Lovastatin and (+)‐geodin production by Aspergillus terreus from crude glycerol

The use of pure substrate represents a significant proportion of the cost of manufacturing a drug such as lovastatin. This study explores the production of lovastatin and (+)‐geodin by Aspergillus terreus ATCC 20542 using biodiesel‐derived crude glycerol (CG) as a feedstock. Shake flask experiments showed reduced lovastatin production and glycerol consumption in the presence of 10–50 g/L CG with respect to pure glycerol controls. At 50 g/L, lovastatin and (+)‐geodin production was significantly reduced by 82 and 73%, respectively. The lowest lovastatin inhibition was detected in 30 g/L of CG (48%), which was accompanied by a significant rise in (+)‐geodin production (338%). Further investigation was performed on three major impurities found in CG, namely methanol (MeOH), sodium chloride (NaCl), and fatty acids (oleic acid and palmitic acid (PA), soap). None was particularly inhibitory for lovastatin, except soap and PAs, which reduced its production by more than 50% at all concentrations tested. In contrast, (+)‐geodin was inhibited in the presence of MeOH and PA by up to 46 and 91%, respectively. These observations indicate that partial purification of CG would be potentially useful in improving production of lovastatin and (+)‐geodin by A. terreus.     

Local adaptation across a fertility gradient is influenced by soil biota in the invasive grass, <Emphasis Type="Italic">Bromus inermis</Emphasis>

Biotic soil factors, such as fungi, bacteria and herbivores affect resource acquisition and fitness in plants, yet little is known of their role as agents of selection. Evolutionary responses to these selective agents could be an important mechanism that explains the success of invasive species. In this study, we tested whether populations of the invasive grass Bromus inermis are adapted to their home soil environment, and whether biotic factors influence the magnitude of this adaptation. We selected three populations growing at sites that differed in soil fertility and grew individuals from each population in each soil. To assess whether biotic factors influence the magnitude of adaptation, we also grew the same populations in sterilized field soil. To further examine the role of one element of the soil biota (fungi) in local adaptation, we measured colonization by arbuscular mycorrhizal (AM) and septate fungi, and tested whether the extent of colonization differed between local and foreign plants. In non-sterilized (living) soil, there was evidence of a home site advantage because local plants produced significantly more biomass than at least one of the two populations of foreign plants in all three soil origins. By contrast, there was no evidence of a home site advantage in sterilized soil because local plants never produced significantly more biomass than either population of foreign plants. Fungal colonization differed between local and foreign plants in the living soil and this variation corresponded with biomass differences. When local plants produced more biomass than foreign plants, they were also less intensively colonized by AM fungi. Colonization by septate fungi did not vary between local and foreign plants. Our results suggest that biotic soil factors are important causes of plant adaptation, and that selection for reduced interactions with mycorrhizae could be one mechanism through which adaptation to a novel environment occurs.     

Immunoglobulin G depletion from human serum with metal-chelated beads under magnetic field

Magnetic poly(ethylene glycol dimethacrylate-N-methacryloyl-(L)-histidine methyl ester) [mag-poly(EGDMA-MAH) beads, 50-100 microm in diameter, were produced by suspension polymerization for affinity depletion of immunoglobulin G (IgG) from human serum. Cu2+ ions were complexed directly via MAH groups (Cu2+ loading: 4.1 micromol/g). IgG depletion studies were performed by magnetically stabilized fluidized bed column. Acetate, Tris-HCl, MES and phosphate buffers all allow adsorption of similar quantities of IgG (27.3-45.6 mg/g). MOPS and HEPES allow higher adsorption quantities (79.6 mg/g and 74.1mg/g, respectively). Maximum adsorption capacities in MOPS buffer were 46.8 mg/g for mag-poly(EGDMA-MAH) and 102.1mg/g for Cu2+ chelated mag-poly(EGDMA-MAH) beads. The adsorption capacity decreased drastically from 102.1mg/g to 30.7 mg/g with the increase of the flow rate from 0.2 ml/min to 3.5 ml/min. The elution studies were performed by 1.0M NaCl. The elution results demonstrated that the adsorption of IgG to the adsorbent was reversible. To test the efficiency of IgG depletion from human serum, proteins in the serum and eluted portion were analyzed by two-dimensional gel electrophoresis. The depletion efficiency for IgG was above 99.4%. Eluted proteins include mainly IgG, and a small number of non-albumin proteins such as apo-lipoprotein A1, sero-transferrin, haptoglobulin and alpha1-antitrypsin. When anti-HSA-sepharose adsorbent is used together with our metal-chelated mag-beads, IgG and HSA can be depleted in a single step.     

