Determination of Mass Transfer Coefficients for A Mixture of Compost,Sugarcane Bagasse,and Granulated Activated Carbon as Packing Medium in Biofilter

ABSTRACT

A laboratory-scale biofilter unit packed with a mixture of compost, sugarcane bagasse, and granulated activated carbon (GAC) in the ratio of 55:30:15 by weight was used for a biofiltration study of air stream containing benzene, toluene, ethylbenzene, and o-xylene (BTEX). The effect of superficial velocity on mass transfer coefficient for the packing was studied by maintaining gas flow rates of 3, 4, 5, 6, and 8 L min^?1 for inlet concentrations of 0.1, 0.4, and 0.8 g m^?3 for each of benzene, toluene, ethylbenzene, and o-xylene. The maximum elimination capacity was found to be 20.92, 22.72, 20.73, and 18.94 g m^?3 h^?1 for BTEX, respectively, for stated flow rates. Removal efficiency of BTEX decreased from 99% to 71% for increasing inlet concentration from 0.1 to 0.8 g m^?3. Gas film mass transfer coefficient predicted by modified Onda's equation was within ±10% of the experimental values.     

Molecular cross-talk between sponge host and associated microbes

Marine organisms especially those that live sessile, as sponges, are well known to have specific relationships with a great variety of microorganisms including bacteria and fungi. As most simple metazoan phylum, the Porifera, which emerged first during the transition from the non-Metazoa to the Metazoa from the common ancestor, comprise wide arrays of recognition molecules, both for Gram-negative bacteria and for Gram-positive bacteria as well as for fungi. They react specifically with effector molecules to inhibit or kill the invading microorganisms. The elicitation and the subsequent effector reactions of the sponges towards these microbes are outlined. However, besides of the elimination of bacteria and fungi, some of those taxa are kept as symbionts of the sponges, allowing them, for example, to accumulate the essential element manganese or to synthesize carotinoids. The sponges produce low-molecular-weight bioactive compounds, secondary metabolites, to eliminate the microorganisms. In addition, they are armed with cationic antimicrobial peptides allowing them to defend against invasive microorganisms and, in parallel, to kill or repel also metazoan invaders. The broad range of chemically and functionally different compounds qualifies the Porifera as the most important animal phylum to be exploited as a source for the isolation of new potential drugs. First molecular biological strategies have been outlined to obtain those compounds in a sustainable way, by producing them recombinantly.     

Cloning,characterization, expression analysis and inhibition studies of a novel gene encoding Bowman–Birk type protease inhibitor from rice bean

This paper presents the first study describing the isolation, cloning and characterization of a full length gene encoding Bowman–Birk protease inhibitor (RbTI) from rice bean (Vigna umbellata). A full-length protease inhibitor gene with complete open reading frame of 327 bp encoding 109 amino acids was cloned from rice bean seeds using degenerate primer set. BlastP search revealed that the RbTI encoded amino acid of approx 13.0 kDa and shared 99% homology each with BBI from Phaseolus parvulus, Vigna trilobata and Vigna vexilata. Phylogenetic tree also showed close relationship of RbTI with BBI from other members of Leguminaceae family. RbTI gene was further confirmed as intronless (GenBank accession no. KJ159908). The secondary and 3D-structural models for the RbTI were predicted with homology modeling. qRT-PCR studies revealed the highest RbTI expression in the seeds nearing maturity, whereas the low expression of the gene was noticed in young leaves. The isolated RbTI was successfully expressed in Escherichiacoli and the highest expression was recorded after 5.5 h of induction. Study on the inhibitory activity of expressed protein against the gut proteases of Hessian fly larvae revealed 87% inhibition. The novel RbTI gene will further broaden the pool of plant defense genes and could be an ideal choice for developing transgenic crops resistant to insect pests with high economic value. In addition, it has the potential to be used as a probe for selection of insect- and pathogen-resistant genotypes.     

