Cyclodextrin glucosyltransferase production by <Emphasis Type="Italic">Bacillus megaterium</Emphasis> NCR: evaluation and optimization of culture conditions using factorial design

Statistically-based experimental designs were used to optimize the production of cyclodextrin glucosyltransferase (CGTase) from a local isolate of Bacillus megaterium using shack culture fermentation. Seven cultural conditions were examined for enzyme production and specific activity using Plackett-Burman factorial design. Fermentation time and K₂HPO₄ level were the crucial for factors improving enzyme production process. The steepest ascent design was adopted-based on the results recorded with Plackett-Burman design. Maximal enzyme estimates (activity 56.1 U/ml, and specific activity 62.7 U/mg protein) were achieved. A verification experiment was carried out to examine model validation of this optimization.     

Bio-production of compost with low pH and high soluble phosphorus from sugar cane bagasse enriched with rock phosphate

Summary Aspergillus niger and Trichoderma viride strains were used together as a fungal activator in the presence or absence of farmyard manure (FM) for composting of bagasse enriched with rock phosphate. Quality of the composts produced was compared with that obtained from non-inoculated bagasse. The composts were evaluated as organic phosphatic fertilizers, for broad bean plants. The results showed that composting of bagasse without microbial inoculation or FM addition was not complete after 105 days of fermentation. An excellent decomposition in a relatively short time however was obtained with the use of A. niger and T. viride as inoculant agents with or without FM. The inoculation with A. niger + T. viridewith or without FM, also represented the most suitable conditions for phosphate solubilization. Acidic conditions (pH 4–5) at the end of the experiment were obtained in all piles receiving Aspergillus niger and there was a correlation between the amounts of soluble phosphorus and the reduction in pH values in the compost piles. There were no phosphate-dissolving fungi present in any composted piles except those treated with Aspergillus niger and Trichoderma viride. The number of phosphate-dissolving bacteria increased only in the treatments that were treated with FM. The non-fertilized sandy soil and the non-inoculated bagasse compost did not provide broad bean plants with phosphorus while the composts produced by inoculation with A. niger + T. viride provided the plants with the highest amounts of phosphorus.     

Regulation of integrin function by CD47 ligands. Differential effects on alpha vbeta 3 and alpha 4beta1 integrin-mediated adhesion

We examined the regulation of alpha4beta1 integrin function in melanoma cells and T cells by ligands of CD47. A CD47 antibody (B6H12) that inhibited alphavbeta3-mediated adhesion of melanoma cells induced by CD47-binding peptides from thrombospondin-1 directly stimulated alpha4beta1-mediated adhesion of the same cells to vascular cell adhesion molecule-1 and N-terminal regions of thrombospondin-1 or thrombospondin-2. B6H12 also stimulated alpha4beta1- as well as alpha2beta1- and alpha5beta1-mediated adhesion of CD47-expressing T cells but not of CD47-deficient T cells. alpha4beta1 and CD47 co-purified as a detergent-stable complex on a CD47 antibody affinity column. CD47-binding peptides based on C-terminal sequences of thrombospondin-1 also specifically enhanced adhesion of melanoma cells and T cells to alpha4beta1 ligands. Unexpectedly, activation of alpha4beta1 function by the thrombospondin-1 CD47-binding peptides also occurred in CD47-deficient T cells. CD47-independent activation of alpha4beta1 required the Val-Val-Met (VVM) motif of the peptides and was sensitive to inhibition by pertussis toxin. These results indicate that activation of alpha4beta1 by the CD47 antibody B6H12 and by VVM peptides occurs by different mechanisms. The antibody directly activates a CD47-alpha4beta1 complex, whereas VVM peptides may target an unidentified Gi-linked receptor that regulates alpha4beta1.     

Experimental and theoretical approaches for Cd(II) biosorption from aqueous solution using Oryza sativa biomass

Biomass of Oryza sativa (OS) was tested for the removal of Cd(II) ions from synthetic and real wastewater samples. Batch experiments were conducted to investigate the effects of operating parameters on Cd(II) biosorption. Fourier transform infrared spectroscopy, scanning electron microscopy, and energy-dispersive x-ray spectroscopy were used to examine the surface characteristics of the Cd(II)-loaded biomass. The maximum removal efficiency of Cd(II) was 89.4% at optimum pH 6.0, biosorbent dose 10.0 g L^?1, initial Cd(II) 50 mg L^?1, and biosorbent particle size 0.5 mm. The applicability of Langmuir and Freundlich isotherms to the sorbent system implied the existence of both monolayer and heterogeneous surface conditions. Kinetic studies revealed that the adsorption process of Cd(II) followed the pseudo-second-order model (r2: 0.99). On the theoretical side, an adaptive neuro-fuzzy inference system (ANFIS) was applied to select the operating parameter that mostly influences the Cd(II) biosorption process. Results from ANFIS indicated that pH was the most influential parameter affecting Cd(II) removal efficiency, indicating that the biomass of OS was strongly pH sensitive. Finally, the biomass was confirmed to adsorb Cd(II) from real wastewater samples with removal efficiency close to 100%. However, feasibility studies of such systems on a large-scale application remain to be investigated.     

