Automated assay for screening the enzymatic release of reducing sugars from micronized biomass

Background  

To reduce the production cost of bioethanol obtained from fermentation of the sugars provided by degradation of lignocellulosic biomass (i.e., second generation bioethanol), it is necessary to screen for new enzymes endowed with more efficient biomass degrading properties. This demands the set-up of high-throughput screening methods. Several methods have been devised all using microplates in the industrial SBS format. Although this size reduction and standardization has greatly improved the screening process, the published methods comprise one or more manual steps that seriously decrease throughput. Therefore, we worked to devise a screening method devoid of any manual steps.     

First report of Lutzomyia araracuarensis (Morales & Minter) (Diptera: Psychodidae) in Brazil

A male of Lutzomyia araracuarensis (Morales & Minter) and possibly six females of this same species were found in the northeastern area of Manacapuru county, Amazonas State. Samples were collected using light traps CDC, from April 2003 to June 2004.     

Epipona media cooper (Hymenoptera: Vespidae), a social wasp new to the Brazilian Atlantic Forest

An occupied nest of Epipona media Cooper was discovered and collected in a cabruca (cocoa plantation with native tree cover). This is the first record of E. media from Bahia State. We described the nest structure and compared the adults with the closely related species Epipona tatua Cuvier.     

Metallothioneins and trace elements in digestive gland,gills, kidney and gonads of Octopus vulgaris

Metallothionein-like proteins (MT) and V, Cr, Co, Ni, Zn, Cu, As and Cd were determined in digestive gland, gills, kidney and gonads of Octopus vulgaris, from the Portuguese coast. To our knowledge these are the first data on MT in octopus. High concentrations (µg g^− 1, dry mass) of Zn (48050) and Cd (555) were found in digestive gland, and MT reached levels one order of magnitude above the ones registered in wild bivalves. Significantly higher levels of MT in digestive gland and gills of specimens from A and B were in line with elevated Cd concentrations. Principal component analyses (PCA) point to MT-Cd and MT-Cr associations in digestive gland and gills. Despite the high levels of Zn in specimens from B, association with Zn was not obtained. Due to the affinity of MT to various elements, it should not be excluded the possibility of Cd replacing Zn in Zn-MT. Kidney presented higher levels of Cd, Co, Ni and As than gills and gonads, and in the case of As surpassing the levels in digestive gland, but PCA showed no relation with MT. Likewise the MT levels in gonads had no correspondence to the metal concentration variation.     

Impaired Innate Immunity in Tlr4 ?/? Mice but Preserved CD8+ T Cell Responses against Trypanosoma cruzi in Tlr4-, Tlr2-, Tlr9- or Myd88-Deficient Mice

The murine model of T. cruzi infection has provided compelling evidence that development of host resistance against intracellular protozoans critically depends on the activation of members of the Toll-like receptor (TLR) family via the MyD88 adaptor molecule. However, the possibility that TLR/MyD88 signaling pathways also control the induction of immunoprotective CD8⁺ T cell-mediated effector functions has not been investigated to date. We addressed this question by measuring the frequencies of IFN-γ secreting CD8⁺ T cells specific for H-2K^b-restricted immunodominant peptides as well as the in vivo Ag-specific cytotoxic response in infected animals that are deficient either in TLR2, TLR4, TLR9 or MyD88 signaling pathways. Strikingly, we found that T. cruzi-infected Tlr2^−/−, Tlr4^−/−, Tlr9^{−/ −} or Myd88^−/− mice generated both specific cytotoxic responses and IFN-γ secreting CD8⁺ T cells at levels comparable to WT mice, although the frequency of IFN-γ⁺CD4⁺ cells was diminished in infected Myd88^−/− mice. We also analyzed the efficiency of TLR4-driven immune responses against T. cruzi using TLR4-deficient mice on the C57BL genetic background (B6 and B10). Our studies demonstrated that TLR4 signaling is required for optimal production of IFN-γ, TNF-α and nitric oxide (NO) in the spleen of infected animals and, as a consequence, Tlr4^−/− mice display higher parasitemia levels. Collectively, our results indicate that TLR4, as well as previously shown for TLR2, TLR9 and MyD88, contributes to the innate immune response and, consequently, resistance in the acute phase of infection, although each of these pathways is not individually essential for the generation of class I-restricted responses against T. cruzi.     

Analysis of metal-induced DNA lesions and DNA-repair replication in mammalian cells

The potency of several metal compounds in causing lesions in DNA either directly or by exposure of intact cultured cells has been examined using the neutral conditions of nucleoid gradient sedimentation. HgCl2 was clearly the most potent inducer of single-strand breakage when added to isolated nucleoids or when nucleoids were prepared from cells treated with this compound. CaCrO4 , however, caused DNA-strand breaks in nucleoids isolated from cells treated with this agent but did not induce DNA strand breaks when added directly to nucleoids. Although less potent than HgCl2, NiCl2 also caused significant single strand breakage in isolated nucleoids or in nucleoids prepared from cells treated with this metal. Since strand breakage of DNA in intact cells may occur secondary to activation of DNA-dependent nucleases during repair replication, CsCl gradient density sedimentation was utilized to examine whether repair processes were induced by exposure of cells to NiCl2, HgCl2 and CaCrO4 . CaCrO4 and NiCl2 induced substantial DNA-repair activity at concentrations and exposure times where DNA lesions could not be detected whereas HgCl2 induced a 10-fold lower level of DNA-repair activity compared to CaCrO4 at optimal concentrations which again were below the concentrations of this metal that produced measurable DNA lesions. Both the induction of DNA-repair activity and DNA-strand breakage by these metals was concentration- and time-dependent. These results demonstrate some unique aspects of the interaction of HgCl2, NiCl2 and CaCrO4 with the DNA of intact cells and point to the possible important correlation of induction of DNA repair to carcinogenesis since nickel and chromate have clearly been implicated as carcinogens and induce considerable repair whereas HgCl2 is not considered a carcinogen and induces the least DNA repair despite its potency in producing DNA lesions.     

