Panning of a Phage Display Library against a Synthetic Capsule for Peptide Ligands That Bind to the Native Capsule of Bacillus anthracis

Bacillus anthracis is the causative agent of anthrax with the ability to not only produce a tripartite toxin, but also an enveloping capsule comprised primarily of γ-D-glutamic acid residues. The purpose of this study was to isolate peptide ligands capable of binding to the native capsule of B. anthracis from a commercial phage display peptide library using a synthetic form of the capsule consisting of 12 γ-D-glutamic acid residues. Following four rounds of selection, 80 clones were selected randomly and analysed by DNA sequencing. Four clones, each containing a unique consensus sequence, were identified by sequence alignment analysis. Phage particles were prepared and their derived 12-mer peptides were also chemically synthesized and conjugated to BSA. Both the phage particles and free peptide-BSA conjugates were evaluated by ELISA for binding to encapsulated cells of B. anthracis as well as a B. anthracis capsule extract. All the phage particles tested except one were able to bind to both the encapsulated cells and the capsule extract. However, the peptide-BSA conjugates could only bind to the encapsulated cells. One of the peptide-BSA conjugates, with the sequence DSSRIPMQWHPQ (termed G1), was fluorescently labelled and its binding to the encapsulated cells was further confirmed by confocal microscopy. The results demonstrated that the synthetic capsule was effective in isolating phage-displayed peptides with binding affinity for the native capsule of B. anthracis.     

Life Cycle of Heterodera zeae Koshy, Swarup,and Sethi on Zea mays L. Axenic Root Explants

Monoxenic cultures of Heterodera zeae, the corn cyst nematode (CCN), were established on root explants of corn Zea mays L., cv. Kenworthy. The life cycle of H. zeae was determined from light anti scanning electron microscopic observations of the root explants grown in the dark at 29.5 ± .5 C under gnotobiotic conditions. The life cycle, from the time the explants were inoculated with second-stage larvae (L2) to the first appearance of newly hatched second-generation L2, required 22 days. The occurrence of males was rare suggesting that reproduction in H. zeae is parthenogenetic.     

A new putrescine bisamide phenolic glycoside from the seeds of Lallemantia iberica (M. Bieb.) Fisch. & C. A. Mey

A new putrescine bisamide phenolic glycoside, N-(trans-feruloyl)-N′-(para-hydroxybenzoyl) putrescine bisamide-4′-O-α-l-rhamnopyranoside (1), designated as lallenmantoside (1), together with one known phenolic glycoside, cucurbitoside d (2), were isolated from the seeds of Lallemantia iberica (M. Bieb.) Fisch. & C. A. Mey. Their structures were elucidated by spectroscopic analysis, and by comparison with literature data. This is the first report of phenolic glycosides from genus Lallemantia.     

Incorporating Uncertainty into a Life Cycle Assessment (LCA) Model of Short-Rotation Willow Biomass (Salix spp.) Crops

To estimate fossil fuel demand and greenhouse gas emissions associated with short-rotation willow (Salix spp.) crops in New York State, we constructed a life cycle assessment model capable of estimating point values and measures of variability for a number of key processes across eight management scenarios. The system used 445.0 to 1,052.4 MJ of fossil energy per oven-dry tonne (odt) of delivered willow biomass, resulting in a net energy balance of 18.3:1 to 43.4:1. The largest fraction of the energy demand across all scenarios was driven by the use of diesel fuels. The largest proportion of diesel fuel was associated with harvesting and delivery of willow chips seven times on 3-year rotations over the life of the crop. Similar patterns were found for greenhouse gas emissions across all scenarios, as fossil fuel use served as the biggest source of emissions in the system. Carbon sequestration in the belowground portion of the willow system provided a large carbon sink that more than compensated for carbon emissions across all scenarios, resulting in final greenhouse gas balances of ?138.4 to ?52.9 kg CO₂ eq. per odt biomass. The subsequent uncertainty analyses revealed that variability associated with data on willow yield, litterfall, and belowground biomass eliminated some of the differences between the tested scenarios. Even with the inclusion of uncertainty analysis, the willow system was still a carbon sequestration system after a single crop cycle (seven 3-year rotations) in all eight scenarios. A better understanding and quantification of factors that drive the variability in the biological portions of the system is necessary to produce more precise estimates of the emissions and energy performance of short-rotation woody crops.     

