Chemical Characterization of Atlantic Cod (Gadus morhua) Collagen Hydrolyzed Using Enzyme Preparation Derived from Red King Crab (Paralithodes camtschaticus) and Its Potential as a Core Component of Bacterial Culture Medium

The Atlantic cod (Gadus morhua) and red king crab (Paralithodes camtschaticus) processing wastes are massive and unutilized in the Murmansk region of Russia. The samples of skin-containing waste of Atlantic cod fillets production were hydrolyzed using enzyme preparations derived from red king crab hepatopancreases, porcine pancreases, and Bacillus subtilis bacteria. The activity of enzymes from crab hepatopancreases was significantly higher than the activity of enzymes derived from other sources. The optimal conditions of the hydrolysis process have been figured out. The samples of cod processing waste hydrolysate were analyzed for amino acid composition and molecular weight distribution. The samples of hydrolysate were used as core components for bacterial culture medium samples. The efficiency of the medium samples was tested for Escherichia coli growth rate; the most efficient sample had an efficiency of 95.3% of that of a commercially available medium based on fish meal. Substitution of medium components with those derived from industrial by-products is one of the ways to decrease a cost of a culture medium in biopharmaceutical drug production.     

The V-antigen of Yersinia forms a distinct structure at the tip of injectisome needles

Many pathogenic bacteria use injectisomes to deliver effector proteins into host cells through type III secretion. Injectisomes consist of a basal body embedded in the bacterial membranes and a needle. In Yersinia, translocation of effectors requires the YopB and YopD proteins, which form a pore in the target cell membrane, and the LcrV protein, which assists the assembly of the pore. Here we report that LcrV forms a distinct structure at the tip of the needle, the tip complex. This unique localization of LcrV may explain its crucial role in the translocation process and its efficacy as the main protective antigen against plague.     

Identification of a DNA nonhomologous end-joining complex in bacteria

In eukaryotic cells, double-strand breaks (DSBs) in DNA are generally repaired by the pathway of homologous recombination or by DNA nonhomologous end joining (NHEJ). Both pathways have been highly conserved throughout eukaryotic evolution, but no equivalent NHEJ system has been identified in prokaryotes. The NHEJ pathway requires a DNA end-binding component called Ku. We have identified bacterial Ku homologs and show that these proteins retain the biochemical characteristics of the eukaryotic Ku heterodimer. Furthermore, we show that bacterial Ku specifically recruits DNA ligase to DNA ends and stimulates DNA ligation. Loss of these proteins leads to hypersensitivity to ionizing radiation in Bacillus subtilis. These data provide evidence that many bacteria possess a DNA DSB repair apparatus that shares many features with the NHEJ system of eukarya and suggest that this DNA repair pathway arose before the prokaryotic and eukaryotic lineages diverged.     

Molecular Analysis of Phytophthora infestans (Mont.) de Bary from Chapingo,Mexico. Phylogeographic Referential

An Andean origin of Phytophthora infestans was originally based on written records, and recently inferred from mitochondrial and nuclear gene genealogies, which emphasize a common South American origin of the European isolates, and absence of the I-b haplotype in Mexico (recently identified in Tlaxcala, Mexico). In order to compare such results, we sequenced the nuclear genes β-tubulin, Ras, and Intron Ras, and rDNA ITS regions in 24 P. infestans genotypes isolated, identified, and selected, during three crop growing cycles in Chapingo, Mexico. The pathogen showed homology and 100 % sequence similarities to the ones reported for the Andes and Europe β-tubulin, Ras, and Intron Ras genes. Results for the ITS region were inconclusive. The molecular oomycete similarities from the three geographical regions (South America, Europe, and Mexico), and the Mexican genotypes characteristics reported in the species supports the hypothesis of the location of P. infestans diversity and a center of dispersal in the central highlands of Mexico.     

Lithothamnion muelleri Controls Inflammatory Responses,Target Organ Injury and Lethality Associated with Graft-versus-Host Disease in Mice

Lithothamnion muelleri (Hapalidiaceae) is a marine red alga, which is a member of a group of algae with anti-inflammatory, antitumor, and immunomodulatory properties. The present study evaluated the effects of treatment with Lithothamnion muelleri extract (LM) in a model of acute graft-versus-host disease (GVHD), using a model of adoptive splenocyte transfer from C57BL/6 donors into B6D2F1 recipient mice. Mice treated with LM showed reduced clinical signs of disease and mortality when compared with untreated mice. LM-treated mice had reduced tissue injury, less bacterial translocation, and decreased levels of proinflammatory cytokines and chemokines (interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), chemokine (C-C motif) ligand 2 (CCL2), chemokine (C-C motif) ligand 3 (CCL3) and chemokine (C-C motif) ligand 5 (CCL5)). The polysaccharide-rich fraction derived from LM could inhibit leukocyte rolling and adhesion in intestinal venules, as assessed by intravital microscopy. LM treatment did not impair the beneficial effects of graft-versus-leukaemia (GVL). Altogether, our studies suggest that treatment with Lithothamnion muelleri has a potential therapeutic application in GVHD treatment.     