CXCL‐10 and Interleukin‐6 are reliable serum markers for vitiligo activity: A multicenter cross‐sectional study

This cross‐sectional multicenter study aimed to evaluate serum CXCL‐10, as an activity marker for vitiligo, and compare it with other putative serum and tissue markers. Serum CXCL‐10 was compared to interferon gamma (IFN‐γ), interleukin 6 (IL‐6), and IL‐17 using ELISA in 55 non‐segmental vitiligo patients (30 active and 25 stable) and 30 healthy controls. Marginal skin biopsy was taken for immunohistochemical evaluation of CD8+T cells and CXCL‐10+ve cells. Serum levels of CXCL‐10, IL‐17, and IL‐6 were elevated in all vitiligo patients compared to controls (p < .05). All investigated serum markers were higher in active versus stable vitiligo. Tissue expression of CXCL‐10+ve cells and CD8+ve T cells was stronger in vitiligo patients compared to controls, and tissue CXCL‐10+ve cell expression was stronger in active versus stable cases. Positive correlations were noted between the different serum and tissue markers. CXCL‐10 was the most specific, whereas IL‐6 was the most sensitive serum marker to distinguish active from stable disease.     

Vitamin D status and vitamin D receptor gene polymorphism in Saudi children with acute lower respiratory tract infection

Molecular Biology Reports - There is a significant association exists between vitamin D deficiencies, low respiratory tract infections, and certain types of VDR gene polymorphism. Various studies...     

Synergistic larvicidal and repellent effects of essential oils of three Origanum species on Rhipicephalus annulatus tick

Ticks are of great economic importance worldwide, both because they represent major obstacles to livestock productivity and because of their ability to transmit diseases to humans and animals. Although synthetic acaricides are the most common method for tick control, their overuse has led to the development of resistance as well as unacceptable residual levels in animal products and in the environment in general. There is therefore an urgent need to identify alternative treatments. Among such alternative approaches for tick control is plant essential oil (EO) therapy. In the present study, we investigated the synergistic effect of EOs of three oregano species—Origanum onites, O. majorana and O. minutiflorum—against Rhipicephalus annulatus larvae. Gas chromatography–mass spectrometry profiles of the three EOs revealed that carvacrol was their major component, with a concentration of 86.2% in O. majorana, 79.1% in O. minutiflorum and 77.4% in O. onites. The results of larvicidal assays revealed that the doses that lead to the death of 50% of the ticks (LC₅₀) were 22.99, 25.08 and 27.06 µL/mL for O. majorana, O. minutiflorum and O. onites EOs, respectively, whereas the doses that lead to the death of 99% (LC₉₉) were 41.26, 43.62 and 48.96 µL/mL. In addition, the LC₅₀ and LC₉₉ of the three oils combined was lower (viz., 4.01 and 6.97 µL/mL) than that of each oil alone. The tested EOs were also able to repel larvae of R. annulatus to varying degrees, with O. onites oil exhibiting the greatest repellent effect, as shown by the lowest RC₅₀ dose, followed by O. minutiflorum and O. majorana. Interestingly, this means that the oil that was least effective in killing the larvae was the most effective in repelling them. The calculated synergistic factor of any combination was higher than 1 which means that combinations have a synergistic effect. In conclusion, the combination of all three oils showed higher toxic and repellent activities than either oil separately or combinations of any two oils, suggesting synergistic effects with low doses. Further studies including field trials and the establishment of the mode of action and side effects are urgently needed to expand on these findings, and other tick stages such as adults should also be tested.

     

Identification of a New cry1I-Type Gene as a Candidate for Gene Pyramiding in Corn To Control Ostrinia Species Larvae

Pyramiding of diverse cry toxin genes from Bacillus thuringiensis with different modes of action is a desirable strategy to delay the evolution of resistance in the European corn borer (Ostrinia nubilalis). Considering the dependency of susceptibility to Cry toxins on toxin binding to receptors in the midgut of target pests, a diverse mode of action is commonly defined as recognition of unique binding sites in the target insect. In this study, we present a novel cry1Ie toxin gene (cry1Ie2) as a candidate for pyramiding with Cry1Ab or Cry1Fa in corn to control Ostrinia species larvae. The new toxin gene encodes an 81-kDa protein that is processed to a protease-resistant core form of approximately 55 kDa by trypsin digestion. The purified protoxin displayed high toxicity to Ostrinia furnacalis and O. nubilalis larvae but low to no activity against Spodoptera or heliothine species or the coleopteran Tenebrio molitor. Results of binding assays with ¹²⁵I-labeled Cry1Ab toxin and brush border membrane vesicles from O. nubilalis larvae demonstrated that Cry1Ie2 does not recognize the Cry1Ab binding sites in that insect. Reciprocal competition binding assays with biotin-labeled Cry1Ie2 confirmed the lack of shared sites with Cry1Ab or Cry1Fa in O. nubilalis brush border membrane vesicles. These data support Cry1Ie2 as a good candidate for pyramiding with Cry1Ab or Cry1Fa in corn to increase the control of O. nubilalis and reduce the risk of resistance evolution.