Lippold F.,University of Bonn |
Lippold F.,Aevotis GmbH |
vom Dorp K.,University of Bonn |
Abraham M.,Max Planck Institute of Molecular Plant Physiology |
And 10 more authors.
Plant Cell | Year: 2012
During stress or senescence, thylakoid membranes in chloroplasts are disintegrated, and chlorophyll and galactolipid are broken down, resulting in the accumulation of toxic intermediates, i.e., tetrapyrroles, free phytol, and free fatty acids. Chlorophyll degradation has been studied in detail, but the catabolic pathways for phytol and fatty acids remain unclear. A large proportion of phytol and fatty acids is converted into fatty acid phytyl esters and triacylglycerol during stress or senescence in chloroplasts. We isolated two genes (PHYTYL ESTER SYNTHASE1 [PES1] and PES2) of the esterase/lipase/ thioesterase family of acyltransferases from Arabidopsis thaliana that are involved in fatty acid phytyl ester synthesis in chloroplasts. The two proteins are highly expressed during senescence and nitrogen deprivation. Heterologous expression in yeast revealed that PES1 and PES2 have phytyl ester synthesis and diacylglycerol acyltransferase activities. The enzymes show broad substrate specificities and can employ acyl-CoAs, acyl carrier proteins, and galactolipids as acyl donors. Double mutant plants (pes1 pes2) grow normally but show reduced phytyl ester and triacylglycerol accumulation. These results demonstrate that PES1 and PES2 are involved in the deposition of free phytol and free fatty acids in the form of phytyl esters in chloroplasts, a process involved in maintaining the integrity of the photosynthetic membrane during abiotic stress and senescence. © 2012 American Society of Plant Biologists. All rights reserved. Source
Maki K.C.,Biofortis Clinical Research |
Rains T.M.,Biofortis Clinical Research |
Kelley K.M.,Biofortis Clinical Research |
Cook C.M.,Biofortis Clinical Research |
And 2 more authors.
International Journal of Food Sciences and Nutrition | Year: 2013
In this randomized, double-blind crossover trial, the digestive tolerance of a novel dietary fibre (fibermalt, an indigestible maltose alternan oligosaccharide) was assessed in healthy men and women. Twenty-nine subjects consumed 0 (control), 45 or 60 g of fibre in two doses per day for 2-week treatment periods, each separated by a 2-week washout. Results indicated no differences between treatments in composite gastrointestinal (GI) symptom scores (sum of six GI symptom ratings), individual GI symptoms (nausea, bloating, GI rumbling, gas/flatulence, abdominal pain, diarrhoea), bowel characteristics (frequency, faecal consistency, faecal hardness, straining, discomfort and incomplete evacuation) or average daily faecal output. The symptom scores were consistently low for each treatment period with means averaging below 1 out of a possible range of 0-12 for the composite score. The results of this study suggest that fibermalt is well tolerated at intakes up to 60 g of fibre per day. © 2012 Informa UK, Ltd. Source
Dolan L.C.,Burdock Group |
Gietl E.,Aevotis GmbH |
La Cognata U.,Aevotis GmbH |
Landschutze V.,Aevotis GmbH |
And 2 more authors.
Food and Chemical Toxicology | Year: 2012
Fibermalt is a new soluble fiber food ingredient produced with the use of an alternansucrase enzyme from Leuconostoc mesenteroides expressed in a non-pathogenic strain of Escherichia coli. Fibermalt is predominantly composed of indigestible maltose alternan oligosaccharides (≥80%). Fibermalt was non-mutagenic in a bacterial reverse mutation test. In a 13-week dietary rat study, fibermalt was administered at 0 (control), 50,000, 100,000 or 150,000. ppm. Statistically significant increases in food consumption were generally observed throughout the study in males receiving 100,000 or 150,000. ppm and in females receiving 100,000. ppm. However, there was no effect of fibermalt on mean body weight, body weight gain or food efficiency. All animals survived to scheduled termination and no adverse clinical signs were attributed to administration of fibermalt. There were no toxicologically relevant changes in hematology, clinical chemistry or urinalysis parameters or organ weights in males or females ingesting any concentration of fibermalt. Any macroscopic or microscopic findings were considered incidental, of normal variation and/or of minimal magnitude for test substance association. Based on these results, fibermalt is not mutagenic as evaluated in a bacterial reverse mutation test and has an oral subchronic (13-week) no observable adverse effect level (NOAEL) of 150,000. ppm in rats. © 2012 Elsevier Ltd. Source