Phytoplankton consortia as a blueprint for mutually beneficial eukaryote-bacteria ecosystems based on the biocoenosis of Botryococcus consortia

Bacteria occupy all major ecosystems and maintain an intensive relationship to the eukaryotes, developing together into complex biomes (i.e., phycosphere and rhizosphere). Interactions between eukaryotes and bacteria range from cooperative to competitive, with the associated microorganisms affecting their host`s development, growth and health. Since the advent of non-culture dependent analytical techniques such as metagenome sequencing, consortia have been described at the phylogenetic level but rarely functionally. Multifaceted analysis of the microbial consortium of the ancient phytoplankton Botryococcus as an attractive model food web revealed that its all abundant bacterial members belong to a niche of biotin auxotrophs, essentially depending on the microalga. In addition, hydrocarbonoclastic bacteria without vitamin auxotrophies seem adversely to affect the algal cell morphology. Synthetic rearrangement of a minimal community consisting of an alga, a mutualistic and a parasitic bacteria underpins the model of a eukaryote that maintains its own mutualistic microbial community to control its surrounding biosphere. This model of coexistence, potentially useful for defense against invaders by a eukaryotic host could represent ecologically relevant interactions that cross species boundaries. Metabolic and system reconstruction is an opportunity to unravel the relationships within the consortia and provide a blueprint for the construction of mutually beneficial synthetic ecosystems.

Bioinformatics in Germany: toward a national-level infrastructure

The German Network for Bioinformatics Infrastructure (de.NBI) is a national initiative funded by the German Federal Ministry of Education and Research (BMBF). The mission of de.NBI is (i) to provide high-quality bioinformatics services to users in basic and applied life sciences research from academia, industry and biomedicine; (ii) to offer bioinformatics training to users in Germany and Europe through a wide range of workshops and courses; and (iii) to foster the cooperation of the German bioinformatics community with international network structures such as the European life-sciences Infrastructure for biological Information (ELIXIR). The network was launched by the BMBF in March 2015 and now includes 40 service projects operated by 30 project partners that are organized in eight service centers. The de.NBI staff develops further and maintains almost 100 bioinformatics services for the human, plant and microbial research fields and provides comprehensive training courses to support users with different expertise levels in bioinformatics. In the future, de.NBI will expand its activities to the European level, as the de.NBI consortium was assigned by the BMBF to establish and run the German node of ELIXIR.

Fabry disease: Detection of Alu-mediated exon duplication by NGS

Monogenetic diseases can be analyzed routinely by targeted DNA sequencing. If causative variants are not found, complementary methods like RNA sequencing or analysis of copy number variations by multiplex ligation-dependent probe amplification have to be considered. In the latter, especially exonic duplications or deletions can be detected, but the precise sites of mutations remain unclear. As we demonstrate in this casuistic report of Fabry disease, next-generation sequencing (NGS) of a long-range PCR product can identify the recombination site directly and illuminate the underlying molecular mechanism.

Biosynthetic reconstitution of deoxysugar phosphoramidate metalloprotease inhibitors using an N-P-bond-forming kinase

Phosphoramidon is a potent metalloprotease inhibitor and a widespread tool in cell biology research. It contains a dipeptide backbone that is uniquely linked to a 6-deoxysugar via a phosphoramidate bridge. Herein, we report the identification of a gene cluster for the formation of phosphoramidon and its detailed characterization. In vitro reconstitution of the biosynthesis established TalE as a phosphoramidate-forming kinase and TalC as the glycosyltransferase which installs the l-rhamnose moiety by phosphoester linkage.

