stages of chill chain and individual spore behavior. Input parameters were fitted to the appropriate distributions and A. niger colony's diameter at each stage of the chill chain was estimated using Monte Carlo simulation. By combining the output of the growth model with the fungus prevalence, that can be estimated by the industry using challenge tests, the risk of spoilage translated to number of yogurt cups in which a visible mycelium of A. niger is being formed at the time of consumption was assessed. The risk assessment output showed that for a batch of 100,000 cups in which the percentage of contaminated cups with A. niger was 1% the predicted numbers (median (5 th , 95 th percentiles)) of the cups with a visible mycelium at consumption time were 8 (5, 14). For higher percentages of 3, 5 and 10 the predicted numbers (median (5 th , 95 th percentiles)) of the spoiled cups at consumption time were estimated to be 24 (16, 35), 39 (29, 52) and 80 (64, 94), respectively. The developed model can lead to a more effective risk-based quality management of yogurt and support the decision making in yogurt production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optimization of chloroxylenol degradation by Aspergillus niger using ...

African Journals Online (AJOL)

Chloroxylenol is a very toxic phenolic derivative and it represents potential hazard towards human health and to the environment. Aspergillus niger, local isolate, is an efficient fungus to degrade 99.72% of 2 mg/L of chloroxylenol after 7 days of fermentation. It also has a high capacity to degrade 91.83% of higher ...

Ethnic Minority Problems in the Niger Delta | Quaker-Dokubo ...

African Journals Online (AJOL)

As a conceptual background typical types of minorities and typical sources of minority conflict are outlined. A historical overview is given of the problems Niger Delta minorities have been experiencing. Their grievances and demands are highlighted, and the responses of different Nigerian governments are discussed.

Metabolic control analysis of Aspergillus niger L-arabinose catabolism

NARCIS (Netherlands)

Groot, de M.J.L.; Prathumpai, W.; Visser, J.; Ruijter, G.J.G.

2005-01-01

A mathematical model of the L-arabinose/D-xylose catabolic pathway of Aspergillus niger was constructed based on the kinetic properties of the enzymes. For this purpose L-arabinose reductase, L-arabitol dehydrogenase and D-xylose reductase were purified using dye-affinity chromatography, and their

Pectinases of Aspergillus niger : a molecular and biochemical characterisation

NARCIS (Netherlands)

Parenicová, L.

2000-01-01

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

Hydroxylative activity of Aspergillus niger towards androst-4-ene and androst-5-ene steroids.

Science.gov (United States)

Świzdor, Alina; Panek, Anna; Milecka-Tronina, Natalia

2017-10-01

Aspergillus niger, one of fungal species most frequently used for experimental and industrial-scale biotransformations of various organic compounds, is generally known to transform steroids at 16β position. In this work, application of the strain A. niger KCH910 to bioconversion of dehydroepiandrosterone (DHEA), androstenediol and testosterone is described, with emphasis on the metabolic steps leading to the products. Evidence from this study indicated that incubated 5-ene steroids underwent bioconversion within two metabolic pathways: oxidation by the action of 3β-HSD (3β-hydroxysteroid dehydrogenase) to 4-ene steroids, and minor allylic hydroxylation to epimeric 7-alcohols. Further transformation of the 3-oxo-4-ene metabolites resulted in non-selective 16-hydroxylation. It is the first report on an A. niger strain able to introduce not only 16β- but also 16α-hydroxyl function into steroids. Copyright © 2017. Published by Elsevier Inc.

Xylanase production by a newly isolated Aspergillus niger SS7 in submerged culture.

Science.gov (United States)

Bakri, Yasser; Al-Jazairi, Manal; Al-Kayat, Ghassan

2008-01-01

Xylanase production by a newly isolated Aspergillus niger SS7 was studied in submerged culture. The optimum initial pH for xylanase production was found to be 7.0. Different agricultural and industrial wastes were evaluated for their ability to induce xylanase production by this isolate. The best xylanase production (293.82 IU/ml) was recorded at 3% (w/v) corn cob hulls after 120 h of incubation. The Aspergillus niger SS7 isolate grown in a simple medium, proved to be a promising microorganism for xylanase production.

An inducible tool for random mutagenesis in Aspergillus niger based on the transposon Vader.

Science.gov (United States)

Paun, Linda; Nitsche, Benjamin; Homan, Tim; Ram, Arthur F; Kempken, Frank

2016-07-01

The ascomycete Aspergillus niger is widely used in the biotechnology, for instance in producing most of the world's citric acid. It is also known as a major food and feed contaminant. While generation of gene knockouts for functional genomics has become feasible in ku70 mutants, analyzing gene functions or metabolic pathways remains a laborious task. An unbiased transposon-based mutagenesis approach may aid this process of analyzing gene functions by providing mutant libraries in a short time. The Vader transposon is a non-autonomous DNA-transposon, which is activated by the homologous tan1-transposase. However, in the most commonly used lab strain of A. niger (N400 strain and derivatives), we found that the transposase, encoded by the tan1 gene, is mutated and inactive. To establish a Vader transposon-based mutagenesis system in the N400 background, we expressed the functional transposase of A. niger strain CBS 513.88 under the control of an inducible promoter based on the Tet-on system, which is activated in the presence of the antibiotic doxycycline (DOX). Increasing amounts of doxycycline lead to higher Vader excision frequencies, whereas little to none activity of Vader was observed without addition of doxycycline. Hence, this system appears to be suitable for producing stable mutants in the A. niger N400 background.

Expression and Characterization of Glucose Oxidase from Aspergillus niger in Yarrowia lipolytica.

Science.gov (United States)

Khadivi Derakshan, Fatemeh; Darvishi, Farshad; Dezfulian, Mehrouz; Madzak, Catherine

2017-08-01

Glucose oxidase (GOX) is currently used in clinical, pharmaceutical, food and chemical industries. The aim of this study was expression and characterization of Aspergillus niger glucose oxidase gene in the yeast Yarrowia lipolytica. For the first time, the GOX gene of A. niger was successfully expressed in Y. lipolytica using a mono-integrative vector containing strong hybrid promoter and secretion signal. The highest total glucose oxidase activity was 370 U/L after 7 days of cultivation. An innovative method was used to cell wall disruption in current study, and it could be recommended to use for efficiently cell wall disruption of Y. lipolytica. Optimum pH and temperature for recombinant GOX activity were 5.5 and 37 °C, respectively. A single band with a molecular weight of 80 kDa similar to the native and pure form of A. niger GOX was observed for the recombinant GOX in SDS-PAGE analysis. Y. lipolytica is a suitable and efficient eukaryotic expression system to production of recombinant GOX in compered with other yeast expression systems and could be used to production of pure form of GOX for industrial applications.

The occurrence of a phosphorylated glycosphingolipid in Aspergillus niger.

Science.gov (United States)

Brennan, P J; Roe, J

1975-01-01

A novel type of water-soluble phosphorylated glycosphingolipid was isolated from Aspergillus niger by a simple procedure involving precipitation, DEAE-cellulose chromatography and preparative t.l.c. Besides ceramide and phosphorus it contains inositol, galactose, mannose and small amounts of glucosamine. Images PLATE 1 PMID:1156383

Fuzzy Failure Probability of Transmission Pipelines in the Niger ...

African Journals Online (AJOL)

We undertake the apportioning of failure possibility on twelve identified third party activities contributory to failure of transmission pipelines in the Niger Delta region of Nigeria, using the concept of fuzzy possibility scores. Expert elicitation technique generates linguistic variables that are transformed using fuzzy set theory ...

Evaluation of xylanases from Aspergillus niger and Trichoderma sp ...

African Journals Online (AJOL)

Despite being present in relatively low amounts, pentosans and hemicelluloses play an important role in dough rheology and bread properties. The aim of this work is to understand how the xylanases from Aspergillus niger and Trichoderma sp. influence dough rheology, such as elasticity, extensibility, strength and stability.

Optimization for cellulase production by Aspergillus niger using saw ...

African Journals Online (AJOL)

Cellulases are a group of hydrolytic enzymes and are capable of degrading lignocellulosic materials. Cellulases have wide range of applications. This work focuses on factors relevant for improvement of enzymatic hydrolysis of saw dust by using Aspergillus niger. Different cultural conditions were examined to assess their ...

Enhancing stakeholder participation in the Niger Delta region: the ...

African Journals Online (AJOL)

Nigeria's indigenous people, found in the Niger Delta area, have for many years experienced developmental challenges associated with oil exploration. The region has been perennially engulfed in various forms of agitation pertaining to self-government and resource control. Over the years, attempts to solve these ...

Aspergillus tubingensis and Aspergillus niger as the dominant black Aspergillus, use of simple PCR-RFLP for preliminary differentiation.

Science.gov (United States)

Mirhendi, H; Zarei, F; Motamedi, M; Nouripour-Sisakht, S

2016-03-01

This work aimed to identify the species distribution of common clinical and environmental isolates of black Aspergilli based on simple restriction fragment length polymorphism (RFLP) analysis of the β-tubulin gene. A total of 149 clinical and environmental strains of black Aspergilli were collected and subjected to preliminary morphological examination. Total genomic DNAs were extracted, and PCR was performed to amplify part of the β-tubulin gene. At first, 52 randomly selected samples were species-delineated by sequence analysis. In order to distinguish the most common species, PCR amplicons of 117 black Aspergillus strains were identified by simple PCR-RFLP analysis using the enzyme TasI. Among 52 sequenced isolates, 28 were Aspergillus tubingensis, 21 Aspergillus niger, and the three remaining isolates included Aspergillus uvarum, Aspergillus awamori, and Aspergillus acidus. All 100 environmental and 17 BAL samples subjected to TasI-RFLP analysis of the β-tubulin gene, fell into two groups, consisting of about 59% (n=69) A. tubingensis and 41% (n=48) A. niger. Therefore, the method successfully and rapidly distinguished A. tubingensis and A. niger as the most common species among the clinical and environmental isolates. Although tardy, the Ehrlich test was also able to differentiate A. tubingensis and A. niger according to the yellow color reaction specific to A. niger. A. tubingensis and A. niger are the most common black Aspergillus in both clinical and environmental isolates in Iran. PCR-RFLP using TasI digestion of β-tubulin DNA enables rapid screening for these common species. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

Molecular Dynamics Approach in Designing Thermostable Aspergillus niger Xylanase

Science.gov (United States)

Malau, N. D.; Sianturi, M.

2017-03-01

Molecular dynamics methods we have applied as a tool in designing thermostable Aspergillus niger Xylanase, by examining Root Mean Square Deviation (RMSD) and The Stability of the Secondary Structure of enzymes structure at its optimum temperature and compare with its high temperature behavior. As RMSD represents structural fluctuation at a particular temperature, a better understanding of this factor will suggest approaches to bioengineer these enzymes to enhance their thermostability. In this work molecular dynamic simulations of Aspergillus niger xylanase (ANX) have been carried at 400K (optimum catalytic temperature) for 2.5 ns and 500K (ANX reported inactive temperature) for 2.5 ns. Analysis have shown that the Root Mean Square Deviation (RMSD) significant increase at higher temperatures compared at optimum temperature and some of the secondary structures of ANX that have been damaged at high temperature. Structural analysis revealed that the fluctuations of the α-helix and β-sheet regions are larger at higher temperatures compared to the fluctuations at optimum temperature.

Biocatalytic potential of laccase-like multicopper oxidases from Aspergillus niger

Directory of Open Access Journals (Sweden)

Tamayo-Ramos Juan Antonio

2012-12-01

Full Text Available Abstract Background Laccase-like multicopper oxidases have been reported in several Aspergillus species but they remain uncharacterized. The biocatalytic potential of the Aspergillus niger fungal pigment multicopper oxidases McoA and McoB and ascomycete laccase McoG was investigated. Results The laccase-like multicopper oxidases McoA, McoB and McoG from the commonly used cell factory Aspergillus niger were homologously expressed, purified and analyzed for their biocatalytic potential. All three recombinant enzymes were monomers with apparent molecular masses ranging from 80 to 110 kDa. McoA and McoG resulted to be blue, whereas McoB was yellow. The newly obtained oxidases displayed strongly different activities towards aromatic compounds and synthetic dyes. McoB exhibited high catalytic efficiency with N,N-dimethyl-p-phenylenediamine (DMPPDA and 2,2-azino-di(3-ethylbenzthiazoline sulfonic acid (ABTS, and appeared to be a promising biocatalyst. Besides oxidizing a variety of phenolic compounds, McoB catalyzed successfully the decolorization and detoxification of the widely used textile dye malachite green. Conclusions The A. niger McoA, McoB, and McoG enzymes showed clearly different catalytic properties. Yellow McoB showed broad substrate specificity, catalyzing the oxidation of several phenolic compounds commonly present in different industrial effluents. It also harbored high decolorization and detoxification activity with the synthetic dye malachite green, showing to have an interesting potential as a new industrial biocatalyst.

[You will become a saleswoman, my girl. Press review: Niger].

Science.gov (United States)

1999-12-01

In the Maradi district of southwestern Niger, the country¿s commercial hub, children are born with business sense. Parents in the district expect their young daughters to take part in the region¿s business activities by selling products at village markets. Therefore, only 13% of girls in the district attend school and during market days, classrooms are almost empty, but particularly devoid of female students. Students in Sabon Machi village have school vacation every Tuesday in order to attend the weekly market, then catch up on coursework on Wednesdays. Parents approve of such district norms because they prefer to keep their girls at home to help with household chores. Otherwise, they enroll their daughters in a Koranic school, where they can learn the basics of becoming a wife. Girls in this part of Niger are either promised to someone else in the future or they are under the control of their mothers, who are charged with teaching daughters what they need to know to be proper wives. Girls sell market products to slowly accumulate funds for their dowries. Also with regard to daughters, many parents believe that school attendance is synonymous with unwanted pregnancies, abortions, and other sorts of aberrations. Niger¿s government and nongovernmental organizations (NGOs) are wondering how to convince parents in this region to send their daughters to school. Some approaches employed to reassure and convince parents to that end are described.

Molecular Cloning and Characteristic Features of a Novel Extracellular Tyrosinase from Aspergillus niger PA2.

Science.gov (United States)

Agarwal, Pragati; Singh, Jyoti; Singh, R P

2017-05-01

Aspergillus niger PA2, a novel strain isolated from waste effluents of food industry, is a potential extracellular tyrosinase producer. Enzyme activity and L-DOPA production were maximum when glucose and peptone were employed as C source and nitrogen source respectively in the medium and enhanced notably when the copper was supplemented, thus depicting the significance of copper in tyrosinase activity. Tyrosinase-encoding gene from the fungus was cloned, and amplification of the tyrosinase gene yielded a 1127-bp DNA fragment and 374 amino acid residue long product that encoded for a predicted protein of 42.3 kDa with an isoelectric point of 4.8. Primary sequence analysis of A. niger PA2 tyrosinase had shown that it had approximately 99% identity with that of A. niger CBS 513.88, which was further confirmed by phylogenetic analysis. The inferred amino acid sequence of A. niger tyrosinase contained two putative copper-binding sites comprising of six histidines, a characteristic feature for type-3 copper proteins, which were highly conserved in all tyrosinases throughout the Aspergillus species. When superimposed onto the tertiary structure of A. oryzae tyrosinase, the conserved residues from both the organisms occupied same spatial positions to provide a di-copper-binding peptide groove.

Subungual onychomycosis due to Aspergillus niger mimicking a glomus tumor: A case report.

Science.gov (United States)

Matsuyama, Yumi; Nakamura, Tomoki; Hagi, Tomohito; Asanuma, Kunihiro; Sudo, Akihiro

2017-12-01

Onychomycosis is a common nail infection caused by dermatophytes, while non-dermatophytes including Aspergillus spp. are causes of nail onychomycosis. Aspergillus niger is not common as a cause of nail onychomycosis. In the current study we present a 60-year-old woman with subungual onychomycosis due to Aspergillus niger mimicking a glomus tumor. Physical examination revealed right thumb had a black color of nail bed. Localized tenderness and severe pain were observed. However, the cold sensitivity test, Loves pin test and Hildreths test were negative. On radiograph, bone erosion was found in a part of distal phalanx at the right thumb. Magnetic resonance imaging identified a mass at the subungual space, which exhibited low signal intensity on T1-weighted images and high signal intensity on T2-weighted images. The differential diagnosis included glomus tumor and infection. The histological findings demonstrated dichotomous septate hyphae. The culture was positive for Aspergillus niger . The results suggested that when physical examination is not typical for a glomus tumor, other diseases may be considered. Additionally, frozen section diagnosis may be useful.

Efficient Conversion of Inulin to Inulooligosaccharides through Endoinulinase from Aspergillus niger.

Science.gov (United States)

Xu, Yanbing; Zheng, Zhaojuan; Xu, Qianqian; Yong, Qiang; Ouyang, Jia

2016-03-30

Inulooligosaccharides (IOS) represent an important class of oligosaccharides at industrial scale. An efficient conversion of inulin to IOS through endoinulinase from Aspergillus niger is presented. A 1482 bp codon optimized gene fragment encoding endoinulinase from A. niger DSM 2466 was cloned into pPIC9K vector and was transformed into Pichia pastoris KM71. Maximum activity of the recombinant endoinulinase, 858 U/mL, was obtained at 120 h of the high cell density fermentation process. The optimal conditions for inulin hydrolysis using the recombinant endoinulinase were investigated. IOS were harvested with a high concentration of 365.1 g/L and high yield up to 91.3%. IOS with different degrees of polymerization (DP, mainly DP 3-6) were distributed in the final reaction products.

Mapping palaeolakes in the Ténéré Desert of northeastern Niger using space-borne data for groundwater potential

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Gloria Molina

2017-12-01

Full Text Available Groundwater resources in arid lands are crucial for supporting life. Thus, delineation of low land areas, where surface runoff accumulated during pluvial periods assists in groundwater explorations. Therefore, the drainage patterns in northeastern Niger using various sources of DEMs of optical (ASTER and radar (SRTM satellite data were extracted. These data reveal three palaeolakes in the Ténéré Desert. In addition, the DEMs together with the optical and radar satellite data were used to define a major watershed measuring 634,000 km2. This watershed may have led to the formation of one major palaeolake as an ancestor of the three palaeolakes. The latter extend to 11,514 km2, 17,571 km2 and 18,453 km2. The optical and radar satellites images show that the boundaries of these three lakes have been modified by extensive longitudinal and transverse sand dunes of considerable thickness. These dunes accumulated during a much later arid episode in geologic time, probably during the late Quaternary. Prior to that, the former marshlands received water from the Tibesti Mountains of northern Chad, the Ahaggar Plateau of southeastern Algeria and the Air Mountain of northern Niger. The drainage patterns clearly show the pathway of water down to the ground level. The longest drainage line is emanating from the Ahaggar Plateau and extends south west for 837 km. The water overflow of the southernmost lake led to the formation of another distinct drainage line, leading to the southwestern edge of the ancestral Megalake Chad. This drainage line begins in the vicinity of the town of Fachi and extends southward through the town of Dillia as a single tributary, and is here named the Dillia Palaeoriver. These observations, which are based on the study of satellite data require geophysical fieldwork to ascertain the interpretations, and evaluate the potential for groundwater accumulation in the region. Keywords: DEMs, Optical and

Screening a strain of Aspergillus niger and optimization of fermentation conditions for degradation of aflatoxin B₁.

Science.gov (United States)

Zhang, Wei; Xue, Beibei; Li, Mengmeng; Mu, Yang; Chen, Zhihui; Li, Jianping; Shan, Anshan

2014-11-13

Aflatoxin B₁, a type of highly toxic mycotoxin produced by some species belonging to the Aspergillus genus, such as Aspergillus flavus and Aspergillus parasiticus, is widely distributed in feed matrices. Here, coumarin was used as the sole carbon source to screen microorganism strains that were isolated from types of feed ingredients. Only one isolate (ND-1) was able to degrade aflatoxin B₁ after screening. ND-1 isolate, identified as a strain of Aspergillus niger using phylogenetic analysis on the basis of 18S rDNA, could remove 26.3% of aflatoxin B₁ after 48 h of fermentation in nutrient broth (NB). Optimization of fermentation conditions for aflatoxin B₁ degradation by selected Aspergillus niger was also performed. These results showed that 58.2% of aflatoxin B₁ was degraded after 24 h of culture under the optimal fermentation conditions. The aflatoxin B₁ degradation activity of Aspergillus niger supernatant was significantly stronger than cells and cell extracts. Furthermore, effects of temperature, heat treatment, pH, and metal ions on aflatoxin B₁ degradation by the supernatant were examined. Results indicated that aflatoxin B₁ degradation of Aspergillus niger is enzymatic and this process occurs in the extracellular environment.

Retting of Flax by Aspergillus niger

Science.gov (United States)

De França, F. P.; Rosemberg, J. A.; De Jesus, A. M.

1969-01-01

In this study, retting was carried out by Aspergillus niger. The pH, galacturonic acid (GA), and total reducing sugar were determined; the end point was identified by the classic empirical processes and by the maximal GA content of the retting water. The process gave clear and resistent fibers, and the retting time was similar to that of current industrial processes with bacterial enzymes. Control of total acidity was not required, since the pH remained close to neutrality throughout the entire process. PMID:16349835

The situation in the Niger Delta

International Nuclear Information System (INIS)

Vitalis, E.

2007-01-01

An energy issue for the United States and a political challenge for Europe, Nigeria is experiencing growing instability and is on the verge of civil war; the ecosystem and the population of the Niger Delta are the main victims. The State, corrupt, is powerless to contain the rising violence and redistribute the proceeds of oil sales. It is high time for oil-consuming countries, starting with the United States, to concern themselves with stabilizing the region. Europe must contribute to the lasting development of this country. (author)

A Highly Efficient Xylan-Utilization System in Aspergillus niger An76: A Functional-Proteomics Study

OpenAIRE

Weili Gong; Lin Dai; Huaiqiang Zhang; Lili Zhang; Lushan Wang; Lushan Wang

2018-01-01

Xylan constituted with β-1,4-D-xylose linked backbone and diverse substituted side-chains is the most abundant hemicellulose component of biomass, which can be completely and rapidly degraded into fermentable sugars by Aspergillus niger. This is of great value for obtaining renewable biofuels and biochemicals. To clarify the underlying mechanisms associated with highly efficient xylan degradation, assimilation, and metabolism by A. niger, we utilized functional proteomics to analyze the secre...

Pharmacopée vétérinaire traditionnelle des éleveurs du sud-Niger

Directory of Open Access Journals (Sweden)

Puffet, H.

1985-01-01

Full Text Available Traditional veterinary medicine in southern Niger. Investigations have been carried out in Southern Niger (Dosso department to make up an inventory of plants used for local veterinary cures. The results are presented in a report destined for field technical agents. This report displays the results in tables, showing the symptoms and diseases of different species of domestic animals, as well as the remedial plants and their manners of use.

Characterization of four new antifungal yanuthones from Aspergillus niger

DEFF Research Database (Denmark)

Petersen, Lene Maj; Holm, Dorte Koefoed; Knudsen, Peter Boldsen

2015-01-01

Four new yanuthone analogs (1–4) were isolated from the filamentous fungus Aspergillus niger. The structures of the new compounds were elucidated on the basis of UHPLC-DAD-HRMS data and one-dimensional and two-dimensional NMR spectroscopy. Labeling studies with 13C8-6-methylsalicylic acid...

Niger institute focuses on financial accountability | CRDI - Centre de ...

International Development Research Centre (IDRC) Digital Library (Canada)

28 avr. 2016 ... ... of its budgeting and reporting systems, and in staff morale. It plans further efforts to improve internal communications and achieve greater visibility. Read the story of change, Renewing financial management systems: Institut National de la Recherche Agronomique du Niger (PDF, 95 KB, in French only) ...