Horizontal Transfer of a Subtilisin Gene from Plants into an Ancestor of the Plant Pathogenic Fungal Genus Colletotrichum

The genus Colletotrichum contains a large number of phytopathogenic fungi that produce enormous economic losses around the world. The effect of horizontal gene transfer (HGT) has not been studied yet in these organisms. Inter-Kingdom HGT into fungal genomes has been reported in the past but knowledge about the HGT between plants and fungi is particularly limited. We describe a gene in the genome of several species of the genus Colletotrichum with a strong resemblance to subtilisins typically found in plant genomes. Subtilisins are an important group of serine proteases, widely distributed in all of the kingdoms of life. Our hypothesis is that the gene was acquired by Colletotrichum spp. through (HGT) from plants to a Colletotrichum ancestor. We provide evidence to support this hypothesis in the form of phylogenetic analyses as well as a characterization of the similarity of the subtilisin at the primary, secondary and tertiary structural levels. The remarkable level of structural conservation of Colletotrichum plant-like subtilisin (CPLS) with plant subtilisins and the differences with the rest of Colletotrichum subtilisins suggests the possibility of molecular mimicry. Our phylogenetic analysis indicates that the HGT event would have occurred approximately 150–155 million years ago, after the divergence of the Colletotrichum lineage from other fungi. Gene expression analysis shows that the gene is modulated during the infection of maize by C. graminicola suggesting that it has a role in plant disease. Furthermore, the upregulation of the CPLS coincides with the downregulation of several plant genes encoding subtilisins. Based on the known roles of subtilisins in plant pathogenic fungi and the gene expression pattern that we observed, we postulate that the CPLSs have an important role in plant infection.     

A Note on Acrocladium trifarium (W. & M.) Richards & Wallace in Ireland

Abstract

Chains of 3–4-celled gemmae have been observed on the protonema of Trematodon brevicalyx, both in nature as well as in cultures. They are produced in abundance and may help in its survival, propagation and wide dispersal.     

Characterization of L-asparaginase from Bacillus sp. isolated from an intertidal marine alga (Sargassum sp.)

B.R. MOHAPATRA, R.K. SANI AND U.C. BANERJEE. 1995. The bacterial flora associated with an intertidal marine alga ( Sargassum sp.) were screened for the presence of extracellular L-asparaginase; one out of five Bacillus strains was found positive. The maximum L-asparaginase activity was found at 37°C and pH 8.0. The optimum NaCl concentration for enzyme activity was found to be 2% (w/v). The enzyme activity was not affected by the addition of different metal ions (Ca²⁺, Co²⁺, Fe²⁺, Mg²⁺and Ni²⁺) at 10 mmol 1^-1, but was strongly inhibited by EDTA.     

Genotoxic potential of the latex from cotton-leaf physicnut (Jatropha gossypiifolia L.)

Jatropha gossypiifolia L. (Euphorbiaceae), popularly known ascotton-leaf physicnut, is a milky shrub notable for its medicinal properties. Thepresent study aimed to evaluate the toxic, cytotoxic and genotoxic effects of thelatex of J. gossypiifolia, using Allium cepa L. astest system. Seeds of A. cepa were exposed to five concentrations ofthe latex (1.25; 2.5; 5; 10 and 20 mL/L) in order to evaluate parameters of toxicity(evaluation of root growth), cytotoxicity (mitotic index frequency) and genotoxicity(frequency of chromosome alterations). The latex showed a significant decrease inroot mean growth value as well as mitotic index for the tested concentrations, exceptfor 1.25 mL/L, when compared to results from the negative control. The 1.25, 2.5 and5 mL/L concentrations induced significant chromo-some adherences, C-metaphases and/orchromosome bridges, as genotoxic effects. The significant frequency of chromosomebridges also indicated mutagenic potential for chromosomes of J.gossypiifolia as discussed in the paper. Considering that the latex isused in popular therapies, and that the test system A. cepa presentsgood correlation with tests carried out in mammals, it can be pointed out that itsuse for medicinal purposes may be harmful to human health especially if ingested.     

A Novel Erythromycin Resistance Plasmid from Bacillus Sp. Strain HS24, Isolated from the Marine Sponge Haliclona Simulans

A better understanding of the origin and natural reservoirs of resistance determinants is fundamental to efficiently tackle antibiotic resistance. This paper reports the identification of a novel 5.8 kb erythromycin resistance plasmid, from Bacillus sp. HS24 isolated from the marine sponge Haliclona simulans. pBHS24B has a mosaic structure and carries the erythromycin resistance gene erm(T). This is the first report of an erythromycin resistance plasmid from a sponge associated bacteria and of the Erm(T) determinant in the genus Bacillus.     

Heterodera canadensis n. sp. (Nematoda: Heteroderidae) from Spike-Rush (Eleocharis acicularis (L.) R. &S.) in Quebec,Canada

Heterodera canadensis n. sp. is described and illustrated from the roots of spike-rush, Eleocharis acicularis (L.) R. &S., in Deschenes, Quebec. This new abullate species is related to Heterodera graminophila Golden and Birchfield, 1972, but differs significantly in cyst shape, cone top structures, body length of the second-stage larva (520-600 μm, vs. 380-400 for H. graminophila) and tail length (110-120 μm, vs. 57-67 for H. graminophila). A taxonomic key based on cyst and second-stage larva characters is provided for identification of the fifteen species in the Heterodera goettingiana group.