Genome Analysis of the Anaerobic Thermohalophilic Bacterium Halothermothrix orenii

Halothermothirx orenii is a strictly anaerobic thermohalophilic bacterium isolated from sediment of a Tunisian salt lake. It belongs to the order Halanaerobiales in the phylum Firmicutes. The complete sequence revealed that the genome consists of one circular chromosome of 2578146 bps encoding 2451 predicted genes. This is the first genome sequence of an organism belonging to the Haloanaerobiales. Features of both Gram positive and Gram negative bacteria were identified with the presence of both a sporulating mechanism typical of Firmicutes and a characteristic Gram negative lipopolysaccharide being the most prominent. Protein sequence analyses and metabolic reconstruction reveal a unique combination of strategies for thermophilic and halophilic adaptation. H. orenii can serve as a model organism for the study of the evolution of the Gram negative phenotype as well as the adaptation under thermohalophilic conditions and the development of biotechnological applications under conditions that require high temperatures and high salt concentrations.     

Lamin A as a Determinant of Mechanical Properties of the Cell Nucleus in Health and Disease

Biochemistry (Moscow) - One of the main factors associated with worse prognosis in oncology is metastasis, which is based on the ability of tumor cells to migrate from the primary source and to...     

Nasal Priming with Lactobacillus rhamnosus CRL1505 Stimulates Mononuclear Phagocytes of Immunocompromised Malnourished Mice: Improvement of Respiratory Immune Response

The effect of Lactobacillus rhamnosus CRL1505 (Lr) on macrophages (Ma) and dendritic cells (DC) in the orchestration of anti-pneumococcal immunity was stud     

Synthesis and induction of apoptosis signaling pathway of ent-kaurane derivatives

Thirty one ent-kaurane derivatives were prepared from kaurenoic acid (1), grandiflorenic acid (16), 15α-acetoxy-kaurenoic acid (26) and 16α-hydroxy-kaurenoic acid (31). They were tested for their ability to inhibit cell viability in the mouse leukemic macrophagic RAW 264.7 cell line. The most effective compounds were 12, 20, 21, and 23. These were selected for further evaluation in other human cancer cell lines such as Hela, HepG2, and HT-29. Similar effects were obtained although RAW 264.7 cells were more sensitive. In addition, these compounds were significantly less cytotoxic in non-transformed cells. The apoptotic potential of the most active compounds was investigated and they were able to induce apoptosis with compound 12 being the best inducer. The caspase-3, -8 and -9 activities were measured. The results obtained showed that compounds 12, 21, and 23 induce apoptosis via the activation of caspase-8, whereas compound 20 induces apoptosis via caspase-9. Immunoblot analysis of the expression of p53, Bax, Bcl-2, Bcl-xl, and IAPs in RAW 264.7 cells was also carried out. When cells were exposed to 5 μM of the different compounds, expression levels of p53 and Bax increased whereas levels of antiapoptotic proteins such as Bc1-2, Bc1-x1, and IAPs decreased. In conclusion, kaurane derivatives (12, 20, 21, and 23) induce apoptosis via both the mitochondrial and membrane death receptor pathways, involving the Bcl-2 family proteins. Taken together these results provide a role of kaurane derivatives as apoptotic inducers in tumor cells.     

Stability and transformations of bis-PNA/DNA triplex structural isomers

Structurally isomeric complexes formed between homopyrimidine bis-PNAs (T(2)JT(2)JT(4)-linker-T(4)CT(2)CT(2)) and single- and double-stranded DNA targets were investigated. These complexes are triplexes designated S1, S2 and S3 in order of increased mobility by polyacrylamide gel electrophoresis. It is shown that the S3 isomer is formed only on double-stranded DNA and possesses highest stability. Isomers S2 and S1 are formed upon binding of bis-PNA to double-stranded as well as to single-stranded DNA. It was found that the stability of the isomer S1 increases dramatically in the presence of excess single-stranded oligonucleotide complementary to the bis-PNA. The structure of the stabilized S1 isomer is proposed to consist of two bis-PNA/DNA triplexes. The relationship between the yield of the isomer S1 formed on single-stranded DNA and the bis-PNA concentration was investigated and a kinetic model of the formation of S1 is presented.     

