Occurrence and properties of bacterial pectate lyases

Some 100 pectolytic bacteria belonging to different genera and species, were obtained by isolation from vegetables and by screening of culture collections. The crude enzyme preparations of 19 of these strains were typed by mutual comparison. Differences in the composition of five commercial fungal 'pectinase' preparations were also studied. Purified endo pectate lyase of Arthrobacter which was studied in detail, appeared to attack pectate far 'less randomly', than endo pectate lyases of Bacillus polymyxa or Pseudomonas. The best substrates for pectate lyases were not pectates but 21 to 44% esterified pectins. A new method for the determination of the number average degree of polymerization of pectic substances was introduced. The literature on pectolytic enzymes was reviewed

Microben in ons voedsel - Bedreiging en uitdaging.

Rede Wageningen, 4 juni 198

The effect of a multispecies probiotic on the composition of the faecal microbiota and bowel habits in chronic obstructive pulmonary disease patients treated with antibiotics

Short-term antibiotic treatment profoundly affects the intestinal microbiota, which may lead to sustained changes in microbiota composition. Probiotics may restore such a disturbance. The objective of the present study was to investigate the effect of a multispecies probiotic on the faecal microbiota during and after antibiotic intake in patients with a history of frequent antibiotic use. In this randomised, placebo-controlled, double-blind study, thirty chronic obstructive pulmonary disease (COPD) patients treated with antibiotics for a respiratory tract infection received 5 g of a multispecies probiotic or placebo twice daily for 2 weeks. Faecal samples were collected at 0, 7, 14 and 63 d. Changes in the composition of the dominant faecal microbiota were determined by PCR-denaturing gradient gel electrophoresis (DGGE). Changes in bacterial subgroups were determined by quantitative PCR and culture. Bowel movements were scored daily according to the Bristol stool form scale. During and after antibiotic treatment, DGGE-based similarity indices (SI) were high ( >/= 84 %) and band richness was relatively low, both remaining stable over time. No difference in SI was observed between patients with and without diarrhoea-like bowel movements. The multispecies probiotic had a modest effect on the bacterial subgroups. Nevertheless, it affected neither the composition of the dominant faecal microbiota nor the occurrence of diarrhoea-like bowel movements. The dominant faecal microbiota was not affected by antibiotics in this COPD population, suggesting an existing imbalance of the microbiota, which may also have contributed to the lack of effect by probiotic intak

Medicine, Medea and the Media: The Rise and Fall of Roy Meadow

For more than three decades eminent British paediatrician, Professor Sir Roy Meadow, was courted by the media for his startling pronouncements on maternal child murder and abuse, including his now infamous Meadow's Law and his creation ofMunchausen Syndrome by Proxy. His compelling evidence made headline news in the trials of several women, including Sally Clark, Donna Anthony, Angela Cannings and Trupti Patel. Journalists, however, persistently failed to investigate Meadow's potent claims, using the eminent paediatrician as a primary source to create highly newsworthy news narratives. Through an analysis of newspaper stories, primarily in the London Times, this study maps the rise and fall of Roy Meadow. My critique deploys a narrative trope I have called the Medea-Factor to explore the fictive qualities of news, and to develop an argument for understanding how Roy Meadow became the media's national authority on maternal child murder and abuse, as well as how his glittering career came to an ignominious end. An important key to revealing Meadow's power-and why it was that journalists continued to privilege his voice for so long--came in the unearthing of Meadow's nineteenth-century counterpart, and the first primary definer of infanticide news, Dr Edwin Lankester. This study concludes that the pattern for creating news narratives about mothers accused of murdering their children is so compelling that journalists, even when faced with the evidence of flawed science, will continue to create narratives shaped by the ideology ofthe Medea-Factor. The thesis is situated within the discipline of English, and its approach and methodology belong to that discipline. Its textual sources, however, come from newspapers, and to the extent that it is concerned with the use of expert witnesses the thesis engages with matters important to the discipline of journalism and is therefore interdisciplinary

Viability and physiological state transitions of Rhizopus oligosporus sporangiospores in tempe starter culture

The viability and various physiological characteristics of individual sporangiospores of Rhizopus oligosporus in tempe starter cultures that had been stored for 8, 10, 16 and 30 months were examined by flow cytometry in combination with fluorescent dyes. Besides live, dead, and dormant spores we distinguished a category of sublethally damaged spores. Results indicated that the shelf-life of tempe starters was not limited by the death of spores, but by sublethal damage to spores as well as by dormancy which can be overcome by resuscitation, respiratory activation. During storage, the number of dormant and sublethally damaged spores increased: the longer the starter cultures were stored, the less dormant spores could still be activated. In contrast, the transition from sublethally damaged (spores that are not able to transform cFDA and emit green fluorescence except by activation treatment) to activated spores did not decrease with longer storage. However, after very long (30 months) storage, sublethally damaged spores could still be activated but could not germinate anymore. The shelf-life of spores in tempe starter is related to the physiological state of spores being sublethally damaged; a mechanism of physiological state transitions of R. oligosporus sporangiospores is proposed

What is the future for therapies derived from the microbiome (pharmabiotics)?

The personal gut microbiota is characterized by species composition, enterotype, and bacterial gene counts. Gut microbiota can be viewed as a complex microecosystem. Regulation of the diversity and stability of the gut microbiota is therefore critical for the development of future therapies. The areas with high potential for personalized management of gut microbiota are obesity and the metabolic syndrome, prevention and control of (recurrent) infections, immune-mediated disorders, and the gut-brain axis. A true and deeper understanding of the interaction between the microbiota and the host, as well as a better matching of probiotic and prebiotic mechanisms with clinical indications will be required for successful future implementation of these therapies