Erratum to: Purification and characterization of a nitrilase from Aspergillus niger

Czech Academy of Sciences Publication Activity Database

Kaplan, Ondřej; Vejvoda, Vojtěch; Plíhal, O.; Pompach, P.; Kavan, D.; Bojarová, Pavla; Bezouška, K.; Macková, M.; Cantarella, M.; Jirků, V.; Křen, Vladimír; Martínková, Ludmila

2013-01-01

Roč. 97, č. 8 (2013), s. 3745-3746 ISSN 0175-7598 Institutional support: RVO:61388971 Keywords : nitrilase * Aspergillus niger Subject RIV: EE - Microbiology, Virology Impact factor: 3.811, year: 2013

Exploiting proteomic data for genome annotation and gene model validation in Aspergillus niger

Directory of Open Access Journals (Sweden)

Grigoriev Igor V

2009-02-01

Full Text Available Abstract Background Proteomic data is a potentially rich, but arguably unexploited, data source for genome annotation. Peptide identifications from tandem mass spectrometry provide prima facie evidence for gene predictions and can discriminate over a set of candidate gene models. Here we apply this to the recently sequenced Aspergillus niger fungal genome from the Joint Genome Institutes (JGI and another predicted protein set from another A.niger sequence. Tandem mass spectra (MS/MS were acquired from 1d gel electrophoresis bands and searched against all available gene models using Average Peptide Scoring (APS and reverse database searching to produce confident identifications at an acceptable false discovery rate (FDR. Results 405 identified peptide sequences were mapped to 214 different A.niger genomic loci to which 4093 predicted gene models clustered, 2872 of which contained the mapped peptides. Interestingly, 13 (6% of these loci either had no preferred predicted gene model or the genome annotators' chosen "best" model for that genomic locus was not found to be the most parsimonious match to the identified peptides. The peptides identified also boosted confidence in predicted gene structures spanning 54 introns from different gene models. Conclusion This work highlights the potential of integrating experimental proteomics data into genomic annotation pipelines much as expressed sequence tag (EST data has been. A comparison of the published genome from another strain of A.niger sequenced by DSM showed that a number of the gene models or proteins with proteomics evidence did not occur in both genomes, further highlighting the utility of the method.

Exploiting proteomic data for genome annotation and gene model validation in Aspergillus niger.

Science.gov (United States)

Wright, James C; Sugden, Deana; Francis-McIntyre, Sue; Riba-Garcia, Isabel; Gaskell, Simon J; Grigoriev, Igor V; Baker, Scott E; Beynon, Robert J; Hubbard, Simon J

2009-02-04

Proteomic data is a potentially rich, but arguably unexploited, data source for genome annotation. Peptide identifications from tandem mass spectrometry provide prima facie evidence for gene predictions and can discriminate over a set of candidate gene models. Here we apply this to the recently sequenced Aspergillus niger fungal genome from the Joint Genome Institutes (JGI) and another predicted protein set from another A.niger sequence. Tandem mass spectra (MS/MS) were acquired from 1d gel electrophoresis bands and searched against all available gene models using Average Peptide Scoring (APS) and reverse database searching to produce confident identifications at an acceptable false discovery rate (FDR). 405 identified peptide sequences were mapped to 214 different A.niger genomic loci to which 4093 predicted gene models clustered, 2872 of which contained the mapped peptides. Interestingly, 13 (6%) of these loci either had no preferred predicted gene model or the genome annotators' chosen "best" model for that genomic locus was not found to be the most parsimonious match to the identified peptides. The peptides identified also boosted confidence in predicted gene structures spanning 54 introns from different gene models. This work highlights the potential of integrating experimental proteomics data into genomic annotation pipelines much as expressed sequence tag (EST) data has been. A comparison of the published genome from another strain of A.niger sequenced by DSM showed that a number of the gene models or proteins with proteomics evidence did not occur in both genomes, further highlighting the utility of the method.

Biocatalytic potential of laccase-like multicopper oxidases from Aspergillus niger

NARCIS (Netherlands)

Tamayo Ramos, J.A.; Berkel, van W.J.H.; Graaff, de L.H.

2012-01-01

BACKGROUND: Laccase-like multicopper oxidases have been reported in several Aspergillus species but they remain uncharacterized. The biocatalytic potential of the Aspergillus niger fungal pigment multicopper oxidases McoA and McoB and ascomycete laccase McoG was investigated. RESULTS: The

Utilization of waste cellulose. III. Comparative study of the activity of the cellulases of trichoderma viride and Aspergillus niger towards different cellulosic substrates

Energy Technology Data Exchange (ETDEWEB)

David, C.; Thiry, P.

1981-01-01

The kinetics of the saccharification of filter paper-derived cellulose by cellulases of Aspergillus niger and Tricoderma viride were studied. The formation of glucose and of total reducing sugar was measured as a function of time for the hydrolysis of cellulose by the same quantity of filter paper units from T. viride and (or) A. niger. Long term efficiency was lower for A. niger but an important synergistic effect was observed for the mixture of the enzymes. This synergistic action was attributed to a better balance of endo- and exoglucananses and to the addition to T. viride of thermally stable endoglucanases from A. niger. The beta-glucosidases formed in large quantity by A. niger were thermally unstable and susceptible to product inhibition and did not play any role in the observed synergistic action.

Characterization of a polyketide synthase in Aspergillus niger whose product is a precursor for both dihydroxynaphthalene (DHN) melanin and naphtho-γ-pyrone.

Energy Technology Data Exchange (ETDEWEB)

Chiang, Yi Ming; Meyer, Kristen M; Praseuth, Michael; Baker, Scott E; Bruno, Kenneth S; Wang, Clay C

2010-12-06

The genome sequencing of the fungus Aspergillus niger, an industrial workhorse, uncovered a large cache of genes encoding enzymes thought to be involved in the production of secondary metabolites yet to be identified. Identification and structural characterization of many of these predicted secondary metabolites are hampered by their low concentration relative to the known A. niger metabolites such as the naphtho-γ-pyrone family of polyketides. We deleted a nonreducing PKS gene in A. niger strain ATCC 11414, a daughter strain of A. niger ATCC strain 1015 whose genome was sequenced by the DOE Joint Genome Institute. This PKS encoding gene is a predicted ortholog of alb1 from Aspergillus fumigatus which is responsible for production of YWA1, a precursor of fungal DHN melanin. Our results show that the A. niger alb1 PKS is responsible for the production of the polyketide precursor for DHN melanin biosynthesis. Deletion of alb1 elimnates the production of major metabolites, naphtho-γ-pyrones. The generation of an A. niger strain devoid of naphtho-γ-pyrones will greatly facilitate the elucidation of cryptic biosynthetic pathways in this organism.

Effects Of Solid State Fermentation By Aspergillus niger and ...

African Journals Online (AJOL)

fermentation and incubated for O (control), 4,8 and 10 days to evaluate the changes in crude protein (CP), crude fibre (CF), neutral detergent fibre (NDF), acid detergent fibre (ADF) and hemicellulose (HEMI). Ten days after inoculation of Cassava peel meal (CPM) with Aspergillus niger, the crude protein increased from ...

Quality characterization of Niger seed oil ( Guizotia Abyssinica Cass ...

African Journals Online (AJOL)

In the present investigation, an attempt has been made to find out cholesterol and total free fatty acid content in Niger seed oil which is the most available edible oil in Ethiopia. Acid value, peroxide value, saponification value and cholesterol content were determined. The analysis performed using Liebermann-Burchard ...

Assessing soil erosion risk in the Tillabery landscape, Niger ...

African Journals Online (AJOL)

The results show that soil erosion output scenarios predict greater soil erosion in the study area from 2070 onwards. They suggest that human disturbance and topographic factors are the main impact factors in the affected areas. Key words: Tillabéry landscape (Niger), sheet and rill erosion modelling, data mining.

Sawaba's rebellion in Niger (1964-1965) : narrative and meaning

NARCIS (Netherlands)

Walraven, van K.

2003-01-01

One of the least-studied revolts in postcolonial Africa, the invasion of Niger in 1964 by guerrillas of the outlawed Sawaba party, was a dismal failure and culminated in a failed attempt on the life of President Diori in the spring of 1965. Personal aspirations for higher education, access to jobs

Amnesty in the Niger Delta: vertical movement towards self ...

African Journals Online (AJOL)

... promises of infrastructure development in the region and direct payments of oil revenues to host-communities. This paper seeks to examine the recent developments vis-à-vis the government's amnesty initiative to determine if this policy has bridged the gap in the longstanding selfdetermination demands of the Niger Delta ...

The Niger Delta Region and the Woman's Predicament: A Study of ...

African Journals Online (AJOL)

FIRST LADY

exposes the moral laxity caused by poverty, joblessness and lack of social amenities ... which later transformed to Shell Petroleum Development Company shipped ... Apart from these ecological problems, the Niger Delta region lacks basic.

The feeding ecology of schilbeid catfishes in river Ase, Niger delta ...

African Journals Online (AJOL)

The feeding ecology of schilbeid catfishes in river Ase, Niger delta, Southern Nigeria. ... Open Access DOWNLOAD FULL TEXT ... in feeding intensity were described for Eutropius niloticus and Schilbe mystus which had adequate data.

Control of Aspergillus niger with garlic, onion and leek extracts | Irkin ...

African Journals Online (AJOL)

Allium cepa L.) and leek (Allium porrum L.) were investigated against Aspergillus niger. Minimal inhibitory concentrations (MIC) and minimal fungicidal concentrations (MFC) of aqueous, ethyl alcohol and acetone extracts were determined by ...

Coupled biochemical genetic and karyomorphological analyses for ...

African Journals Online (AJOL)

S. esocinus showed five bands, S. curvifrons five, S. niger seven, S. labiatus and S. plagiostomus each showed six bands; they also showed species characteristic bands. Karyotypic study of these was carried out. The diploid chromosome numbers recorded were 98 in S. niger (24 m + 32 sm + 22 st + 20 t), 98 in S. esocinus ...

Evaluation of Antimicrobial Activity of Glucose Oxidase from Aspergillus niger EBL-A and Penicillium notatum

OpenAIRE

Zia, Muhammad Anjum; Riaz, Ayesha; Rasul, Samreen; Abbas, Rao Zahid

2013-01-01

This work aimed to study the production and purification of glucose oxidase by Aspergillus niger and Penicillium notatum using corn steep liquor as the substrate and evaluate its antimicrobial activity for use in pharmaceutical and food industries. The enzyme was purified by ammonium sulfate precipitation (60-85%), DEAE-cellulose ion exchange and Sephadex G-200 size exclusion chromatography. The crude enzyme extracts of A. niger and P. notatum showed 2.32 and 5.53 U mg-1 specific activities, ...

Secretome data from Trichoderma reesei and Aspergillus niger cultivated in submerged and sequential fermentation methods

Directory of Open Access Journals (Sweden)

Camila Florencio

2016-09-01

Full Text Available The cultivation procedure and the fungal strain applied for enzyme production may influence levels and profile of the proteins produced. The proteomic analysis data presented here provide critical information to compare proteins secreted by Trichoderma reesei and Aspergillus niger when cultivated through submerged and sequential fermentation processes, using steam-explosion sugarcane bagasse as inducer for enzyme production. The proteins were organized according to the families described in CAZy database as cellulases, hemicellulases, proteases/peptidases, cell-wall-protein, lipases, others (catalase, esterase, etc., glycoside hydrolases families, predicted and hypothetical proteins. Further detailed analysis of this data is provided in “Secretome analysis of Trichoderma reesei and Aspergillus niger cultivated by submerged and sequential fermentation process: enzyme production for sugarcane bagasse hydrolysis” C. Florencio, F.M. Cunha, A.C Badino, C.S. Farinas, E. Ximenes, M.R. Ladisch (2016 [1]. Keywords: Tricoderma reesei, Aspergillus Niger, Enzyme Production, Secretome

Genome mining and functional genomics for siderophore production in Aspergillus niger.

Science.gov (United States)

Franken, Angelique C W; Lechner, Beatrix E; Werner, Ernst R; Haas, Hubertus; Lokman, B Christien; Ram, Arthur F J; van den Hondel, Cees A M J J; de Weert, Sandra; Punt, Peter J

2014-11-01

Iron is an essential metal for many organisms, but the biologically relevant form of iron is scarce because of rapid oxidation resulting in low solubility. Simultaneously, excessive accumulation of iron is toxic. Consequently, iron uptake is a highly controlled process. In most fungal species, siderophores play a central role in iron handling. Siderophores are small iron-specific chelators that can be secreted to scavenge environmental iron or bind intracellular iron with high affinity. A second high-affinity iron uptake mechanism is reductive iron assimilation (RIA). As shown in Aspergillus fumigatus and Aspergillus nidulans, synthesis of siderophores in Aspergilli is predominantly under control of the transcription factors SreA and HapX, which are connected by a negative transcriptional feedback loop. Abolishing this fine-tuned regulation corroborates iron homeostasis, including heme biosynthesis, which could be biotechnologically of interest, e.g. the heterologous production of heme-dependent peroxidases. Aspergillus niger genome inspection identified orthologues of several genes relevant for RIA and siderophore metabolism, as well as sreA and hapX. Interestingly, genes related to synthesis of the common fungal extracellular siderophore triacetylfusarinine C were absent. Reverse-phase high-performance liquid chromatography (HPLC) confirmed the absence of triacetylfusarinine C, and demonstrated that the major secreted siderophores of A. niger are coprogen B and ferrichrome, which is also the dominant intracellular siderophore. In A. niger wild type grown under iron-replete conditions, the expression of genes involved in coprogen biosynthesis and RIA was low in the exponential growth phase but significantly induced during ascospore germination. Deletion of sreA in A. niger resulted in elevated iron uptake and increased cellular ferrichrome accumulation. Increased sensitivity toward phleomycin and high iron concentration reflected the toxic effects of excessive

Evaluation of Culture Conditions for Tannase Production by Aspergillus niger GH1

Directory of Open Access Journals (Sweden)

Mario Cruz-Hernández

2006-01-01

Full Text Available Extra- and intracellular tannase production by Aspergillus niger GH1 has been evaluated using submerged (SmF and solid-state fermentation (SSF at different temperatures (30, 40 and 50 °C. Effects of initial substrate (tannic acid concentration, incubation time and temperature on tannase production in SSF have been studied. A. niger GH1 produced the highest tannase level (2291 U/L in SSF at 30 °C during the first 20 h of culture at tannic acid concentration of 50 g/L, and under these conditions enzyme production was entirely extracellular. The decline in tannase activity after 20 h of incubation was associated with a concomitant increase in protease activity.

Glucoamylase production by a newly isolated strain of Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Sinkar, V.P.; Lewis, N.F.

1982-01-01

Glucoamylase production by Aspergillus niger 57 was studied in complex and synthetic media under stationary vs. submerged conditions. Stationary cultivation resulted in significantly greater yields than did submerged culture. Crude enzyme activity was optimum at 60 degrees and pH 4.0.

Cytochemical Localization of Glucose Oxidase in Peroxisomes of Aspergillus niger

NARCIS (Netherlands)

Veenhuis, Marten; Dijken, Johannes Pieter van

1980-01-01

The subcellular localization of glucose oxidase (E.C. 1.1.3.4) in mycelia of Aspergillus niger has been investigated using cytochemical staining techniques. Mycelia from fermenter cultures, which produced gluconic acid from glucose, contained elevated levels of glucose oxidase and catalase. Both

Towards an Ethics of the Environment in the Niger Delta

African Journals Online (AJOL)

FIRST LADY

and the responsibility for both human and non-human components of nature are indeed wholly ... intend to do in this work therefore is to evolve an ethics of the Niger Delta environment which ... African Research Review Vol. 4(3a) July, 2010.

the search for environmental justice in the niger delta and corporate

African Journals Online (AJOL)

OLAWUYI

Keywords: Environmental Justice, Niger Delta, Corporate Accountability, Torts, kiobel .... U.S. Courts to Victims of Corporate Human Rights Abuses', 146 Columbia ... 7 Amokaye O.G., Environmental Law and Practice in Nigeria (Lagos, Unilag ...

The Place of Bonny in Niger Delta History (Pp. 36-45)

African Journals Online (AJOL)

User

implications for the reconstruction of the history of other Niger Delta communities. .... political units and the many communal market groups in the tribal interior, ..... Some Fresh Thoughts on Eastern Ijo Origins, Expansions and Migrations.

Biotransformation of Progesterone by the Ascomycete Aspergillus niger N402.

Science.gov (United States)

Savinova, O S; Solyev, P N; Vasina, D V; Tyazhelova, T V; Fedorova, T V; Savinova, T S

2018-01-01

The ability of the ascomycete Aspergillus niger N402 to transform exogenous progesterone was investigated. We found that this strain has steroid-hydroxylating activity and can introduce a hydroxyl group into the progesterone molecule mainly at positions C11(α) and C21 with predominant formation of 21-hydroxyprogesterone (deoxycortone). In addition, formation of 6β,11α-dihydroxyprogesterone was also observed. Studying the effects of the growth medium composition and temperature on progesterone conversion by A. niger N402 showed that the most intense accumulation of 21-hydroxyprogesterone occurred in minimal synthetic medium at 28°C. Increasing the cultivation temperature to 37°C resulted in almost complete inhibition of the hydroxylase activity in the minimal medium. In the complete medium, a similar increase in temperature inhibited 11α-hydroxylase activity and completely suppressed 6β-hydroxylase activity, but it produced no effect on 21-hydroxylating activity.

The Effectiveness of Antifungal Controlling Aspergillus Niger Growth on Plasterboard

Directory of Open Access Journals (Sweden)

Parjo Umi Kalthsom

2017-01-01

Full Text Available Good indoor environmental quality is desired for a healthy indoor environment. The microbial growth under indoor environments contribute to the poor indoor environmental quality that can cause various of health problems. In this study, the applications of three types of antifungals to prevent microbial migration, subsequent growth and bio-deterioration of the substrates. The aim of this research was to evaluate the coating-bio resistance in remediation of indoor fungal using three types of antifungals with different types of wall finishing materials. The treatment was exposed to optimum temperature and relative humidity at 30°C and 90% respectively. The potassium sorbate, zinc salicylate and calcium benzoate are tested against Aspergillus niger which is collected from indoor rooms. This study has revealed the growth of A. niger are more affected by the potassium sorbate on thick wallpaper, which is the percentage growth are 47%.

Uranium leaching using mixed organic acids produced by Aspergillus niger

International Nuclear Information System (INIS)

Yong-dong Wang; Guang-yue Li; De-xin Ding; Zhi-xiang Zhou; Qin-wen Deng; Nan Hu; Yan Tan

2013-01-01

Both of culture temperature and pH value had impacts on the degree of uranium extraction through changing types and concentrations of mixed organic acids produced by Aspergillus niger, and significant interactions existed between them though pH value played a leading role. And with the change of pH value of mixed organic acids, the types and contents of mixed organic acids changed and impacted on the degree of uranium extraction, especially oxalic acid, citric acid and malic acid. The mean degree of uranium extraction rose to peak when the culture temperature was 25 deg C (76.14 %) and pH value of mixed organic acids was 2.3 (82.40 %) respectively. And the highest one was 83.09 %. The optimal culture temperature (25 deg C) of A. niger for uranium leaching was different from the most appropriate growing temperature (37 deg C). (author)

Activities of Protection against Ionizing Radiation in Niger

International Nuclear Information System (INIS)

Kando Hamadou, M.

2008-01-01

Niger, sahelian country of Western Africa, is limited to North by Libya and Algeria, to the South by Nigeria and the Benin, to the East by Chad and the West by Mali and Burkina Faso. It covers a surface of 1 267 000 km2 and has a population of approximately 12 000 000 inhabitants. Niger is a large uranium producer with two extraction and treatment development companies of uranium ore which are the company of the mines of Air (SOMAIR) created in 1971 and the mining company of Akouta (COMINAK) created in 1978. Beyond the mining sector, ionizing radiation sources are used in the fields of industry, health, teaching and research. The first lawful text of protection against ionizing radiation was signed on December 5, 1979 and specifically related to the mining activities of uranium. With the multiform assistance of International Atomic Energy Agency (IAEA) protection against radiation knew a significant evolution. A national centre of protection against radiation was created in 1998, two laws relating to the field were adopted in June 2006 and three lawful texts of application of these laws are in the process of finalization

Application in Down-hole Milling Operations In Niger Delta.

African Journals Online (AJOL)

ENGINEERS

export terminals, 275 flow stations, 10 gas plants, 3 refineries and a massive natural ..... clear of the Niger Delta', adding that, 'The Chinese government by investing in stolen .... Development Agency (SMEDAN); to help boost the growth of both countries' ..... “The Rule of Oil: Petro-Politics and the Anatomy of an Insurgency”.

Adolescent Sexual and Reproductive Health in the Niger Delta ...

African Journals Online (AJOL)

There has been an increasing awareness of the need to pay special focus on the adolescent and their sexual and reproductive health. This article reviews the sexual and reproductive health of adolescents in the Niger Delta region (NDR) of Nigeria. The objective is to bring to focus these important issues in the region.

Production of Aspergillus niger beta-mannosidase in Pichia pastoris

Czech Academy of Sciences Publication Activity Database

Fliedrová, Barbora; Gerstorferová, Daniela; Křen, Vladimír; Weignerová, Lenka

2012-01-01

Roč. 85, č. 2 (2012), s. 159-164 ISSN 1046-5928 R&D Projects: GA ČR GAP207/10/0321; GA ČR GD305/09/H008; GA MŠk(CZ) 7E11011 Keywords : Beta-mannosidase * Aspergillus niger * Cloning Subject RIV: CE - Biochemistry Impact factor: 1.429, year: 2012

An annotated list of Fishes from the Niger Delta

NARCIS (Netherlands)

Boeseman, M.

1963-01-01

At the end of November 1960, the Leiden Museum received an interesting collection of animals, mostly fishes, from the Niger delta. All specimens were collected by Mr. H. J. G. Beets, at the time employed by Shell B.P. — Delta Investigations, during the period May to August 1960, and in the region

Environmental Degradation in Oil Producing Areas of Niger Delta ...

African Journals Online (AJOL)

Due to oil exploration and other human activities in the Niger Delta region, there is evidence of environmental degradation all over the area (Oronto, 1998). Environmental degradation is occasioned by consistent flow of industrial waste, oil spills, gas flares, fire disaster, acid rain, flooding erosion, etc., which has led to the ...

Comparative Study of Fructo oligosaccharides Production by Xanthophyllomyces dendrorhous and Aspergillus niger

International Nuclear Information System (INIS)

EI-Bialy, H.A.

2009-01-01

Neo-fructo oligosaccharides (neo-FOS) production by the red yeast Xanthophyllollfyces dendrorhous NRRL Y-10921 was studied in comparison to fructo oligosaccharides (FOS) produced by crude enzyme of local Aspergillus niger isolates. The lost active FOS producers (Two isolates of A. niger) which converted about 40% or the initial sucrose concentration to FOS were selected out of fifty-two mould isolates. The FOS- transfructosylating enzyme complex slightly increased the yield of FOS production by both selected A. niger isolates. The neo-FOS produced by X. dendrorhous was maximized by optimization of cultivation conditions and reaction parameters. Exponential growth phase of X. dendrorhous slightly enhanced the transferred fructose compared to stationary one. Sucrose is a main nutritional factor affecting the transfructosylating activity of the red yeast cells. Eighteen hours, two hundred grams of sucrose per liter, ph 6 and 30 degree C were the most favorable reaction parameters. Gamma irradiation at dose level equal to 0.2 kGy slightly increased the neo-FOS produced by X. dendrorhous whereas one kGy clearly decreased the production. Also, results revealed the negative effect of X. dendrorhous cell recycling on neo-FOS production either in sucrose syrup or sugarcane juice, the earlier exhibited more negative effect

A new group of exo-acting family 28 glycoside hydrolases of Aspergillus niger that are involved in pectin degradation

NARCIS (Netherlands)

Martens-Uzunova, E.S.; Zandleven, J.S.; Benen, J.A.E.; Awad, H.; Kools, H.J.; Beldman, G.; Voragen, A.G.J.; Berg, van den J.A.; Schaap, P.J.

