Nematode-trapping fungi (NTF) are a large and diverse group of fungi, which may switch from a saprotrophic to a predatory lifestyle if nematodes are present. Different fungi have developed different trapping devices, ranging from adhesive cells to constricting rings. After trapping, fungal hyphae penetrate the worm, secrete lytic enzymes and form a hyphal network inside the body. We sequenced the genome of Duddingtonia flagrans , a biotechnologically important NTF used to control nematode populations in fields. The 36.64 Mb genome encodes 9,927 putative proteins, among which are more than 638 predicted secreted proteins. Most secreted proteins are lytic enzymes, but more than 200 were classified as small secreted proteins (< 300 amino acids). 117 putative effector proteins were predicted, suggesting interkingdom communication during the colonization. As a first step to analyze the function of such proteins or other phenomena at the molecular level, we developed a transformation system, established the fluorescent proteins GFP and mCherry, adapted an assay to monitor protein secretion, and established gene-deletion protocols using homologous recombination or CRISPR/Cas9. One putative virulence effector protein, PefB, was transcriptionally induced during the interaction. We show that the mature protein is able to be imported into nuclei in Caenorhabditis elegans cells. In addition, we studied trap formation and show that cell-to-cell communication is required for ring closure. The availability of the genome sequence and the establishment of many molecular tools will open new avenues to studying this biotechnologically relevant nematode-trapping fungus.

No abstract

Two novel, anaerobic, Gram-positive, rod-shaped bacterial strains, ResAG-85 and ResAG-96, were isolated from a faecal sample of a male human. 16S rRNA gene sequences analyses indicated that these strains represent a distinct lineage within the family Eggerthellaceae. Strain ResAG-85 showed 92.3 % similarity to the type strains of the genera Eggerthella and Gordonibacter. Strain ResAG-96 clustered together with Paraeggerthella hongkongensis and the newly (but not validly) published genus 'Arabia massiliensis' (94.8 % similarity). Analysis of quinones revealed that MK-5 (21 % in ResAG-85 and 95 % in ResAG-96) and MK-7 (53 % in strain ResAG-85) were present, which were described for the first time for members of the Eggerthellaceae. Furthermore, MK-6 was present in both strains (25 % ResAG-85 and 5 % in ResAG-96). The polar lipids detected in ResAG-85 and ResAG-96 consisted of eight and six glycolipids, respectively. Both strains possessed three phospholipids, one phosphatidylglycerol and one diphosphatidylglycerol. Analysis of fatty acids revealed that the percentage of total branched fatty acids was relatively high in comparison to related strains with 42 and 50 % of strains ResAG-85 and ResAG-96 but comparable to the value obtained for Gordonibacter pamelaeae DSM 19378. On the basis of this polyphasic approach including molecular (16S rRNA gene sequencing) and biochemical methods (analysis of fatty acids, quinones, polar lipids, Rapid ID 32A and API 20A), the new genera and species Rubneribacter badeniensis with ResAG-85 (=DSM 105129=JCM 32272) and Enteroscipio rubneri with ResAG-96 (=DSM 105130=JCM 32273) as the type and only strains are described.

In this paper, the structuring of liquid oils, also known as oleogelation, is systematically investigated for the first time using a quasi-quaternary mixing system approach. Native waxes with different quantities of wax esters (WE), n-alkanes (hydrocarbons (HC)), fatty acids (FA), and fatty alcohols (FaOH) are applied in mixtures with hydrolyzed waxes to systematically change the composition. Hydrolyzed waxes contain high levels of FA and FaOH. The model systems are investigated on microscopic level (brightfield light microscopy (BFM), cryogenic scanning electron microscopy (cryo-SEM)) as well as on their macroscopic properties (rheology, gel hardness) and calorimetric behavior (differential scanning calorimetry (DSC)). It is found that sunflower wax (SFW)-based gels (12% structurant) become less hard on any admixture. Beeswax (BW)-based gels show significant increases in hardness when 25% and 50% (w/w) hydrolyzate are admixed. This could be related to stepwise crystallization. Further analysis reveals that the dissolution/melting behavior of the wax ester mixtures can be surprisingly well described as ideal solubility of a single pseudocomponent. The approach to unravel the individual contributions of the different species present in waxes is successful and marks a first step to better understand the systematic of wax functionality as oleogelators. Practical Application: The substitution of hardstock fats in structured oil phases is of interest for two reasons. The improved nutritional profile oleogels offer are beneficial for public health while the elimination of palm oil based ingredients appears to be a general public desire. Among the technical solutions for non-TAG oil structuring waxes are very promising. This is primarily due to their availability, prior consumption, potentially low cost for functionality. Currently waxes are technically and scientifically wrongly treated as single components. In order to better utilize the potential of waxes and design future sourcing strategies it is necessary to understand the wax functionality at a compositional/molecular level. This contribution marks the first step into this direction by considering classes of molecules with respect to their contribution to functionality. This understanding is considered as a key for future compositional design.

No abstract