A moderately halophilic, motile, Gram-negative, rod-shaped bacterium, strain LC6^T, was isolated from a water sample of lake Laguna Colorada in the Bolivian Andes. The major cellular fatty acids were C_18 : 1 ω7c, iso-C_16 : 1 ω7c 2-OH, C_16 : 0 and C_12 : 0 3-OH. The respiratory ubiquinones found in strain LC6^T were Q-9 (97 %) and Q-8 (3 %). Strain LC6^T was aerobic, heterotrophic, and able to utilize various carbohydrates and other substrates as carbon source. The G+C content of the genomic DNA of strain LC6^T was 52.5 mol%. The organism was able to grow at pH 6.0–11.0 (optimum, pH 7.0–8.0), at 4–45 °C (optimum, 30–35 °C) and in the presence of 0.5–20 % (w/v) NaCl (optimum, 1–3 %, w/v). Based on 16S rRNA gene sequence analysis, strain LC6^T was most closely related to Halomonas hydrothermalis DSM 15725^T and Halomonas venusta DSM 4743^T (98.8 % similarity), followed by Halomonas aquamarina DSM 30161^T, Halomonas axialensis DSM 15723^T and Halomonas meridiana DSM 5425^T (98.4 %). However, levels of DNA–DNA relatedness between strain LC6^T and the above type strains were low (<31 %). Strain LC6^T resembled recognized Halomonas species with respect to various physiological, biochemical and nutritional characteristics. Combined phenotypic data and DNA–DNA hybridization data supported the conclusion that strain LC6^T represents a novel species of the genus Halomonas, for which the name Halomonas andesensis is proposed. The type strain is LC6^T (=CCUG 54844^T=LMG 24243^T=DSM 19434^T).

Scaffolds made from poly(3-hydroxybutyrate) were prepared by thermally induced phase separation from solutions in dioxane at temperatures above (23°C) or below the freezing point of the solvent. At 23°C, gelation occured with nano-fibrous network formation. The scaffolds prepared at —12°C and —25°C exhibited a highly porous morphology, with pores in the range of 3—25 μm, caused by freezing of dioxane. The macroporous scaffolds, prepared at —12°C, were treated with lipase to generate functional groups to which gelatin and glucosamine, respectively, were chemically coupled. The modified scaffolds had lower molecular weight, higher water content, lower melting temperature, and enthalpy. Cultivation of human embryonic fibroblasts on the macroporous scaffolds confirmed that the cells proliferated and adhered to the materials.

Background: Halomonas boliviensis is a halophilic bacterium that is included in the γ-Proteobacteria sub-group, and is able to assimilate different types of carbohydrates. H. boliviensis is also able to produce poly(3-hydroxybutyrate) (PHB) in high yields using glucose as the carbon precursor. Accumulation of PHB by microorganisms is induced by excess of intracellular NADH. The genome sequences and organization in microorganisms should be the result of evolution and adaptation influenced by mutation, gene duplication, horizontal gen transfer (HGT) and recombination. Furthermore, the nearly neutral theory of evolution sustains that genetic modification of DNA could be neutral or selected, albeit most mutations should be at the border between neutrality and selection, i.e. slightly deleterious base substitutions in DNA are followed by a slightly advantageous substitutions. Results: This article reports the genome sequence of H. boliviensis. The chromosome size of H. boliviensis was 4 119 979 bp, and contained 3 863 genes. A total of 160 genes of H. boliviensis were related to carbohydrate transport and metabolism, and were organized as: 70 genes for metabolism of carbohydrates; 47 genes for ABC transport systems and 43 genes for TRAP-type C4-dicarboxylate transport systems. Protein sequences of H. boliviensis related to carbohydrate transport and metabolism were selected from clusters of orthologous proteins (COGs). Similar proteins derived from the genome sequences of other 41 archaea and 59 bacteria were used as reference. We found that most of the 160 genes in H. boliviensis, c.a. 44%, were obtained from other bacteria by horizontal gene transfer, while 13% of the genes were acquired from haloarchaea and thermophilic archaea, only 34% of the genes evolved among Proteobacteria and the remaining genes encoded proteins that did not cluster with any of the proteins obtained from the reference strains. Furthermore, the diversity of the enzymes derived from these genes led to polymorphism in glycolysis and gluconeogenesis. We found further that an optimum ratio of glucose and sucrose in the culture medium of H. boliviensis favored cell growth and PHB production. Conclusions: Results obtained in this article depict that most genetic modifications and enzyme polymorphism in the genome of H. boliviensis were mainly influenced by HGT rather than nearly neutral mutations. Molecular adaptation and evolution experienced by H. boliviensis were also a response to environmental conditions such as the type and amount of carbohydrates in its ecological niche. Consequently, the genome evolution of H. boliviensis showed to be strongly influenced by the type of microorganisms, genetic interaction among microbial species and its environment. Such trend should also be experienced by other prokaryotes. A system for PHB production by H. boliviensis that takes into account the evolutionary adaptation of this bacterium to the assimilation of combinations of carbohydrates suggests the feasibility of a bioprocess economically viable and environmentally friendly.

Salar de Uyuni is a vast, high-altitude salt flat in Bolivia with extreme physico-geochemical properties approaching multiple limits of life. Evidence for diverse halophilic bacteria and archaea was found in its surface and near-surface salt crust using 16S amplicon analysis, providing a snapshot of prokaryotic life.

Two extremely halophilic archaea, namely, Natrinema versiforme BOL5-4 and Natrinema pallidum BOL6-1, were isolated from a Bolivian salt mine and their genomes sequenced using single-molecule real-time sequencing. The GC-rich genomes of BOL5-4 and BOL6-1 were 4.6 and 3.8 Mbp, respectively, with large chromosomes and multiple megaplasmids. Genome annotation was incorporated into HaloWeb and methylation patterns incorporated into REBASE.