2006-01-01

The fungus Aspergillus niger is an industrial producer of pectin degrading enzymes. The recent solving of the genomic sequence of A. niger allowed an inventory of the entire genome of the fungus for potential carbohydrate degrading enzymes. By applying bioinformatics tools 12 new genes putatively

An antifungal role of hydrogen sulfide on the postharvest pathogens Aspergillus niger and Penicillium italicum.

Directory of Open Access Journals (Sweden)

Liu-Hui Fu

Full Text Available In this research, the antifungal role of hydrogen sulfide (H2S on the postharvest pathogens Aspergillus niger and Penicillium italicum growing on fruits and under culture conditions on defined media was investigated. Our results show that H2S, released by sodium hydrosulfide (NaHS effectively reduced the postharvest decay of fruits induced by A. niger and P. italicum. Furthermore, H2S inhibited spore germination, germ tube elongation, mycelial growth, and produced abnormal mycelial contractions when the fungi were grown on defined media in Petri plates. Further studies showed that H2S could cause an increase in intracellular reactive oxygen species (ROS in A. niger. In accordance with this observation we show that enzyme activities and the expression of superoxide dismutase (SOD and catalase (CAT genes in A. niger treated with H2S were lower than those in control. Moreover, H2S also significantly inhibited the growth of Saccharomyces cerevisiae, Rhizopus oryzae, the human pathogen Candida albicans, and several food-borne bacteria. We also found that short time exposure of H2S showed a microbicidal role rather than just inhibiting the growth of microbes. Taken together, this study suggests the potential value of H2S in reducing postharvest loss and food spoilage caused by microbe propagation.

Strategies for Mitigation of Flood Risk in the Niger Delta, Nigeria ...

African Journals Online (AJOL)

Strategies for Mitigation of Flood Risk in the Niger Delta, Nigeria. ... Journal of Applied Sciences and Environmental Management ... a false sense of security to flood plain dwellers and thereby encouraging investments in flood prone areas.

POTENSI DARI KAPANG Aspergilus niger, Rhizophus oryzae DAN Neurospora sitophila SEBAGAI PENGHASIL EZIM FITASE DAN AMILASE PADA SUBSTRATE AMPAS TAHU

Directory of Open Access Journals (Sweden)

Atit - Kanti

2017-02-01

Full Text Available Penambahan enzim hidrolisis untuk pakan ternak dapat meningkatkan nilai nutrisi pakan. Penelitian bertujuan untuk mendapatkan kondisi optimal untuk produksi enzim amilase dan fitase pada media ampas tahu menggunakan Aspergilus niger, Rhizophus oryzae dan Neurospora sitophila. Uji kemampuan produksi enzim fitase dan amilase oleh Aspergilus niger, Rhizophus oryzae dan Neurospora sitophila dilakukan menggunakan media ampas tahu yang disterilisasi. Pemilihan ketiga isolat ini diawali dengan uji produksi enzim amilase pada kultur cair yang mengandung 2 % pati, dan uji fitase dilakukan pada media yang mengandung 0.5 % sodium fitat. Hasil uji pada medium cair selanjutnya digunakan untuk uji produksi enzim fitase dan fitase pada sistem fermentasi padat (SSF menggunakan ampas tahu sebagai media fermentasi. Untuk mendapatkan produksi enzim yang tinggi dilakukan melalui optimasi waktu inkubasi, suhu inkubasi dan pH media. Fitase dan amilase dapat diproduksi dengan media ampas tahu oleh R. oryzae, A. niger dan N. sitophila. Kondisi optimum untuk produksi fitase, yaitu waktu inkubasi pada hari keempat untuk ketiga kapang, suhu 25 °C untuk R. oryzae dan A. niger, suhu 30°C untuk N. sitophila, pH 8 untuk R. oryzae, pH 6 untuk Aspergillus niger dan N. Sitophila. Neurospora sitophila menghasilkan amilase optimum pada suhu 35°C, sedangkan Aspergillus niger dan Rhizopus oryzae optimum pada suhu 30°C. Penurunan aktivitas produksi amilase menurun oleh R. oryzae pada suhu 40°C. Amilase diproduksi optimal pada pH 6-7. Pakan ternak yang mengandung asam fitat mampu dihidrolisis oleh fitase pada kondisi optimum. Ketiga kapang juga menghasilkan enzim amilase pada media ampas tahu mengindikasikan bahwa ampas tahu merupakan susbtrat yang baik untuk produksi enzim hidrolisis yang berguna untuk meningkatkan nilai nutrisi pakan ternak. (Kata kunci: Amilase, Aspergilus niger, Neurospora sitophila, phytase, Rhizophus oryzae

Northern blotting analysis

DEFF Research Database (Denmark)

Josefsen, Knud; Nielsen, Henrik

2011-01-01

Northern blotting analysis is a classical method for analysis of the size and steady-state level of a specific RNA in a complex sample. In short, the RNA is size-fractionated by gel electrophoresis and transferred by blotting onto a membrane to which the RNA is covalently bound. Then, the membrane...... is analysed by hybridization to one or more specific probes that are labelled for subsequent detection. Northern blotting is relatively simple to perform, inexpensive, and not plagued by artefacts. Recent developments of hybridization membranes and buffers have resulted in increased sensitivity closing...

Waste management in the uranium companies of Niger

International Nuclear Information System (INIS)

Hama, A.

2002-01-01

Two companies produce uranium (yellowcake) in Niger: the 'Societe des Mines de l'Air (SOMAIR)' and the 'Compagnie Miniere d'Akouta (COMINAK)'. The SOMAIR operation uses open pit mining whereas COMINAK employs underground mining. Uranium ores have been treated by SOMAIR and COMINAK since 1971 and 1978 respectively. The wastes produced by the two companies will be managed to reduce health and environment impacts. (author)

Induction, purification and characterisation of arabinases produced by Aspergillus niger.

NARCIS (Netherlands)

Veen, van de P.; Flipphi, M.J.A.; Voragen, A.G.J.; Visser, J.

1991-01-01

The induction of arabinases in Aspergillus niger N400 was studied on different simple and complex carbon sources. Sugar beet pulp was found to be an inducer of three arabinan degrading enzymes (alpha-L-arabinofuranosidase A, alpha-L-arabinofuranosidase B and endoarabinase). These enzymes were

Executive Summary: Forests of the Northern United States

Science.gov (United States)

Stephen R. Shifley; Francisco X. Aguilar; Nianfu Song; Susan I. Stewart; David J. Nowak; Dale D. Gormanson; W. Keith Moser; Sherri Wormstead; Eric J. Greenfield

2012-01-01

This executive summary provides an overview of the 200-page report, Forests of the Northern United States, which covers in detail current forest conditions, recent trends, issues, threats and opportunities in the forests in the 20 Northern States. It provides a context for subsequent Northern Forest Futures Project analyses that will forecast alternative future...

Ecophysiological characterization of Aspergillus carbonarius, Aspergillus tubingensis and Aspergillus niger isolated from grapes in Spanish vineyards.

Science.gov (United States)

García-Cela, E; Crespo-Sempere, A; Ramos, A J; Sanchis, V; Marin, S

2014-03-03

The aim of this study was to evaluate the diversity of black aspergilli isolated from berries from different agroclimatic regions of Spain. Growth characterization (in terms of temperature and water activity requirements) of Aspergillus carbonarius, Aspergillus tubingensis and Aspergillus niger was carried out on synthetic grape medium. A. tubingensis and A. niger showed higher maximum temperatures for growth (>45 °C versus 40-42 °C), and lower minimum aw requirements (0.83 aw versus 0.87 aw) than A. carbonarius. No differences in growth boundaries due to their geographical origin were found within A. niger aggregate isolates. Conversely, A. carbonarius isolates from the hotter and drier region grew and produced OTA at lower aw than other isolates. However, little genetic diversity in A. carbonarius was observed for the microsatellites tested and the same sequence of β-tubulin gene was observed; therefore intraspecific variability did not correlate with the geographical origin of the isolates or with their ability to produce OTA. Climatic change prediction points to drier and hotter climatic scenarios where A. tubingensis and A. niger could be even more prevalent over A. carbonarius, since they are better adapted to extreme high temperature and drier conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

The Economic Dimensions of the Niger Delta Ethnic Conflicts ...

African Journals Online (AJOL)

This paper presents a descriptive analysis of the remote and immediate causes of the armed ethnic conflicts in the Niger Delta in Nigeria and attempts to proffer a strategic approach rather than the use of brute force in managing the conflicts. The study revealed that the underlying cause of the conflict is the prolonged ...

Study of a High-Yield Cellulase System Created by Heavy-Ion Irradiation-Induced Mutagenesis of Aspergillus niger and Mixed Fermentation with Trichoderma reesei

Science.gov (United States)

Chen, Ji-Hong; Li, Wen-Jian; Liu, Jing; Hu, Wei; Xiao, Guo-Qing; Dong, Miao-Yin; Wang, Yu-Chen

2015-01-01

The aim of this study was to evaluate and validate the efficiency of 12C6+ irradiation of Aspergillus niger (A. niger) or mutagenesis via mixed Trichoderma viride (T. viride) culturing as well as a liquid cultivation method for cellulase production via mixed Trichoderma reesei (T. reesei) and A. niger culture fermentation. The first mutagenesis approach was employed to optimize yield from a cellulase-producing strain via heavy-ion mutagenesis and high-throughput screening, and the second was to effectively achieve enzymatic hydrolysis of cellulase from a mixed culture of mutant T. viride and A. niger. We found that 12C6+-ion irradiation induced changes in cellulase biosynthesis in A. niger but had no effect on the time course of the synthesis. It is notable that the exoglucanases (CBH) activities of A. niger strains H11-1 and H differed (6.71 U/mL vs. 6.01 U/mL) and were significantly higher than that of A. niger mutant H3-1. Compared with strain H, the filter paper assay (FPA), endoglucanase (EG) and β-glucosidase (BGL) activities of mutant strain H11-1 were increased by 250.26%, 30.26% and 34.91%, respectively. A mixed culture system was successfully optimized, and the best ratio of T. reesei to A. niger was 5:1 for 96 h with simultaneous inoculation. The BGL activity of the mixed culture increased after 72 h. At 96 h, the FPA and BGL activities of the mixed culture were 689.00 and 797.15 U/mL, respectively, significantly higher than those of monocultures, which were 408.70 and 646.98 U/mL for T. reesei and 447.29 and 658.89 U/mL for A. niger, respectively. The EG activity of the mixed culture was 2342.81 U/mL, a value that was significantly higher than that of monocultures at 2206.57 U/mL for T. reesei and 1727.62 U/mL for A. niger. In summary, cellulose production and hydrolysis yields were significantly enhanced by the proposed combination scheme. PMID:26656155

Study of a High-Yield Cellulase System Created by Heavy-Ion Irradiation-Induced Mutagenesis of Aspergillus niger and Mixed Fermentation with Trichoderma reesei.

Directory of Open Access Journals (Sweden)

Shu-Yang Wang

Full Text Available The aim of this study was to evaluate and validate the efficiency of 12C6+ irradiation of Aspergillus niger (A. niger or mutagenesis via mixed Trichoderma viride (T. viride culturing as well as a liquid cultivation method for cellulase production via mixed Trichoderma reesei (T. reesei and A. niger culture fermentation. The first mutagenesis approach was employed to optimize yield from a cellulase-producing strain via heavy-ion mutagenesis and high-throughput screening, and the second was to effectively achieve enzymatic hydrolysis of cellulase from a mixed culture of mutant T. viride and A. niger. We found that 12C6+-ion irradiation induced changes in cellulase biosynthesis in A. niger but had no effect on the time course of the synthesis. It is notable that the exoglucanases (CBH activities of A. niger strains H11-1 and H differed (6.71 U/mL vs. 6.01 U/mL and were significantly higher than that of A. niger mutant H3-1. Compared with strain H, the filter paper assay (FPA, endoglucanase (EG and β-glucosidase (BGL activities of mutant strain H11-1 were increased by 250.26%, 30.26% and 34.91%, respectively. A mixed culture system was successfully optimized, and the best ratio of T. reesei to A. niger was 5:1 for 96 h with simultaneous inoculation. The BGL activity of the mixed culture increased after 72 h. At 96 h, the FPA and BGL activities of the mixed culture were 689.00 and 797.15 U/mL, respectively, significantly higher than those of monocultures, which were 408.70 and 646.98 U/mL for T. reesei and 447.29 and 658.89 U/mL for A. niger, respectively. The EG activity of the mixed culture was 2342.81 U/mL, a value that was significantly higher than that of monocultures at 2206.57 U/mL for T. reesei and 1727.62 U/mL for A. niger. In summary, cellulose production and hydrolysis yields were significantly enhanced by the proposed combination scheme.

Value addition of vegetable wastes by solid-state fermentation using Aspergillus niger for use in aquafeed industry.

Science.gov (United States)

Rajesh, N; Imelda-Joseph; Raj, R Paul

2010-11-01

Vegetable waste typically has high moisture content and high levels of protein, vitamins and minerals. Its value as an agricultural feed can be enhanced through solid-state fermentation (SSF). Two experiments were conducted to evaluate the nutritional status of the products derived by SSF of a mixture of dried vegetable waste powder and oil cake mixture (soybean flour, wheat flour, groundnut oil cake and sesame oil cake at 4:3:2:1 ratio) using fungi Aspergillus niger S(1)4, a mangrove isolate, and A. niger NCIM 616. Fermentation was carried out for 9 days at 35% moisture level and neutral pH. Significant (p<0.05) increase in crude protein and amino acids were obtained in both the trials. The crude fat and crude fibre content showed significant reduction at the end of fermentation. Nitrogen free extract (NFE) showed a gradual decrease during the fermentation process. The results of the study suggest that the fermented product obtained on days 6 and 9 in case of A. niger S(1)4 and A. niger NCIM 616 respectively contained the highest levels of crude protein. Copyright © 2010 Elsevier Ltd. All rights reserved.

Triangulation, Emotional Reactivity, and Violence in the Niger Delta

Directory of Open Access Journals (Sweden)

Benjamin Aigbe Okonofua

2013-04-01

Full Text Available The Niger Delta conflict, for many years, was blamed on myriad forces, including greed, economic exploitation, pollution and ecological damage, resource appropriation and distribution disputes, ethno-religious antagonisms, poverty, unemployment, large-scale infrastructural deficits, corruption, militarization of oil producing communities and election processes, sociopolitical marginalization, cultism, and weapons proliferation. While all of these issues are important, they are not nearly as important as the deliberate roles played by high-level social, economic, and political interests who activated violence as a means to secure economic advantage from the delta’s oil industry. This study shines the light on this small, exclusive, and very powerful group whose actions triggered off the violence and yet are at the center of efforts to institute peace including the current disarmament, demobilization, and reintegration (DDR program. I argue that unless the contributions of these powerful interests are carefully teased out and the structures they have built to advantage themselves from the conflict are dismantled, peace will remain elusive in the Niger Delta.

The influence of Aspergillus niger inoculum dosage on nutritive value and metabolizable energy of apu-apu meal (Pistia stratiotes L.) on broiler chicken

Science.gov (United States)

Gloria, J.; Tafsin, M.; Hanafi, N. D.; Daulay, A. H.

2018-02-01

Apu-apu lives at tropical and subtropical fresh waterways. The apu-apu meals ultization as feed still limited. The problem of ultization apu-apu meals as ingredients is a high crude fiber and need a treatment to decrease crude fiber. This study aim to find out the influence of Aspergillus niger inoculums dosage on apu-apu meal (Pistia stratiotes L.) on metabolizable energy on broiler chicken. This research used completely randomize design (CRD). The treatments consists of Aspergillus niger inoculum dosage (CFU/g) such as P0 (0), P1 (104 CFU/g), P2 (106 CFU/g), and P3 (108 CFU/g). The variable were observed : apparent metabolizable energy (AME), true metabolizable energy (TME), apparent metabolizable energy nitrogen corrected (AMEn) and true metabolizable energy nitrogen corrected (TMEn).The results showed that the dosage of Aspergillus niger increase nutritive value of Aspergillus niger. Dosage of Aspergillus niger also influence (P<0.05) metabolizable energy of apu-apu meals. Dosage 108 CFU/g had metabolizable energy significantly higher than other treatments. Conclusion of this research is the Aspergillus niger at the dosage 108 CFU/g increased nutritive value and metabolizable energy of apu-apu meal.

Engineering properties of the crude oil–contaminated soils of Niger ...

African Journals Online (AJOL)

There was a reverse trend when soil samples with appreciable percentages of sand and crude oil of low THC were used. The knowledge of these will aid geotechnical engineers on their designs and remediation techniques. Keywords: Engineering properties, soils, crude oil, hydrocarbon, Niger Delta, Nigeria ...

Comparative study of Aspergillus niger and Penicillium sp. in the ...

African Journals Online (AJOL)

STORAGESEVER

2010-06-14

Jun 14, 2010 ... The comparative study of Aspergillus niger and Penicillium sp. in the biodegradation of automotive gas oil (AGO) and premium motor spirit (PMS) was carried out to ascertain the effectiveness of using these microorganisms in cleaning and restoring the ecosystem when polluted by petroleum products.

PENGGUNAAN Aspergilus niger YANG DIRADIASI GAMMA SEBAGAI BIOREMEDIAN RESIDU TRIAZOFOS DAN LOGAM BERAT PADA BAWANG MERAH (Allium cepa L.

Directory of Open Access Journals (Sweden)

Beny Maulana Satria

2015-06-01

Full Text Available The use of pesticides and fertilizers containing Pb in agriculture will leave residues in soil, water, and plants. This Pb will be accumulated in the human body and, have a negative impact gradually on human health. The use of gamma-irradiation of Aspergillus niger is expected to reduce the levels of metals and residues triazofos onions. Bioremediation technique using gamma rays against a. niger is still quite a bit or a new research so the research on this is still a little The purpose of this study was to determine the effectiveness of technology A. niger low dose gamma irradiation in reducing heavy metals and low triazofos residue on onion. Apergillus niger low dose gamma irradiated, mixed with organic materials such as Kohe, rice husk and bran. The mixture is fermented for 8 days and then applied to the soil of onion in Bradford to measure levels of Pb and triazofosnya residue. The Atomic Absorption Spectrophotometer (AAS and Gas Chromatography Mass Spectrophotometer (GCMS was used in this study. The result showed Pb that goes into the water very small and more are stuck in the ground and Pb accumulated in onion is still quite high. Triazofos residue concentrations in onions undetectable or very low in quality standards established under 0,005 ppm. The conclusion of this study, Aspergillus niger were not irradiated and irradiated can withstand heavy metals Pb in soil so it goes into the water a little, but not optimal in Pb which adsorbs into the onion and pesticide residues on onions Triazofos undetected.Keywords: Aspergillus niger, residual triazofos, gamma radiation, onion

Biosorption of heavy metals by pretreated biomass of aspergillus niger

International Nuclear Information System (INIS)

Javaid, A.; Bajwa, R.; Manzoor, T.

2011-01-01

The present study reports the bio sorption potential of chemically pretreated mycelial biomass of fungus Aspergillus niger van. Tieghem for Cu(II) and Ni(II) ions from aqueous phase. Fungal biomass was pretreated with different types of alkaline/salts (NaOH, NaHCO/sub 3/, Na/sub 2/CO/sub 3/, NaCl and CaCl/sub 2/), acids (HCl and H/sub 2/SO/sub 4/) and detergent. Pretreatment of biomass with Na/sub 2/CO/sub 3/ and NaOH were proved to increase or maintain adsorption efficiency and capacity in comparison to untreated biomass. Pretreatment with NaHCO/sub 3/, detergent, NaCl and CaCl/sub 2/ significantly reduce (10-40%) metal sequestering efficiency of the adsorbent. Whereas, acid treatments resulted in drastic loss (80%) in metal uptake efficiency of the biomass. Amongst various pretreatments, Na/sub 2/CO/sub 3/ could be use efficiently for the removal of Ni(II) and Cu(II) ions from aqueous solution using A. niger. (author)

Production of Proteolytic Enzymes by a Keratin-Degrading Aspergillus niger

Directory of Open Access Journals (Sweden)

Fernanda Cortez Lopes

2011-01-01

Full Text Available A fungal isolate with capability to grow in keratinous substrate as only source of carbon and nitrogen was identified as Aspergillus niger using the sequencing of the ITS region of the rDNA. This strain produced a slightly acid keratinase and an acid protease during cultivation in feather meal. The peak of keratinolytic activity occurred in 48 h and the maximum proteolytic activity in 96 h. These enzymes were partly characterized as serine protease and aspartic protease, respectively. The effects of feather meal concentration and initial pH on enzyme production were evaluated using a central composite design combined with response surface methodology. The optimal conditions were determined as pH 5.0 for protease and 7.8 for keratinase and 20 g/L of feather meal, showing that both models were predictive. Production of keratinases by A. niger is a less-exploited field that might represent a novel and promising biotechnological application for this microorganism.

Panacea for Youth Restiveness in the Niger Delta Region of Nigeria

African Journals Online (AJOL)

FIRST LADY

Egbe, Aneozeng A. - Department of Business Administration Cross River. University of .... insecurity and violence that is easily identifiable in the Niger Delta region. These oil and ... start and meticulously nurture its growth to maturity. This is the ...

Ibani (Niger Delta) Traditional Religion and Social Morality | Jaja ...

African Journals Online (AJOL)

The Ibani is of the Ijo extraction in the Niger Delta of Nigeria. The belief in a Supreme Being called Tamuno but also on multitude of deities because of the environment in which they live. They believe that these deities perform social functions that stabilize society. Ibani cosmology revolve round the tripod – God, deities and ...

Flood vulnerability: Impending danger in Sabon-Gari Minna, Niger ...

African Journals Online (AJOL)

This study examines the vulnerability of buildings to flooding and the danger posed at Sabo Gari area of Minna, Niger State. Sabon-Gari which is one of the 22 neighborhoods found in Minna is a highly populated area as people who cannot afford to stay in the low density areas (Government Reserve Area - G.R.A) move to ...

Application of glucoamylase produced by aspergillus niger mutant a. S. 3. 4309 in alcohol industry

Energy Technology Data Exchange (ETDEWEB)

1981-01-01

A glucoamylase (I) A. niger mutant was used for the industrial-scale production of EtOH. Thus, enough A. niger A.S. 3.4309 equiv to 63-79 units I/g substrate was added to a medium (pH 4.5) containing 6-10% corn powder, 2% corn steep liquor, and 2% soybean powder. The mixture was first saccharified at 55-60 degrees and then fermented at 30 degrees for 72 hours. The production of EtOH was approximately 13 tons in a 5000 L fermentor system.

