Phylogenetic analysis of the triterpene cyclase protein family in prokaryotes and eukaryotes suggests bidirectional lateral gene transfer

Functional constraints to modifications in triterpene cyclase amino acid sequences make them good candidates for evolutionary studies on the phylogenetic relatedness of these enzymes in prokaryotes as well as in eukaryotes. In this study, we used a set of identified triterpene cyclases, a group of mainly bacterial squalene cyclases and a group of predominantly eukaryotic oxidosqualene cyclases, as seed sequences to identify 5288 putative triterpene cyclase homologues in publicly available databases. The Cluster Analysis of Sequences software was used to detect groups of sequences with increased pairwise sequence similarity. The sequences fall into two main clusters, a bacterial and a eukaryotic. The conserved, informative regions of a multiple sequence alignment of the family were used to construct a neighbour-joining phylogenetic tree using the AsaturA and maximum likelihood phylogenetic tree using the PhyML software. Both analyses showed that most of the triterpene cyclase sequences were similarly grouped to the accepted taxonomic relationships of the organism the sequences originated from, supporting the idea of vertical transfer of cyclase genes from parent to offspring as the main evolutionary driving force in this protein family. However, a small group of sequences from three bacterial species (Stigmatella, Gemmata and Methylococcus) grouped with an otherwise purely eukaryotic cluster of oxidosqualene cyclases, while a small group of sequences from seven fungal species and a sequence from the fern Adiantum grouped consistently with a cluster of otherwise purely bacterial squalene cyclases. This suggests that lateral gene transfer may have taken place, entailing a transfer of oxidosqualene cyclases from eukaryotes to bacteria and a transfer of squalene cyclase from bacteria to an ancestor of the group of Pezizomycotina fungi

A Rhizobium leguminosarum AcpXL Mutant Produces Lipopolysaccharide Lacking 27-Hydroxyoctacosanoic Acid

The structure of the lipid A from Rhizobium etli and Rhizobium leguminosarum lipopolysaccharides (LPSs) lacks phosphate and contains a galacturonosyl residue at its 4′ position, an acylated 2-aminogluconate in place of the proximal glucosamine, and a very long chain ω-1 hydroxy fatty acid, 27-hydroxyoctacosanoic acid (27OHC28:0). The 27OHC28:0 moiety is common in lipid A's among members of the Rhizobiaceae and also among a number of the facultative intracellular pathogens that form chronic infections, e.g., Brucella abortus, Bartonella henselae, and Legionella pneumophila. In this paper, a mutant of R. leguminosarum was created by placing a kanamycin resistance cassette within acpXL, the gene which encodes the acyl carrier protein for 27OHC28:0. The result was an LPS containing a tetraacylated lipid A lacking 27OHC28:0. A small amount of the mutant lipid A may contain an added palmitic acid residue. The mutant is sensitive to changes in osmolarity and an increase in acidity, growth conditions that likely occur in the nodule microenvironment. In spite of the probably hostile microenvironment of the nodule, the acpXL mutant is still able to form nitrogen-fixing root nodules even though the appearance and development of nodules are delayed. Therefore, it is possible that the acpXL mutant has a host-inducible mechanism which enables it to adapt to these physiological changes

The Pea Nodule Environment Restores the Ability of a Rhizobium leguminosarum Lipopolysaccharide acpXL Mutant To Add 27-Hydroxyoctacosanoic Acid to Its Lipid A

Members of the Rhizobiaceae contain 27-hydroxyoctacosanoic acid (27OHC(28:0)) in their lipid A. A Rhizobium leguminosarum 3841 acpXL mutant (named here Rlv22) lacking a functional specialized acyl carrier lacked 27OHC(28:0) in its lipid A, had altered growth and physiological properties (e.g., it was unable to grow in the presence of an elevated salt concentration [0.5% NaCl]), and formed irregularly shaped bacteroids, and the synchronous division of this mutant and the host plant-derived symbiosome membrane was disrupted. In spite of these defects, the mutant was able to persist within the root nodule cells and eventually form, albeit inefficiently, nitrogen-fixing bacteroids. This result suggested that while it is in a host root nodule, the mutant may have some mechanism by which it adapts to the loss of 27OHC(28:0) from its lipid A. In order to further define the function of this fatty acyl residue, it was necessary to examine the lipid A isolated from mutant bacteroids. In this report we show that addition of 27OHC(28:0) to the lipid A of Rlv22 lipopolysaccharides is partially restored in Rlv22 acpXL mutant bacteroids. We hypothesize that R. leguminosarum bv. viciae 3841 contains an alternate mechanism (e.g., another acp gene) for the synthesis of 27OHC(28:0), which is activated when the bacteria are in the nodule environment, and that it is this alternative mechanism which functionally replaces acpXL and is responsible for the synthesis of 27OHC(28:0)-containing lipid A in the Rlv22 acpXL bacteroids

Cell Wall Carbohydrate Compositions of Strains from the Bacillus cereus Group of Species Correlate with Phylogenetic Relatedness▿