Tocopherol Transfer Protein Sensitizes Prostate Cancer Cells to Vitamin E

Prostate cancer is a major cause of mortality in men in developed countries. It has been reported that the naturally occurring antioxidant α-tocopherol (vitamin E) attenuates prostate cancer cell proliferation in cultured cells and mouse models. We hypothesized that overexpression of the tocopherol transfer protein (TTP), a vitamin E-binding protein that regulates tocopherol status, will sensitize prostate cancer cells to the anti-proliferative actions of the vitamin. To test this notion, we manipulated the expression levels of TTP in cultured prostate cells (LNCaP, PC3, DU145, and RWPE-1) using overexpression and knockdown approaches. Treatment of cells with tocopherol caused a time- and dose-dependent inhibition of cell proliferation. Overexpression of TTP dramatically sensitized the cells to the apoptotic effects of α-tocopherol, whereas reduction (“knockdown”) of TTP expression resulted in resistance to the vitamin. TTP levels also augmented the inhibitory effects of vitamin E on proliferation in semi-solid medium. The sensitizing effects of TTP were paralleled by changes in the intracellular accumulation of a fluorescent analog of vitamin E and by a reduction in intracellular levels of reactive oxygen species and were not observed when a naturally occurring, ligand binding-defective mutant of TTP was used. We conclude that TTP sensitizes prostate cancer cells to the anti-proliferative effects of vitamin E and that this activity stems from the ability of protein to increase the intracellular accumulation of the antioxidant. These observations support the notion that individual changes in the expression level or activity of TTP may determine the responsiveness of prostate cancer patients to intervention strategies that utilize vitamin E.     

Proteomic analysis of oil body membrane proteins accompanying the onset of desiccation phase during sunflower seed development

A noteworthy metabolic signature accompanying oil body (OB) biogenesis during oilseed development is associated with the modulation of the oil body membranes proteins. Present work focuses on 2-dimensional polyacrylamide gel electrophoresis (2-D PAGE)-based analysis of the temporal changes in the OB membrane proteins analyzed by LC-MS/MS accompanying the onset of desiccation (20–30 d after anthesis; DAA) in the developing seeds of sunflower (Helianthus annuus L.). Protein spots unique to 20–30 DAA stages were picked up from 2-D gels for identification and the identified proteins were categorized into 7 functional classes. These include proteins involved in energy metabolism, reactive oxygen scavenging, proteolysis and protein turnover, signaling, oleosin and oil body biogenesis-associated proteins, desiccation and cytoskeleton. At 30 DAA stage, exclusive expressions of enzymes belonging to energy metabolism, desiccation and cytoskeleton were evident which indicated an increase in the metabolic and enzymatic activity in the cells at this stage of seed development (seed filling). Increased expression of cruciferina-like protein and dehydrin at 30 DAA stage marks the onset of desiccation. The data has been analyzed and discussed to highlight desiccation stage-associated metabolic events during oilseed development.     

Unaided trifluoroacetic acid pretreatment solubilizes polyglutamine peptides and retains their biophysical properties of aggregation

Understanding the biophysical mechanism of polyglutamine (polyGln) aggregation is important to unravel the role of aggregates in the pathology of polyGln repeat disorders. To achieve this, synthetic polyGln peptides are widely used. Their disaggregation and solubilization is essential because it plays a crucial role in reproducing biophysical experimental data under in vitro conditions. Pretreatment with trifluoroacetic acid (TFA) and hexafluoroisopropanol (HFIP) at a 1:1 ratio is currently the method of choice to achieve solubility of polyGln peptides. Here we report that the disaggregation and solubilization of polyGln peptides can be achieved by TFA alone. We tested TFA due to the close similarity of it with HFIP in the nature of H-bond breakage and formation, higher cost, and the problems faced by us in the availability of HFIP. Our results demonstrate that the TFA disaggregated polyGln sequences give similar solubilization yield, aggregation kinetics, thioflavin T (ThT) binding, and structural features in comparison with the TFA/HFIP method. Furthermore, we show by limited validation studies that the proposed TFA method can replace the existing TFA/HFIP disaggregation method of polyGln sequences.