National presentation on Introduction of National Nuclear Power (NNP) in Niger

International Nuclear Information System (INIS)

Moutapha, S.T

2010-01-01

Niger is one of the world largest uranium producers with 62 % of Electricity needs imported. Decision was made in May 2009 with an official notification of Niger to the IAEA to consider a NPP. Discussions with IAEA Director General and his staff have been conducted in Vienna on broad considerations of NPP. The Ministry of Mines and Energy has been mandated to coordinate the established of a strategy for the NPP. For the moment, there is not any draft law but the nuclear regulatory body CNRP is the Central Regulatory Body. IRRS mission (2006): Evaluate the CNRP status and activities to the requirements of GS-R-1. CNRP actually performed Self-Assessment with IAEA SATCNRP responsibilities: Developing and implementing Regulations in RP; nuclear safety and security; Issuing authorizations; Performing controls and inspections in nuclear and radiological activities and facilities

Regulatory processes in Aspergillus niger

DEFF Research Database (Denmark)

Poulsen, Lars

characteristics, as a lower oxalic ii acid formation and wild type growth performance; it was therefore argued that this strain could be an attractive alternative to ΔprtT. Finally, in order to characterize the formation of the carcinogenic mycotoxin fumonisin, a reporter strain of A. niger was constructed, where...... the promoter from the fumonisin synthase was fused to the green fluorescent protein. This strain was used together with the commercial large-scale nutrient profiling platform, Biolog Phenotype MicroArrays. Out of the 476 conditions tested, six compounds significantly induce fumonisin production, identified....... These formed the basis for the subsequent examinations, which resulted in the identification of azelaic acid, a plant hormone and a very potent fumonisin inducer....

Northern blotting analysis

DEFF Research Database (Denmark)

Josefsen, Knud; Nielsen, Henrik

2011-01-01

is analysed by hybridization to one or more specific probes that are labelled for subsequent detection. Northern blotting is relatively simple to perform, inexpensive, and not plagued by artefacts. Recent developments of hybridization membranes and buffers have resulted in increased sensitivity closing...

Effects of Aspergillus niger treated Shea butter cake based diets on ...

African Journals Online (AJOL)

STORAGESEVER

2008-05-02

May 2, 2008 ... Full Length Research Paper. Effects of Aspergillus niger treated ... nutritional factors and high content of lignin which prevents the ... environment contains 15.02% CP, 26.00% cellulose,. 55.40% acid ... Corn bran. 50.00. 50.00.

politics of conflict oilification and petro-violence in the niger delta

African Journals Online (AJOL)

DJFLEX

KEY WORDS: Conflict, Oilification, Petro-violence, Niger Delta ..... state's conflict management strategy that seems to give fillip to ..... sum game of the state takes all. .... Online: http://www.njas.helsinki.fi\\pdf files\\vol. 14 num. 2\\Ikelegbe.pdf.

Towards ending conflict and insecurity in the Niger Delta region: A ...

African Journals Online (AJOL)

Towards ending conflict and insecurity in the Niger Delta region: A collective ... State as conflicts in different parts of the country have continued to make life insecure. ... Findings from the work show that the Federal Government's approach to ...

Northern Sotho grammatical descriptions: the design of a tokeniser ...

African Journals Online (AJOL)

Since Northern Sotho uses the disjunctive method of writing, it creates difficulties for the morphological analyser to correctly analyse Northern Sotho verbs. In order to overcome this obstacle a tokeniser, which could isolate verbs from raw texts, needs to be created. The verbal element a ka be a se a re šadišetša 'he had not ...

Lipase production by recombinant strains of Aspergillus niger expressing a lipase-encoding gene from Thermomyces lanuginosus

DEFF Research Database (Denmark)

Prathumpai, Wai; Flitter, S.J.; Mcintyre, Mhairi

2004-01-01

Two recombinant strains of Aspergillus niger (NW 297-14 and NW297-24) producing a heterologous lipase from Thermomyces lanuginosus were constructed. The heterologous lipase was expressed using the TAKA amylase promoter from Aspergillus oryzae. The production kinetics of the two strains on different...... shows that it is possible to obtain high productivities of heterologous fungal enzymes in A. niger. However, SDS-PAGE analysis showed that most of the produced lipase was bound to the cell wall....

Socio-economic activities of fisher folk in Niger Delta, Nigeria ...

African Journals Online (AJOL)

This study examined the socio-economic activities and potentials of rural fisher folk in Niger Delta, Nigeria. One thousand and two hundred (1,200) structured questionnaires were administered to fisher folks in one hundred (100) fishing communities, and only one thousand (1000) were retrieved. The questionnaires dealt ...

assessment of millennium development goal 7 in the niger delta ...

African Journals Online (AJOL)

user

the largest in Africa and is second only to Russia in gas flaring [3]. The Niger ..... emission values of CO2, CH4 and N2O, and BC and GHGs from 1990 to .... Billion. This value consists of the cost of gas flared ..... Private Partnership. Washington ...

In-situ thermal conductivity estimates in the Western Niger Delta ...

African Journals Online (AJOL)

An estimate of thermal conductivity was carried out in 21 well-spaced petroleum wells in the western Niger Delta using sonic and continuous temperature logs. The temperature logs were measured after the wells had attained thermal equilibrium as a result of drilling activities. Regional thermal conductivity varies from ...

Mannitol is required for stress tolerance in Aspergillus niger conidiospores

NARCIS (Netherlands)

Ruijter, G.J.G.; Bax, M.; Patel, H.; Flitter, S.J.; Vondervoort, van de P.J.I.; Vries, de R.P.; Kuyk, van P.A.; Visser, J.

2003-01-01

D-Mannitol is the predominant carbon compound in conidiospores of the filamentous fungus Aspergillus niger and makes up 10 to 15% of 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

Comparative study of Aspergillus niger and Penicillium sp. in the ...

African Journals Online (AJOL)

The comparative study of Aspergillus niger and Penicillium sp. in the biodegradation of automotive gas oil (AGO) and premium motor spirit (PMS) was carried out to ascertain the effectiveness of using these microorganisms in cleaning and restoring the ecosystem when polluted by petroleum products. These fungi were ...

The Niger Delta wetlands: Threats to ecosystem services, their importance to dependent communities and possible management measures

OpenAIRE

Adekola, O.; Mitchell, G.

2011-01-01

The Niger Delta wetlands are changing rapidly, raising concern for the wetlands' health and for communities relying upon its ecosystem services. Knowledge on ecosystem service provision is important for effective ecosystem and livelihoods management, but is currently lacking for the Niger Delta. We synthesised literature and used the ‘Drivers–pressure–state–impact–response’ (DPSIR) framework to structure information on changes in the wetlands' ecosystem services and implications for dependent...

The Portrayal of Liberation and the Niger Delta Question in Arnold Udoka’s Akon, Long Walk to a Dream and Iyene: A Dance Drama

Directory of Open Access Journals (Sweden)

Jonas Egbudu Akung

2016-05-01

Full Text Available Nigeria’s Niger Delta has become a thorny issue in the multidisciplinary intellectual discourse in the sense that local inequalities have assumed global dimensions. Human rights have been violated by the Nigerian government and global multi-national oil companies in such a way that make the Niger delta an environmental disaster zone. This problem has spawned local insurrections in the Niger Delta as multinational oil companies have had to either quit the zone or re-organize their modus operandi, with a general impact on Nigeria’s economy. From the time of the state-murdered Ogoni writer and environmentalist, Ken Saro Wiwa and Adaka Boro before him, these problems have been articulated through various forms of political and literary expressions. One of such literary expressions is Arnold Udoka’s plays which form the bases for analysis of the issues in this paper. Using the Marxist paradigm which enables inter-disciplinarily, this study takes a deeper look at the many variations of inequalities that have led to the Niger Delta problem. One of such is the gender question in the Niger Delta which Arnold Udoka articulates in Akon, which investigates the place of women in the political liberation of Nigeria, particularly in the Niger Delta region. There is also the Niger Delta question in Long Walk to a Dream which explores the struggle of the people of this region to live a meaningful life in the midst of their environmental challenges. Iyene on the other hand looks at the global dimension of multinational companies and the local elites in resolving the Niger Delta question, which has become a wasteland. This is particularly so because the Nigerian Land Use Act vests the ownership of land on the government which in turn has led to multiple violations of the peoples’ rights. It is therefore the position of this paper that the armed struggle, militancy, kidnapping in the Niger Delta are different manifestations of the aspiration of the violated

High yield of amylase from Aspergillus niger by the effect of gamma irradiation

Energy Technology Data Exchange (ETDEWEB)

El-Saadany, R.M.A.; Salem, F.A.; El-Manawaty, H.K.

1984-02-01

When irradiated rice was used as a media for Aspergillus niger a noticeable increase of amylase production was observed. Molecular degradation of starch molecules did occur, and an increase in starch acidity and solubility was noticed, whereas a marked decrease in viscosity as well as swelling capacity was observed. Gelatinization time and temperature of irradiated starch became shorter or lower resp. These results showed that internal changes in irradiated starch molecules and an alteration in its molecular configuration occured. They may affect the pathway of the growth of the fungi Aspergillus niger. When the amount of amylase was determined by measuring enzyme activity, it was observed that amylases in the irradiated media were higher than in the control media.

Vegetative Propagation Trial of Prosopis africana (Guill. et Perr.) Taub. by Air Layering under Sudano-Sahelian Climate in the South-Central Niger

OpenAIRE

Abdou, Laouali; Karim, Saley; Habou, Rabiou; Mahamane, Ali

2015-01-01

Prosopis africana is a species of great socioeconomic importance but threatened with extinction in Niger because of overuse and regeneration problem. This study, conducted in the Maradi (Niger) area, precisely at El Gueza in the south of Gazaoua department, aims to evaluate the vegetative propagation capacity of P. africana by air layering under the Sudano-Sahelian climate of the south-central Niger. A ring of bark was taken on each selected branch and the wound was covered with a black plast...

Conflict and Conflict Resolution in the Niger-Delta the Bayelsa ...

African Journals Online (AJOL)

Conflicts, crisis, youths restiveness, hostage taking, kidnapping are recent phenomena that appear synonymous with the Niger Delta, the oil rich region of the Nigerian Nation-State. This region serves as the economic nerve center of the federation. Since the discovery and the production of oil in commercial quantities in ...

Structures Deduced From Gravity Data In The Lower Niger Benue ...

African Journals Online (AJOL)

Based on a recent gravity data collected over the area, the Lower Niger and Lower Benue basins are interpreted to comprise five major structural zones. The locations, trends, extent and relationships between most previously known structures in the area are confirmed and detailed by the data. However, the structure ...

Evolution of the Niger Delta, present dynamics and the future ...

African Journals Online (AJOL)

Evolution of the Niger Delta is closely linked to the geodynamics related to the separation of the African and South American continents and the tectonics of the formation of the Benue Trough. Tectonic activities, climate and eustasy are the major factors responsible for transgression and regression through the entrant point ...

What are pregnant women in a rural Niger Delta community's ...

African Journals Online (AJOL)

To date, studies have sought cause and effect and have neglected the opinion of the people about what they perceive to be problematic and what they believe constitutes satisfactory maternity service provision. An exploratory qualitative study was carried out to identify pregnant women in a rural Niger Delta community's ...

In vivo and in vitro control activity of plant essential oils against three strains of Aspergillus niger.

Science.gov (United States)

Kumar, Peeyush; Mishra, Sapna; Kumar, Atul; Kumar, Sanjeev; Prasad, Chandra Shekhar

2017-09-01

Contamination of environment and food from the prevalent spores and mycotoxins of Aspergillus niger has led to several diseases in humans and other animals. The present study investigated the control activity of plant essential oils against three strains of A. niger. In the elaborate assays done through microdilution plate assay and agar disk diffusion assay in the lab condition and in vivo assay on the stored wheat grains, the essential oil of Thymus vulgaris depicted overall superior efficacy. In microdilution plate assay, the oil of Anethum graveolens showed best fungistatic activity, while best fungicidal activity was depicted by Syzygium aromaticum oil. The oil of T. vulgaris showed moderate control efficacy against A. niger strains with its antifungal activity resulting mainly due to killing of microorganism rather than growth inhibition. In agar disk diffusion assay, T. vulgaris oil with a zone of inhibition (ZOI) of 23.3-61.1% was the most effective fungicide. The in vivo assay to evaluate the protection efficacy of oils for stored wheat grains against A. niger (AN1) revealed T. vulgaris (90.5-100%) to be the best control agent, followed by the oil of S. aromaticum (61.9-100%). The GC-MS analysis of T. vulgaris oil indicated the presence of thymol (39.11%), γ-terpinene (19.73%), o-cymene (17.21%), and β-pinene (5.38%) as major oil components. Phytotoxic effects of the oils on wheat seeds showed no significant phytotoxic effect of oils in terms of seed germination or seedling growth. The results of the study demonstrated control potentiality of essential oils for the protection of stored wheat against A. niger with prospect for development of eco-friendly antifungal products.

Comprehensive reconstruction and in silico analysis of Aspergillus niger genome-scale metabolic network model that accounts for 1210 ORFs.

Science.gov (United States)

Lu, Hongzhong; Cao, Weiqiang; Ouyang, Liming; Xia, Jianye; Huang, Mingzhi; Chu, Ju; Zhuang, Yingping; Zhang, Siliang; Noorman, Henk

2017-03-01

Aspergillus niger is one of the most important cell factories for industrial enzymes and organic acids production. A comprehensive genome-scale metabolic network model (GSMM) with high quality is crucial for efficient strain improvement and process optimization. The lack of accurate reaction equations and gene-protein-reaction associations (GPRs) in the current best model of A. niger named GSMM iMA871, however, limits its application scope. To overcome these limitations, we updated the A. niger GSMM by combining the latest genome annotation and literature mining technology. Compared with iMA871, the number of reactions in iHL1210 was increased from 1,380 to 1,764, and the number of unique ORFs from 871 to 1,210. With the aid of our transcriptomics analysis, the existence of 63% ORFs and 68% reactions in iHL1210 can be verified when glucose was used as the only carbon source. Physiological data from chemostat cultivations, 13 C-labeled and molecular experiments from the published literature were further used to check the performance of iHL1210. The average correlation coefficients between the predicted fluxes and estimated fluxes from 13 C-labeling data were sufficiently high (above 0.89) and the prediction of cell growth on most of the reported carbon and nitrogen sources was consistent. Using the updated genome-scale model, we evaluated gene essentiality on synthetic and yeast extract medium, as well as the effects of NADPH supply on glucoamylase production in A. niger. In summary, the new A. niger GSMM iHL1210 contains significant improvements with respect to the metabolic coverage and prediction performance, which paves the way for systematic metabolic engineering of A. niger. Biotechnol. Bioeng. 2017;114: 685-695. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

The Situations Bank, a Tool for Curriculum Design Focused on Daily Realities: The Case of the Reform in Niger

Science.gov (United States)

Charland, Patrick; Cyr, Stéphane

2013-01-01

In the context of the curriculum reform in Niger, the authors describe the process of developing a situations bank which focusses on everyday life situations in Niger. The bank plays a central role in the formulation of new study programmes guided by the so-called "situated" approach. The authors also describe various issues that arose…

Decolorization and detoxification of Synozol red HF-6BN azo dye, by Aspergillus niger and Nigrospora sp

Directory of Open Access Journals (Sweden)

Sidra Ilyas

2013-01-01

Full Text Available In the present investigation the fungi, Aspergillus niger and Nigrospora sp. were employed for decolorization of Synazol red HF-6BN. Decolorization study showed that Aspergillus niger and Nigrospora sp. were able to decolorize 88% and 96% Synazol red 6BN, respectively, in 24 days. It was also studied that 86% and 90% Synazol red containing of dye effluent was decolorized by Aspergillus niger and Nigrospora sp. after 28 days of incubation at room temperature. A fungal-based protein with relative molecular mass of 70 kDa was partially purified and examined for enzymatic characteristics. The enzyme exhibited highest activity at temperature ranging from 40-50[degree sign]C and at pH=6.0. The enzyme activity was enhanced in the presence of metal cations. High performance liquid chromatography analysis confirmed that these fungal strains are capable to degrade Synazol red dye into metabolites. No zones of inhibition on agar plates and growth of Vigna radiata in the presence of dye extracted sample, indicated that the fungal degraded dye metabolites are nontoxic to beneficial micro-flora and plant growth. Aspergillus niger and Nigrospora sp. have promising potential in color removal from textile wastewater-containing azo dyes.

Spatially resolving the secretome within the mycelium of the cell factory Aspergillus niger.

Science.gov (United States)

Krijgsheld, Pauline; Altelaar, A F Maarten; Post, Harm; Ringrose, Jeffrey H; Müller, Wally H; Heck, Albert J R; Wösten, Han A B

2012-05-04

Aspergillus niger is an important cell factory for the industrial production of enzymes. These enzymes are released into the culture medium, from which they can be easily isolated. Here, we determined with stable isotope dimethyl labeling the secretome of five concentric zones of 7-day-old xylose-grown colonies of A. niger that had either or not been treated with cycloheximide. As expected, cycloheximide blocked secretion of proteins at the periphery of the colony. Unexpectedly, protein release was increased by cycloheximide in the intermediate and central zones of the mycelium when compared to nontreated colonies. Electron microscopy indicated that this is due to partial degradation of the cell wall. In total, 124 proteins were identified in cycloheximide-treated colonies, of which 19 secreted proteins had not been identified before. Within the pool of 124 proteins, 53 secreted proteins were absent in nontreated colonies, and additionally, 35 proteins were released ≥4-fold in the central and subperipheral zones of cycloheximide-treated colonies when compared to nontreated colonies. The composition of the secretome in each of the five concentric zones differed. This study thus describes spatial release of proteins in A. niger, which is instrumental in understanding how fungi degrade complex substrates in nature.

Rewiring a secondary metabolite pathway towards itaconic acid production in Aspergillus niger.

Science.gov (United States)

Hossain, Abeer H; Li, An; Brickwedde, Anja; Wilms, Lars; Caspers, Martien; Overkamp, Karin; Punt, Peter J

2016-07-28

The industrially relevant filamentous fungus Aspergillus niger is widely used in industry for its secretion capabilities of enzymes and organic acids. Biotechnologically produced organic acids promise to be an attractive alternative for the chemical industry to replace petrochemicals. Itaconic acid (IA) has been identified as one of the top twelve building block chemicals which have high potential to be produced by biotechnological means. The IA biosynthesis cluster (cadA, mttA and mfsA) has been elucidated in its natural producer Aspergillus terreus and transferred to A. niger to enable IA production. Here we report the rewiring of a secondary metabolite pathway towards further improved IA production through the overexpression of a putative cytosolic citrate synthase citB in a A. niger strain carrying the IA biosynthesis cluster. We have previously shown that expression of cadA from A. terreus results in itaconic acid production in A. niger AB1.13, albeit at low levels. This low-level production is boosted fivefold by the overexpression of mttA and mfsA in itaconic acid producing AB1.13 CAD background strains. Controlled batch cultivations with AB1.13 CAD + MFS + MTT strains showed increased production of itaconic acid compared with AB1.13 CAD strain. Moreover, preliminary RNA-Seq analysis of an itaconic acid producing AB1.13 CAD strain has led to the identification of the putative cytosolic citrate synthase citB which was induced in an IA producing strain. We have overexpressed citB in a AB1.13 CAD + MFS + MTT strain and by doing so hypothesize to have targeted itaconic acid production to the cytosolic compartment. By overexpressing citB in AB1.13 CAD + MFS + MTT strains in controlled batch cultivations we have achieved highly increased titers of up to 26.2 g/L IA with a productivity of 0.35 g/L/h while no CA was produced. Expression of the IA biosynthesis cluster in Aspergillus niger AB1.13 strain enables IA production. Moreover, in the AB1.13 CAD

Mycological Assessment of Suya Sold in Some Parts of Minna, Niger ...

African Journals Online (AJOL)

Admin

different locations A total of fifty seven (57) fungi isolates were obtained from suya in all sampled locations. Fungi species such as Candida tropicalis, Penicillium chrysogenum,. Aspergillus niger Mucor spp, Aspergillus flavus ,Fusarium oxysporum, Penicillium digitatum,. Fusarium solanii, Rhizopus stolonifer and Aspergillus ...

A functional genomics study of extracellular protease production by Aspergillus niger

NARCIS (Netherlands)

Braaksma, Machtelt

2010-01-01

The objective of the project described in this thesis was to study the complex induction of extracellular proteases in the filamentous fungus Aspergillus niger using information gathered with functional genomics technologies. A special emphasis is given to the requirements for performing a

Winter diets of immature green turtles (Chelonia mydas) on a northern feeding ground: integrating stomach contents and stable isotope analyses

Science.gov (United States)

Williams, Natalie C.; Bjorndal, Karen A.; Lamont, Margaret M.; Carthy, Raymond R.

2015-01-01

The foraging ecology and diet of the green turtle, Chelonia mydas, remain understudied, particularly in peripheral areas of its distribution. We assessed the diet of an aggregation of juvenile green turtles at the northern edge of its range during winter months using two approaches. Stomach content analyses provide a single time sample, and stable isotope analyses integrate diet over a several-month period. We evaluated diet consistency in prey choice over time by comparing the results of these two approaches. We examined stomach contents from 43 juvenile green turtles that died during cold stunning events in St. Joseph Bay, Florida, in 2008 and 2011. Stomach contents were evaluated for volume, dry mass, percent frequency of occurrence, and index of relative importance of individual diet items. Juvenile green turtles were omnivorous, feeding primarily on seagrasses and tunicates. Diet characterizations from stomach contents differed from those based on stable isotope analyses, indicating the turtles are not feeding consistently during winter months. Evaluation of diets during warm months is needed.

Antifungal mechanism of antibacterial peptide, ABP-CM4, from Bombyx mori against Aspergillus niger.

Science.gov (United States)

Zhang, Jie; Wu, Xi; Zhang, Shuang-Quan

2008-12-01

Antibacterial peptide, CM4 (ABP-CM4), a 35 amino acid peptide from Chinese silkworm-Bombyx mori, displayed a strong antifungal activity against Aspergillus niger, Trichoderma viride and Gibberella saubinetii. Scanning electron microcopy showed that the morphology of conidia became more irregular and swelled when treated with ABP-CM4 at its minimal inhibitory concentration (MIC) of 8 muM. A cell wall regeneration assay indicated that the plasma membrane was the prime target of ABP-CM4 action. Confocal laser scanning microscopy showed that the cytoskeleton of A. niger was destroyed when treated with ABP-CM4 at 8 muM. Furthermore, transmission electron microscopy showed that the membrane and the cellular organelles of fungus were disrupted and there were many vacuoles in the fungal cellular space after the treatment with ABP-CM4. A gel-retardation assay showed that ABP-CM4 bound the DNA of A. niger. Our results suggest that ABP-CM4 exerts its antifungal activity by disrupting the structure of cell membranes and the cytoskeleton and interacts with the organelles, such as the mitochondrion and with the DNA in the fungal cell, subsequently resulting in cell death.

Production of vanillin from waste residue of rice bran oil by Aspergillus niger and Pycnoporus cinnabarinus.

Science.gov (United States)

Zheng, Lirong; Zheng, Pu; Sun, Zhihao; Bai, Yanbing; Wang, Jun; Guo, Xinfu

2007-03-01

A new technology of transforming ferulic acid, which was from waste residue of rice bran oil, into vanillin was developed by a combination of fungal strains Aspergillus niger CGMCC0774 and Pycnoporus cinnabarinus CGMCC1115. Various concentrations of ferulic acid were compared, and the highest yield reached 2.2 g l(-1) of vanillic acid by A. niger CGMCC0774 in a 25 l fermenter when concentration of ferulic acid was 4 g l(-1). The filtrate of A. niger CGMCC0774 culture was concentrated and vanillic acid in the filtrate was bio-converted into vanillin by P. cinnabarinus CGMCC1115. The yield of vanillin reached 2.8 g l(-1) when 5 g l(-1) of glucose and 25 g of HZ802 resin were supplemented in the bioconversion medium. The 13C isotope analysis indicated that delta13C(PDB) of vanillin prepared was much different from chemically synthesized vanillin.

