Phylogenetic Reappraisal of the Genus Monomorphina (Euglenophyceae) Based on Molecular and Morphological Data

A morphological and molecular examination of the genus Monomorphina was conducted on 46 strains isolated mainly from Korea. The strains were divided into two types based on morphological data: Monomorphina aenigmatica and M. pyrum ‐ like species. Phylogenetic analysis based on a combined data set of nuclear SSU and LSU and plastid SSU and LSU rDNA showed that the strains could be divided into eight clades: Clade A of M. aenigmatica, Clade B of the isolates (M. pyropsis) from Michigan, USA, Clade C of M. pseudopyrum, Clade D of the isolates (M. pyroria) from Bremen, Germany, Clade E of M. soropyrum, Clade F of M. pyriformis, Clade G of M. parapyrum, and Clade H of M. pyrum. Six of these clades came from strains that would be considered M. pyrum sensu Kosmala et Zakry?, one of which could be recognized as a traditional species (M. pyrum) and five were designated as new species; each species had unique molecular signatures at nr SSU rDNA helix 17 and 17′ and spacer E23_14′‐E23_15. The species of Monomorphina had a wide range of genetic diversity with interspecies sequence similarity of 85.6%–97.1% and intraspecies similarity of 96.4%–99.9%. Our results suggested that genetic diversity found in the M. pyrum complex justifies the recognition of a minimum of eight species within this genus, based on specific molecular signatures and gene divergence of the nr SSU rDNA sequences.     

Bovine lactoferricin is anti‐inflammatory and anti‐catabolic in human articular cartilage and synovium

Bovine lactoferricin (LfcinB) is a multi‐functional peptide derived from proteolytic cleavage of bovine lactoferrin. LfcinB was found to antagonize the biological effects mediated by angiogenic growth factors such as vascular endothelial growth factor (VEGF) and fibroblast growth factor 2 (FGF‐2) in endothelial cells. However, the effect of LfcinB on human articular cartilage remained unknown. Here, our findings demonstrate that LfcinB restored the proteoglycan loss promoted by catabolic factors (interleukin‐1β) IL‐1β and FGF‐2 in vitro and ex vivo. Mechanistically, LfcinB attenuated the effects of IL‐1β and FGF‐2 on the expression of cartilage‐degrading enzymes (MMP‐1, MMP‐3, and MMP‐13), destructive cytokines (IL‐1β and IL‐6), and inflammatory mediators (iNOS and TLR2). LfcinB induced protective cytokine expression (IL‐4 and IL‐10), and downregulated aggrecanase basal expression. LfcinB specifically activated ERK MAPK and Akt signaling pathways, which may account for its anti‐inflammatory activity. We also revealed that LfcinB exerted similar protective effects on human synovial fibroblasts challenged by IL‐1β, with minimal cytotoxicity. Collectively, our results suggest that LfcinB possesses potent anti‐catabolic and anti‐inflammatory bioactivities in human articular tissues, and may be utilized for the prevention and/or treatment of OA in the future. J. Cell. Physiol. 228: 447–456, 2013. © 2012 Wiley Periodicals, Inc.     

A Model of the Membrane-bound Cytochrome b5-Cytochrome P450 Complex from NMR and Mutagenesis Data

Microsomal cytochrome b₅ (cytb₅) is a membrane-bound protein that modulates the catalytic activity of its redox partner, cytochrome P4502B4 (cytP450). Here, we report the first structure of full-length rabbit ferric microsomal cytb₅ (16 kDa), incorporated in two different membrane mimetics (detergent micelles and lipid bicelles). Differential line broadening of the cytb₅ NMR resonances and site-directed mutagenesis data were used to characterize the cytb₅ interaction epitope recognized by ferric microsomal cytP450 (56 kDa). Subsequently, a data-driven docking algorithm, HADDOCK (high ambiguity driven biomolecular docking), was used to generate the structure of the complex between cytP4502B4 and cytb₅ using experimentally derived restraints from NMR, mutagenesis, and the double mutant cycle data obtained on the full-length proteins. Our docking and experimental results point to the formation of a dynamic electron transfer complex between the acidic convex surface of cytb₅ and the concave basic proximal surface of cytP4502B4. The majority of the binding energy for the complex is provided by interactions between residues on the C-helix and β-bulge of cytP450 and residues at the end of helix α4 of cytb₅. The structure of the complex allows us to propose an interprotein electron transfer pathway involving the highly conserved Arg-125 on cytP450 serving as a salt bridge between the heme propionates of cytP450 and cytb₅. We have also shown that the addition of a substrate to cytP450 likely strengthens the cytb₅-cytP450 interaction. This study paves the way to obtaining valuable structural, functional, and dynamic information on membrane-bound complexes.     

