Search

Using lignocellulosic raw materials as substrate for biotechnological applications has been a focus of research during the last two decades. They contain sugars, which can be used in industrial fermentation processes, in from of polysaccharides (cellulose, hemicellulose). Wheat straw, one representative of lignocellulosic materials, is sustainably and abundantly available, especially in Europe and North America. However, wheat straw, just like any other lignocellulosic material, needs to be pretreated in one way or the other in order to generate sufficient quantities of monosaccharides. One widely used pretreatment for lignocellulosic material is steam explosion combined with enzymatic hydrolysis. In this study, the effects of steam exploding wheat straw in combination with water are presented. By impregnation with water, saccharide yields from subsequent enzymatic hydrolysis increased from 18.8 to 22.6 g L−1for glucose and 13.8 to 16.4 g L−1for xylose, respectively. Moreover, the basic steam explosion parameters residence time and temperature were optimized in ranges from 5 to 20 min and 180–200 °C. This further optimization increased the maximum saccharide yield to 41.2 g L−1for glucose (200 °C, 15 min) and 18.9 g L−1for xylose (190 °C, 10 min). Finally, the growth of the intensively investigated biotechnological production host Yarrowia lipolyticaon hydrolysates derived from different steam explosion parameters was evaluated. Y. lipolyticagrew well in media containing up to 90% wheat straw hydrolysate as sole carbon source, demonstrating the potential as substrate for biotechnological processes.

Preterm infants are at high risk of developing neonatal sepsis. γδ T cells are thought to be an important set of effector cells in neonates. Here, γδ T cells were investigated in a longitudinal cohort of preterm neonates using next-generation sequencing, flow cytometry, and functional assays. During the first year of life, the Vγ9Vδ2 T cell subset showed dynamic phenotypic changes and elevated levels of fetal-derived Vγ9Vδ2 T cells were evident in infants with sepsis. Single-cell transcriptomics identified HLA-DRhiCD83+ γδ T cells in neonatal sepsis, which expressed genes related to antigen presentation. In vitro assays showed that CD83 was expressed on activated Vγ9Vδ2 T cells in preterm and term neonates, but not in adults. In contrast, activation of adult Vγ9Vδ2 T cells enhanced CD86 expression, which was presumably the key receptor to induce CD4 T cell proliferation. Together, we provide a map of the maturation of γδ T cells after preterm birth and highlight their phenotypic diversity in infections.

Supplemental Digital Content is available in the text.

In this Tools of the Trade article, Manuela Richter (Dumont lab) describes a method to probe mechanisms of cytoskeletal network re-organization that uses a targeted laser to both trigger network remodelling and track network dynamics.

Helicobacter pylori isolates from 18 patients were examined by macrorestriction DNA analysis to determine whether >2 strains can coexist in the human stomach. Four biopsy samples from different sites in each patient's stomach were cultured, and 12-14 clones of H. pylori per patient were analyzed. DNA of 15 of the 18 isolates was digestible: 12 by NotI and 3by NruI. Within 14 of these digestible isolates, the patterns of all clones were identical. The isolate of 1 patient showed two digestion patterns, a finding that was confirmed by arbitrary primer polymerase chain reaction. The typeable isolates of all patients, except 2 who underwent gastroscopy on the same day, differed markedly from each other. These results indicate a noticeable discrepancy between the pronounced interpatient heterogeneity and the rare intrapatient variation of H. pylori.