Biennialism and Vernalization-Promoted Flowering in \u3cem\u3eHyoscyamus niger\u3c/em\u3e: a Comparison with \u3cem\u3eArabidopsis\u3c/em\u3e

There are genetic similarities between the biennial growth habit of Hyoscyamus niger (H. niger) and winter annual ecotypes of Arabidopsis thaliana, including the response to demethylating agents. One focus of our research group at Marquette is to determine whether FLOWERING LOCUS C (FLC) homologs or FLC-related MADS-box genes are involved in biennialism of H. niger. This review also summarizes our initial characterization of expression profiles of 4 groups of H. niger MADS-box genes. Our results suggest that B-class floral homeotic gene homologs of H. niger are differentially expressed in flowers of annual and vernalized, biennial plants

Cellulase Production by Wild-type Aspergillus niger, Penicillium chrysogenum and Trichoderma harzianum Using Waste Cellulosic Materials

Waste cellulosic materials (corncob, sawdust and sugarcane pulp) and crystalline cellulose induced cellulase production in wild strains of Aspergillus niger, Penicillium chrysogenum and Trichoderma harzianum isolated from a wood-waste dump in Lagos, Nigeria. Cellulose-supplemented media gave the maximum cellulase activity of 0.54, 0.67 and 0.39 units mg Protein-1 for A. niger, P. chrysogenum and T. harzianum respectively. The maximum enzyme activity for A. niger was obtained at 36 h of cultivation, while P. chrysogenum and T. harzianum gave their maximum enzyme activities at 12 and 60 h respectively. For the cellulosic wastes, highest enzyme activity was obtained with sawdust where A. niger, P. chrysogenum and T. harzianum gave the maximum enzyme activity of 0.30, 0.24 and 0.20 units mg Protein-1 respectively after 144 h of cultivation. A. niger recorded the highest enzyme activity with any of the three cellulosic materials followed by P. chrysogenum. It thus appears that the use of sawdust presents the best option for low-cost commercial production of cellulase using A. niger and P. chrysogenum as discussed herewith

Addition of arenesulfenyl chlorides to quadricyclene

The addition of arenesulfenyl chlorides to quadricyclene has been investigated. These reactions are rapid, exothermic and yield primairly three isomers. Two of the isomers (type I and type II structures) have the norbornene and nortricyclene carbon skeletons respectively. The structure of the nortricyclene isomer has been thoroughly established with a wide variety of techniques including 2D NMR. It has been found that a bridged sulfonium ion is not an important product precurser in these electrophilic addition reactions. In a attempt to force the formation of a bridged ion, preliminary studies using arenesulfenyl chlorides in which the aromatic ring contains electron-donating groups have been carried out. The results of these reactions suggest that the amount of bridged ion precurser present is minor at best. Studies of the ratio of isomers I to I I to I 1 1 reveal complex patterns, and suggest conclusions about kinetic control. In summary, a significant niche in mechanistic theory has been established, but more exploration would be necessary to induce bridged ion formation and to completely establish all the caveats of this process

Plant Waste Hydrolysis by Extracellular Enzymes of Aspergillus niger and Penicillium chrysogenum: Effect of Ammonia Pretreatment

Aspergillus niger (ANL301) and Penicillium chrysogenum (PCL 501) cultured in basal media with cellulose as sole carbon source yielded extracellular enzymes which partially hydrolyzed sawdust and sugarcane pulp into simple sugars. Pre-treatment of sawdust by ammonium hydroxide steeping increased the yield of simple sugars. The reducing sugars released from the pretreated sawdust by the crude enzymes of A. niger (ANL301) and P. chrysogenum (PCL 501) were 3.58% and 7.02% of the total hydrolysable sugars respectively. This is in contrast to the 0.92% and 1.02% of the total hydrolysable sugars released respectively by the enzymes of A. niger (ANL301) and P. chrysogenum (PCL 501) from the non-pretreated sawdust. Enzymatic hydrolysis of sugarcane pulp by the crude enzymes was not significantly affected by ammonia pre-treatment. Reducing sugars released from non-pretreated sugarcane pulp by the crude enzymes of A. niger (ANL301) and P. chrysogenum (PCL 501) were respectively 4.17% and 5.08% of the total hydrolysable sugars

Adaptive response to oxidative stress in the filamentous fungus Aspergillus niger B1-D

In the present study, we used a recombinant filamentous fungus strain, Aspergillus niger B1-D, as a model system, and investigated the antioxidant defences in this organism. Our findings indicate that pretreatment with low concentrations of H2O2 completely prevents killing by this oxidant at high concentrations. It shows that A. niger adapts to exposure to H2O2 by reducing growth and inducing a number of antioxidant enzyme activities, including superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, of which the induction of catalase is the most pronounced. Moreover the decline of these antioxidant enzymes activities after H2O2 detoxification, coincides with recommencement of growth. Results from monitoring the extracellular H2O2 concentration clearly indicate a very rapid detoxification rate for H2O2 in adapted A. niger cultures. A mathematical model predicts only very low concentrations of intracellular H2O2 accumulating in such cultures. Our results also show that glutathione plays a role in the oxidative defence against H2O2 in A. niger. On addition of H2O2, the intracellular pool of glutathione increases while the redox state of glutathione becomes more oxidized