Female sexual receptivity after partial copulations in the wolf spider (Schizocosa malitiosa)

Mated females of the wolf spider Schizocosa malitiosa are frequently refractory to further copulations. Copulation consists of two successive behavioural patterns: pattern I (PI) and pattern II (PII). During PI males make multiple consecutive insertions with each palp, and in PII males alternate the use of palps after each insertion until dismounting. As both patterns are inseminatory, another function – such as generating female reluctance – is suggested for this complex behaviour. Here we test experimentally whether female spiders mated only with PI, or only with PII, are reluctant to re-mate. Each copulating male was interrupted immediately after the end of PI (phase A), and the same male was instantly exposed to a second virgin female. After re-mounting, the male initially performed a brief recapitulation of PI followed by PII (both together considered as phase B). For testing female sexual reluctance, females were exposed to a second male 3 days after the partial mating, but whenever the mounting occurred it was interrupted. Females were raised and progeny was counted. Phase-A-mated females were more reluctant to re-mating than phase-B-mated females, but their respective progeny was similar. We suggest that female reluctance is caused by sperm-associated substances transferred during PI.     

Reproductive Behaviour of the Annona Fruit Borer, Cerconota anonella

The Annona fruit borer, Cerconota anonella, causes significant damage to the fruits of Annona squamosa (custard apple) and A. muricata (soursop). The methods currently available for the control of this pest are costly and new techniques, possibly involving the use of pheromones for trapping or disrupting the mating cycle of the insect are required. In order to provide the basic information required for the development of new control systems, the reproductive behaviour of the moth was observed under laboratory conditions. The calling and courtship behaviours exhibited by virgin females and males of C. anonella commenced at the eighth hour of the scotophase and continued for a 3.5‐h period. Males were attracted by conspecific females as young as 1 d old, and showed a courtship behaviour composed of three steps: antennation, wing fanning and short flights. Mating mainly occurred when both males and females were between 2 and 5 d old, but maximum activity was observed on the third day after emergence. Receptive females elevated their wings, showing their abdomens where the abdominal hairpencils were already exposed. As part of the courtship repertoire and immediately prior to copula, males performed pronounced sideways movements of their abdomens, a behaviour that appears to be exclusive to C. anonella.     

Distribution of saltmarsh plant communities associated with environmental factors along a latitudinal gradient on the south‐west Atlantic coast

Aim To produce an inventory of south‐west Atlantic saltmarshes (from latitude 31°48′ S to 43°20′ S) using remotely sensed images and field sampling; to quantify their total area; to describe the biogeographical variation of the main habitats characterized by dominant vascular plants, in relation to major environmental factors; to test the hypothesis of predominance of the reversal pattern in plant distribution (sedges and grasses dominate the lower, regularly inundated zones, while the upper zones are occupied by more halophytic species) previously described; and to compare these south‐west Atlantic saltmarshes with others world‐wide. Location South‐western Atlantic saltmarshes Methods Field samples of dominant emergent plant species positioned by the global positioning system (GPS) were obtained from most coastal saltmarshes (14) between southern Brazil and northern Patagonia, Argentina. Landsat satellite images were obtained and coastal saltmarsh habitats were quantified by supervised classification, utilizing points gathered in the field. Results Three main plant species dominated the low and middle intertidal saltmarsh, Spartina alterniflora Loesel., Spartina densiflora Brong. and Sarcocornia perennis (P. Mill.) A.J. Scott. The total area of the studied coastal saltmarshes was 2133 km², comprising 380 km² of Sp. alterniflora marsh, 366 km² of Sp. densiflora marsh, 746 km² of Sar. perennis marsh and 641 km² of brackish marsh (dominated by Juncus acutus L., Juncus kraussii Hochst., Scirpus maritimus L., Scirpus americanus Pers. and Phragmites australis (Cav.) Trin.). Cluster analysis showed three habitat types: saltmarshes dominated by (1) Sp. densiflora and brackish species,(2) Sp. alterniflora and Sar. perennis and (3) Sp.densiflora only. The analysis of abiotic variables showed significant differences between groups of habitats and coordinated gradients of the abiotic variables. The south‐west Atlantic coast showed decreasing mean annual rainfall (1200 to 196 mm) and increasing mean tidal amplitude (< 0.5 to > 2.5 m) from latitude 31° to 43°. Main conclusions South‐west Atlantic saltmarshes are globally important by virtue of their total extent. Remote sensing showed that the reversal pattern in plant distribution is not widespread. Indeed, south‐west Atlantic saltmarshes are better characterized by the presence of the halophytic genera Spartina and Sarcocornia. Our results support the interpretation that south‐west Atlantic saltmarshes constitute a class of temperate type (sensu Adam, 1990 ) with transitional characteristics between Australasian–South African saltmarshes and west Atlantic saltmarshes.