Cryptic Speciation in the Genus Cryptoglena (Euglenaceae) Revealed by Nuclear and Plastid SSU and LSU rRNA Gene

The photosynthetic euglenoid genus Cryptoglena is differentiated from other euglenoid genera by having a longitudinal sulcus, one chloroplast, two large trough‐shaped paramylon plates positioned between the chloroplast and pellicle, and lack of metaboly. The genus contains only two species. To understand genetic diversity and taxonomy of Cryptoglena species, we analyzed molecular and morphological data from 25 strains. A combined data set of nuclear SSU and LSU and plastid SSU and LSU rRNA genes was analyzed using Bayesian, maximum likelihood, maximum parsimony, and distance (neighbor joining) methods. Although morphological data of all strains showed no significant species‐specific pattern, molecular data segregated the taxa into five clades, two of which represented previously known species: C. skujae and C. pigra, and three of which were designated as the new species, C. soropigra, C. similis, and C. longisulca. Each species had unique molecular signatures that could be found in the plastid SSU rRNA Helix P23_1 and LSU rRNA H2 domain. The genetic similarity of intraspecies based on nr SSU rDNA ranged from 97.8% to 100% and interspecies ranged from 95.3% to 98.9%. Therefore, we propose three new species based on specific molecular signatures and gene divergence of the nr SSU rDNA sequences.     

Engineered Escherichia coli with Periplasmic Carbonic Anhydrase as a Biocatalyst for CO2 Sequestration

Carbonic anhydrase is an enzyme that reversibly catalyzes the hydration of carbon dioxide (CO₂). It has been suggested recently that this remarkably fast enzyme can be used for sequestration of CO₂, a major greenhouse gas, making this a promising alternative for chemical CO₂ mitigation. To promote the economical use of enzymes, we engineered the carbonic anhydrase from Neisseria gonorrhoeae (ngCA) in the periplasm of Escherichia coli, thereby creating a bacterial whole-cell catalyst. We then investigated the application of this system to CO₂ sequestration by mineral carbonation, a process with the potential to store large quantities of CO₂. ngCA was highly expressed in the periplasm of E. coli in a soluble form, and the recombinant bacterial cell displayed the distinct ability to hydrate CO₂ compared with its cytoplasmic ngCA counterpart and previously reported whole-cell CA systems. The expression of ngCA in the periplasm of E. coli greatly accelerated the rate of calcium carbonate (CaCO₃) formation and exerted a striking impact on the maximal amount of CaCO₃ produced under conditions of relatively low pH. It was also shown that the thermal stability of the periplasmic enzyme was significantly improved. These results demonstrate that the engineered bacterial cell with periplasmic ngCA can successfully serve as an efficient biocatalyst for CO₂ sequestration.     

Interference of ferric ions with ferrous iron quantification using the ferrozine assay

The ferrozine assay is a widely used colorimetric method for determining soluble iron concentrations. We provide evidence for a heretofore unrecognized interference of ferric ions (Fe^3 +) on ferrous iron (Fe^2 +) measurements performed in the dark. Fe^3 + concentrations affected the absorbance measurements, which linearly increased with incubation time.     

The effect of genomic information on optimal contribution selection in livestock breeding programs

Background

Long-term benefits in animal breeding programs require that increases in genetic merit be balanced with the need to maintain diversity (lost due to inbreeding). This can be achieved by using optimal contribution selection. The availability of high-density DNA marker information enables the incorporation of genomic data into optimal contribution selection but this raises the question about how this information affects the balance between genetic merit and diversity.

