Expression and purification of <Emphasis Type="Italic">Zantedeschia aethiopica</Emphasis> agglutinin in <Emphasis Type="Italic">Escherichia </Emphasis><Emphasis Type="Italic">coli</Emphasis>

Recombinant Zantedeschia aethiopica agglutinin (ZAA) was expressed in Escherichia coli as N-terminal His-tagged fusion. After induction with isopropylthio-β-d-galactoside (IPTG), the recombinant ZAA was purified by metal-affinity chromatography. The purified ZAA protein was applied in anti-fungal assay and the result showed that recombinant ZAA had anti-fungal activity towards leaf mold (Fulvia fulva), one of the most serious phytopathogenic fungi causing significant yield loss of crops. This study suggests that ZAA could be an effective candidate in genetic engineering of plants for the control of leaf mold.     

Co-expression of α and β subunits of the 3-methylcrotonyl-coenzyme A carboxylase from <Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis>

Pseudomonas aeruginosa is a versatile bacterium that can grow using citronellol or leucine as sole carbon source. For both compounds the degradation pathways converge at the key enzyme 3-methylcrotonyl coenzyme-A carboxylase (MCCase). This enzyme is a complex formed by two subunits (α and β), encoded by the liuD and liuB genes, respectively; both are essential for enzyme function. Previously, both subunits had been separately expressed and then the complex re-constituted, however this methodology is laborious and produces low yield of active enzyme. In this work, the MCCase subunits were co-expressed in the same plasmid and purified in one step by affinity chromatography using the LiuD-His tag protein, interacting with the LiuB-S tag recombinant protein. The purified enzyme lost most of the activity within few hours of storage. The co-expressed subunits formed an (αβ)₄ complex that suffered a modification of its oligomerization state after storage, which probably contributed to the loss on activity observed. The recombinant MCCase enzyme presented optimum pH and temperature values of 9.0 and 30o C, respectively. Functionally, MCCase showed Michaelian kinetics behavior with a K_m for its substrate and V_max of 168 μM and 430 nmoles mg⁻¹min⁻¹, respectively. The results suggest that the co-expression and co-purification of the subunits is a suitable procedure to obtain the active complex of the MCCase from Pseudomonas aeruginosa in a single step.     

Butterfly diversity in Mediterranean islands and in Pentadaktylos <Emphasis Type="Italic">Pinus</Emphasis><Emphasis Type="BoldItalic"> </Emphasis><Emphasis Type="Italic">brutia</Emphasis> forests of Cyprus

We analysed the influence of contemporary geography on butterfly diversity for islands in the Mediterranean Basin. We found that island size and distance from the mainland has a significant effect on the number of species. We also used butterflies as an indicator group to identify the importance of forest habitats for biodiversity conservation in the island of Cyprus. To understand the relative importance of local vegetation characteristics of butterflies in the Pentadaktylos mountains transect counts were used to assess the abundance and butterfly diversity in two different forest types. A total of 1,602 butterflies and 23 species were recorded during this research. We observed highly significant effects of forest type on abundance and species richness of butterflies. For example, number of butterflies was significantly higher in old forest than young pine forest. Also, the abundance of endemic butterflies was highest in old forest habitats. Therefore, the survival of the majority of endemic butterflies in Cyprus may depend on conservation of old forests and their understorey plants.     

<Emphasis Type="Bold">A user guide to the</Emphasis><Emphasis Type="BoldItalic">Brassica</Emphasis><Emphasis Type="Bold">60K Illumina Infinium</Emphasis>™ <Emphasis Type="Bold">SNP genotyping array</Emphasis>

The Brassica napus 60K Illumina Infinium? SNP array has had huge international uptake in the rapeseed community due to the revolutionary speed of acquisition and ease of analysis of this high-throughput genotyping data, particularly when coupled with the newly available reference genome sequence. However, further utilization of this valuable resource can be optimized by better understanding the promises and pitfalls of SNP arrays. We outline how best to analyze Brassica SNP marker array data for diverse applications, including linkage and association mapping, genetic diversity and genomic introgression studies. We present data on which SNPs are locus-specific in winter, semi-winter and spring B. napus germplasm pools, rather than amplifying both an A-genome and a C-genome locus or multiple loci. Common issues that arise when analyzing array data will be discussed, particularly those unique to SNP markers and how to deal with these for practical applications in Brassica breeding applications.     

High-level expression,purification and characterization of a recombinant medium-temperature <Emphasis Type="Italic">α</Emphasis>-amylase from <Emphasis Type="Italic">Bacillus subtilis</Emphasis>

Alpha-amylases are important industrial enzymes with a wide range of applications. Although medium-temperature alpha amylase (AmyE) has some practical advantages, its low yield has limited its applications. When an amyE gene from Bacillus subtilis BF768 was cloned into vector pWB980 and over-expressed in B. subtilis WB600, high activities (723 U ml⁻¹) of secreted AmyE were produced. Recombinant AmyE was purified to a specific activity of 36 U mg⁻¹ having optimal activity at pH 6.0 and 60°C.     

