Exopolysaccharide biosynthesis by a fast-producing strain of Aureobasidium pullulans

Summary The mutant strain Aureobasidium pullulans ICCF-68 was able to produce in batch fermentation on a glucose medium of 80 g/l, exopolysaccharide at high volumetric productivity and final concentration (1.05 g/l.h and 50.2 g/l, respectively). A specific pH pattern and very high oxygen requirement were shown.     

Epigenetic changes of CXCR4 and its ligand CXCL12 as prognostic factors for sporadic breast cancer

Chemokines and their receptors are involved in the development and cancer progression. The chemokine CXCL12 interacts with its receptor, CXCR4, to promote cellular adhesion, survival, proliferation and migration. The CXCR4 gene is upregulated in several types of cancers, including skin, lung, pancreas, brain and breast tumors. In pancreatic cancer and melanoma, CXCR4 expression is regulated by DNA methylation within its promoter region. In this study we examined the role of cytosine methylation in the regulation of CXCR4 expression in breast cancer cell lines and also correlated the methylation pattern with the clinicopathological aspects of sixty-nine primary breast tumors from a cohort of Brazilian women. RT-PCR showed that the PMC-42, MCF7 and MDA-MB-436 breast tumor cell lines expressed high levels of CXCR4. Conversely, the MDA-MB-435 cell line only expressed CXCR4 after treatment with 5-Aza-CdR, which suggests that CXCR4 expression is regulated by DNA methylation. To confirm this hypothesis, a 184 bp fragment of the CXCR4 gene promoter region was cloned after sodium bisulfite DNA treatment. Sequencing data showed that cell lines that expressed CXCR4 had only 15% of methylated CpG dinucleotides, while the cell line that not have CXCR4 expression, had a high density of methylation (91%). Loss of DNA methylation in the CXCR4 promoter was detected in 67% of the breast cancer analyzed. The absence of CXCR4 methylation was associated with the tumor stage, size, histological grade, lymph node status, ESR1 methylation and CXCL12 methylation, metastasis and patient death. Kaplan-Meier curves demonstrated that patients with an unmethylated CXCR4 promoter had a poorer overall survival and disease-free survival. Furthermore, patients with both CXCL12 methylation and unmethylated CXCR4 had a shorter overall survival and disease-free survival. These findings suggest that the DNA methylation status of both CXCR4 and CXCL12 genes could be used as a biomarker for prognosis in breast cancer.     

Grazing hay meadows: History,distribution, and ecological context

Aims

Once widely used across Europe, grazing of hay meadows is now a rare agricultural practice that is mainly applied in rural regions with maintained traditional agriculture. In this review, we examine the knowledge on grazing hay meadows in the Carpathian Mountains, including its historical distribution, implementation and timing, potential impacts on grassland productivity and biodiversity, and implications for grassland conservation and restoration.

Location

The Carpathian Mountains (43.8–50.1°N, 16.9–27.1°E).

Methods

We conducted a literature review including biological, ecological, agricultural, ethnological, and historical sources.

Results and Conclusions

In each of the seven farming systems that existed in parallel in the Carpathian Mountains before agricultural intensification, grazing of hay meadows was applied regularly. Spring, autumn, and occasionally summer grazing, along with corralling and manuring of hay meadows, were integral parts of these systems, adapted to the seasonal movement of dairy farms across various agroecosystems. The data reviewed provide insight into the role of animals in hay meadow management, as well as how the breakdown of these historical farming systems is impacting local biodiversity, the economy, and the community. According to the literature sources, grazing hay meadows has numerous positive impacts on grassland biodiversity, including suppressing fast-growing competitors, reducing the accumulation of litter, increasing the availability of germination gaps, dispersing seeds through zoochory, supporting ground-nesting birds through later mowing, and promoting the regeneration of plants from seeds. From this perspective, the combination of mowing and grazing can be considered a promising tool in current grassland conservation and restoration efforts.     

Construction and Characterization of aPlasmodium vivaxGenomic Library in Yeast Artificial Chromosomes

Here we describe the construction of a representative YAC library for the human malarial parasitePlasmodium vivax.AsP. vivaxcannot be maintained continuously under laboratory conditions, theP. vivaxDNA necessary for the library construction was isolated from a single human patient presenting himself with vivax malaria to a local hospital in the Brazilian Amazon. Thus, this YAC library is the first of its kind to be generated from patient-derived material. The YAC library consists of 560 clones with an average insert size of 180 kb. Of 9 publishedP. vivaxgenes, 8 were found to be present in the library. In addition, 12P. vivaxtelomeric YAC clones were identified.     