Comparative efficacy of conventional and new rodenticides against Microtus arvalis (Pallas, 1778) in wheat and alfalfa crops

In order to compare the efficacies of new rodenticides (sodium selenite and cellulose) and conventional ones (bromadiolone, brodifacoum and cholecalciferol) in controlling Microtus arvalis (Pallas, 1778) in wheat and alfalfa crops, experiments were conducted at two sites near Belgrade, Serbia, in the spring of 2008, using a standard EPPO method. The presence of rodent populations, their spatial distribution and density indexes were evaluated by pre-treatment census, and rodenticide efficacy by counting active holes 14 and 28 days after treatment.     

Weak effects of habitat type on susceptibility to invasive freshwater species: an Italian case study

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Occurrence and present status of coastal dolphins (Delphinus delphis and Tursiops truncatus) in the eastern Ionian Sea

• 1. Boat surveys aimed at studying short‐beaked common dolphins and common bottlenose dolphins in eastern Ionian Sea coastal waters were conducted between 1993 and 2003. During 835 survey days, 24 771 km of total effort was distributed within an area of 480 km², resulting in 428 common dolphin and 235 bottlenose dolphin sightings.
• 2. Individual photo‐identification was performed extensively throughout this study, making it possible to monitor the number of animals seen in the study area each year and their long‐term residency patterns.
• 3. Common dolphins declined across the study period, from 2.18 encounters/100 km in 1997 to 0.40 encounters/100 km in 2003. In contrast, there was a relatively stable presence of bottlenose dolphins, some individuals showing high levels of site fidelity and others using the area only occasionally.
• 4. The local decline of common dolphins and the low density of bottlenose dolphins appeared to reflect the general status of these cetacean species in the wider Mediterranean region, where common dolphins were classified as endangered in the IUCN Red List in 2003.
• 5. Based on the available evidence, we infer that the present unfavourable status of common dolphins in eastern Ionian Sea coastal waters is largely a consequence of prey depletion.

Copyright © 2005 John Wiley & Sons, Ltd.     

Pearl grafting: Tracking the biological origin of nuclei by straightforward immunological methods

French Polynesia is renowned for the production of Tahitian black pearl. These gems are obtained by grafting a nucleus into the gonad of a receiving oyster together with a graft, i.e. a small section of mantle tissue of a donor oyster. This procedure initiates the formation of a pearl sack around the nucleus, and subsequently, the deposition of concentric layers of nacre. The nucleus plays a key‐role in pearl formation and its characteristics influence markedly the quality of the final product. As it is manufactured from mollusc shells, it contains a small percentage of organics. In the present paper, we used a set of biochemical techniques to characterize and compare the organic matrices from two types of nuclei that are currently used in French Polynesia: that from the freshwater mussel Amblema sp., and that from the pearl oyster Pinctada sp. To this end, we extracted the matrices from nuclei and performed FT‐IR, monodimensional electrophoresis, and enzyme‐linked immuno‐sorbent assay (ELISA). Our data show that the matrix associated with Amblema nuclei has a very different biochemical signature from that of Pinctada nuclei, a fact that may explain the improved tolerance of grafted oysters to nuclei of Pinctada origin. In the absence of complex physical methods of investigation, simple immunological techniques and FT‐IR performed on the extracted organic matrix are extremely reliable and effective for discriminating nuclei from these two sources. We assert that such techniques can be used as a diagnostic test to track unambiguously the biological origin of nuclei to avoid fraud.     

Autochthonous probiotic as growth promoter and immunomodulator for Astyanax bimaculatus cultured in water recirculation system

This work aimed to evaluate the probiotic Lactobacillus spp. in the microbiota of Astyanax bimaculatus reared in a water recirculation system. The experiment was randomized, using 800 postlarvae distributed into eight polyethylene containers, separated into two treatments, in quadruplicate: supplementation with Lactobacillus spp. (Probiotic) and no supplementation (Control). After 90 days of culture, 13 fish per container were anaesthetized. Three of these underwent microbiological evaluation, and haematological analyses were carried out on five. Immunological assessment was performed on another five fish. Zootechnical parameters were evaluated for all animals. In the microbiological evaluation, the probiotic group presented higher counts of lactic acid bacteria, but lower counts of Vibrio spp., Pseudomonas spp., and Staphylococcus spp., when compared with control. After haematological analysis, the supplemented group presented low haematimetric indices of Mean Corpuscular Haemoglobin Concentration and Mean Corpuscular Haemoglobin (MCHC and MCH, respectively) and higher amounts of total leucocytes, thrombocytes and circulating monocytes when compared with control. The immunological profile did not differ between treatments. In the zootechnical performance, probiotic group presented higher productivity, survival and apparent food efficiency when compared with control. Therefore, when Lactobacillus spp. was supplemented in the diet of A. bimaculatus, immunocompetence and the zootechnical performance of animals increased.