Revisiting Corynebacterium glyciniphilum (ex Kubota et al., 1972) sp. nov., nom. rev., isolated from putrefied banana

A strain of a species of the genus Corynebacterium, designated AJ 3170(T), was isolated during the 1980s from putrefied bananas. Since then, there have been no further updates on the description of the strain or its phylogenetic classification. However, phylogenetic analysis of this strain using 16S rRNA and in silico DNA-DNA hybridization has confirmed that it is a member of the genus Corynebacterium and that strain AJ 3170(T) clusters with Corynebacterium variabile DSM 44702(T), Corynebacterium terpenotabidum Y-11(T) and Corynebacterium nuruki S6-4(T) in one subgroup. Furthermore, a combination of enzymatic, chemical, and morphological characterization techniques was applied in order to describe strain AJ 3170(T) further. The strain grew well at pH values of 6-10 and at temperatures of 30-41 °C. The major fatty acids were C16 : 0 (42.15 %), C18 : 1ω9c (41.6 %) and C18 : 0 10-methyl (TBSA) (8.56 %). The whole-cell sugars were determined to comprise galactose, arabinose and ribose. On the basis of this phenotypic, chemotaxonomic and phylogenetic characterization, it is proposed that strain AJ 3170(T) represents a novel species, for which the name Corynebacterium glyciniphilum sp. nov. is proposed; the type strain is AJ 3170(T) ( = DSM 45795(T) = ATCC 21341(T)).

Complete genome sequence of Corynebacterium vitaeruminis DSM 20294T, isolated from the cow rumen as a vitamin B producer

We report the complete genome sequence of Corynebacterium vitaeruminis DSM 20294(T) which was identified as the producer of B vitamins in the rumen of cows. The genome of C. vitaeruminis DSM 20294(T) consists of a single replicon, the chromosome with a size of 2,931,780 bp and a G+C content of 65.53%. The genome encodes for 2,580 protein coding genes, among them those for a complete pathway to synthesize biotin.

Genome sequence of the squalene-degrading bacterium Corynebacterium terpenotabidum type strain Y-11(T) (= DSM 44721(T))

Corynebacterium terpenotabidum Takeuchi et. al 1999 is a member of the genus Corynebacterium, which contains Gram-positive and non-spore forming bacteria with a high G+C content. C. terpenotabidum was isolated from soil based on its ability to degrade squalene and belongs to the aerobic and non-hemolytic Corynebacteria. It displays tolerance to salts (up to 8%) and is related to Corynebacterium variabile involved in cheese ripening. As this is a type strain of Corynebacterium, this project describing the 2.75 Mbp long chromosome with its 2,369 protein-coding and 72 RNA genes will aid the G enomic E ncyclopedia of Bacteria and Archaea project.

Reconstruction of the lipid metabolism for the microalga Monoraphidium neglectum from its genome sequence reveals characteristics suitable for biofuel production

BACKGROUND

Microalgae are gaining importance as sustainable production hosts in the fields of biotechnology and bioenergy. A robust biomass accumulating strain of the genus Monoraphidium (SAG 48.87) was investigated in this work as a potential feedstock for biofuel production. The genome was sequenced, annotated, and key enzymes for triacylglycerol formation were elucidated.

RESULTS

Monoraphidium neglectum was identified as an oleaginous species with favourable growth characteristics as well as a high potential for crude oil production, based on neutral lipid contents of approximately 21% (dry weight) under nitrogen starvation, composed of predominantly C18:1 and C16:0 fatty acids. Further characterization revealed growth in a relatively wide pH range and salt concentrations of up to 1.0% NaCl, in which the cells exhibited larger structures. This first full genome sequencing of a member of the Selenastraceae revealed a diploid, approximately 68 Mbp genome with a G + C content of 64.7%. The circular chloroplast genome was assembled to a 135,362 bp single contig, containing 67 protein-coding genes. The assembly of the mitochondrial genome resulted in two contigs with an approximate total size of 94 kb, the largest known mitochondrial genome within algae. 16,761 protein-coding genes were assigned to the nuclear genome. Comparison of gene sets with respect to functional categories revealed a higher gene number assigned to the category "carbohydrate metabolic process" and in "fatty acid biosynthetic process" in M. neglectum when compared to Chlamydomonas reinhardtii and Nannochloropsis gaditana, indicating a higher metabolic diversity for applications in carbohydrate conversions of biotechnological relevance.