<Emphasis Type="Italic">Carex</Emphasis> × <Emphasis Type="Italic">involuta</Emphasis> and <Emphasis Type="Italic">Carex juncella</Emphasis> in the flora of Slovakia

The paper brings information on an isolated occurrence and morphological characters of Carex × involuta and C. juncella populations in the Vel’ká Fatra Mts. Their presence has been known neither from the territory of Slovakia nor from the whole Western Carpathians till now.     

Molecular cloning,overexpression and characterization of the raw-starch-digesting <Emphasis Type="Italic">α</Emphasis>-amylase of <Emphasis Type="Italic">Bacillus amyloliquefaciens</Emphasis>

Raw starch is the most abundant source of glucose in the world. Therefore, finding enzymes capable of digesting raw starch would find high industrial demand. The α-amylase gene of Bacillus amyloliquefaciens ATCC 23842 was amplified, cloned and overexpressed in Escherichia coli BL21 (DE3) cells. The recombinant enzyme was purified to apparent homogeneity using ion exchange and gel filtration chromatography. The raw-starch digestibility of the purified enzyme was characterized by studying the hydrolysis and adsorption rate on a variety of raw starches (potato, cassava, corn, wheat and rice). The raw-starch digestion was further confirmed by scanning electron microscopy studies, which revealed an effective rate of hydrolysis. The kinetic studies revealed a relatively low K _m of 2.76 mg/mL, exhibiting high affinity towards the soluble starch as the most preferred substrate and the inhibition kinetic studies revealed a high K _i value (350 mM).     

Brood cell size of <Emphasis Type="Italic">Apis</Emphasis> <Emphasis Type="Italic">mellifera</Emphasis> modifies the reproductive behavior of <Emphasis Type="Italic">Varroa</Emphasis> <Emphasis Type="Italic">destructor</Emphasis>

We undertook a field study to determine whether comb cell size affects the reproductive behavior of Varroa destructor under natural conditions. We examined the effect of brood cell width on the reproductive behavior of V. destructor in honey bee colonies, under natural conditions. Drone and worker brood combs were sampled from 11 colonies of Apis mellifera. A Pearson correlation test and a Tukey test were used to determine whether mite reproduction rate varied with brood cell width. Generalized additive model analysis showed that infestation rate increased positively and linearly with the width of worker and drone cells. The reproduction rate for viable mother mites was 0.96 viable female descendants per original invading female. No significant correlation was observed between brood cell width and number of offspring of V. destructor. Infertile mother mites were more frequent in narrower brood cells.     

Functional expression of the lipase gene Lip2 of <Emphasis Type="Italic">Pleurotus</Emphasis> <Emphasis Type="Italic">sapidus</Emphasis> in <Emphasis Type="Italic">Escherichia</Emphasis> <Emphasis Type="Italic">coli</Emphasis>

The lipase Lip2 of the edible basidiomycete, Pleurotus sapidus, is an extracellular enzyme capable of hydrolysing xanthophyll esters with high efficiency. The gene encoding Lip2 was expressed in Escherichia coli TOP10 using the gene III signal sequence to accumulate proteins in the periplasmatic space. The heterologous expression under control of the araBAD promoter led to the high level production of recombinant protein, mainly as inclusion bodies, but partially in a soluble and active form. A fusion with a C-terminal His tag was used for purification and immunochemical detection of the target protein. This is the first example of a heterologous expression and periplasmatic accumulation of a catalytically active lipase from a basidiomycete fungus.     

Characteristics of β-lactamases and their genes (<Emphasis Type="Italic">blaA</Emphasis> and <Emphasis Type="Italic">blaB</Emphasis>) in <Emphasis Type="Italic">Yersinia intermedia</Emphasis> and <Emphasis Type="Italic">Y. frederiksenii</Emphasis>

Background  

The presence of β-lactamases in Y. enterocolitica has been reported to vary with serovars, biovars and geographical origin of the isolates. An understanding of the β-lactamases in other related species is important for an overall perception of antibiotic resistance in yersiniae. The objective of this work was to study the characteristics of β-lactamases and their genes in strains of Y. intermedia and Y. frederiksenii, isolated from clinical and non-clinical sources in India.     

<Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation of <Emphasis Type="Italic">Codonopsis lanceolata</Emphasis> using the <Emphasis Type="Italic">γ-TMT</Emphasis> gene

Efficient transformation of leaf disc-derived callus of Codonopsis lanceolata was obtained using Agrobacterium tumefaciens strain LBA4404 harboring a binary vector, pYBI121, that carries the neomycin phosphotransferase (npt II) gene as a selectable marker. The green shoots recovered from agroinfected explants on selection medium (containing 0.1 mg/l α-naphthaleneacetic acid (NAA), 1 mg/l 6-benzylaminopurine (BAP), 100 mg/l kanamycin, and 250 mg/l cefotaxime) were rooted on Murashige and Skoog (MS) medium supplemented with 2 mg/l IBA and 10 mg/l kanamycin. To optimize the transformation conditions, several factors were assessed, including the co-cultivation period, the duration of pre- and post-culture in darkness and light, the kanamycin concentration, and the Agrobacterium densities. We produced transgenic Codonopsis lanceolata overexpressing γ-tocopherol methyltransferase (γ-TMT) by this protocol. Moreover, the α-tocopherol content of the plants was enhanced by the overexpression of this gene. Bimal Kumar Ghimire and Eun Soo Seong contributed equally to this work.     

Conjugal transfer using the bacteriophage ϕC31 <Emphasis Type="Italic">att</Emphasis>/<Emphasis Type="Italic">int</Emphasis> system and properties of the <Emphasis Type="Italic">attB</Emphasis> site in <Emphasis Type="Italic">Streptomyces ambofaciens</Emphasis>

To facilitate molecular genetic studies of Streptomyces ambofaciens that produces spiramycin, a commercially important macrolide antibiotic used in human medicine against Gram-positive pathogenic bacteria, the conditions for the conjugal transfer of DNA from E. coli to S. ambofaciens were established using a bacteriophage ϕC31 att/int system. The transconjugation efficiency of S. ambofaciens varied with the medium used; the highest frequency was obtained on AS-1 medium containing 10 mM MgCl₂ without heat treatment of the spores. In addition, by cloning and sequencing the attB site, we identified that S. ambofaciens contains a single attB site within an ORF coding for a pirin homolog, and its attB site sequence shows 100% nt identity to the sequence of S. coelicolor and S. lividans, which have the highest efficiency in transconjugation using the ϕC31 att/int system.     

Is the <Emphasis Type="Italic">Mnr</Emphasis> locus of Triticeae species the same as the <Emphasis Type="Italic">Ndh</Emphasis> and <Emphasis Type="Italic">Dia</Emphasis> loci?

The menadione reductase (MNR), the nicotinamide adenine dinucleotide dehydrogenase (NDH) and diaphorase (DIA) isozymes were studied in the allohexaploid Triticum aestivum cv ”Chinese Spring” and in five diploid Triticeae species. The Mnr1, Ndh3 and Dia1 loci were located on the chromosome arms 3AL, 3BL and 3DL of T. aestivum, respectively. These loci were also located on the 3H chromosome of Hordeum vulgare cv ”Betzes”, the 3L chromosome of Aegilops longissima and the 6RL chromosome arm of Secale cereale cv ”Imperial”. The chromosomal location results together with the segregation studies support a tetrameric behaviour of the MNR1, NDH3 and DIA1 isozymes. The Ndh1 and Dia3 loci were located on homoeologous group 4 showing a monomeric behaviour. The chromosomal locations and linkage data of the Mnr, Ndh and Dia loci suggest that Mnr1=Ndh3=Dia1; Ndh1=Dia3 and Ndh2=Dia2. Received: 3 June 2001 / Accepted: 11 July 2001     

Carbohydrate and Ethane Release with <Emphasis Type="Italic">Erwinia carotovora</Emphasis> Subspecies <Emphasis Type="Italic">betavasculorum</Emphasis><Emphasis Type="Italic">–</Emphasis>Induced Necrosis

Erwinia carotovora subspecies betavasculorum, also known as E. betavasculorum and Pectobacterium betavasculorum, is a soil bacterium that has the capacity to cause root rot necrosis of sugarbeets. The qualitatively different pathogenicity exhibited by the virulent E. carotovora strain and two avirulent strains, a Citrobacter sp. and an Enterobacter cloacae, was examined using digital analysis of photographic evidence of necrosis as well as for carbohydrate, ethane, and ethylene release compared with uninoculated potato tuber slices. Visual scoring of necrosis was superior to digital analysis of photographs. The release of carbohydrates and ethane from potato tuber slices inoculated with the soft rot necrosis-causing Erwinia was significantly greater than that of potato tuber slices that had not been inoculated or that had been inoculated with the nonpathogenic E. cloacae and Citrobacter sp. strains. Interestingly, ethylene production from potato slices left uninoculated or inoculated with the nonpathogenic Citrobacter strain was 5- to 10-fold higher than with potato slices inoculated with the pathogenic Erwinia strain. These findings suggest that (1) carbohydrate release might be a useful measure of the degree of pathogenesis, or relative virulence; and that (2) bacterial suppression of ethylene formation may be a critical step in root rot disease formation.     

