Degradation of Wheat Straw by Fibrobacter succinogenes S85: a Liquid- and Solid-State Nuclear Magnetic Resonance Study

• Published in: Applied and Environmental Microbiology Vol. 71; no. 3; pp. 1247 - 1253
• Main Authors: Matulova, M, Nouaille, R, Capek, P, Péan, M, Forano, E, Delort, A.-M
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for Microbiology 01.03.2005
• Subjects: Animals; Biodegradation; Biological and medical sciences; cellulose; Cellulose - metabolism; Culture Media; Dietary Fiber - metabolism; endo-1,4-beta-xylanase; esterases; Fibrobacter - growth & development; Fibrobacter - metabolism; Fibrobacter succinogenes; Fundamental and applied biological sciences. Psychology; hemicellulose; in vitro digestion; In Vitro Techniques; Kinetics; Life Sciences; Lignin - metabolism; Magnetic Resonance Spectroscopy; Microbiology; Microbiology and Parasitology; nuclear magnetic resonance spectroscopy; oligosaccharides; Oligosaccharides - metabolism; Polysaccharides - metabolism; Rumen - microbiology; rumen bacteria; sugar phosphates; sugars; Triticum - metabolism; wheat straw; Biodegradation; Fibrobacter succinogenes; Bacteria; NMR spectrometry; Wheat; Bacteroidaceae; Straw; WHEAT STRAW; MICROBIAL LIGNINOLYSIS; FIBROBACTER SUCCINOGENES
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.71.3.1247-1253.2005

Wheat straw degradation by Fibrobacter succinogenes was monitored by nuclear magnetic resonance (NMR) spectroscopy and chemolytic methods to investigate the activity of an entire fibrolytic system on an intact complex substrate. In situ solid-state NMR with ¹³C cross-polarization magic angle spinning was used to monitor the modification of the composition and structure of lignocellulosic fibers (of ¹³C-enriched wheat straw) during the growth of bacteria on this substrate. There was no preferential degradation either of amorphous regions of cellulose versus crystalline regions or of cellulose versus hemicelluloses in wheat straw. This suggests either a simultaneous degradation of the amorphous and crystalline parts of cellulose and of cellulose and hemicelluloses by the enzymes or degradation at the surface at a molecular scale that cannot be detected by NMR. Liquid-state two-dimensional NMR experiments and chemolytic methods were used to analyze in detail the various sugars released into the culture medium. An integration of NMR signals enabled the quantification of oligosaccharides produced from wheat straw at various times of culture and showed the sequential activities of some of the fibrolytic enzymes of F. succinogenes S85 on wheat straw. In particular, acetylxylan esterase appeared to be more active than arabinofuranosidase, which was more active than [alpha]-glucuronidase. Finally, cellodextrins did not accumulate to a great extent in the culture medium.