CONCLUSIONS

The genome of M. neglectum, as well as the metabolic reconstruction of crucial lipid pathways, provides new insights into the diversity of the lipid metabolism in microalgae. The results of this work provide a platform to encourage the development of this strain for biotechnological applications and production concepts.

Genome sequence of the halotolerant bacterium Corynebacterium halotolerans type strain YIM 70093(T) (= DSM 44683(T))

Corynebacterium halotolerans Chen et al. 2004 is a member of the genus Corynebacterium which contains Gram-positive bacteria with a high G+C content. C. halotolerans, isolated from a saline soil, belongs to the non-lipophilic, non-pathogenic corynebacteria. It displays a high tolerance to salts (up to 25%) and is related to the pathogenic corynebacteria C. freneyi and C. xerosis. As this is a type strain in a subgroup of Corynebacterium without complete genome sequences, this project describing the 3.14 Mbp long chromosome and the 86.2 kbp plasmid pCha1 with their 2,865 protein-coding and 65 RNA genes will aid the Genomic Encyclopedia ofBacteria andArchaea project.

Complete genome sequence of Saccharothrix espanaensis DSM 44229(T) and comparison to the other completely sequenced Pseudonocardiaceae

Background

The genus Saccharothrix is a representative of the family Pseudonocardiaceae, known to include producer strains of a wide variety of potent antibiotics. Saccharothrix espanaensis produces both saccharomicins A and B of the promising new class of heptadecaglycoside antibiotics, active against both bacteria and yeast.

Results

To better assess its capabilities, the complete genome sequence of S. espanaensis was established. With a size of 9,360,653 bp, coding for 8,501 genes, it stands alongside other Pseudonocardiaceae with large genomes. Besides a predicted core genome of 810 genes shared in the family, S. espanaensis has a large number of accessory genes: 2,967 singletons when compared to the family, of which 1,292 have no clear orthologs in the RefSeq database. The genome analysis revealed the presence of 26 biosynthetic gene clusters potentially encoding secondary metabolites. Among them, the cluster coding for the saccharomicins could be identified.

Conclusion

S. espanaensis is the first completely sequenced species of the genus Saccharothrix. The genome discloses the cluster responsible for the biosynthesis of the saccharomicins, the largest oligosaccharide antibiotic currently identified. Moreover, the genome revealed 25 additional putative secondary metabolite gene clusters further suggesting the strain’s potential for natural product synthesis.

Whole genome sequencing of environmental Vibrio cholerae O1 from 10 nanograms of DNA using short reads

Multiple Displacement Amplification (MDA) of DNA using φ29 (phi29) DNA polymerase amplifies DNA several billion-fold, which has proved to be potentially very useful for evaluating genome information in a culture-independent manner. Whole genome sequencing using DNA from a single prokaryotic genome copy amplified by MDA has not yet been achieved due to the formation of chimeras and skewed amplification of genomic regions during the MDA step, which then precludes genome assembly. We have hereby addressed the issue by using 10 ng of genomic Vibrio cholerae DNA extracted within an agarose plug to ensure circularity as a starting point for MDA and then sequencing the amplified yield using the SOLiD platform. We successfully managed to assemble the entire genome of V. cholerae strain LMA3984-4 (environmental O1 strain isolated in urban Amazonia) using a hybrid de novo assembly strategy. Using our method, only 178 out of 16,713 (1%) of contigs were not able to be inserted into either chromosome scaffold, and out of these 178, only 3 appeared to be chimeras. The other contigs seem to be the result of template-independent non-specific amplification during MDA, yielding spurious reads. Extraction of genomic DNA within an agarose plug in order to ensure circularity of the extracted genome might be key to minimizing amplification bias by MDA for WGS.