Extracellular targeting of an active endoxylanase by a TolB negative mutant of Gluconobacter oxydans.

Gluconobacter (G.) oxydans strains have great industrial potential due to their ability to incompletely oxidize a wide range of carbohydrates. But there is one major limitation preventing their full production potential. Hydrolysis of polysaccharides is not possible because extracellular hydrolases are not encoded in the genome of Gluconobacter species. Therefore, as a first step for the generation of exoenzyme producing G. oxydans, a leaky outer membrane mutant was created by deleting the TolB encoding gene gox1687. As a second step the xynA gene encoding an endo-1,4-ß-xylanase from Bacillus subtilis was expressed in G. oxydans ΔtolB. More than 70 % of the total XynA activity (0.91 mmol h(-1) l culture(-1)) was detected in the culture supernatant of the TolB mutant and only 10 % of endoxylanase activity was observed in the supernatant of G. oxydans xynA. These results showed that a G. oxydans strain with an increased substrate spectrum that is able to use the renewable polysaccharide xylan as a substrate to produce the prebiotic compounds xylobiose and xylooligosaccharides was generated. This is the first report about the combination of the process of incomplete oxidation with the degradation of renewable organic materials from plants for the production of value-added products.

Religious belief as a coping strategy: an explorative trial in patients irradiated for head-and-neck cancer.

PURPOSE: To explore the role of religious belief in coping with disease symptoms and treatment-related side effects in patients with head-and-neck cancer under radiotherapy. PATIENTS AND METHODS: Prospectively collected data were used with a cohort of head-and-neck cancer patients treated by radiotherapy and epoetin beta or placebo within a double-blind multicenter trial. All patients were divided into believers and nonbelievers. Answers to a quality of life questionnaire at four points in time during radiotherapy were analyzed according to both groups. Clinical parameters and therapy side effects were controlled regularly. RESULTS: 62.1% of the patients (66/105) sent back a baseline questionnaire discriminating between believers and nonbelievers. For 34.2% (40/105) data of all four measures could be obtained. On average, believers felt better in all categories of side effects at all points of time before, during and directly after therapy. CONCLUSION: Religious faith seems to play an important role in coping strategies of radiotherapy patients. More research in this area would be worthwhile.