Whole-Genome Characterization of Epidemic Neisseria meningitidis Serogroup C and Resurgence of Serogroup W, Niger, 2015

Science.gov (United States)

Kretz, Cecilia B.; Retchless, Adam C.; Sidikou, Fati; Issaka, Bassira; Ousmane, Sani; Schwartz, Stephanie; Tate, Ashley H.; Pana, Assimawè; Njanpop-Lafourcade, Berthe-Marie; Nzeyimana, Innocent; Nse, Ricardo Obama; Deghmane, Ala-Eddine; Hong, Eva; Brynildsrud, Ola Brønstad; Novak, Ryan T.; Meyer, Sarah A.; Oukem-Boyer, Odile Ouwe Missi; Ronveaux, Olivier; Caugant, Dominique A.; Taha, Muhamed-Kheir

2016-01-01

In 2015, Niger reported the largest epidemic of Neisseria meningitidis serogroup C (NmC) meningitis in sub-Saharan Africa. The NmC epidemic coincided with serogroup W (NmW) cases during the epidemic season, resulting in a total of 9,367 meningococcal cases through June 2015. To clarify the phylogenetic association, genetic evolution, and antibiotic determinants of the meningococcal strains in Niger, we sequenced the genomes of 102 isolates from this epidemic, comprising 81 NmC and 21 NmW isolates. The genomes of 82 isolates were completed, and all 102 were included in the analysis. All NmC isolates had sequence type 10217, which caused the outbreaks in Nigeria during 2013–2014 and for which a clonal complex has not yet been defined. The NmC isolates from Niger were substantially different from other NmC isolates collected globally. All NmW isolates belonged to clonal complex 11 and were closely related to the isolates causing recent outbreaks in Africa. PMID:27649262

Lethal Effects of Aspergillus niger against Mosquitoes Vector of Filaria, Malaria, and Dengue: A Liquid Mycoadulticide

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Gavendra Singh

2012-01-01

Full Text Available Aspergillus niger is a fungus of the genus Aspergillus. It has caused a disease called black mold on certain fruits and vegetables. The culture filtrates released from the A. niger ATCC 66566 were grown in Czapek dox broth (CDB then filtered with flash chromatograph and were used for the bioassay after a growth of thirty days. The result demonstrated these mortalities with LC50, LC90, and LC99 values of Culex quinquefasciatus 0.76, 3.06, and 4.75, Anopheles stephensi 1.43, 3.2, and 3.86, and Aedes aegypti 1.43, 2.2, and 4.1 μl/cm2, after exposure of seven hours. We have calculated significant LT90 values of Cx. quinquefasciatus 4.5, An. stephensi 3.54, and Ae. aegypti 6.0 hrs, respectively. This liquid spray of fungal culture isolate of A. niger can reduce malaria, dengue, and filarial transmission. These results significantly support broadening the current vector control paradigm beyond chemical adulticides.

Effect Of Aspergillus Niger Biodegradation On The Nutriti0nal ...

African Journals Online (AJOL)

The effect of Aspergillus niger on the nutritional potential of cowpea seed hull after different physical treatments was investigated. The crude protein ranges from 14.11% to 15.07 and 16.71% in the untreated seed hull (UCH), soaked and boiled (SBCH) and soaked (SCH) respectively, before fungi degradation but after the ...

Localization of Glucose Oxidase and Catalase Activities in Aspergillus niger

NARCIS (Netherlands)

Witteveen, Cor F.B.; Veenhuis, Marten; Visser, Jaap

The subcellular localization of glucose oxidase (EC 1.1.3.4) in Aspergillus niger N400 (CBS 120.49) was investigated by (immuno)cytochemical methods. By these methods, the bulk of the enzyme was found to be localized in the cell wall. In addition, four different catalases (EC 1.11.1.6) were

Production of bio-ethanol from corncobs using Aspergillus niger and ...

African Journals Online (AJOL)

Maize is the most abundant cereal grown in Ghana and is accompanied by enormous amount of agrowastes of which corncobs form 30%. This agrowaste which is currently under utilized was used to produce bio-ethanol. Aspergillus niger isolated from soil sampled from Ejura farms was used to hydrolyze the corncobs into ...

Towards semisynthetic natural compounds with a biaryl axis: Oxidative phenol coupling in Aspergillus niger.

Science.gov (United States)

Hugentobler, Katharina Gloria; Müller, Michael

2018-04-01

Regio- and stereoselective phenol coupling is difficult to achieve using synthetic strategies. However, in nature, cytochrome P450 enzyme-mediated routes are employed to achieve complete axial stereo- and regiocontrol in the biosynthesis of compounds with potent bioactivity. Here, we report a synthetic biology approach whereby the bicoumarin metabolic pathway in Aspergillus niger was specifically tailored towards the formation of new coupling products. This strategy represents a manipulation of the bicoumarin pathway in A. niger via interchange of the phenol-coupling biocatalyst and could be applied to other components of the pathway to access a variety of atropisomeric natural product derivatives. Copyright © 2017 Elsevier Ltd. All rights reserved.

The promoter of the glucoamylase-encoding gene of Aspergillus niger functions in Ustilago maydis

Energy Technology Data Exchange (ETDEWEB)

Smith, T.L. (Dept. of Agriculture, Madison, WI (United States) Univ. of Wisconsin, Madison (United States)); Gaskell, J.; Cullen, D. (Dept. of Agriculture, Madison, WI (United States)); Berka, R.M.; Yang, M.; Henner, D.J. (Genentech Inc., San Francisco, CA (United States))

1990-01-01

Promoter sequences from the Aspergillus niger glucoamylase-encoding gene (glaA) were linked to the bacterial hygromycin (Hy) phosphotransferase-encoding gene (hph) and this chimeric marker was used to select Hy-resistant (Hy[sup R]) Ustilago maydis transformants. This is an example of an Ascomycete promoter functioning in a Basidiomycete. Hy[sup R] transformants varied with respect to copy number of integrated vector, mitotic stability, and tolerance to Hy. Only 216 bp of glaA promoter sequence is required for expression in U. maydis but this promoter is not induced by starch as it is in Aspergillus spp. The transcription start points are the same in U. maydis and A. niger.

Living with Oil: Towards an Ethics of the Environment in the Niger ...

African Journals Online (AJOL)

Living with Oil: Towards an Ethics of the Environment in the Niger Delta. ... African Research Review ... the issues of resource allocation and the responsibility for both human and non-human components of nature are indeed wholly ethical.

Isolated theropod teeth from the Middle Jurassic of Niger and the early dental evolution of Spinosauridae

Directory of Open Access Journals (Sweden)

Alejandro Serrano-Martínez

2016-06-01

Full Text Available Four isolated theropod teeth from the ?Bathonian “Argiles de l’Irhazer” in Niger are described. The teeth were found in association with the holotype of the basal sauropod Spinophorosaurus nigerensis. These specimens have been assigned to two different taxa by independent analyses, such as direct comparison with teeth previously described in the literature, discriminant and morphometric analyses from metric characters, and cladistic and cluster analyses from discrete characters. The results suggest that three teeth share affinities with those of Megalosauridae and Allosauridae, belonging most likely to the former. The fourth tooth might be from a member of the stem group Spinosauridae. If so, this would be the oldest representative of this clade. This tooth shows a combination of characters that are unusual in typical spinosaurid teeth (crown moderately compressed labiolingually and curved distally with minute denticles on the carina and a deeply veined enamel surface texture without apicobasal ridges. This could shed light on the morphological transition from the plesiomorphic ziphodont dental pattern to that of Spinosauridae. This tooth would also allow a better understanding of the origin of the spinosaurids, supporting a Gondwanan origin for the group.

Prévention et gestion des conflits au Niger

OpenAIRE

Souley, A.

1996-01-01

Metadata only record A general description of conflict causes and management in Niger. The author identifies five different types of causes according to their nature: political, socio-economic, management of natural resources, frontier, and ethnic/religious. Natural resource management conflicts stem from demographic pressure, urbanization, drought, and a deteriorating resource base. The current conflict between herders and farmers is characterized as occurring during a transitional phase ...

Utilization of Brewery Spent Grain Liquor by Aspergillus niger1

Science.gov (United States)

Hang, Y. D.; Splittstoesser, D. F.; Woodams, E. E.

1975-01-01

Aspergillus niger was found capable of rapidly converting about 97% of the sugar from brewery spent grain liquor to fungal mass. The yield of dry mycelium, based on the sugar consumed, was approximately 57%. This fungus produced 1.10% titratable acid calculated as citric acid and reduced the biochemical oxygen demand by 96%. PMID:1200633

Extracellular acid protease from Aspergillus niger I1: purification and ...

African Journals Online (AJOL)

STORAGESEVER

2009-09-15

Sep 15, 2009 ... A new strain of Aspergillus niger producing acid protease was isolated and identified by universal primers NL1 and .... Media were autoclaved at 120°C for 20 min. ... molecular weight calibration kit as markers consisting of bovine ... then removed by washing the gel three times with 100 mM ..... New York.

The search for environmental justice in the Niger Delta and ...

African Journals Online (AJOL)

Right from the beginning Man has been given the privilege by his Creator to tender the earth and take dominion over his environment. But for the impoverished people of the Niger Delta region, the mainstay of Nigeria's oil wealth, the situation is ironically abysmal. The region has been the scene of protest, sometimes ...

Stimulation of germination of conidium Aspergillus niger, a citric acid producer, under the action of mutagenic factors

International Nuclear Information System (INIS)

Golubtsova, V.M.; Shcherbakova, E.Ya.; Smirnov, V.A.; Runkovskaya, L.Ya.

1976-01-01

The action of low doses of various mutagens, namely, 2% cyclophosphane solution (30 min), 1% thiophosphamide solution (30 min), 0.05% nitrosomethylurea solution (30 and 60 min), γ-rays (10 krads) and UV-rays (10000 erg/mm 2 ) stimulates germination of conidium Aspergillus niger, a citric acid producer. At the above-mentioned doses of mutagens, a minor quantity of morphological varieties are formed, and the variability value of acid production by Asp. niger is maintained at the spontaneous level

Biotransformation of the streptomyces scabies phytotoxin thaxtomin A by the fungus aspergillus niger

International Nuclear Information System (INIS)

Lazarovits, G.; Hill, J.; King, R.; Calhoun, L.A.

2004-01-01

Of several hundred microorganisms randomly selected from the environment, only a fungal isolate identified as Aspergillus niger van Tiegham var. niger was found to transform the phytotoxin thaxtomin A to much less toxic metabolites. The rate and extent of transformation of thaxtomin A was tested under a variety of conditions, including different growth media, biomass concentrations, incubation periods, and shaker speeds. Under optimum conditions the fungus converted thaxtomin A into two major and five minor metabolites. The two major metabolites and three of the five minor metabolites were fully characterized by a combination of mass spectral and nuclear magnetic resonance techniques. When assayed on aseptically produced mini-tubers, the major metabolites proved to be much less phytotoxic than thaxtomin A. (author)

Biotransformation of the streptomyces scabies phytotoxin thaxtomin A by the fungus aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Lazarovits, G.; Hill, J. [Agriculture and Agri-Food Canada, Southern Crop Protection and Food Research Centre, London, Ontario (Canada)]. E-mail: Lazarovitsg@agr.gc.ca; King, R. [Agriculture and Agri-Food Canada, Potato Research Centre, Fredericton, New Brunswick (Canada); Calhoun, L.A. [Univ. of New Brunswick, Dept. of Chemistry, Fredericton, New Brunswick (Canada)

2004-07-01

Of several hundred microorganisms randomly selected from the environment, only a fungal isolate identified as Aspergillus niger van Tiegham var. niger was found to transform the phytotoxin thaxtomin A to much less toxic metabolites. The rate and extent of transformation of thaxtomin A was tested under a variety of conditions, including different growth media, biomass concentrations, incubation periods, and shaker speeds. Under optimum conditions the fungus converted thaxtomin A into two major and five minor metabolites. The two major metabolites and three of the five minor metabolites were fully characterized by a combination of mass spectral and nuclear magnetic resonance techniques. When assayed on aseptically produced mini-tubers, the major metabolites proved to be much less phytotoxic than thaxtomin A. (author)

Thermal Models of the Niger Delta: Implications for Charge Modelling

International Nuclear Information System (INIS)

Ejedawe, J.

2002-01-01

There are generally three main sources of temperature data-BHT data from log headers, production temperature data, and continuo's temperature logs. Analysis of continuous temperature profiles of over 100 wells in the Niger Delta two main thermal models (single leg and dogleg) are defined with occasional occurrence of a modified dogleg model.The dogleg model is characterised by a shallow interval of low geothermal gradient ( 3.0.C/100m). This is characteristically developed onshore area is simple, requiring only consideration of heat transients, modelling in the onshore require modelling programmes with built in modules to handle convective heat flow dissipation in the shallow layer. Current work around methods would involve tweaking of thermal conductivity values to mimic the underlying heat flow process effects, or heat flow mapping above and below the depth of gradient change. These methods allow for more realistic thermal modelling, hydrocarbon type prediction, and also more accurate prediction of temperature prior to drilling and for reservoir rock properties. The regional distribution of the models also impact on regional hydrocarbon distribution pattern in the Niger Delta

IMMOBILIZATION OF TANNIN ACYL HYDROLASE FROM ASPERGILLUS NIGER

OpenAIRE

B. Lenin Kumar*, N. Lokeswari and D. Sriramireddy

2013-01-01

ABSTRACT: Tannin acyl hydrolase, commonly referred to as tannase (E.C. 3.1.1.20), an inducible extra-cellular enzyme produced by a number of animals, plants and microbes. In this investigation, tannase production under solid-state fermentation by using Aspergillus niger and the waste residue of cashew husk was used as substrate for obtaining the desired fermented product. Microbial tannase is more stable than tannase from other sources like plants or animals. Tannase from fungal sources are r...

Post traumatic stress in the Niger Delta of Nigeria: A qualitative ...

African Journals Online (AJOL)

Post traumatic stress in the Niger Delta of Nigeria: A qualitative analysis of narrative of women. ... PROMOTING ACCESS TO AFRICAN RESEARCH ... Keywords: Resource-curse, Post-traumatic Stress disorder (PTSD), Psychosocial ... Rwanda (3); Senegal (6); Sierra Leone (1); South Africa (96); South Sudan (1); Sudan (3) ...

Aspergillus niger Enhance Bioactive Compounds Biosynthesis As Well As Expression of Functional Genes in Adventitious Roots of Glycyrrhiza uralensis Fisch.

Science.gov (United States)

Li, Jing; Wang, Juan; Li, Jinxin; Liu, Dahui; Li, Hongfa; Gao, Wenyuan; Li, Jianli; Liu, Shujie

2016-02-01

In the present study, the culture conditions for the accumulation of Glycyrrhiza uralensis adventitious root metabolites in balloon-type bubble bioreactors (BTBBs) have been optimized. The results of the culture showed that the best culture conditions were a cone angle of 90° bioreactor and 0.4-0.6-0.4-vvm aeration volume. Aspergillus niger can be used as a fungal elicitor to enhance the production of defense compounds in plants. With the addition of a fungal elicitor (derived from Aspergillus niger), the maximum accumulation of total flavonoids (16.12 mg g(-1)) and glycyrrhetinic acid (0.18 mg g(-1)) occurred at a dose of 400 mg L(-1) of Aspergillus niger resulting in a 3.47-fold and 1.8-fold increase over control roots. However, the highest concentration of polysaccharide (106.06 mg g(-1)) was achieved with a mixture of elicitors (Aspergillus niger and salicylic acid) added to the medium, resulting in a 1.09-fold increase over Aspergillus niger treatment alone. Electrospray ionization tandem mass spectrometry (ESI-MS(n)) analysis was performed, showing that seven compounds were present after treatment with the elicitors, including uralsaponin B, licorice saponin B2, liquiritin, and (3R)-vestitol, only identified in the mixed elicitor treatment group. It has also been found that elicitors (Aspergillus niger and salicylic acid) significantly upregulated the expression of the cinnamate 4-hydroxylase (C4H), β-amyrin synthase (β-AS), squalene epoxidase (SE) and a cytochrome P450 monooxygenase (CYP72A154) genes, which are involved in the biosynthesis of bioactive compounds, and increased superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) activity.

aranthus cruentus L) in the Niger Delta Region of Nigeria

African Journals Online (AJOL)

ABSTRACT. Experiments were conducted in 1987 and 1988 to study the response of Amaranthus cruentus L. to flooded soils at Ekpoma, situated in-the Niger Delta Region of Nigeria. The objective of this study was to examine the effect of flooding on yield of A. Céiieiìtus. The study revealed that the negative response of the ...

Survey of heavy metals in sediments of Kolo creek in the Niger Delta ...

African Journals Online (AJOL)

user

1Department of Chemical Sciences, Niger Delta University, Wilberforce Island, Bayelsa State, Nigeria. 2Department of Pure and Industrial Chemistry, University of Port Harcourt, Rivers State, Nigeria. ..... Tecate River, Mexico. Environ. Geol.

Continuous citric acid production in repeated-fed batch fermentation by Aspergillus niger immobilized on a new porous foam.

Science.gov (United States)

Yu, Bin; Zhang, Xin; Sun, Wenjun; Xi, Xun; Zhao, Nan; Huang, Zichun; Ying, Zhuojun; Liu, Li; Liu, Dong; Niu, Huanqing; Wu, Jinglan; Zhuang, Wei; Zhu, Chenjie; Chen, Yong; Ying, Hanjie

2018-03-24

The efficiency of current methods for industrial production of citric acid is limited. To achieve continuous citric acid production with enhanced yield and reduced cost, immobilized fermentation was employed in an Aspergillus niger 831 repeated fed-batch fermentation system. We developed a new type of material (PAF201), which was used as a carrier for the novel adsorption immobilization system. Hydrophobicity, pore size and concentration of carriers were researched in A. niger immobilization. The efficiency of the A. niger immobilization process was analyzed by scanning electron microscopy. Then eight-cycle repeated fed-batch cultures for citric acid production were carried out over 600 h, which showed stable production with maximum citric acid concentrations and productivity levels of 162.7 g/L and 2.26 g L -1  h -1 , respectively. Compared with some other literatures about citric acid yield, PAF201 immobilization system is 11.3% higher than previous results. These results indicated that use of the new adsorption immobilization system could greatly improve citric acid productivity in repeated fed-batch fermentation. Moreover, these results could provide a guideline for A.niger or other filamentous fungi immobilization in industry. Copyright © 2018 Elsevier B.V. All rights reserved.

The legal and regulatory framework relative to safety and environment in the uranium mines in Niger

International Nuclear Information System (INIS)

Mahamane, S.

2001-01-01

The mining sector holds an important position in Niger economy. Considerable funds have been invested for the promotion, exploration and exploitation of mineral resources since the colonial period. This has resulted in the discovery of numerous deposits among which are those of uranium. Today, uranium represents more than 3/4 of Niger export revenues. The mining sector is supervised by the Ministry of Mines and Energy. The Ministry applies the mining policy as defined by the government. It elaborates legislative and regulatory texts and sees to their implementation. Regarding uranium, mining activities have been governed since 1961 by various orientation laws and implementation decrees. However, to face up to the harmful consequences on national economy of successive drops of price and sales of its major export product, and taking into account the new international requirements relating to economy globalization and sustainable development, Niger set up a diversification strategy of its mining productions as part of which a new mining code particularly incentive has been established in 1993. The new mining code provides significant advantages to investors. These advantages insure them a great cost effectiveness of their investments in Niger and easy and less onerous respect of regulations regarding safety and protection of environment. Tremendous efforts have been, thus, provided by the IAEA, the Ministry of Mines and Energy and the uranium companies for an optimal protection of workers and the public, especially against the hazards of ionizing radiations. This will to improve the situation has resulted in the adoption of several laws and their application decrees as well as various sectorial laws designed by various Ministry departments concerned with environmental issues and risks prevention. Among these texts are the renewal of the order No 31 M/MH which has defined since 1979 the main axis of the Niger regulations as regards to radioprotection and the design of

The Portrayal of Liberation and the Niger Delta Question in Arnold Udoka’s Akon, Long Walk to a Dream and Iyene: A Dance Drama

OpenAIRE

Jonas Egbudu Akung

2016-01-01

Nigeria’s Niger Delta has become a thorny issue in the multidisciplinary intellectual discourse in the sense that local inequalities have assumed global dimensions. Human rights have been violated by the Nigerian government and global multi-national oil companies in such a way that make the Niger delta an environmental disaster zone. This problem has spawned local insurrections in the Niger Delta as multinational oil companies have had to either quit the zone or re-organize their modus operan...

[Medical fault or professional negligence? Case studies in two recovery nutrition centers in Niger].

Science.gov (United States)

Halidou Doudou, M; Manzo, M L; Guero, D

2014-12-01

In developing countries such as Niger, the risk of medical malpractice is ubiquitous in health, jeopardizing patient safety. The aim of this work was to contribute to patients' safety and respect of code of ethics and conduct in the exercise of the medical profession. The reported cases involved two children under 5 years who were admitted to nutrition rehabilitation centers, died as a result of medical malpractice. In Niger, there are no statistics on this phenomenon and a few cases found have always been considered "accident" or "fate." The establishment of an observatory collections of such information should improve their frequency, consequences and propose a prevention plan. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

Analysis of CDM Projects' Portfolio in West African Economic and Monetary Union - Regional Baseline Assessment in Energy Sector. Case Study: Benin, Burkina Faso, Niger and Togo

OpenAIRE

Satoguina, Honorat

2006-01-01

This study analyses current energy projects in Benin, Burkina Faso, Niger and Togo. Based on the size of these projects, the study shows that currently, only small scale CDM projects can be developed in these countries in energy sectors. Moreover, baseline emissions factors are assessed for the different electricity grids. These baselines are very low in interconnected grids in cities, while they are relatively high for isolated and non-connected utilities in remote areas. Consequently, count...

Use of Aspergillus niger for improving the feeding value of rice offal ...

African Journals Online (AJOL)

, 5 and 7% inclusion levels. A hundred and sixty five (165) day old chicks were randomly selected and allotted to five (5) treatments. Each treatment had three replicates and each replicate had eleven birds. Aspergillus niger was inoculated into ...

Black Terns Chlidonias niger and their dietary problems in Dutch wetlands

NARCIS (Netherlands)

Beintema, Albert J.; van der Winden, Jan; Baarspul, Teun; de Krijger, Jan Pieter; van Oers, Kees; Keller, Marek

2010-01-01

Black Terns Chlidonias niger have shown a decrease of well over 90% as a breeding bird in The Netherlands during the twentieth century. Two hypotheses have been put forward for this decline: the disappearance of the floating plant Water Soldier Stratiotes aloides, which used to be the favourite

Effects of Aspergillus niger treated Shea butter cake based diets on ...

African Journals Online (AJOL)

Effects of feed intake, weight gain and digestibility when growing Red Sokoto goats consuming Aspergillus niger treated and untreated shea-butter cake (SBC) were determined. Twenty five Red Sokoto goats in a completely randomized design model with 56 d periods consumed diet A (control, without SBC), B (15% ...

Social Licensing in the Uranium Cycle Production (Case of Niger)

Energy Technology Data Exchange (ETDEWEB)

Dari, A., E-mail: dariayouba@yahoo.fr [Ministry of Mining and Energy, Mines Direction/DEM, Niamey (Niger)

2014-05-15

In Niger Republic, uranium exploitation has begun since 1970. It is an economic resource but also causes social and environmental problems. To exploit according to the rule, to protect social environment, to work in safe conditions and contribute to the development of local population one side and Niger Republic in the other side, a mining law was voted in March 1993. It is about the ordinance n°93-16 on mining law which was modified in August 2006 by a new mining law, the ordinance n°2006-26 of 9 August 2006. As well as the presidential decree affecting the application of this new law was issued. Other legislative and regulatory texts have been taken as far as exploration and exploitation mining. For example, the mining agreement, the order n°0073/PM of 4 July 2005 relative to the transparency on mining exploitation; ordinance n°97-001 of 10 January 1997 appointing the environmental studying impact and the law 98–56 of 29 December 1998 relative to the management of environment. For acquisition of an exploration licence or a mining licence, a mining agreement is signed between the mining company and Niger Republic which makes clear social, environmental, financial, and economic conditions in which the mining company must exploit natural resources. The ordinance n°93-16 of 2 March 1993 related to the mining law in chapter IV, clarifies conditions for acquisition of exploration and mining licence in Niger Republic. It clarifies again in the same chapter, title VI, rights and obligations relating to mine or quarry operations for companies and tax provisions relative those activities. In the same order, in title VIII, hygiene and security conditions in mines are been specified. The mining agreement in title IV, specify rights, obligations and administration in mining activities, particularly article 18.2 which stipulates “the mining company undertakes to contribute to the development of municipalities in which it shall carry out activities, by contributing to

Conservation of food tree species in Niger: towards a participatory approach in rural communities

International Nuclear Information System (INIS)

Agúndez Leal, D.; Douma, S.; Madrigal, J.; Gómez-Ramos, A.; Vicenti, B.; Alía, R.; Mahamane, A.