RE-ENGINEERING THE NDDC’S MASTER PLAN: AN ANALYTICAL APPROACH

This paper examined the Niger Delta Development Commission (NDDC)’s master plan, which promised different programmes such as: employment generation, education, and health, among others. The authors reviewed competing analysis of the extant development policies and conclude that the NDDC’s master plan is not radically different from the extant policies and may aggravate the antimonies to development in the region. If lasting solution to the lingering crisis in the Niger Delta is desired, it is essential to positively utilize combined powers of local organizations. Ultimately, rather than romancing with military and political approaches that have not engendered sustainable development, the people who live with and whose lives are directly affected by the Niger Delta crisis should be reckoned with in arresting the crisis and positively transforming the region

In silico Gene Characterization and biological annotation of Aspergillus niger CBS 513.88

Genome annotation is the process of estimation of biological features from genomic data. The target of a genome annotation is to identify the key features of the genome sequence particularly, the genes and gene products. The characteristics of a gene, its products, and gene prediction programs of Aspergillus niger are discussed. Although the number of genomes in genomic databases are increasing day by day, genome-wide analyses are affected by the quality of the genome annotations. This study illustrates the importance of integrative approaches for automatic annotations of genomes of Aspergillus niger by computational methods. However, the annotation process is more complicated in Eukaryotes; we used a comparative study for gene prediction using the FgenesH algorithm by various software providers. The final annotation of Aspergillus niger CBS 513.88. has been created as a GB file in Artemis, A sequence viewer and annotation tool was developed in the anger Institute

Niger's infrastructure : a continental perspective

Between 2000 and 2005 infrastructure made a net contribution of less than a third of a percentage point to the improved per capita growth performance of Niger, one of the lowest contributions in Sub-Saharan Africa. Raising the country's infrastructure endowment to that of the region’s middle-income countries could boost annual growth in Niger by about 4.5 percentage points. Niger has made significant progress in some areas of its infrastructure, including water and telecommunications. But the country still faces a number of important infrastructure challenges, the most pressing of which is probably in the water and sanitation sector, as 82 percent of Nigeriens still practice open defecation, the highest in the continent. Niger also faces significant challenges in the power sector, as only 8 percent of the population is electrified. Niger currently spends about $225 million per year on infrastructure, leaving an annual funding gap of$460 million even after savings from curing inefficiencies are taken into account. Niger can close that gap by tapping alternative sources of financing or by adopting lower-cost technologies. There is plenty of room for private-sector participation in Niger's infrastructure sectors, and the adoption of lower-cost technologies could reduce the funding gap by almost half.Transport Economics Policy&Planning,Infrastructure Economics,Town Water Supply and Sanitation,Water Supply and Systems,Energy Production and Transportation

Aspergillus niger Spores Are Highly Resistant to Space Radiation

The filamentous fungus Aspergillus niger is one of the main contaminants of the International Space Station (ISS). It forms highly pigmented, airborne spores that have thick cell walls and low metabolic activity, enabling them to withstand harsh conditions and colonize spacecraft surfaces. Whether A. niger spores are resistant to space radiation, and to what extent, is not yet known. In this study, spore suspensions of a wild-type and three mutant strains (with defects in pigmentation, DNA repair, and polar growth control) were exposed to X-rays, cosmic radiation (helium- and iron-ions) and UV-C (254 nm). To assess the level of resistance and survival limits of fungal spores in a long-term interplanetary mission scenario, we tested radiation doses up to 1000 Gy and 4000 J/m2. For comparison, a 360-day round-trip to Mars yields a dose of 0.66 ± 0.12 Gy. Overall, wild-type spores of A. niger were able to withstand high doses of X-ray (LD90 = 360 Gy) and cosmic radiation (helium-ion LD90 = 500 Gy; and iron-ion LD90 = 100 Gy). Drying the spores before irradiation made them more susceptible toward X-ray radiation. Notably, A. niger spores are highly resistant to UV-C radiation (LD90 = 1038 J/m2), which is significantly higher than that of other radiation-resistant microorganisms (e.g., Deinococcus radiodurans). In all strains, UV-C treated spores (1000 J/m2) were shown to have decreased biofilm formation (81% reduction in wild-type spores). This study suggests that A. niger spores might not be easily inactivated by exposure to space radiation alone and that current planetary protection guidelines should be revisited, considering the high resistance of fungal spores