Biological kinetics evaluation of anaerobic stabilization pond treatment of palm oil mill effluent

Biological kinetic (bio-kinetic) study of the anaerobic stabilization pond treatment of palm oil mill effluent (POME) was carried out in a laboratory anaerobic bench scale reactor (ABSR). The reactor was operated at different feed flow-rates of 0.63, 0.76, 0.95, 1.27, 1.9 and 3.8 l of raw POME for a day. Chemical oxygen demand (COD) as influent substrates was selected for bio-kinetic study. The investigation showed that the growth yield (Y_G), specific biomass decay (b), maximum specific biomass growth rate (μ_max), saturation constant (K_s) and critical retention time (Θ_c) were in the range of 0.990 g VSS/g COD_removed day, 0.024 day⁻¹, 0.524 day⁻¹, 203.433 g COD l⁻¹ and 1.908 day, respectively.     

Competition amongst Eph receptors regulates contact inhibition of locomotion and invasiveness in prostate cancer cells

Metastatic cancer cells typically fail to halt migration on contact with non-cancer cells. This invasiveness is in contrast to normal mesenchymal cells that retract on contact with another cell. Why cancer cells are defective in contact inhibition of locomotion is not understood. Here, we analyse the dynamics of prostate cancer cell lines co-cultured with fibroblasts, and demonstrate that a combinatorial code of Eph receptor activation dictates whether cell migration will be contact inhibited. The unimpeded migration of metastatic PC-3 cells towards fibroblasts is dependent on activation of EphB3 and EphB4 by ephrin-B2, which we show activates Cdc42 and cell migration. Knockdown of EphB3 and EphB4 restores contact inhibition of locomotion to PC-3 cells. Conversely, homotypic collisions between two cancer cells results in contact inhibition of locomotion, mediated by EphA-Rho-Rho kinase (ROCK) signalling. Thus, the migration of cancer cells can switch from restrained to invasive, depending on the Eph-receptor profile of the cancer cell and the reciprocal ephrin ligands expressed by neighbouring cells.     

Adipocyte/macrophage fatty acid binding proteins control integrated metabolic responses in obesity and diabetes

Fatty acid binding proteins (FABPs) are cytosolic fatty acid chaperones whose biological role and mechanisms of action are not well understood. Here, we developed mice with targeted mutations in two related adipocyte FABPs, aP2 and mal1, to resolve their role in systemic lipid, glucose, and energy metabolism. Mice lacking aP2 and mal1 exhibited a striking phenotype with strong protection from diet-induced obesity, insulin resistance, type 2 diabetes, and fatty liver disease. These mice have altered cellular and systemic lipid transport and composition, leading to enhanced insulin receptor signaling, enhanced muscle AMP-activated kinase (AMP-K) activity, and dramatically reduced liver stearoyl-CoA desaturase-1 (SCD-1) activity underlying their phenotype. Taken together with the previously reported strong protection against atherosclerosis, these results demonstrate that adipocyte/macrophage FABPs have a robust impact on multiple components of metabolic syndrome, integrating metabolic and inflammatory responses in mice and constituting a powerful target for the treatment of these diseases.     

Genetic Diversity and Pathogenic Variability of Colletotrichum truncatum Causing Anthracnose of Pepper in Malaysia

Colletotrichum truncatum was initially described from pepper and has been reported to infect 180 host genera in 55 plant families worldwide. Samples were collected from pepper plants showing typical anthracnose symptoms. Diseased samples after isolation were identified as C. truncatum based on morphological characters and ITS‐rDNA and β‐tubulin sequence data. Intersimple sequence repeat (ISSR) markers were used to estimate genetic diversity in C. truncatum from Malaysia. A set of 3 ISSR primers revealed a total 26 allele from the amplified products. Cluster analysis with UPGMA method clustered C. truncatum isolates into two main groups, which differed with a distance of 0.64. However, the genetic diversity of C. truncatum isolates showed correlation between genetic and geographical distribution, but it failed to reveal a relationship between clustering and pathogenic variability. Phylogenetic analyses discriminated the C. truncatum isolates from other reference Colletotrichum species derived from GenBank. Among the morphological characters, shape, colour of colony and growth rate in culture were partially correlated with the ISSR and phylogenetic grouping. Pathogenicity tests revealed that C. truncatum isolates were causal agents for pepper anthracnose. In the cross‐inoculation assays, C. truncatum isolates were able to produce anthracnose symptoms on tomato, eggplant, onion, lettuce and cabbage. A pathogenicity and cross‐inoculation studies indicated the potential of C. truncatum for virulence and dominancy on plant resistance.     