2016-01-01

Aim of the study: Indigenous woody species play an important role as a complement on the diet of rural populations in Niger, especially in periods of food scarcity. However, these species are nowadays overexploited and management programmes are necessary to conserve them. In order to design a conservation programme for edible woody species, this paper presents a sociological analysis about the use of edible woody species and their products during shortage periods in Niger. Area of study: Four villages in two distinct agro-ecological regions were selected to conduct structured enquiries based on focus group discussions and surveys with key informants. Material and Methods: Perceptions of the conservation status of these species were identified; as well the factors affecting food values, perceptions, management and collection practices. Main results: Results show that B. senegalensis was a staple food in the driest areas, and M. crassifolia was used for fodder and human consumption in the most critical situations. The local communities related the drivers of species conservation status specific to the agro-ecological regions, and gender and ethnic differences were also identified. Research highlights: Understanding these factors constitutes a first step towards adaptive management strategies for the conservation of woody food species in rural communities of Niger. (Author)

IMPACTS OF WETLAND DEGRADATION IN NIGER DELTA NIGERIA AND ITS SIGNIFICANCE IN FLOOD CONTROL

Directory of Open Access Journals (Sweden)

Enwere Chidimma Loveline

2015-08-01

Full Text Available  Wetlands perform a wide variety of functions that include flood control, ground water recharge, shore line stabilization, storm protection and climate moderation. However, despite these huge wetland functions, it has witnessed poor appreciation and dreadful conditions. Niger Delta has witnessed constant coastal erosion and rising sea level, this has led to large portions of the landmass being eroded. This paper aims to review some environmental effects of flooding in the Niger Delta region of Nigeria to provide the desired knowledge of role that wetlands play in reducing flood impacts. However, having witnessed the flood, the experience opened my eyes to the environmental challenges facing Niger Delta with respect to Wetlands degradation, poor perception of wetland values and functions, poor environmental practices and non-implementation of environmental regulations. This memorable experience rekindled the desire and motivation to seek a solution to wetland degradation with the aim of recognizing significance of wetlands at the centre of achieving both livelihood and biodiversity improvements to address coastal flooding problem.The study therefore concludes that wetlands are very significant in flood control and thus the conservation and restoration of wetlands, should put in place measures to reduce wetland destruction.International Journal of EnvironmentVolume-4, Issue-3, June-August 2015Page: 177-184

Efficacy and possible mechanisms of perillaldehyde in control of Aspergillus niger causing grape decay.

Science.gov (United States)

Tian, Jun; Wang, Yanzhen; Zeng, Hong; Li, Zongyun; Zhang, Peng; Tessema, Akalate; Peng, Xue

2015-06-02

A variety of plant products have been recognized for their antifungal activity and recently have attracted food industry attention for their efficacy in controlling postharvest fungal decay of fruits. The antifungal activity of perillaldehyde (PAE) was evaluated against Aspergillus niger, a known cause of grape spoilage, and possible mechanisms were explored. PAE showed notable antifungal activity against A. niger, with a minimum inhibitory concentration (MIC) and a minimum fungicidal concentration (MFC) of 0.25 and 1 μl/ml, respectively. The accumulation of mycelial biomass was also inhibited by PAE in a dose-dependent manner, completely inhibiting mycelial growth at 1 μl/ml. In vivo data confirmed that the vapour treatment of grapes with various concentrations of PAE markedly improved control of A. niger and suppressed natural decay. Concentrations of PAE of 0.075 μl/ml air showed the greatest inhibition of fungal growth compared to the controls. Further experiments indicated that PAE activated a membrane-active mechanism that inhibits ergosterol synthesis, increases membrane permeability (as evidenced by extracellular pH and conductivity measurements), and disrupts membrane integrity, leading to cell death. Our findings suggest that this membrane-active mechanism makes PAE a promising potential antifungal agent for postharvest control of grape spoilage. Copyright © 2015 Elsevier B.V. All rights reserved.

Conservation of food tree species in Niger: towards a participatory approach in rural communities

Energy Technology Data Exchange (ETDEWEB)

Agúndez Leal, D.; Douma, S.; Madrigal, J.; Gómez-Ramos, A.; Vicenti, B.; Alía, R.; Mahamane, A.

2016-07-01

Aim of the study: Indigenous woody species play an important role as a complement on the diet of rural populations in Niger, especially in periods of food scarcity. However, these species are nowadays overexploited and management programmes are necessary to conserve them. In order to design a conservation programme for edible woody species, this paper presents a sociological analysis about the use of edible woody species and their products during shortage periods in Niger. Area of study: Four villages in two distinct agro-ecological regions were selected to conduct structured enquiries based on focus group discussions and surveys with key informants. Material and Methods: Perceptions of the conservation status of these species were identified; as well the factors affecting food values, perceptions, management and collection practices. Main results: Results show that B. senegalensis was a staple food in the driest areas, and M. crassifolia was used for fodder and human consumption in the most critical situations. The local communities related the drivers of species conservation status specific to the agro-ecological regions, and gender and ethnic differences were also identified. Research highlights: Understanding these factors constitutes a first step towards adaptive management strategies for the conservation of woody food species in rural communities of Niger. (Author)

Proteome analysis of Aspergillus niger: Lactate added in starch-containing medium can increase production of the mycotoxin fumonisin B2 by modifying acetyl-CoA metabolism

DEFF Research Database (Denmark)

Sørensen, Louise Marie; Lametsch, Rene; Andersen, Mikael Rørdam

2009-01-01

Background Aspergillus niger is a filamentous fungus found in the environment, on foods and feeds and is used as host for production of organic acids, enzymes and proteins. The mycotoxin fumonisin B2 was recently found to be produced by A. niger and hence very little is known about production...... and regulation of this metabolite. Proteome analysis was used with the purpose to reveal how fumonisin B2 production by A. niger is influenced by starch and lactate in the medium. Results Fumonisin B2 production by A. niger was significantly increased when lactate and starch were combined in the medium....... Production of a few other A. niger secondary metabolites was affected similarly by lactate and starch (fumonisin B4, orlandin, desmethylkotanin and pyranonigrin A), while production of others was not (ochratoxin A, ochratoxin alpha, malformin A, malformin C, kotanin, aurasperone B and tensidol B...

Collective violence and attitudes of women toward intimate partner violence: Evidence from the Niger Delta

Directory of Open Access Journals (Sweden)

Antai Diddy

2009-06-01

Full Text Available Abstract Background The Niger Delta region of Nigeria has been undergoing collective violence for over 25 years, which has constituted a major public health problem. The objectives of this study were to investigate the predictors of women's attitudes toward intimate partner violence in the Niger Delta in comparison to that of women in other parts of Nigeria. Methods The 2003 Nigeria Demographic and Health Survey was used for this study. Respondents were selected using a stratified two-stage cluster sampling procedure through which 3725 women were selected and interviewed. These women contributed 6029 live born children born to the survey. Internal consistency of the measure of the women's attitudes towards intimate partner violence against a woman was assessed using Cronbach's alpha (α. Percentage distributions of the relevant characteristics of the respondents were carried out, and multivariable logistic regression analysis was used to measure the magnitude and direction of the relationship between the outcome and predictor variables were expressed as odds ratios (OR and statistical significance was determined at the 95 percent confident interval level (CI. Results Tolerance for intimate partner violence among the women in the Niger delta (47 percent was higher than that of women from the rest of the country (42 percent. Rural residence, lower household wealth, lower status occupations, and media access (newspaper and radio were associated with lower risk of justifying IPV among the women in the Niger Delta. In contrast full or partial autonomy in household decisions regarding food to be cooked, and access to television were associated with a lower risk of justifying violence. Conclusion The increased justification of intimate partner violence among the women in the Niger Delta could be explained by a combination of factors, among which are cognitive dissonance theory (attitudes that do not fit with other opinions they hold as a means of

Induced mutant for male sterility in niger

International Nuclear Information System (INIS)

Sujatha, M.

2001-01-01

Full text: Niger (Guizotia abyssinica Cass.), an important oilseed crop of the family Compositae is highly cross-pollinated due to the twin mechanisms of protandry and incompatibility. Studies revealed the functional nature of protandry and the breakdown of incompatibility with alteration in temperature. It has very small flowers (disc florets) arranged in a capitulum that open on 3-4 consecutive days which pose problems in emasculation for cross-breeding. To induce mutations, seeds of variety 'IGP-76' were irradiated with γ-rays 200 to 1000 Gy. All seeds of M 1 plants were sown separately in individual plant-to progeny rows. The results of screening of M 2 segregating material indicated that γ-ray treatment was effective in induction of male sterility. Frequency of visible mutations were higher in sibbed progeny as compared to open pollinated population and male sterile plants were observed only in sibbed population (1000 Gy). Male sterile plants could easily be identified at the flowering stage by their altered floral morphology (disc florets transformed into ligulate ray florets) and complete absence or presence of a rudimentary anther column. Seeds were collected following sib-mating with the fertile counterparts. Progeny segregated in a ration of 3 normal : 1 male sterile. Further work on the mechanism of sterility, maintenance and linkage relationships with associated characters is under progress. This is the first report of induction of male sterility in niger through the use of physical mutagens. The availability of this mutant will be of great value for exploitation of heterosis on commercial basis. (author)

Effect of different substrates on the production of amino acids by aspergillus niger

International Nuclear Information System (INIS)

Almani, F.; Memon, M. A.; Dahot, M. U.

2006-01-01

In the present work, attempts were made to utilize sugarcane waste as carbon source for amino acid production by Aspergillus nigher. Different concentration (0.3N and 0.6N) of H/sub 2/SO/sub 4/ and NH/sub 4/OH were used to hydrolyze lignocellulosic material of the sugar cane bagasse to release the fermentable sugar, which were incorporated with mineral medium for the growth of Aspergillus niger and amino acid production. Whereas, molasses was diluted in 2.5% and 5% and was mixed with mineral medium for amino acid production by Aspergillus niger. The results were compaired with sugar cane bagasse for amino acid production. Molasses 5% was found better substrate for higher production of amino acids in comparison to hydrolysates of sugar can bagasse. (author)

PARTIAL CHARACTERIZATION OF ENZYMATIC ACTIVITIES PRODUCED BY A WILD STRAIN OF A. NIGER

Directory of Open Access Journals (Sweden)

María Martos

2012-12-01

Full Text Available Aspergillus niger, isolated from decay citrus peels in the province of Misiones, was able to produce pectinases by submerged fermentation. The enzymatic extract exhibited polygalacturonase, pectinesterase and lyase activities. Others enzymes capable of degrading cell wall polymers were also detected in the enzymatic extract such as cellulases and xylanases. Polygalacturonase was an endo-polygalacturonase. The enzyme exhibited a maximal activity at pH range between 4.5 to 5.0, was stable in the pH range from 2.5 to 5.5 and remained unchanged when was incubated at temperatures lower than 50 ºC. The fungi produced three PG isoenzymes. The enzymatic extract was able to clarify apple juice. The results observed make the pectinolytic enzymes produced by A. niger appropriate for future application in fruit juice processing industries.

Soil Dust Aerosols and Wind as Predictors of Seasonal Meningitis Incidence in Niger

Science.gov (United States)

Perez Garcia Pando, Carlos; Stanton, Michelle C.; Diggle, Peter J.; Trzaska, Sylwia; Miller, Ron L.; Perlwitz, Jan P.; Baldasano, Jose M.; Cuevas, Emilio; Ceccato, Pietro; Yaka, Pascal;

Effect of adaptive skill acquisition on youth development in the Niger ...

African Journals Online (AJOL)

This paper examines the effect of adaptive skill acquisition on youth development in the Niger delta area of Nigeria with emphasis on Bayelsa State. A structured questionnaire was used to collect relevant information from 99 respondents, which cut across four stakeholder institutions in the study area. Data analysis was by ...

Acid protease and formation of multiple forms of glycoamylase in batch and continuous cultures of Aspergillus niger

DEFF Research Database (Denmark)

Aalbæk, Thomas; Reeslev, Morten; Jensen, Bo

2002-01-01

In order to identify factors responsible for production of multiple forms of glucoamylase (GA) by Aspergillus niger Bo-1, the fungus was cultured in both complex and defined media in pH-controlled batch fermenters and chemostats. At all culture conditions three forms of GA were produced...... degradation of the GA forms at low pH. It was concluded that the observed modifications of the extracellular profile of GA isoforms in A. niger Bo-1 are due to changes in pH and medium composition....

Isolation and genetic analysis of Aspergillus niger mutants with reduced extracellular glucoamylase

International Nuclear Information System (INIS)

Valent, G.U.; Calil, M.R.; Bonatelli Junior, R.

1992-01-01

Mutants with impaired production of extracellular glucoamylase were isolated at a high frequency (2% of survivors) from an Aspergillus niger strain treated with UV light. These were designated as low glucoamylase producers (lgp, up to 30% of the parental yield) and medium producers (mgp, a 35 to 50% decrease in enzyme level). All the mutants were shown to be recessive; one strain segregated two unlinked genes. Complementation tests, and segregation from heterozygous diploid, suggested at least three to four unlinked genes, each able to impair glucoamylase production. There is evidence of a single structural gene for glucoamylase in A. niger. Therefore, as production of extracellular enzymes is normally the final result of several steps at intracellular and membrane levels, including regulation of enzyme synthesis, we suggest intergenic interaction that controls extracellular enzyme accumulation and that mutation in any of these genes would result in impaired production. (author)

A Polyketide Synthase Encoded by the Gene An15g07920 Is Involved in the Biosynthesis of Ochratoxin A in Aspergillus niger.

Science.gov (United States)

Zhang, Jian; Zhu, Liuyang; Chen, Haoyu; Li, Min; Zhu, Xiaojuan; Gao, Qiang; Wang, Depei; Zhang, Ying

2016-12-28

The polyketide synthase gene An15g07920 was known in Aspergillus niger CBS 513.88 as putatively involved in the production of ochratoxin A (OTA). Genome resequencing analysis revealed that the gene An15g07920 is also present in the ochratoxin-producing A. niger strain 1062. Disruption of An15g07920 in A. niger 1062 removed its capacity to biosynthesize ochratoxin β (OTβ), ochratoxin α (OTα), and OTA. These results indicate that the polyketide synthase encoded by An15g07920 is a crucial player in the biosynthesis of OTA, in the pathway prior to the phenylalanine ligation step. The gene An15g07920 reached its maximum transcription level before OTA accumulation reached its highest level, confirming that gene transcription precedes OTA production. These findings will not only help explain the mechanism of OTA production in A. niger but also provide necessary information for the development of effective diagnostic, preventive, and control strategies to reduce the risk of OTA contamination in foods.

Purification and characterisation of a novel enantioselective epoxide hydrolase from Aspergillus niger M200

Czech Academy of Sciences Publication Activity Database

Kotík, Michael; Kyslík, Pavel

2006-01-01

Roč. 1760, - (2006), s. 245-252 ISSN 0006-3002 Institutional research plan: CEZ:AV0Z50200510 Keywords : epoxide hydrolase * enantioselectivity * aspergillus niger Subject RIV: EE - Microbiology, Virology

Recombinant hepatitis B surface antigen production in Aspergillus niger: evaluating the strategy of gene fusion to native glucoamylase

CSIR Research Space (South Africa)

James, ER

2012-10-01

Full Text Available Microbiology and Biotechnology October 2012/ Vol. 96, No.2 Recombinant hepatitis B surface antigen production in Aspergillus niger: evaluating the strategy of gene fusion to native glucoamylase ER James a,c & WH van Zyl b & PJ van Zyl c & JF Görgens..., Pretoria 0001, South Africa Abstract This study demonstrates the potential of Aspergillus niger as a candidate expression system for virus- like particle production using gene fusion. Hepatitis B surface antigen (HBsAg) production, targeted...

Contribution of the clean development mechanism to sustainable energy production. The energy sector in the West African Economic and Monetary Union - Case study: Benin, Burkina Faso, Niger and Togo

Energy Technology Data Exchange (ETDEWEB)

Satoguina, H.

2007-07-01

This study assesses the contribution of the CDM to Sustainable Development in energy sectors in the West African Economic and Monetary Union, concentrating on Benin, Burkina Faso, Niger and Togo. Through a cross-sectional survey of different stakeholder groups, the prospective sustainable development criteria for the CDM are examined and prospective small-scale CDM projects are analysed. One efficient option to reduce transaction costs to small scale CDM projects is the creation of a regional centre for capacity building and project pre-validation. This study analyses how the WAEMU could be used as a vehicle to attract CDM financing. (orig.)

Chitooligosaccharides--preparation with the aid of pectinase isozyme from Aspergillus niger and their antibacterial activity.

Science.gov (United States)

Kittur, Farooqahamed S; Vishu Kumar, Acharya B; Varadaraj, Mandyam C; Tharanathan, Rudrapatnam N

2005-05-02

An isozyme of pectinase from Aspergillus niger with polygalacturonase activity caused chitosanolysis at pH 3.5, resulting in low-molecular weight chitosan (86%), chitooligosaccharides (COs, 4.8%) and monomers (2.2%). HPLC showed the presence of COs with DP ranging from 2 to 6. Charcoal-Celite chromatography and re-N-acetylation of the COs followed by CD, IR, MALDI-TOF-MS and FAB-MS analyses revealed an abundance of chitobiose, chitotriose and chitotetraose. The COs-monomeric mixture showed a bactericidal effect towards Bacillus cereus and Escherichia coli more efficiently than native chitosan. Among the chitooligomers, the hexamer showed maximum antibacterial effect followed by the penta-, tetra-, tri- and dimers. Of the two monomers, only GlcN showed slight bacterial growth inhibition. SEM revealed bactericidal action patterns of COs-monomeric mixture towards B. cereus and E. coli.

Isolation, Purification, and Identification of Taxol and Related Taxanes from Taxol-Producing Fungus Aspergillus niger subsp. taxi.

Science.gov (United States)

Li, Dan; Fu, Dongwei; Zhang, Yue; Ma, Xueling; Gao, Liguo; Wang, Xioahua; Zhou, Dongpo; Zhao, Kai

2017-08-28

The content of taxol in the bark of yews is very low, and this is not affordable from the environmental point of view. Thus, it is a necessity to look for alternative sources of taxol production to solve its supply. Currently, a large portion of the taxol in the market comes from chemical semi-synthesis, but the semi-synthetic precursors such as baccatin III and 10-deacetyl-baccatin III are extracted from needles and twigs of yew trees. Taxol-producing fungi as a renewable resource is a very promising way to increase the scale of taxol production. Our group has obtained a taxol-producing endophytic fungus, Aspergillus niger subsp. taxi HD86-9, to examine if A. niger can produce the taxanes. Six compounds from the fermentation broth of strain HD86-9 were isolated and identified by 1 H NMR, 13 C NMR, and ESI-MS. The results showed that the six compounds included four taxane diterpenoids (taxol, cephalomannine, baccatin III, and 10-deacetyl-baccatin III) and two non-taxane compounds (β-sitosterol and flavonoid isovitexin). The study verified that the taxanes can be produced by the A. niger , which is very important to taxol production via chemical semi-synthesis. Additionally, the finding is potentially very significant to solve the taxol semi-synthetic precursors extracted from needles and twigs of yew trees, and the precursor production can be easily increased through the culture condition optimization, genetic breeding, and metabolic engineering of the A. niger .

Alienation and Militancy in the Niger Delta: Hostage Taking and the ...

African Journals Online (AJOL)

This paper examines the linkages between alienation and militancy in Nigeria's Niger Delta region, and the dilemma the Nigerian State faces in dealing with the menace of hostage taking of oil workers in the region by militant groups. To achieve this objective, the paper critically discusses the centrality of alienation in the ...

Alienation and Militancy in the Niger Delta : Hostage Taking and the ...

African Journals Online (AJOL)

feelings of alienation are a fundamental cause of conflict in the Niger. Delta. Secondly ... people/communities of the right to ownership and control of our lives. .... see the ethnicised Nigerian State and its disabled federal system as fun- damental ..... Oil companies usually shut down production as a safety measure. At times ...

Insecurity in the Niger Delta and the Future of Nigeria's Federalism ...

African Journals Online (AJOL)

For over five decades oil from the Niger Delta has been the pivot of the Nigerian economy. However, while other areas enjoyed the benefits of oil revenues, the region has wallowed in misery. This contradiction of wealth without development led to protests for restructuring of the federation to reflect existing structures at ...

The nature and forms of socio-political administration of West Niger ...

African Journals Online (AJOL)

This paper shows that the absence of the large and expansive state system in the West Niger Igbo area does not mean that the communities did not evolve any organizational forms suitable to their needs. It also shows that the communities in fact developed methods of organising their social and political administration.

Strategies for Mitigation of Flood Risk in the Niger Delta, Nigeria ...

African Journals Online (AJOL)

jen

ABSTRACT: The study has the major objective of evaluating flood risk mitigation strategies in the Niger. Delta, a coastal region of Nigeria that suffers from perennial flooding. The Raper argues that the structural methods of flood control tends to give a false sense of security to flood plain dwellers and thereby encouraging.

Application of Aspergillus niger SA1 for the enhanced bioremoval of ...

African Journals Online (AJOL)

Biological remediation is always envisaged as cost effective and eco-friendly for the treatment of recalcitrant dyes and effluents. Aspergillus niger SA1, a brown rot fungi, isolated from storage pond of textile wastewater, showed a great mineralizing ability for azo dyes, acid red (AR) 151 and orange (Or) II. Decolorization ...

Induction, purification and characterization of alfa-N-acetylgalactosaminidase from Aspergillus Niger

Czech Academy of Sciences Publication Activity Database

Weignerová, Lenka; Filipi, Tomáš; Manglová, Dana; Křen, Vladimír

2008-01-01

Roč. 79, č. 5 (2008), s. 769-774 ISSN 0175-7598 R&D Projects: GA MŠk(CZ) LC06010; GA ČR GA203/05/0172 Institutional research plan: CEZ:AV0Z50200510 Keywords : aspergillus niger * glycosidase library Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.569, year: 2008

HPLC Quantification of Cytotoxic Compounds from Aspergillus niger

Directory of Open Access Journals (Sweden)

Paula Karina S. Uchoa

2017-01-01

Full Text Available A high-performance liquid chromatography method was developed and validated for the quantification of the cytotoxic compounds produced by a marine strain of Aspergillus niger. The fungus was grown in malt peptone dextrose (MPD, potato dextrose yeast (PDY, and mannitol peptone yeast (MnPY media during 7, 14, 21, and 28 days, and the natural products were identified by standard compounds. The validation parameters obtained were selectivity, linearity (coefficient of correlation > 0.99, precision (relative standard deviation below 5%, and accuracy (recovery > 96.