Acute inflammatory demyelinating polyneuropathy after treatment with pegylated interferon alfa-2a in a patient with chronic hepatitis C virus infection: a case report

ABSTRACT: INTRODUCTION: The combination of polyethylene glycol (PEG)ylated interferon (pegylated interferon) and ribavirin has been shown to be an effective treatment for chronic hepatitis C virus. In general, common side effects related to this combination therapy are mild and are well tolerated. However, peripheral neuropathy including demyelinating polyneuropathy related to PEG-interferon alpha2a (pegylated interferon alfa-2a) is extremely rare. In the literature, only one case of acute inflammatory demyelinating polyneuropathy related to PEG-interferon alpha2a has been published previously. CASE PRESENTATION: To the best of our knowledge we present only the second case of acute inflammatory demyelinating polyneuropathy related to PEG-interferon alpha2a, occurring in a 63-year-old Caucasian man. He developed tingling, numbness, and weakness of his upper and lower extremities with acute neurological deficits after five weeks of a combination therapy with PEG-interferon alpha2a and ribavirin for chronic hepatitis C virus infection. His clinical course, neurological findings, and his electromyogram results were all consistent with acute inflammatory demyelinating polyneuropathy. Our patient recovered completely after interferon was stopped and symptomatic treatment and a further electromyogram showed a disappearance of neuropathy. Four weeks later, PEG-interferon alpha2a was reintroduced with a gradually increasing dose without any reappearance of neurological symptoms allowing hepatitis C seroconversion. CONCLUSIONS: Recognition of this rare yet possible presentation is important for early and accurate diagnosis and treatment. This case report also suggests that the reintroduction of PEGylated interferon in patients who had presented with acute inflammatory demyelinating polyneuropathy related to interferon alpha may be safe, but this must be confirmed by further studies.     

Laccase from Aspergillus niger: A novel tool to graft multifunctional materials of interests and their characterization

In the present study, we propose a green route to prepare poly(3-hydroxybutyrate) [(P(3HB)] grafted ethyl cellulose (EC) based green composites with novel characteristics through laccase-assisted grafting. P(3HB) was used as a side chain whereas, EC as a backbone material under ambient processing conditions. A novel laccase obtained from Aspergillus niger through its heterologous expression in Saccharomyces cerevisiae was used as a green catalyst for grafting purposes without the use of additional initiator and/or cross-linking agents. Subsequently, the resulting P(3HB)-g-EC composites were characterized using a range of analytical and imagining techniques. Fourier transform infrared spectroscopy (FT-IR) spectra showed an increase in the hydrogen-bonding type interactions between the side chains of P(3HB) and backbone material of EC. Evidently, X-ray diffraction (XRD) analysis revealed a decrease in the crystallinity of the P(3HB)-g-EC composites as compared to the pristine individual polymers. A homogeneous P(3HB) distribution was also achieved in case of the graft composite prepared in the presence of 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) as a mediator along with laccase as compared to the composite prepared using pure laccase alone. A substantial improvement in the thermal and mechanical characteristics was observed for grafted composites up to the different extent as compared to the pristine counterparts. The hydrophobic/hydrophilic properties of the grafted composites were better than those of the pristine counterparts.     

Olfactory behavior and response of household ants (Hymenoptera) to different types of coffee odor: A coffee-based bait development prospect

Odor sensation is a sensory modality of considerable significance in the foraging behavior and interactional organization of ants. In the food bait technology, smell is the basis of attraction, which, in turn, is the line of bait use and a key parameter for judging efficacy. Yet, the currently available baits possess low attractiveness to many ant pests. Hence, strategies to produce ant bait with increased attractiveness are needed. Despite evidence that coffee has a diverse aroma complex that affects the behavior of honey bees and ants, its attraction to house-invading ants has yet to be investigated. In a series of Y-tube olfactometer bioassays, we examined the behavioral responses of Tapinoma indicum (TI), Monomorium pharaonis (MP) and Solenopsis geminata (SG) to various coffee-induced odor stimuli, comprised of extracts from Arabica, Robusta and Liberica. All coffee extracts showed an influence on the behavior of TI, MP and SG workers, with Arabica showed the most significant influence to the tested ants. The workers of TI, MP and SG were more attracted to the odor of 0.01% Arabica extract (ONE), in comparison with 0.05% Arabica extract (TWO) or 0.10% Arabica extract (THREE). Arabica extract mixed with sugar (S) elicited a significant attraction from workers of all three species in a balanced competition with either unsweetened Arabica extract or water. These results indicated that coffee, particularly Arabica, was attractive to the foragers of TI, MP and SG, thus, the use of coffee as a novel stimulus agent seems plausible in ant bait development.     

An Integrated Understanding of the Rapid Metabolic Benefits of a Carbohydrate-Restricted Diet on Hepatic Steatosis in Humans

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Modeling the effect of imperfect staggering in product inflow using queuing theory: revisiting block stacking layout

Conventional approaches to layout design of block stacked warehouses assume perfect staggering of product inflow leading to perfect sharing of space among products. Since such an assumption is seldom true, we argue that warehouses designed using the conventional approach may result in choking situations with large quantities of inventory waiting outside the storage areas. On the other hand, liberal space allocation such as in dedicated policy might lead to under-utilization of space. In this paper, we take a fresh look at the block stacked layout problem, modeling the effect of imperfectly staggered product arrivals using queuing theory. Analytical expressions are derived for arrival time and processing time coefficients of variation using warehouse parameters and design variables. Further, we develop a bi-objective optimization model to minimize both the space cost and waiting time. Our approach provides design options over a total space cost-waiting time trade-off frontier as opposed to singular design points given by conventional approaches. Computational experiments are conducted to derive further insights into the design of block stacked warehouses.