Members of the Bacillus cereus group contain cell wall carbohydrates that vary in their glycosyl compositions. Recent multilocus sequence typing (MLST) refined the relatedness of B. cereus group members by separating them into clades and lineages. Based on MLST, we selected several B. anthracis, B. cereus, and B. thuringiensis strains and compared their cell wall carbohydrates. The cell walls of different B. anthracis strains (clade 1/Anthracis) were composed of glucose (Glc), galactose (Gal), N-acetyl mannosamine (ManNAc), and N-acetylglucosamine (GlcNAc). In contrast, the cell walls from clade 2 strains (B. cereus type strain ATCC 14579 and B. thuringiensis strains) lacked Gal and contained N-acetylgalactosamine (GalNAc). The B. cereus clade 1 strains had cell walls that were similar in composition to B. anthracis in that they all contained Gal. However, the cell walls from some clade 1 strains also contained GalNAc, which was not present in B. anthracis cell walls. Three recently identified clade 1 strains of B. cereus that caused severe pneumonia, i.e., strains 03BB102, 03BB87, and G9241, had cell wall compositions that closely resembled those of the B. anthracis strains. It was also observed that B. anthracis strains cell wall glycosyl compositions differed from one another in a plasmid-dependent manner. When plasmid pXO2 was absent, the ManNAc/Gal ratio decreased, while the Glc/Gal ratio increased. Also, deletion of atxA, a global regulatory gene, from a pXO2− strain resulted in cell walls with an even greater level of Glc

Analysis of Business Organising in Ornamental Plant Cooperatives

Namen diplomskega dela je bil raziskati pripravljenost pridelovalcev okrasnih rastlin za povezovanje v poslovno organiziranje zadružništvo. Za pridobitev informacij je bilo v maju in juniju 2017 anketiranih 17 pridelovalcev okrasnih rastlin iz severovzhodne Slovenije. Rezultati ankete so pokazali, da so pridelovalci v glavnem seznanjeni z obliko poslovnega organiziranja zadružništvo. Večina pridelovalcev (94 %) je mnenja, da bi bilo potrebno na območju SV Slovenije ustanoviti zadrugo pridelovalcev okrasnih rastlin. Ugotovili smo, da bi v primeru ustanovitve zadruge bila več kot polovica pridelovalcev pripravljena postati član zadruge, iz česar sledi, da so pripravljeni na povezovanje v zadrugo. V primeru ustanovitve zadruge pa pridelovalci ne bi bili pripravljeni zaposliti osebo, ki bi skrbela za nabavo repromateriala, trženje, promocijo in drugo. Raziskava je pokazala, da večina (69 %) pridelovalcev ni zadovoljna s sodelovanjem slovenskih vrtnarjev med seboj.The purpose of the degree was to investigate the willingness of producers of ornamental plants to join business organising cooperatives. To acquire information on the topic, a survey was carried out among 17 growers of ornamental plants from north-eastern Slovenia, and it was carried out in May and June 2017. The results of the survey showed that the growers are mostly familiar with the business organising cooperatives form. Most Growers’ (94%) opinion was that they would be beneficial for the north-eastern area of Slovenia and that Ornamental Plant Cooperatives should be established. We found that, in the event of the establishment of a cooperative, more than half of the growers would be willing to become members of the cooperative and are thus ready to join the cooperative. In case a cooperative should be established, growers would not be willing to employ people who would be responsible for the procurement of raw materials, marketing, promotion and more. The survey showed that a high percentage (69%) of growers are not satisfied with the cooperation of Slovenian gardens with each other

Lipopolysaccharide O-chain core region required for cellular cohesion and compaction of In Vitro and root biofilms developed by Rhizobium leguminosarum

The formation of biofilms is an important survival strategy allowing rhizobia to live on soil particles and plant roots. Within the microcolonies of the biofilm developed by Rhizobium leguminosarum, rhizobial cells interact tightly through lateral and polar connections, forming organized and compact cell aggregates. These microcolonies are embedded in a biofilm matrix, whose main component is the acidic exopolysaccharide (EPS). Our work shows that the O-chain core region of the R. leguminosarum lipopolysaccharide (LPS) (which stretches out of the cell surface) strongly influences bacterial adhesive properties and cell-cell cohesion. Mutants defective in the O chain or O-chain core moiety developed premature microcolonies in which lateral bacterial contacts were greatly reduced. Furthermore, cell-cell interactions within the microcolonies of the LPS mutants were mediated mostly through their poles, resulting in a biofilm with an altered three-dimensional structure and increased thickness. In addition, on the root epidermis and on root hairs, O-antigen core-defective strains showed altered biofilm patterns with the typical microcolony compaction impaired. Taken together, these results indicate that the surface-exposed moiety of the LPS is crucial for proper cell-to-cell interactions and for the formation of robust biofilms on different surfaces.Fil: Russo, Daniela Marta. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Abdian, Patricia Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Posadas, Diana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Williams, Alan. John Innes Institute; Reino UnidoFil: Vozza, Nicolas Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Giordano, Walter Fabian. Universidad Nacional de Río Cuarto; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Kannenberg, Elmar. University of Georgia; Estados UnidosFil: Allan Downie, J.. John Innes Institute; Reino UnidoFil: Zorreguietaa, Angeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; Argentin

Reactivity of monoclonal antiserum EAII-6G6-2-3, specific for <i>Ba</i> neutral cell wall polysaccharide [19], with HF-SCWPs from <i>Bc</i> group strains.

<p>Meso Scale Discovery (MSD) multi-array high bind 96 well plates were coated with a fixed concentration of HF-SCWP antigen (2 μg/ml) from different <i>Bacillus</i> species and probed with the monoclonal antibody in serial two fold dilutions. Bound antibody was detected by using 2.5 μg/ml of sulfo-tagged goat anti-mouse IgM detection antibody. Data points are the average of three independent experiments. Error bars represent one standard error. Reactivity reported as effective concentration (EC₅₀) titer in <b><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0183115#pone.0183115.t004" target="_blank">Table 4</a></b>.</p