Ectomycorrhizal diversity on the roots of Pitch pine (Pinus rigida Mill.) saplings as influenced by remediation and soil metal content

From 1913 to 1980, two zinc smelters in Palmerton, Pennsylvania, emitted large quantities of atmospheric pollutants nearly eliminating forests along a ridge above the town. In 2008, a remediation treatment was applied to the land above one of the smelters that included the planting of several locally adapted plant species. It also included mineral fertilization and mycorrhizal inoculation. One of the species, the Pitch pine (Pinus rigida, Mill.), is a native tree that is both tolerant of metalliferous soils and obligatorily ectomycorrhizal. This report summarizes the results of two observational studies conducted 5 years after the remediation treatment. The first study's objective was to compare ectomycorrhizal communities on treated Pitch pine saplings, with communities on naturally regenerating saplings in an adjacent non-remediated area. The second study's objective was to determine if the composition of the fungal communities on root tips of naturally regenerating Pitch pine saplings differed with distance from the smelters. Fungal community compositions were determined using internal transcribed spacer rRNA sequences. Comparisons of sequences from the remediated and non-remediated sites revealed that communities at the remediated sites had lower taxonomic diversity and were dominated by members of a genus in the remediation inoculant. The results of the smelter-proximity study indicated that although fungal diversity did not differ markedly with distance from the smelters, the relative abundances of some taxa were greater on saplings growing directly above the smelters, where the soils contained highest concentrations of zinc and cadmium.     

Review on the sublethal effects of pure and formulated glyphosate on bees: Emphasis on social bees

Bees are declining worldwide, and the use of pesticides has been linked to this problem. Studies show that even herbicides can negatively impact bees, causing death or compromising health. As a result, concern about the use of glyphosate (GLY) has increased, as it is the most sold pesticide. Studies have shown that exposure of bees to GLY can trigger sublethal effects. Considering the speed with which information is published, reviews become important for the integration of knowledge, aiding understanding of the topic. Therefore, the present study aimed to review the literature on the sublethal effects of GLY and the different commercial formulations on bees. After the literary review, it was observed that the exposition, acute and chronic, of larvae and adults of social and solitary bees, to GLY and its formulations, can trigger alterations in gene expression, enzyme functioning, oxidative metabolism, cell/tissue structure, intestinal microbiota diversity, learning, food consumption, flight and vertical displacement capacity, circadian cycle and body development of these insects. The most used species in the studies was Apis mellifera L. Studies are still necessary to understand the sublethal effects of GLY on bees, in the medium and long term, on colony homeostasis, especially about the information on the toxicity of some surfactants present in the different commercial formulations.     

Computer-aided comparison of protein electrophoretic patterns for grouping and identification of heterotrophic bacteria from mineral water

The microflora of a natural mineral water was studied immediately after bottling (T0) and after 7 d storage (T7) during 6 months, and isolates were clustered by SDS-PAGE of wholecell protein profiles. Isolates from each cluster were further characterized by API 20NE, fatty acid composition and quinone profiles. The numerical analysis of the electrophoregrams of all bacteria isolated from the mineral water formed 15 clusters and five unclustered strains. Except for five minor clusters, all clusters were composed of strains isolated over several months. The numerical analysis of the electrophoregrams of bacteria isolated immediately after bottling formed 15 clusters while after 7 d storage only four of these populations could be isolated, indicating that populations present in the mineral water were stable and that changes occurring after bottling probably resulted from a selection process. Only one unclustered strain was identified simultaneously by all the systems, as Sphingomonas paucimobilis. The monitoring of the aquifer and the bottling system, and the construction of a large database with bacteria of the autochthonous flora allows the detection of alterations in the aquifer by changes in the microflora.     

Extensive MHC class II DRB3 diversity in African and European cattle

Genetic deversity at the highly polymorphic BoLA-DRB3 locus was investigated by DNA sequence analyses of 18 African cattle from two breeds representing the two subspecies of cattle, Bos primigenius indicus and Bos primigenius taurus. Yhe polymorphism was compared with that found in a sample ofd 32 European cattle from four breeds, all classified as B. p. taurus. Particularly extensive genetic diversity was found among African cattle, in which as many as 18 alleles were recognized in this small random sample of animals from two breeds. The observed similarity in allele frequency distribution between the two African populations, N'Dama and Zebu cattle, is consistent with the recent recognition of gene flow between B. p. indicus and B. P taurus cattle in Africa. A total of 30 DRB3 alleles were documented and as many as 26 of these were classified as major allelic types showing at least five amino acid substitutions compared with other major types. The observation of extensive genetic diversity at MHC loci in cattle, as well as in other farm animals, provides a compelling argument against matin-type preferences as a primary cause in maintaining major histocompatibility complex diversity, since the reproduction of these animals has been controlled by humans for many generations.The nucleotide sequence data reported in this paper have been submitted to the EMBL nucleotide sequence database and have been given the accession numbers X87641-X87670     