Efficient Transformation of Oil Palm Protoplasts by PEG-Mediated Transfection and DNA Microinjection

Background

Genetic engineering remains a major challenge in oil palm (Elaeis guineensis) because particle bombardment and Agrobacterium-mediated transformation are laborious and/or inefficient in this species, often producing chimeric plants and escapes. Protoplasts are beneficial as a starting material for genetic engineering because they are totipotent, and chimeras are avoided by regenerating transgenic plants from single cells. Novel approaches for the transformation of oil palm protoplasts could therefore offer a new and efficient strategy for the development of transgenic oil palm plants.

Methodology/Principal Findings

We recently achieved the regeneration of healthy and fertile oil palms from protoplasts. Therefore, we focused on the development of a reliable PEG-mediated transformation protocol for oil palm protoplasts by establishing and validating optimal heat shock conditions, concentrations of DNA, PEG and magnesium chloride, and the transfection procedure. We also investigated the transformation of oil palm protoplasts by DNA microinjection and successfully regenerated transgenic microcalli expressing green fluorescent protein as a visible marker to determine the efficiency of transformation.

Conclusions/Significance

We have established the first successful protocols for the transformation of oil palm protoplasts by PEG-mediated transfection and DNA microinjection. These novel protocols allow the rapid and efficient generation of non-chimeric transgenic callus and represent a significant milestone in the use of protoplasts as a starting material for the development of genetically-engineered oil palm plants.     

The investigation of the secondary structure propensities and free-energy landscapes of peptide ligands by replica exchange molecular dynamics simulations

The conformational states of two peptide sequences that bind to staphylococcal enterotoxin B are sampled by replica exchange molecular dynamic (REMD) simulations in explicit water. REMD simulations were treated with 52 replicas in the range of 280–501 K for both peptides. The conformational ensembles of both peptides are dominated by random coil, bend and turn structures with a small amount of helical structures for each temperature. In addition, while an insignificant presence of β-bridge structures were observed for both peptides, the β-sheet structure was observed only for peptide 3. The results obtained from simulations at 300 K are consistent with the experimental results obtained from circular dichroism spectroscopy. From the analysis of REMD results, we also calculated hydrophobic and hydrophilic solvent accessible surface areas for both peptides, and it was observed that the hydrophobic segments of the peptides tend to form bend or turn structures. Moreover, the free-energy landscapes of both peptides were obtained by principal component analysis to understand how the secondary structural properties change according to their complex space. From the free-energy analysis, we have found several minima for both peptides at decreased temperature. For these obvious minima of both peptides, it was observed that the random coil, bend and turn structures are still dominant and the helix, β-bridge or β-sheet structures can appear or disappear with respect to minima. On the other hand, when we compare the results of REMD with conventional MD simulations for these peptides, the configurations of peptide 3 might be trapped in energy minima during the conventional MD simulations. Hence, it can be said that the REMD simulations have provided a sufficiently high sampling efficiency.     

Evaluation of Gamma-Radiation Inactivation of a Bioterrorism Agent, <Emphasis Type="Italic">Bacillus anthracis</Emphasis> Spores,on Different Materials

Decontamination of suspected packages, such as sealed envelopes, liquids and tools that are likely contaminated with biological agents is of great importance. In this study, we aimed to determine the gamma radiation dose required for the decontamination of paper, fabric and liquid materials without causing any damage to the structure of these materials. Each study group included 11 pieces of paper, fabric and sterile saline contaminated with 0.8 × 10⁵ virulent Bacillus anthracis (B. anthracis) spores. These specimens were exposed to doses of 5.49, 11.58, 17.21, 21.75, 27 and 33.1 kilogray (kGy) of gamma radiation from a cobalt-60 source. After irradiation of all the samples, a viability assessment of the B. anthracis spores was performed. It was found that full decontamination was achieved with 11.58 kGy on the paper samples and 17.21 kGy on the fabric and liquid samples. It was concluded that a dose of 20 kGy of gamma radiation may be recommended for the inactivation of B. anthracis for some surfaces when especially sensitive and valuable materials cannot be wet decontaminated were exposed. In addition, serologic and molecular assays of the suspected packets can be performed for forensic purposes without damaging existing evidence in a bioterror incident.     