Effect of applied and internal hormones on vitrification and apical necrosis of different plants cultured in vitro

Development of vitrification and apical necrosis was followed in Camellia sinensis, Gerbera jamesonii, Malus domestica and hybrid Populus tremula x P. alba shoots cultured in vitro on Murashige & Skoog (MS) medium with different concentrations of growth regulators. High humidity in the culture vessels and excess of BA in the medium were found to be the major factors influencing vitrification. Lack of exogenous cytokinin in the medium during successive subcultures induced apical necrosis in poor-rooting species (Malus domestica, Camellia sinensis). The level of internal phytohormones (ABA, IAA, IPA, 2iP, Z, ZR) was determined in the apple shoots by means of ELISA. The content of internal cytokinins in the vitrified apple shoots was several times greater than in normal ones, which supports the hypothesis that excess of cytokinins, inducing rapid divisions of cells in meristems in the atmosphere with high humidity, is responsible for vitrification. Apical necrosis of the plantlets that appeared after cultivation on cytokinin-free medium is the result of deficiency in endogenous hormones in apple shoots and this being confirmed by analysis of endogenous hormones in apple shoots.Abbreviations BA benzyladenine - BHT butylated hydroxy-toluene - ABA abscisic acid - IAA indole-3-acetic acid - ELISA enzyme-linked immunosorbent assay - IPA isopentenyladenosine - 2iP isopentenyladenine - NAA naphthyl-3-acetic acid - TBS trishydroxymethylaminomethane buffered saline - TLC thin layer chromatography - Z zeatin - ZR zeatin riboside     

Tannin Degradation by a Novel Tannase Enzyme Present in Some Lactobacillus plantarum Strains

Lactobacillus plantarum is frequently isolated from the fermentation of plant material where tannins are abundant. L. plantarum strains possess tannase activity to degrade plant tannins. An L. plantarum tannase (TanB_Lp, formerly called TanLp1) was previously identified and biochemically characterized. In this study, we report the identification and characterization of a novel tannase (TanA_Lp). While all 29 L. plantarum strains analyzed in the study possess the tanB_Lp gene, the gene tanA_Lp was present in only four strains. Upon methyl gallate exposure, the expression of tanB_Lp was induced, whereas tanA_Lp expression was not affected. TanA_Lp showed only 27% sequence identity to TanB_Lp, but the residues involved in tannase activity are conserved. Optimum activity for TanA_Lp was observed at 30°C and pH 6 in the presence of Ca²⁺ ions. TanA_Lp was able to hydrolyze gallate and protocatechuate esters with a short aliphatic alcohol substituent. Moreover, TanA_Lp was able to fully hydrolyze complex gallotannins, such as tannic acid. The presence of the extracellular TanA_Lp tannase in some L. plantarum strains provides them an advantage for the initial degradation of complex tannins present in plant environments.     

Genome sequence of the acid-tolerant Burkholderia sp. strain WSM2230 from Karijini National Park,Australia

Burkholderia sp. strain WSM2230 is an aerobic, motile, Gram-negative, non-spore-forming acid-tolerant rod isolated from acidic soil collected in 2001 from Karijini National Park, Western Australia, using Kennedia coccinea (Coral Vine) as a host. WSM2230 was initially effective in nitrogen-fixation with K. coccinea, but subsequently lost symbiotic competence. Here we describe the features of Burkholderia sp. strain WSM2230, together with genome sequence information and its annotation. The 6,309,801 bp high-quality-draft genome is arranged into 33 scaffolds of 33 contigs containing 5,590 protein-coding genes and 63 RNA-only encoding genes. The genome sequence of WSM2230 failed to identify nodulation genes and provides an explanation for the observed failure of the laboratory grown strain to nodulate. The genome of this strain is one of 100 sequenced as part of the DOE Joint Genome Institute 2010 Genomic Encyclopedia for Bacteria and Archaea-Root Nodule Bacteria (GEBA-RNB) project.