Yeast communities as descriptors of habitat use by the Drosophila fasciola subgroup (repleta group) in Atlantic rain forests

Yeast communities associated with four species of the Drosophila fasciola subgroup (repleta group) in tropical rain forests were surveyed in an abandoned orchard, and rain forest sites of Rio de Janeiro and Ilha Grande, State of Rio de Janeiro, Brazil. Adult flies of Drosophila carolinae, Drosophila coroica, Drosophila fascioloides and Drosophila onca frequently carried Candida colliculosa, Geotrichum sp, Kloeckera apiculata and a Pichia membranaefaciens-like species. The most frequent yeasts in the crop of flies included Candida collicullosa, C. krusei, Pichia kluyveri and a P. membranaefaciens-like species. The physiological abilities and species composition of these yeast communities differed from those of other forest-inhabiting Drosophila. The narrow feeding niches of the fasciola subgroup suggested the use of only part of the substrates available to the flies as food in the forest environment, as noted previously for cactophilic Drosophila serido (mulleri subgroup of the repleta group) in a sand dune ecosystem. The cactophilic yeasts that were isolated have not been previously found in forests. The fasciola subgroup probably used epiphytic cactus substrates as breeding and feeding sites in the forest. The physiological profile of yeasts associated with the fasciola flies was broader than that of yeasts associated with the cactophilic Drosophila serido, suggesting that the fasciola subgroup represents an older lineage from which the South American repleta species evolved.     

Intercontinental spread of promiscuous mercury-resistance transposons in environmental bacteria

We demonstrate that horizontal spread of mer operons similar to worldwide spread of antibiotic-resistance genes in medically important bacteria occurred in bacteria found in ores, soils and waters. The spread was mediated by different transposons and plasmids. Some of the spreading transposons were damaged in different ways but this did not prevent their further spread. Certain transposons are mosaics composed of segments belonging to distinct sequence types. These mosaics arose as a result of homologous and site-specific recombination. Our data suggest that the mercury-resistance operons of Gram-negative environmental bacteria can be considered as a worldwide population composed of a relatively small number of distinct recombining clones shared, at least partially, by environmental and clinical bacteria.     

Action of heparin on protein fractions of isolated nuclei and on their DNA content

Summary Isolated nuclei of rat hepatocytes were incubated with 0.05% sodium heparinate for 2 to 10 min. Alterations in the nuclei were controlled biochemically, determining the amounts of DNA and histones, and by cytophotometric methods determining the amounts of total and nonhistone proteins and DNA. Under the selected experimental conditions 95% of histones are bound already after 5-min incubation with heparin; nonhistone proteins of cell nuclei remain unchanged. The blockade of histones is followed by DNA diffusion into the incubation medium. Experiments with nuclear staining with alcian blue proved the specificity of heparin binding with histones and showed that heparin-histone complex remains in the nuclei, and its histones lose their extractability with 0.25 n HCl.     

Tryptose phosphate broth confers to chick embryo cells resistance to the inhibitory effect of chloramphenicol on growth

Tryptose phosphate broth (10% V/V) prevents the inhibitory effect of chloramphenicol (80 ug/ml) on the growth of chick embryo fibroblasts. Cellular cytochrome $\text{c}$ oxidase activity is rapidly lost indicating that chloramphenicol inhibits the mitochondrial protein-synthesizing system in the presence of the broth. To compensate for the apparent decreased mitochondrial ATP production, pyruvate kinase and lactate dehydrogenase activities, 2-deoxyglucose uptake and lactic acid produced in treated cells are greater than those in the control cells during the first few generations. These fermentation values tend to revert to normal during later cell generations.     

Influence of the carboxyl terminus of luteinizing hormone-releasing hormone and bradykinin on hydrolysis by brain endo-oligopeptidases

A homogeneous preparation of endo-oligopeptidase A from rabbit brain cleaves luteinizing hormone-releasing hormone (less than Glu-His-Trp-Ser-Tyr-Gly-Leu-Arg-Pro-Gly-NH2) at the Tyr-Gly bond only after the removal of Gly-NH2 from the COOH-terminal position of the molecule. The influence of the carboxyl terminus on hydrolysis by brain endo-oligopeptidases was studied using bradykinin as a model substrate. The substitution of the carboxyl group of bradykinin by the amide reduces by 2.5-fold the rate of Phe-Ser bond hydrolysis by endo-oligopeptidase A but has no effect on the rate of hydrolysis of the Pro-Phe bond by endo-oligopeptidase B. On the other hand, the deletion of Phe-Arg from the COOH-terminal portion of bradykinin makes the peptide resistant to hydrolysis by endo-oligopeptidase A whereas it increases by 5-fold the rate of hydrolysis of the Pro-Gly bond by endo-oligopeptidase B.