Sequence Analysis of the <Emphasis Type="Italic">Lactoferrin</Emphasis> Gene and Variation of <Emphasis Type="Italic">g</Emphasis>.<Emphasis Type="Italic">7605C</Emphasis>→<Emphasis Type="Italic">T</Emphasis> in 10 Chinese Indigenous Goat Breeds

Much attention has been focused on the study of lactoferrin at the protein or nucleotide level in mice, humans, and cattle, but little is known about it in goats. The goat LF gene from 5' UTR to exon 17 was amplified, and the variation of g.7605C→T in 10 Chinese indigenous goat breeds was analyzed. Among the three ruminant species (cattle, sheep, and goats), the intron-exon distribution pattern was similar, and all the exons had the same length, but the length of introns varied greatly due to insertions or deletions. The frequency of allele T at g.7605C→T (50.12%) was a little higher than that of allele C (49.88%), and the genotype distribution differed greatly between goat populations. The g.7605C→T site showed higher genetic diversity in goat populations. The genetic differentiation was 0.0783, and gene flow was 2.9433 among the 10 Chinese indigenous goat populations.     

Theoretical study of hydrogen bond interactions of fluvastatin with <Emphasis Type="BoldItalic">ι</Emphasis>-carrageenan and <Emphasis Type="Italic">λ</Emphasis>-carrageenan

The binding of the reductase inhibitor drug fluvastatin, hydroxy-3-methylglutaryl coenzyme A, with the hydrophilic ι- or λ-carrageenan polymers, serving as potential controllers of the drug’s release rate, have been studied at the density functional level of theory with the B3LYP exchange correlation functional. Three low energy conformers of fluvastatin have been calculated. The vibrational spectroscopic properties calculated for the most stable conformer were in satisfactory agreement with the experimental data. A series of hydrogen bonded complexes of the most stable conformer of fluvastatin anion with low molecular weight models of the polymers have been fully optimized. In almost all, intermolecular H-bonds are formed between the sulfate groups of ι- or λ-carrageenan and fluvastatin’s hydroxyls, resulting in a red shift of the fluvastatin’s O − H stretching vibrations. Cooperative intramolecular H-bonds within fluvastatin or ι-, λ-carrageenan are also present. The BSSE and ZPE corrected interaction energies were estimated in the range 281–318 kJ mol⁻¹ for ι-carrageenan - fluvastatin and 145–200 kJ mol⁻¹ for λ-carrageenan - fluvastatin complexes. The electron density (ρ _bcp) and Laplacian (∇² ρ _bcp) properties at critical points of the intermolecular hydrogen bonds, estimated by AIM (atoms in molecules) calculations, have a low and positive character (∇² ρ _bcp > 0), consistent with the electrostatic character of the hydrogen bonds. The structural and energetic data observed, as well as the extent of the red shift of the fluvastatin’s O − H stretching vibrations upon complex formation and the properties of electron density show a stronger binding of fluvastatin to ι- than to λ-carrageenan.     

PCR-based cloning of the complete mouse mitochondrial genome and stable engineering in <Emphasis Type="Italic">Escherichia</Emphasis> <Emphasis Type="Italic">coli</Emphasis>

We have devised a method for cloning an entire mammalian mitochondrial genome (mtDNA) in Escherichia coli using PCR-based amplification and sequential ligation. Here we test this approach by cloning the complete mouse mtDNA. The mtDNA was divided into four to five fragments based on unique restriction enzyme sites and amplified by high-fidelity long-range DNA polymerase. The synthesized fragments were cloned individually to test their toxicity in the E. coli host and then combined sequentially into a vector containing the E. coli R6K origin of DNA replication. The synthetic complete mouse mtDNA clones were replicated stably and faithfully in E. coli when maintained at moderately low copy numbers per cell. The sequence integrity of the synthetic mouse mtDNA clones was confirmed by nucleotide sequencing; no mutations or rearrangements in the genome were found. This approach can facilitate the cloning of entire mammalian mitochondrial genomes in E. coli and assist in the introduction of desired modifications into the mitochondrial genome.     

Polyphasic characterization of “<Emphasis Type="Italic">Aspergillus nidulans</Emphasis> var. <Emphasis Type="Italic">roseus</Emphasis>” ATCC 58397

Polyphasic characterization of the echinocandin B producer Aspergillus nidulans var. roseus ATCC 58397 strain was carried out to elucidate its taxonomical status. According to its carbon source utilization and secondary metabolite spectrum as well as the partial β-tubulin, calmodulin, and γ-actin gene sequences, A. nidulans var. roseus belongs to the Emericella rugulosa species. Auxotroph mutants of A. nidulans var. roseus ATCC 58397 and E. rugulosa CBS 171.71 and CBS 133.60 formed stable heterokaryons on minimal medium with several A. nidulans strains, and in the case of A. nidulans var. roseus, even cleistothecia were developed.