Grafting of softwood kraft pulps fibers with fatty acids under cold plasma conditions

Cold plasma treatment is used to modify the cellulosic fibers for a variety of applications. The grafting of softwood unbleached (UBP) and bleached (BP) kraft pulp fibers has been performed under the action of cold plasma discharges, using different kinds of fatty acids. The grafted samples are characterized by FTIR spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), termogravimetry (TG-DTG) and X-ray diffraction (XRD). All these methods confirm the morphological and structural changes after plasma treatment which determines the modification in cellulosic fiber properties. The active centers created within the cellulose chains by plasma treatment were used to initiate grafting reactions with fatty acids. Such modification is useful to enhance the fibers properties such as softness and to change hydrophilic/hydrophobic balance.     

Distinct patterns of somatic alterations in a lymphoblastoid and a tumor genome derived from the same individual

Although patterns of somatic alterations have been reported for tumor genomes, little is known on how they compare with alterations present in non-tumor genomes. A comparison of the two would be crucial to better characterize the genetic alterations driving tumorigenesis. We sequenced the genomes of a lymphoblastoid (HCC1954BL) and a breast tumor (HCC1954) cell line derived from the same patient and compared the somatic alterations present in both. The lymphoblastoid genome presents a comparable number and similar spectrum of nucleotide substitutions to that found in the tumor genome. However, a significant difference in the ratio of non-synonymous to synonymous substitutions was observed between both genomes (P = 0.031). Protein–protein interaction analysis revealed that mutations in the tumor genome preferentially affect hub-genes (P = 0.0017) and are co-selected to present synergistic functions (P < 0.0001). KEGG analysis showed that in the tumor genome most mutated genes were organized into signaling pathways related to tumorigenesis. No such organization or synergy was observed in the lymphoblastoid genome. Our results indicate that endogenous mutagens and replication errors can generate the overall number of mutations required to drive tumorigenesis and that it is the combination rather than the frequency of mutations that is crucial to complete tumorigenic transformation.     

Chemopreventive effects of the dietary histone deacetylase inhibitor tributyrin alone or in combination with vitamin A during the promotion phase of rat hepatocarcinogenesis

The chemopreventive effects of tributyrin (TB) and vitamin A (VA), alone or in combination, were investigated during the promotion phase of rat hepatocarcinogenesis. Compared to diethylnitrosamine control rats, TB and TB+VA-treated rats, but not VA-treated rats, presented a lower incidence and mean number of hepatocyte nodules and a smaller size of persistent preneoplastic lesions (pPNLs). In addition, TB and TB+VA-treated rats exhibited a higher apoptotic body index in pPNL and remodeling PNL, whereas VA-treated rats presented only a higher apoptotic body index in remodeling PNL. None of the treatments inhibited cell proliferation in PNL. TB and TB+VA-treated rats, but not VA-treated rats, exhibited higher levels of H3K9 acetylation and p21 protein expression. TB and VA-treated rats exhibited increased hepatic concentrations of butyric acid and retinoids, respectively. Compared to normal rats, diethylnitrosamine control animals exhibited lower retinyl palmitate hepatic concentrations. All groups had similar expression levels and exhibited similar unmethylated CRBP-I promoter region in microdissected pPNL, indicating that epigenetic silencing of this gene was not involved in alteration of retinol metabolism in early hepatocarcinogenesis. Data support the effectiveness of TB as a dietary histone deacetylase inhibitor during the promotion phase of hepatocarcinogenesis, which should be considered for chemoprevention combination strategies.     

Coordinated, network-based research as a strategic component of science in Brazil

Scientific research plays a fundamental role in the health and development of any society, since all technological advances depend ultimately on scientific discovery and the generation of wealth is intricately dependent on technological advance. Due to their importance, science and technology generally occupy important places in the hierarchical structure of developed societies, and they receive considerable public and private investment. Publicly funded science is almost entirely devoted to discovery, and it is administered and structured in a very similar way throughout the world. Particularly in the biological sciences, this structure, which is very much centered on the individual scientist and his own hypothesis-based investigations, may not be the best suited for either discovery in the context of complex biological systems, or for the efficient advancement of fundamental knowledge into practical utility. The adoption of other organizational paradigms, which permit a more coordinated and interactive research structure, may provide important opportunities to accelerate the scientific process and further enhance its relevance and contribution to society. The key alternative is a structure that incorporates larger organizational units to tackle larger and more complex problems. One example of such a unit is the research network. Brazil has utilized such networks to great effect in genome sequencing projects, demonstrating their relevance to the Brazilian research community and opening the possibility of their wider utility in the future.     

Improved exopolysaccharide production in fed-batch fermentation of Aureobasidium pullulans, with increased impeller speed

Summary Aureobasidium pullulans — when grown in fed-batch fermentation on 190 g glucose/l produced 68 g exopolysaccharide/l with a productivity of 0.42 g/l-h. When the impeller speed was increased from 280 rpm to 340 rpm, the exopolysaccharide increased to 101 g/l, the productivity was 0.90 g/l-h and the conversion ratio was 63 % (w/w).