Methods

The effect of using genomic information in optimal contribution selection was examined based on simulated and real data on dairy bulls. We compared the genetic merit of selected animals at various levels of co-ancestry restrictions when using estimated breeding values based on parent average, genomic or progeny test information. Furthermore, we estimated the proportion of variation in estimated breeding values that is due to within-family differences.

Results

Optimal selection on genomic estimated breeding values increased genetic gain. Genetic merit was further increased using genomic rather than pedigree-based measures of co-ancestry under an inbreeding restriction policy. Using genomic instead of pedigree relationships to restrict inbreeding had a significant effect only when the population consisted of many large full-sib families; with a half-sib family structure, no difference was observed. In real data from dairy bulls, optimal contribution selection based on genomic estimated breeding values allowed for additional improvements in genetic merit at low to moderate inbreeding levels. Genomic estimated breeding values were more accurate and showed more within-family variation than parent average breeding values; for genomic estimated breeding values, 30 to 40% of the variation was due to within-family differences. Finally, there was no difference between constraining inbreeding via pedigree or genomic relationships in the real data.

Conclusions

The use of genomic estimated breeding values increased genetic gain in optimal contribution selection. Genomic estimated breeding values were more accurate and showed more within-family variation, which led to higher genetic gains for the same restriction on inbreeding. Using genomic relationships to restrict inbreeding provided no additional gain, except in the case of very large full-sib families.     

Metabolic engineering of Clostridium acetobutylicum for the enhanced production of isopropanol‐butanol‐ethanol fuel mixture

Butanol is considered as a superior biofuel, which is conventionally produced by clostridial acetone‐butanol‐ethanol (ABE) fermentation. Among ABE, only butanol and ethanol can be used as fuel alternatives. Coproduction of acetone thus causes lower yield of fuel alcohols. Thus, this study aimed at developing an improved Clostridium acetobutylicum strain possessing enhanced fuel alcohol production capability. For this, we previously developed a hyper ABE producing BKM19 strain was further engineered to convert acetone into isopropanol. The BKM19 strain was transformed with the plasmid pIPA100 containing the sadh (primary/secondary alcohol dehydrogenase) and hydG (putative electron transfer protein) genes from the Clostridium beijerinckii NRRL B593 cloned under the control of the thiolase promoter. The resulting BKM19 (pIPA100) strain produced 27.9 g/l isopropanol‐butanol‐ethanol (IBE) as a fuel alcohols with negligible amount of acetone (0.4 g/l) from 97.8 g/l glucose in lab‐scale (2 l) batch fermentation. Thus, this metabolically engineered strain was able to produce 99% of total solvent produced as fuel alcohols. The scalability and stability of BKM19 (pIPA100) were evaluated at 200 l pilot‐scale fermentation, which showed that the fuel alcohol yield could be improved to 0.37 g/g as compared to 0.29 g/g obtained at lab‐scale fermentation, while attaining a similar titer. To the best of our knowledge, this is the highest titer of IBE achieved and the first report on the large scale fermentation of C. acetobutylicum for IBE production. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 29:1083–1088, 2013     

Decline of dark coniferous stands in Baikal Region

The reasons for the decline in Siberian pine and fir in the Baikal Region (Khamar-Daban) were analyzed using remote sensing techniques, dendrochronology and GIS-technology methods, and in situ observations. It is found that a decrease in the value of the growth index (R ² = 0.69) and an decrease in the SPEI drought index (Standardized Precipitation–Evapotranspiration Index) (R ² = 0.72) has been observed since the 1980s. In the mid-2000s, the increase in aridity led to the division of Siberian pine trees into two cohorts: “survivors” and “decliners.” The spatial distribution of these cohorts is different: dead and declining stands are localized mainly on relief elements with increased risk of water stress (steep and convex slopes of southwestern exposure). The growth index of the trees is closely related to the dryness index in June (r ² = 0.55). Along with water stress, declining trees were also exposed to stem pests and plant pathogens. The primary cause of Siberian pine decline is water stress due to the increasing climate aridity. The weakened waterstressed trees were sensitized to pathogens. The synergism of climatic and biotic effects led to the decline of Siberian pine stands. On the whole, heavily damaged and declining stands (over 50% of dead and declining trees) within the Khamar-Daban ridge are 8–10% of the total area of dark coniferous forests.