Zur genetik der 6-Phosphogluconatdehydrogenase (EC:1.1.1.44) bei Säugern

Zusammenfassung Das Enzym 6-PGD zeigt bei den verschiedensten Species einen genetisch gesteuerten Polymorphismus, der sich bei elektrophoretischer Darstellung in einer Variabilität des Isoenzymmusters äußert. Die Befunde bei den bislang untersuchten Säugern unter Einschluß des Menschen lassen sich formalgenetisch nach dem Modell: 1 Genlocus mit multipler Allelie interpretieren. Zur Prüfung der Frage, ob das Säugergenom einheitlich nur ein Gen für dieses Enzym enthält oder ob bei einzelnen Species eine Duplikation dieses Gens existiert, wurdene eine Anzahl Säuger verschiedener Ordnungen untersucht. In einer ersten Mitteilung wird hier über 6 verschiedene Species der Microtinae berichtet. Die Befunde sprechen durchweg für die Existenz von jeweils nur 1 Genlocus der 6-PGD. Bei Microtus oeconomus wurden 2 Allele an diesem locus nachgewiesen, bei Microtus ochrogaster 3 verschiedene Allele. Durch Familienuntersuchungen bei diesen beiden Species werden alle möglichen Kombinationen dieser Allele nachgewiesen.

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The genetics of 6-PGD (EC: 1.1.1.44) in various mammals I. Studies on 6 species of Microtinae, Rodentia. Isoenzyme polymorphism and family studies in Microtus oeconomus and Microtus ochrogaster

Summary The enzyme 6-PGD exhibits a genetically determined polymorphism which results in a variability of the isoenzyme pattern. In mammals so far examined the findings are to be interpreted according to the model of multiple alleles at one single gene locus. In order to test whether the mammalian genome is uniformly endowed with one single locus for this enzyme or whether a duplication of this locus is present in certain species, we examined various mammals of different orders. Our results in this first communication on 6 different Microtinae species are all in agreement with the assumption of a single 6-PGD locus. In Microtus oeconomus 2 alleles could be demonstrated and in Microtus ochrogaster 3 different alleles. Family studies performed with both species revealed the occurrence of all the expected combinations of these alleles.

     

Inhibition of ATP dephosphorylation by acaricides with emphasis on the anti-ATPase activity of the carbodiimide metabolite of diafenthiuron.

3-(2,6-Diisopropyl-4-phenoxyphenyl)-1-tert-butylcarbodiimide (DFCD), a toxic metabolite and photodegradation product of the propesticide diafenthiuron, and dicyclohexylcarbodiimide (DCCD), a commonly used biochemical inhibitory probe, inhibited Mg(2+)-, Na+K(+)-, and Ca2+Mg(2+)-ATPase activities in preparations from bulb mites (Rhizoglyphus echinopus (Fumouze and Robin)), twospotted spider mites (Tetranychus urticae Koch), and bluegill (Lepomis macrochirus Rafinesque) brain. DCCD was more active than DFCD, but neither carbodiimide was very potent. A possible exception occurred with DCCD, which caused 100% inhibition of bulb mite oligomycin-sensitive Mg(2+)-ATPase activity at a concentration of 0.1 mM. Using house fly, Musca domestica L., thorax mitochondrial Mg(2+)-ATPase, we showed that the binding domain for both carbodiimides was in the F0 portion of the enzyme, probably the transmembrane proton channel which is the known site of DCCD binding in proton-translocating ATPases. Certain other specific acaricides were inhibitors (greater than 50% at 0.1 mM) of ATPase preparations from bulb mites. These acaricides included chloropropylate, bromopropylate, oxythioquinox, cyhexatin, and flubenzimine (Mg2+ and Na+K(+)-ATPase), and ovex, chlorbenside, and propargite (Mg(2+)-ATPase). The role of ATPase inhibition in the modes of acaricidal and insecticidal actions of diafenthiuron, the two carbodiimides, and the other compounds is discussed.