Catalytical Properties of Free and Immobilized Aspergillus niger Tannase

OpenAIRE

Abril Flores-Maltos; Luis V. Rodríguez-Durán; Jacqueline Renovato; Juan C. Contreras; Raúl Rodríguez; Cristóbal N. Aguilar

2011-01-01

A fungal tannase was produced, recovered, and immobilized by entrapment in calcium alginate beads. Catalytical properties of the immobilized enzyme were compared with those of the free one. Tannase was produced intracellularly by the xerophilic fungus Aspergillus niger GH1 in a submerged fermentation system. Enzyme was recovered by cell disruption and the crude extract was partially purified. The catalytical properties of free and immobilized tannase were evaluated using tannic acid and methy...

A high yield of amylase from Aspergillus niger by the effect of gamma irradiation

International Nuclear Information System (INIS)

El-Saadany, R.M.A.; Salem, F.A.; El-Manawaty, H.K.

1984-01-01

When irradiated rice was used as a media for Aspergillus niger a noticeable increase of amylase production was observed. Molecular degradation of starch molecules did occure, and an increase in starch acidity and solubility was noticed, whereas a marked decrease in viscosity as well as swelling capacity was observed. Gelatinization time and temperature of irradiated starch became shorter or lower resp. These results showed that internal changes in irradiated starch molecules and an alteration in its molecular configuration occured. They may affect the pathway of the growth of the fungi Aspergillus niger. When the amount of amylase was determined by measuring enzyme activity, it was observed that amylases in the irradiated media were higher than in the control media. (orig.) [de

Modification of Aspergillus niger by conducting polymer, Polypyrrole, and the evaluation of electrochemical properties of modified cells.

Science.gov (United States)

Apetrei, Roxana-Mihaela; Carac, Geta; Bahrim, Gabriela; Ramanaviciene, Almira; Ramanavicius, Arunas

2018-06-01

The enhancement of bioelectrochemical properties of microorganism by in situ formation of conducting polymer within the cell structures (e.g. cell wall) was performed. The synthesis of polypyrrole (Ppy) within fungi (Aspergillus niger) cells was achieved. Two different Aspergillus niger strains were selected due to their ability to produce glucose oxidase, which initiated the Ppy formation through products of enzymatic reaction. The evolution of Ppy structural features was investigated by absorption spectroscopy, cyclic voltammetry and Fourier transform infrared spectroscopy. Copyright © 2018 Elsevier B.V. All rights reserved.

Variability in growth of Vachellia nilotica provenances tested in the Sudano-Sahelian zone of Niger

DEFF Research Database (Denmark)

Larwanou, Mahamane; Issa, Rabiou; Saadou, Mahamane

2014-01-01

A provenance trial of Vachellia nilotica (Acacia nilotica) was conducted in Niger in order to assess variability in growth among 10 provenances from Africa (subsp. adstringens from Niger, Senegal and Cameroun) and outside the continent (subsp. indica from Pakistan and Yemen). Tree height, diameter...... at breast height and crown diameter were measured 15 years after trial establishment. Comparison of blocks located at slightly different elevation showed that trees had better survival and growth at the lower sites. The African provenances had better survival and total basal area than provenances from Yemen...

Factors Affecting Rural Households’ Resilience to Food Insecurity in Niger

Directory of Open Access Journals (Sweden)

Aboubakr Gambo Boukary

2016-03-01

Full Text Available Niger faces many natural and human constraints explaining the erratic evolution of its agricultural production over time. Unfortunately, this is likely to cause a decline in the food supply. This study attempts to identify factors affecting rural households’ resilience to food insecurity in Niger. For this, we first create a resilience index by using principal component analysis and later apply structural equation modeling to identify its determinants. Data from the 2010 National Survey on Households’ Vulnerability to Food Insecurity done by the National Institute of Statistics is used. The study shows that asset and social safety net indicators are significant and have a positive impact on households’ resilience. Climate change approximated by long-term mean rainfall has a negative and significant effect on households’ resilience. Therefore, to strengthen households’ resilience to food insecurity, there is a need to increase assistance to households through social safety nets and to help them gather more resources in order to acquire more assets. Furthermore, early warning of climatic events could alert households, especially farmers, to be prepared and avoid important losses that they experience anytime an uneven climatic event occurs.

Cadmium biosorption by Aspergillus niger; Biossorcao de cadmio pelo Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Silva, E.P.; Barros Junior, L.M.; Duarte, M.M.L.; Macedo, G.R. [Universidade Federal do Rio Grande do Norte, Natal, RN (Brazil)]. E-mail: edmilson@eq.ufrn.br

2003-07-01

Biosorption is a property of certain types of inactive, dead, microbial biomass to bind and concentrate heavy metals from even very dilute aqueous solutions. Biomass exhibits this property, acting just as a chemical substance, as an ion exchanger of biological origin. It is particularly the cell wall structure of certain algae, fungi and bacteria which was found responsible for this phenomenon. Some of the biomass types come as a waste by-product of large-scale industrial fermentations (the mold Rhizopus or the bacterium Bacillus subtilis). Other metal-binding biomass types, certain abundant seaweeds (particularly brown algae e.g. Sargassum, Ecklonia), can be readily collected from the oceans. These biomass types, serving as a basis for metal biosorption processes, can accumulate in excess of 25% of their dry weight in deposited heavy metals: Pb, Cd, U, Cu, Zn, even Cr and others. Sorption experiments using the Aspergillus niger fungus for cadmium removal were carried out to study the factors influencing and optimizing the biosorption of this metal. The effects of pH, time, biomass concentration, and initial concentration of the heavy metal on the rate of metallic biosorption were examined. (author)

Human resources for the nuclear sector in the Republic of Niger

International Nuclear Information System (INIS)

Hassane, S.

2004-01-01

Full text: 1. Introduction: It is interesting to examine how the need to develop and maintain skills in term of human resources was dealt with Niger's nuclear sector. Although the country is one of poorest in the world, some insight can be derived from its experience. The Niger politics and strategies for both demand and supply side of human resources in the nuclear sector are to promote tangible socio-economic impact to the achievement of major sustainable development priorities. Member state of International Atomic Energy Agency (IAEA) since 1968, Niger was started during the same year, its nuclear activities by extraction and processing uranium from open pit mine of SOMAIR. With 2960 tons of uranium from two big mines, Niger becomes the 3rd world producer. Training and education are critical components of the development of human resources related to the nuclear sector in Niger Republic. The country has gone through a number of initiatives to consolidate its legal framework concerning radiation safety. The National Centre of Radio Protection (NCRP), under the Ministry of Heath, is operational and is responsible for national regulatory activities programme, while the Ministry of Mines and Energy regulates uranium mining and milling activities. Both regulatory authorities need to develop their human resources to be able to inspect users and enforce regulatory requirements in all areas. 2. Human resources suppliers: In order to establish a pool of competency, mining companies send their workers to France for education and training. Incentives (good social condition, salaries etc) were provided to attract people to work in nuclear programme. Many foreign professionals were short-term consultants, but many of them are employed by the companies, forming a pool of well-skilled and motivated professionals. One way that was used to enhance and maintain the pool of trained professionals was the technical co-operation with the IAEA In this regard, we thank IAEA who has

Towards ending conflict and insecurity in the Niger Delta region: A ...

African Journals Online (AJOL)

2017-08-28

Aug 28, 2017 ... efforts made by the Federal Government of Nigeria to address conflicts in ... Dr Angela Ajodo-Adebanjoko is a Senior Lecturer in the Department of Political ... Conflict Management approach – involving a group of negotiators, both .... in the Niger Delta is one of the worst cases in the world of gas flaring.

High level expression and characterization of tannase tan7 using Aspergillus niger SH-2 with low-background endogenous secretory proteins as the host.

Science.gov (United States)

Liu, Fengling; Wang, Bin; Ye, Yanrui; Pan, Li

2018-04-01

Tannin acyl hydrolase (tannase, EC3.1.1.20) catalyzes the hydrolysis of hydrolyzable tannins. It is used in the manufacture of instant tea and in the production of gallic acid. In this study, we reported that the overexpression, purification and characterization of an Aspergillus niger tannase. The tannase gene was cloned from A. niger SH-2 and expressed in the A. niger strain Bdel4 which is low-background of secreted proteins. The recombinant tannase was purified by desalting, followed by gel filtration for characterization. The tannase activity achieved 111.5 U/mL at 168 h, and the purity of the enzyme in the broth supernatant was estimated to be over 70%. The optimum temperature and pH of the recombinant tannase was ∼40 °C and 7.0, respectively. The tannase activity was inhibited by Mg 2+ , Ca 2+ , Cu 2+ , Ba 2+ , Ni 2+ and EDTA, and was enhanced by Mn 2+ and Co 2+ . Since A. niger is a GRAS microorganism, the recombinant tannase could be purification-free due to its high purity. The results of this study suggested that this recombinant strain could be subjected to large-scale production of A. niger tannase. Copyright © 2017. Published by Elsevier Inc.

Mapping the polysaccharide degradation potential of Aspergillus niger

Science.gov (United States)

2012-01-01

Background The degradation of plant materials by enzymes is an industry of increasing importance. For sustainable production of second generation biofuels and other products of industrial biotechnology, efficient degradation of non-edible plant polysaccharides such as hemicellulose is required. For each type of hemicellulose, a complex mixture of enzymes is required for complete conversion to fermentable monosaccharides. In plant-biomass degrading fungi, these enzymes are regulated and released by complex regulatory structures. In this study, we present a methodology for evaluating the potential of a given fungus for polysaccharide degradation. Results Through the compilation of information from 203 articles, we have systematized knowledge on the structure and degradation of 16 major types of plant polysaccharides to form a graphical overview. As a case example, we have combined this with a list of 188 genes coding for carbohydrate-active enzymes from Aspergillus niger, thus forming an analysis framework, which can be queried. Combination of this information network with gene expression analysis on mono- and polysaccharide substrates has allowed elucidation of concerted gene expression from this organism. One such example is the identification of a full set of extracellular polysaccharide-acting genes for the degradation of oat spelt xylan. Conclusions The mapping of plant polysaccharide structures along with the corresponding enzymatic activities is a powerful framework for expression analysis of carbohydrate-active enzymes. Applying this network-based approach, we provide the first genome-scale characterization of all genes coding for carbohydrate-active enzymes identified in A. niger. PMID:22799883

Evaluasi nutrisi campuran onggok dan ampas tahu terfermentasi Aspergillus niger, Rizhopus oligosporus dan kombinasi sebagai bahan pakan pengganti tepung jagung

Directory of Open Access Journals (Sweden)

Maria Yohanista

2014-08-01

Full Text Available The purpose of this study was to evaluate the nutritional value of cassava and tofu mixture fermented by Aspergillus niger, Rizhopus oligosporus and the combination among them (50% of Aspergillus niger and 50% of Oligosporus Rizhopus as a substitute feed ingredients corn meal. The research method was laboratory experiment using the analysis of completely randomized design (CRD factorial (3 x 4. The first factor was the 3 types of microbes (M that consisted of M0 = fermentation by Aspergillus niger, M1 = fermentation with Rhizopus oligosporus and M2 = fermentation with the combination 50% of Aspergillus niger and 50% of Rhizopus oligosporus. The second factor was 4 incubation time (T that consisted of T0 = non-fermented, T1 = 2 days of incubation time, T2 = 4 days of incubation time and T3 = 6 days of incubation time. Each treatment was repeated 3 times. Variables measured were proximate nutrient content, fiber component content (NDF and ADF, silica, lignin, soluble protein content and mineral content (calcium and phosphorus. Data were analyzed by ANOVA, if there were differences among the treatments then it woukd be followed by Duncan's Multiple Range Test. Results showed that microbes provided a significant influence (P <0.01 on ash (%, crude protein (%, crude fiber (%, crude fat (%, gross energy (Kcal / Kg, soluble protein (%, NDF (%, ADF (%, cellulose (%, hemicelluloses (% and silicate (% but they did not provide significant effect on lignin (%. The incubation period had highly significant effect (P <0.01 on ash (%, crude protein (%, crude fiber (%, crude fat (%, gross energy (Kcal / Kg, soluble protein (%, NDF (%, ADF (%, cellulose (%, hemicelluloses (%, lignin (% and silicate (%. It was concluded that fermentation was best treated using a combination between 50% of Aspergillus niger and 50% of Rhizopus oligosporus with 2 days of incubation time. The study suggested for further research (biological test to use a mixture of cassava and

Monitoring the referral system through benchmarking in rural Niger: an evaluation of the functional relation between health centres and the district hospital

Directory of Open Access Journals (Sweden)

Miyé Hamidou

2006-04-01

Full Text Available Abstract Background The main objective of this study is to establish a benchmark for referral rates in rural Niger so as to allow interpretation of routine referral data to assess the performance of the referral system in Niger. Methods Strict and controlled application of existing clinical decision trees in a sample of rural health centres allowed the estimation of the corresponding need for and characteristics of curative referrals in rural Niger. Compliance of referral was monitored as well. Need was matched against actual referral in 11 rural districts. The referral patterns were registered so as to get an idea on the types of pathology referred. Results The referral rate benchmark was set at 2.5 % of patients consulting at the health centre for curative reasons. Niger's rural districts have a referral rate of less than half this benchmark. Acceptability of referrals is low for the population and is adding to the deficient referral system in Niger. Mortality because of under-referral is highest among young children. Conclusion Referral patterns show that the present programme approach to deliver health care leaves a large amount of unmet need for which only comprehensive first and second line health services can provide a proper answer. On the other hand, the benchmark suggests that well functioning health centres can take care of the vast majority of problems patients present with.

Verbal/Social Autopsy in Niger 2012–2013: A new tool for a better understanding of the neonatal and child mortality situation

Directory of Open Access Journals (Sweden)

Khaled Bensaïd

2016-06-01

Full Text Available Niger, one of the poorest countries in the world, recently used for the first time the integrated verbal and social autopsy (VASA tool to assess the biological causes and social and health system determinants of neonatal and child deaths. These notes summarize the Nigerien experience in the use of this new tool, the steps taken for high level engagement of the Niger government and stakeholders for the wide dissemination of the study results and their use to support policy development and maternal, neonatal and child health programming in the country. The experience in Niger reflects lessons learned by other developing countries in strengthening the use of data for evidence–based decision making, and highlights the need for the global health community to provide continued support to country data initiatives, including the collection, analysis, interpretation and utilization of high quality data for the development of targeted, highly effective interventions. In Niger, this is supporting the country’s progress toward achieving Millennium Development Goal 4. A follow–up VASA study is being planned and the tool is being integrated into the National Health Management Information System. VASA studies have now been completed or are under way in additional sub–Saharan African countries, in each through the same collaborative process used in Niger to bring together health policy makers, program planners and development partners.

Arabinase induction and carbon catabolite repression in Aspergillus niger and Aspergillus nidulans

NARCIS (Netherlands)

Veen, van der P.

1995-01-01

The first aim of this thesis was to get a better understanding of the properties and the induction features of arabinan degrading enzymes and enzymes involved in the intracellular L-arabinose catabolic pathway in Aspergillus niger. The second aim was to understand the

Regulation of the alpha-glucuronidase-encoding gene (aguA) from Aspergillus niger

NARCIS (Netherlands)

Vries, de R.P.; Vondervoort, van de P.J.I.; Hendriks, L.; Belt, van de M.; Visser, J.

2002-01-01

The !-glucuronidase gene aguA from Aspergillus niger was cloned and characterised. Analysis of the promoter region of aguA revealed the presence of four putative binding sites for the major carbon catabolite repressor protein CREA and one putative binding site for the transcriptional activator XLNR.

The pre- and protohistoric togué of the Niger alluvial plain, Mali

NARCIS (Netherlands)

Schmidt, Annette Margaretha

2009-01-01

The Inland Niger Delta in Mali is scattered with thousands of tell-like dwelling mounds that testify to the rich archaeological heritage of this attractive occupation area. Little is known about the structure and evolution of this considerable settlement system. The general aim of the present

Statistical optimization for tannase production from Aspergillus niger under submerged fermentation.

Science.gov (United States)

Sharma, S; Agarwal, L; Saxena, R K

2007-06-01

Statistically based experimental design was employed for the optimization of fermentation conditions for maximum production of enzyme tannase from Aspergillus niger. Central composite rotatable design (CCRD) falling under response surface methodology (RSM) was used. Based on the results of 'one-at-a-time' approach in submerged fermentation, the most influencing factors for tannase production from A. niger were concentrations of tannic acid and sodium nitrate, agitation rate and incubation period. Hence, to achieve the maximum yield of tannase, interaction of these factors was studied at optimum production pH of 5.0 by RSM. The optimum values of parameters obtained through RSM were 5% tannic acid, 0.8% sodium nitrate, 5.0 pH, 5 × 10(7) spores/50mL inoculum density, 150 rpm agitation and incubation period of 48 h which resulted in production of 19.7 UmL(-1) of the enzyme. This activity was almost double as compared to the amount obtained by 'one-at-a-time' approach (9.8 UmL(-1)).

Anti-Money Laundering and Combating the Financing of Terrorism : Niger

OpenAIRE

World Bank

2009-01-01

The assessment of the Anti-Money Laundering and Combating the Financing of Terrorism (AML/CFT) regime in Niger was conducted on the basis of the Forty Recommendations and the Nine Special Recommendations on the financing of terrorism drawn up in 2003 and 2001, respectively, by the Financial Action Task Force (FATF), and on the AML/CFT Methodology of 2004. The assessment was based on the la...

Gram-scale production of a basidiomycetous laccase in Aspergillus niger.

Science.gov (United States)

Mekmouche, Yasmina; Zhou, Simeng; Cusano, Angela M; Record, Eric; Lomascolo, Anne; Robert, Viviane; Simaan, A Jalila; Rousselot-Pailley, Pierre; Ullah, Sana; Chaspoul, Florence; Tron, Thierry

2014-01-01

We report on the expression in Aspergillus niger of a laccase gene we used to produce variants in Saccharomyces cerevisiae. Grams of recombinant enzyme can be easily obtained. This highlights the potential of combining this generic laccase sequence to the yeast and fungal expression systems for large-scale productions of variants. Copyright © 2013 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Comparative studies on production of cellulases from three strains of aspergillus niger

International Nuclear Information System (INIS)

Sohail, M.; Ahmad, A.; Khan, S.

2014-01-01

Three strains of Aspergillus niger were retrieved from culture collection of the Department of Microbiology, University of Karachi, Pakistan and were studied for their ability to produce cellulases. Cultivation at different temperatures and in presence of various carbon sources revealed that all the three strains produced more amounts of endoglucanase, glucosidase and filter-paperase activities at 35 degree C; carboxymethyl cellulose promotes the production of filter paperase and endoglucanase activities whereas salicin induced glucosidase activity. Experiments on growth and enzyme production kinetics showed that generation time and hence volumetric rate of biomass production is influenced by the carbon source used in the medium; simple carbon source, such as glucose favored the growth of all the strains. Cellulases from all the strains showed optimum activity at temperature >50 degree C and under acidic range of pH, while melting temperature was 64-65 degree C. These findings affirm that cellulases from A. niger are potential candidates as alternative to Trichoderma cellulases. (author)

A molecular analysis of L-arabinan degradation in Aspergillus niger and Aspergillus nidulans

NARCIS (Netherlands)

Flipphi, M.J.A.

1995-01-01

This thesis describes a molecular study of the genetics ofL-arabinan degradation in Aspergillus niger and Aspergillus nidulans. These saprophytic hyphal fungi produce an extracellular hydrolytic enzyme system to

132 Tanure Ojaide: The Poet-Priest of the Niger-Delta and the Land ...

African Journals Online (AJOL)

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Oil detection in the Niger Delta has had multifarious effects on the Nigerian ..... receives infinite respect and reverence from the people, and to this day, a cult .... appellations, sea animals and bird names and value placements form the oral.

Upgrading of naringinase production by gamma irradiated Aspergillus niger uilizing agro-industrial processing wastes

International Nuclear Information System (INIS)

El-Batal, A.I.; Swailam, H.M.H.

2003-01-01

Naringinase-producing microorganisms were isolated locally from some citrus fruits and soil using a culture enrichment technique, and they were tested for their enzyme producing ability in shake flask cultures. Among the tested microorganisms, aspergillus niger-AH3 proved to be the most potent active isolate which gave 92.1 UMl -1 of naringinase activity in fermentation medium. Optimization effects of various fermentation medium constituents of agro-industrial processing wastes as substrates for naringinase production were studied. Of substrates used, corn steep liquor, soya bean meal, jojoba seed meal and bitter orange seed powder were the best for naringinase production .Maximum enzyme titer (145.5 Uml -1 ) was obtained in the optimized fermentation medium supplemented with 0.5% CaCo 3 after 120 h of incubation. The highly potent ten enhanced isolates which were selected after treatment with gamma irradiation, had significantly elevated titers of naringinase activity compared with the parental wild strain A. niger-AH3. Enhanced isolate A. niger-AH3. γ20 derived from 2.0 kGy treated groups is exhibiting the highest enzyme activity 1.5 folds higher than parental strain. This suggests that a process for efficient utilization of the agro-industrial processing wastes in economical production of naringinase in large quantities which would be suitable for debittering process in the citrus fruit juice industry

Heterogenic expression of genes encoding secreted proteins at the periphery of Aspergillus niger colonies.

Science.gov (United States)

Vinck, Arman; de Bekker, Charissa; Ossin, Adam; Ohm, Robin A; de Vries, Ronald P; Wösten, Han A B

2011-01-01

Colonization of a substrate by fungi starts with the invasion of exploring hyphae. These hyphae secrete enzymes that degrade the organic material into small molecules that can be taken up by the fungus to serve as nutrients. We previously showed that only part of the exploring hyphae of Aspergillus niger highly express the glucoamylase gene glaA. This was an unexpected finding since all exploring hyphae are exposed to the same environmental conditions. Using GFP as a reporter, we here demonstrate that the acid amylase gene aamA, the α-glucuronidase gene aguA, and the feruloyl esterase gene faeA of A. niger are also subject to heterogenic expression within the exploring mycelium. Coexpression studies using GFP and dTomato as reporters showed that hyphae that highly express one of these genes also highly express the other genes encoding secreted proteins. Moreover, these hyphae also highly express the amylolytic regulatory gene amyR, and the glyceraldehyde-3-phosphate dehydrogenase gene gpdA. In situ hybridization demonstrated that the high expressers are characterized by a high 18S rRNA content. Taken together, it is concluded that two subpopulations of hyphae can be distinguished within the exploring mycelium of A. niger. The experimental data indicate that these subpopulations differ in their transcriptional and translational activity. © 2010 Society for Applied Microbiology and Blackwell Publishing Ltd.

Biosynthesis of beta-glucosidase by Aspergillus niger a-5

Energy Technology Data Exchange (ETDEWEB)

Atev, A.; Panayotov, C.; Bubareva, L.; Benadova, R.; Kolev, E.

1984-01-01

Aspergillus niger A-5 produced beta-glucosidase, exocellobihydrolase (C1 enzyme) and endo-1, 4-beta-glucanase (Cx enzyme) in a culture medium containing farm residues of plant origin: wheat straw, ground maize stalks, wheat bran, and micricell as substrates. Maize stalk and wheat bran were the best inducers of the cellulase complex. Intensive aeration stimulated growth and enzyme synthesis. The highest beta-glucosidase activity (54 units/mL) was observed after 96 h of cultivation.

Mathematical model of gluconic acid fermentation by Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Takamatsu, T.; Shioya, S.; Furuya, T.

1981-11-01

A mathematical model for the study of gluconic acid fermentation by Aspergillus niger has been developed. The model has been deduced from the basic biological concept of multicellular filamentous microorganisms, i.e. cell population balance. It can be used to explain the behaviour of both batch and continuous cultures, even when in a lag phase. A new characteristic, involving the existence of dual equilibrium stages during fermentation, has been predicted using this mathematical model. (Refs. 6).

Republic of Niger : Trends of Poverty, Inequality, and Growth, 2005-2011

OpenAIRE

World Bank

2014-01-01

The ability to accurately monitor poverty trends is crucial to ensure the adoption of effective antipoverty policies and to assess progress toward the achievement of national development goals. In Niger, efforts to assess poverty dynamics between 2005 and 2011 are complicated by methodological differences in the three household surveys conducted over the period, in 2005, 2007-08 and 2011. ...

Aspergillus niger PA2: a novel strain for extracellular biotransformation of L-tyrosine into L-DOPA.

Science.gov (United States)

Agarwal, Pragati; Pareek, Nidhi; Dubey, Swati; Singh, Jyoti; Singh, R P

2016-05-01

L-DOPA (3,4-dihydroxyphenyl-L-alanine), an amino acid derivative is the most widely used drug of choice for the treatment of Parkinson's disease and other neurologic injuries. The present study deals with the elevated biochemical transformation of L-tyrosine to L-DOPA by Aspergillus niger PA2, a potent tyrosinase producer, isolated from decomposed food wastes. This appears to be the first report on A. niger as a notable extracellular tyrosinase producer. The extracellular tyrosinase activity produced remarkably higher levels of L-DOPA, i.e. 2.44 mg mL(-1) when the media was supplemented with 5 mg mL(-1) L-tyrosine. The optimum pH for tyrosinase production was 6.0, with the maximal L-DOPA production at the same pH. The product thus produced was analyzed by thin-layer chromatography, UV spectroscopy, high-performance liquid chromatography and Fourier transform infrared spectroscopy, that had denoted this to be L-DOPA. Kinetic parameters viz. Y p/s, Q s and Q p had further indicated the notable levels of production. Thus, Aspergillus niger PA2 could be a promising resource and may be further exploited for large-scale production of L-DOPA.

Les enjeux socio-économiques autour de l'agroforesterie villageoise à Aguié (Niger

Directory of Open Access Journals (Sweden)

Dramé Yayé, A.

2008-01-01

Full Text Available Issues around Village Agroforestry in Aguié (Niger. In the framework of a partnership between the Abdou Moumouni University of Niamey (Niger, The Catholic University of Louvain (Belgium, The Gembloux Agricultural University (Belgium, The University of Liege (Belgium, The asbl ENDA Intermondes and the PPILDA Project, former PDRAA of Aguié (Niger, studies were conducted in 2003 and 2004 in two villages (Dan Saga and Guidan Bakoye in Aguié, located in the Region of Maradi (Middle South of Niger. These studies were requested by farmers, and aimed at precising the feasibility and conditions for creating a rural wood market. They consisted in the evaluation of the assisted natural regeneration obtained through the protection of tree shoots in the fields. Dan Saga and Guidan Bakoye villages are typical Combretum glutinosum and Piliostigma reticulatum areas where farmers from all social categories practised the assisted natural regeneration, leading to densities of more than 100 trees per hectare in the fields. These densities increase with the increasing distance from the villages. The weekly amount of offered firewood (about 10 to 50 bundles of 25 kg each and timber in the local market could generate more than CFA 1 million income. However, the lack of local purchasers makes it difficult to sell more than the third of the wood production. This is what seems to be another reason for creating a wood market network. This network would be a grouping of villages not always belonging to the same administrative entity, but organized around common social and economical development concerns. The PPILDA Projet calls such a network a "Between-Villages Network". The management of the natural regeneration of tree species in the fields has favoured the emergence of various actors whose conflicting interests destabilized the pre-existing social structures. The only way to adapt to these social mutations is to establish an incentive agroforestry policy, to define

Effects of light quality on flowering and morphogenesis in Hyoscyamus niger L.

NARCIS (Netherlands)

Hattab, El A.H.

1968-01-01

The present paper is concerned with bolting and morphogenesis of Hyoscyamus niger L. as reactions upon radiation in the visible spectrum.

Experiments are described in which Hyoscyamus plants were exposed to light of various well defined spectral regions. The light of these

Conversion of fusaric acid to fusarinol by Aspergillus niger: A detoxification reaction

Science.gov (United States)

The fungus Fusarium oxysporum causes wilt diseases of plants and produces a potent phytotoxin fusaric acid (FA) which is also toxic to many microorganisms. An Aspergillus strain with high tolerance to FA was isolated from soil. HPLC analysis of culture filtrates from A. niger grown with the addition...

A 23-year review of sudden natural death autopsies in the Niger ...

African Journals Online (AJOL)

Background: Death occurring suddenly especially when the victim was active and recently fit, call for attention and thorough investigation to rule out secret homicide. Aim: To study the pattern of sudden natural death in the Niger Delta region of Nigeria. Methodology: The coroner's autopsy reports and hospital autopsy ...

Changes in the physiological properties and kinetics of citric acid accumulation via carbon ion irradiation mutagenesis of Aspergillus niger *

Science.gov (United States)

Hu, Wei; Chen, Ji-hong; Wang, Shu-yang; Liu, Jing; Song, Yuan; Wu, Qing-feng; Li, Wen-jian

2016-01-01

The objective of this work was to produce citric acid from corn starch using a newly isolated mutant of Aspergillus niger, and to analyze the relationship between changes in the physiological properties of A. niger induced by carbon ion irradiation and citric acid accumulation. Our results showed that the physiological characteristics of conidia in A. niger were closely related to citric acid accumulation and that lower growth rate and viability of conidia may be beneficial to citric acid accumulation. Using corn starch as a raw material, a high-yielding citric acid mutant, named HW2, was obtained. In a 10-L bioreactor, HW2 can accumulate 118.9 g/L citric acid with a residual total sugar concentration of only 14.4 g/L. This represented an 18% increase in citric acid accumulation and a 12.5% decrease in sugar utilization compared with the original strain.

Gallic acid formation from gallotannins-rich agricultural wastes using Aspergillus niger AUMC 4301 or its tannase enzyme

International Nuclear Information System (INIS)

El-Fouly, M.Z.; Shahin, A.A.M.; El-Bialy, H.A.; El-Saeed, Gh.E.; El-Awamry, Z.; Naeem, E.

2012-01-01

Gallic acid is used in many fields including dye-making, leather and chemical industries. Seven agricultural wastes were chosen for their high gallotannin content. They were apple baggages, green tea waste, mango seed kernel, olive mill, palm kernel cake, peat moss and tamarind. Each waste was used as a carbon source instead of tannic acid in the fermentation medium. Some agricultural wastes under investigation were already contain free gallic acid especially mango seed kernel followed by green tea waste, while olive mill, peat moss and tamarind were found to be free from gallic acid. The highest concentration of liberated gallic acid from wastes fermented by A. niger AUMC 4301 was occurred at the third day of fermentation. After 72 h, a sharp decrease in gallic acid accumulation was noticed. To overcome this sharp decrease, agricultural wastes were treated with extracellular crude A. niger tannase directly in stead of tannase producer. The concentration of gallic acid increased gradually and reached its maximum at 18 h incubation in case of apple baggages, green tea waste and palm kernel cake. On the other hand, gallic acid production was delayed for a lag period (12-18) h depends on the complexity of used agriculture waste. To increase the tannase productivity by A. niger AUMC 4301, the producer fungus was irradiated by different doses of γ rays, D10 value was 0.81 kGy. Radiation dose 0.5 kGy shows a positive effect on tannase productivity. An experiment examined the change in amino acid profile between irradiated and unirradiated A. niger AUMC 4301 was also conducted.

Comparative Secretome Analysis of Trichoderma reesei and Aspergillus niger during Growth on Sugarcane Biomass.

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Gustavo Pagotto Borin

Full Text Available Our dependence on fossil fuel sources and concern about the environment has generated a worldwide interest in establishing new sources of fuel and energy. Thus, the use of ethanol as a fuel is advantageous because it is an inexhaustible energy source and has minimal environmental impact. Currently, Brazil is the world's second largest producer of ethanol, which is produced from sugarcane juice fermentation. However, several studies suggest that Brazil could double its production per hectare by using sugarcane bagasse and straw, known as second-generation (2G bioethanol. Nevertheless, the use of this biomass presents a challenge because the plant cell wall structure, which is composed of complex sugars (cellulose and hemicelluloses, must be broken down into fermentable sugar, such as glucose and xylose. To achieve this goal, several types of hydrolytic enzymes are necessary, and these enzymes represent the majority of the cost associated with 2G bioethanol processing. Reducing the cost of the saccharification process can be achieved via a comprehensive understanding of the hydrolytic mechanisms and enzyme secretion of polysaccharide-hydrolyzing microorganisms. In many natural habitats, several microorganisms degrade lignocellulosic biomass through a set of enzymes that act synergistically. In this study, two fungal species, Aspergillus niger and Trichoderma reesei, were grown on sugarcane biomass with two levels of cell wall complexity, culm in natura and pretreated bagasse. The production of enzymes related to biomass degradation was monitored using secretome analyses after 6, 12 and 24 hours. Concurrently, we analyzed the sugars in the supernatant.Analyzing the concentration of monosaccharides in the supernatant, we observed that both species are able to disassemble the polysaccharides of sugarcane cell walls since 6 hours post-inoculation. The sugars from the polysaccharides such as arabinoxylan and β-glucan (that compose the most external

Comparative Secretome Analysis of Trichoderma reesei and Aspergillus niger during Growth on Sugarcane Biomass

Science.gov (United States)

Borin, Gustavo Pagotto; Sanchez, Camila Cristina; de Souza, Amanda Pereira; de Santana, Eliane Silva; de Souza, Aline Tieppo; Leme, Adriana Franco Paes; Squina, Fabio Marcio; Buckeridge, Marcos; Goldman, Gustavo Henrique; Oliveira, Juliana Velasco de Castro

2015-01-01

Background Our dependence on fossil fuel sources and concern about the environment has generated a worldwide interest in establishing new sources of fuel and energy. Thus, the use of ethanol as a fuel is advantageous because it is an inexhaustible energy source and has minimal environmental impact. Currently, Brazil is the world's second largest producer of ethanol, which is produced from sugarcane juice fermentation. However, several studies suggest that Brazil could double its production per hectare by using sugarcane bagasse and straw, known as second-generation (2G) bioethanol. Nevertheless, the use of this biomass presents a challenge because the plant cell wall structure, which is composed of complex sugars (cellulose and hemicelluloses), must be broken down into fermentable sugar, such as glucose and xylose. To achieve this goal, several types of hydrolytic enzymes are necessary, and these enzymes represent the majority of the cost associated with 2G bioethanol processing. Reducing the cost of the saccharification process can be achieved via a comprehensive understanding of the hydrolytic mechanisms and enzyme secretion of polysaccharide-hydrolyzing microorganisms. In many natural habitats, several microorganisms degrade lignocellulosic biomass through a set of enzymes that act synergistically. In this study, two fungal species, Aspergillus niger and Trichoderma reesei, were grown on sugarcane biomass with two levels of cell wall complexity, culm in natura and pretreated bagasse. The production of enzymes related to biomass degradation was monitored using secretome analyses after 6, 12 and 24 hours. Concurrently, we analyzed the sugars in the supernatant. Results Analyzing the concentration of monosaccharides in the supernatant, we observed that both species are able to disassemble the polysaccharides of sugarcane cell walls since 6 hours post-inoculation. The sugars from the polysaccharides such as arabinoxylan and β-glucan (that compose the most external

Effect of low shear modeled microgravity on phenotypic and central chitin metabolism in the filamentous fungi Aspergillus niger and Penicillium chrysogenum.

Science.gov (United States)

Sathishkumar, Yesupatham; Velmurugan, Natarajan; Lee, Hyun Mi; Rajagopal, Kalyanaraman; Im, Chan Ki; Lee, Yang Soo

2014-08-01

Phenotypic and genotypic changes in Aspergillus niger and Penicillium chrysogenum, spore forming filamentous fungi, with respect to central chitin metabolism were studied under low shear modeled microgravity, normal gravity and static conditions. Low shear modeled microgravity (LSMMG) response showed a similar spore germination rate with normal gravity and static conditions. Interestingly, high ratio of multiple germ tube formation of A. niger in LSMMG condition was observed. Confocal laser scanning microscopy images of calcofluor flurophore stained A. niger and P. chrysogenum showed no significant variations between different conditions tested. Transmission electron microscopy images revealed number of mitochondria increased in P. chrysogenum in low shear modeled microgravity condition but no stress related-woronin bodies in fungal hyphae were observed. To gain additional insight into the cell wall integrity under different conditions, transcription level of a key gene involved in cell wall integrity gfaA, encoding the glutamine: fructose-6-phosphate amidotransferase enzyme, was evaluated using qRT-PCR. The transcription level showed no variation among different conditions. Overall, the results collectively indicate that the LSMMG has shown no significant stress on spore germination, mycelial growth, cell wall integrity of potentially pathogenic fungi, A. niger and P. chrysogenum.

Facile production of Aspergillus niger α-N-acetylgalactosaminidase in yeast

Czech Academy of Sciences Publication Activity Database

Mrázek, Hynek; Benada, Oldřich; Man, Petr; Vaněk, O.; Křen, Vladimír; Bezouška, Karel; Weignerová, Lenka

2012-01-01

Roč. 81, č. 1 (2012), s. 106-114 ISSN 1046-5928 R&D Projects: GA MŠk 1M0505; GA ČR GAP207/10/0321; GA ČR GD305/09/H008; GA ČR GA303/09/0477 Institutional research plan: CEZ:AV0Z50200510 Keywords : Aspergillus niger * alpha-N-Acetylgalactosaminidase * Expression Subject RIV: CE - Biochemistry Impact factor: 1.429, year: 2012

Some factors affecting tannase production by Aspergillus niger Van Tieghem

OpenAIRE

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

2013-01-01

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 attai...

The utilization of coconut waste fermentated by aspergillus niger and saccharomyces cerevisiae on meat quality of weaning males rex rabbit

Science.gov (United States)

Wahyuni, T. H.; Ginting, N.; Yunilas; Hasnudi; Mirwandono, E.; Siregar, G. A.; Sinaga, I. G.; Sembiring, I.

2018-02-01

Coconut waste (CW) could be applied for animal feed while its nutrition quality were low. This study aims to investigate fermented CW effect on meat quality of Rex rabbit which feed by fermented CW either by Aspergillus niger or Tape Yeast. This research was conducted in rabbit farm Brastagi, using 24 male Rex rabbits with initial weight 1012 ± 126.67 gram in July-October 2016. The design used was complete randomized design : 6 treatment 4 replications. Treatment were T1 (unfermented 10%); T2 (unfermented 20%); T3 (a.niger fermentation 10%); T4 (a niger fermentation 20%); T5 (tape yeast fermentation 10%) and T6 (tape yeast fermentation 20%). The parameters were pH, meat texture either raw or cooked, water content, fat content, protein content of meat and cooking loss. The results showed that effect of treatment was not significantly different (P>0.05) on pH and raw meat texture, but significantly different (Pmeat cooked and meat fat content and very significantly different effect ( P> 0,01) on cooking loss, water content and protein content of meat. The conclusion of this research was the utilization of fermented CW by Aspergillius niger and Tape Yeast improved the quality of Rex rabbit meat

Low Prevalence of Pfcrt Resistance Alleles among Patients with Uncomplicated Falciparum Malaria in Niger Six Years after Chloroquine Withdrawal

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Adamou Salissou

2014-01-01

Full Text Available Chloroquine (CQ resistance is widespread in Africa, but few data are available for Niger. Pfcrt haplotypes (aa 56–118 and ex vivo responses to CQ and amodiaquine were characterized for 26 isolates collected in South Niger from children under 15 years of age suffering from uncomplicated falciparum malaria, six years after the introduction of artemisinin-based combinations and the withdrawal of CQ. The wild-type Pfcrt haplotype CVMNK was found in 22 of the 26 isolates, with CVIET sequences observed in only three of the samples. We also describe for the first time a new CVINT haplotype. The ex vivo responses were better for CVMNK than for CVIET parasites. Pfcrt sequence data were compared with those obtained for 26 additional parasitized blood samples collected in Gabon, from an area of CQ resistance used as a control. Our findings suggest that there has been a significant decline in CQ-resistant genotypes since the previous estimates for Niger were obtained. No such decline in molecular resistance to CQ was observed in the subset of samples collected in similar conditions from Gabon. These results have important implications for public health and support the policy implemented in Niger since 2005, which aims to increase the efficacy and availability of antimalarial drugs whilst controlling the spread of resistance.

PRODUCTION AND CHARACTERIZATION OF CELLULOLYTIC ENZYMES BY ASPERGILLUS NIGER AND RHIZOPUS SP . BY SOLID STATE FERMENTATION OF PRICKLY PEAR

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TAMIRES CARVALHO DOS SANTOS

2016-01-01

Full Text Available Prickly palm cactus husk was used as a solid - state fermentation support substrate for the production of cellulolytic enzymes using Aspergillus niger and Rhizopus sp. A Box - Behnken design was used to evaluate the effects of water activity, fermentation time and temperature on endoglucanase and total cellulase production. Response Surface Methodology showed that optimum conditions for endoglucanase production were achieved at after 70.35 h of fermentation at 29.56°C and a water activity of 0.875 for Aspergillus niger and after 68.12 h at 30.41°C for Rhizopus sp. Optimum conditions for total cellulase production were achieved after 74.27 h of fermentation at 31.22°C for Aspergillus niger and after 72.48 h and 27.86°C for Rhizopus sp . Water activity had a significant effect on Aspergillus niger endoglucanase production only. In industrial applications, enzymatic characterization is important for optimizing variables such as temperature and pH. In this study we showed that endoglucanase and total cellulase had a high level of thermostability and pH stability in all the enzymatic extracts. Enzymatic deactivation kinetic experiments indicated that the enzymes remained active after the freezing of the crude extract. Based on the results, bioconversion of cactus is an excellent alternative for the production of thermostable enzymes.

GalX regulates the d-galactose oxido-reductive pathway in Aspergillus niger

NARCIS (Netherlands)

Gruben, B.S.; Zhou, M.; de Vries, R.P.

2012-01-01

Galactose catabolism in Aspergillus nidulans is regulated by at least two regulators, GalR and GalX. In Aspergillus niger only GalX is present, and its role in d-galactose catabolism in this fungus was investigated. Phenotypic and gene expression analysis of a wild type and a galX disruptant

Rupture of the gravid uterus in a referral hospital in Niger Republic ...

African Journals Online (AJOL)

Background: Rupture of the gravid uterus is a major cause of maternal and perinatal morbidity and mortality in developing countries. Methods: A review of the clinical records of all cases of ruptured uterus managed at the Center Hospitalier Regional, Dosso, Niger Republic, between January 2000 and December 2001 were ...

Wind Erosion Processes and Control Techniques in the Sahelian Zone of Niger

NARCIS (Netherlands)

Sterk, G.; Stroosnijder, L.; Raats, P.A.C.

1999-01-01

Wind Erosion Processes and Control Techniques in the Sahelian Zone of Niger G. Sterk, L. Stroosnijder, and P.A.C. Raats Abstract The objective of this paper is to present the main results and conclusions from three years of field research on wind erosion processes and control techniques in the

Tannase Production by Aspergillus niger

Directory of Open Access Journals (Sweden)

N. Lokeswari

2007-01-01

Full Text Available A method for assay of microbial tannase (Tannin acyl hydrolase based on the formation of chromogen between gallic acid and rhodanine is reported. Maximum Tannase production occurred in the culture broth containing 1-2% (w/v tannic acid and 0.05 – 0.1% (w/v glucose. The pH, incubation period, temperature and Glucose concentration optima of Tannase production was found at 5.5, 36 h, 35°C and 0.5% respectively. These properties make the enzyme suitable for pollution control and bioprocess industry. This assay is very simple, reproducible, and very convenient, and with it Tannase activity can be measured in relation to the growth of the organism. Aspergillus niger exhibited higher enzyme activity showing about 65 mole percent conversion respectively after a 36 h incubation period. The assay is complete in a short time, very convenient and reproducible.

Factors Influencing Household Food Security in West Africa: The Case of Southern Niger

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Seydou Zakari

2014-03-01

Full Text Available Food insecurity is a major challenge for Niger and for many African countries. The purpose of this study is to investigate the factors affecting household food security in Niger. Based on survey data covering 500 households, drought, high food prices, poverty, soil infertility, disease and insect attacks are reported by the respondents to be the main causes of food insecurity. The empirical results from logistic regression revealed that the gender of the head of household, diseases and pests, labor supply, flooding, poverty, access to market, the distance away from the main road and food aid are significant factors influencing the odds ratio of a household having enough daily rations. Another important finding is that female headed households are more vulnerable to food insecurity compared to male headed households. The findings of this study provide evidence that food insecurity continues to affect the Nigerien population.

Kinetics of cellobiose hydrolysis using cellobiase composites from Trichoderma reesei and Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Grous, W.; Converse, A.; Grethlein, H.; Lynd, L.

1985-01-01

The enzymatic hydrolysis of cellulose to glucose involves the formation of cellobiose as an intermediate. It has been found necessary to add cellobiase from Aspergillus niger (NOVO) to the cellobiase component of Trichoderma reesei mutant Rut C-30 (Natick) cellulase enzymes in order to obtain after 48 h complete conversion of the cellobiose formed in the enzymatic hydrolysis of biomass. This study of the cellobiase activity of these two enzyme sources was undertaken as a first step in the formation of a kinetic model for cellulose hydrolysis that can be used in process design. In order to cover the full range of cellobiose concentrations, it was necessary to develop separate kinetic parameters for high- and low-concentration ranges of cellobiose for the enzymes from each organism. Competitive glucose inhibition was observed with the enzymes from both organisms. Substrate inhibition was observed only with the A. niger enzymes.

The amyR-deletion strain of Aspergillus niger CICC2462 is a suitable host strain to express secreted protein with a low background.

Science.gov (United States)

Zhang, Hui; Wang, Shuang; Zhang, Xiang Xiang; Ji, Wei; Song, Fuping; Zhao, Yue; Li, Jie

2016-04-28

The filamentous fungus Aspergillus niger is widely exploited as an important expression host for industrial production. The glucoamylase high-producing strain A. niger CICC2462 has been used as a host strain for the establishment of a secretion expression system. It expresses recombinant xylanase, mannase and asparaginase at a high level, but some high secretory background proteins in these recombinant strains still remain, such as alpha-amylase and alpha-glucosidase; lead to a low-purity of fermentation products. The aim was to construct an A. niger host strain with a low background of protein secretion. The transcription factor amyR was deleted in A. niger CICC2462, and the results from enzyme activity assays and SDS-PAGE analysis showed that the glucoamylase and amylase activities of the ∆amyR strains were significantly lower than those of the wild-type strain. High-throughput RNA-sequencing and shotgun LC-MS/MS proteomic technology analysis demonstrated that the expression of amylolytic enzymes was decreased at both the transcriptional and translational levels in the ∆amyR strain. Interestingly, the ∆amyR strain growth rate better than the wild-type strain. Our findings clearly indicated that the ∆amyR strain of A. niger CICC2462 can be used as a host strain with a low background of protein secretion.

Physiology of Aspergillus niger in Oxygen-Limited Continuous Cultures: Influence of Aeration, Carbon Source Concentration and Dilution Rate

DEFF Research Database (Denmark)

Diano, Audrey; Peeters, J.; Dynesen, Jens Østergaard

2009-01-01

In industrial production of enzymes using the filamentous fungus Aspergilhis niger supply of sufficient oxygen is often a limitation, resulting in the formation of by-products such as polyols. In order to identify the mechanisms behind formation of the different by-products we studied the effect...... of low oxygen availability, at different carbon source concentrations and at different specific growth rates, on the metabolism of A. niger, using continuous cultures. The results show that there is an increase in the production of tricarboxylic acid (TCA) cycle intermediates at low oxygen concentrations...