Dynamic study of how the bacterial breakdown of plant cell walls allows the reconstitution of efficient hemicellulasic cocktails

• Published in: Bioresource technology 2014-10, Vol.170, p.331-341
• Main Authors: Rakotoarivonina, H., Hermant, B., Aubry, N., Rabenoelina, F., Baillieul, F., Rémond, C.
• Format: Article
• Language: English
• Subjects: Arabinose - metabolism; Bacillales - enzymology; Biological and medical sciences; Biomass conversion; Biorefinery; Cell Wall - chemistry; Chemical and Process Engineering; Chromatography, High Pressure Liquid; Dietary Fiber; DNA Primers - genetics; DNA, Complementary - biosynthesis; Engineering Sciences; Environmental Sciences; Enzyme synergy; Food engineering; Fundamental and applied biological sciences. Psychology; Glycoside Hydrolases - metabolism; Hemicellulases gene expression; Hydroxybenzoates - metabolism; Life Sciences; Lignin - metabolism; Plant Stems - chemistry; Real-Time Polymerase Chain Reaction; Reverse Transcriptase Polymerase Chain Reaction; Thermobacillus xylanilyticus; Triticum - chemistry; Xylose - metabolism
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2014.07.097

•T. xylanilyticus enzymes strategies were studied during growth on complex biomasses.•Hemicellulases produced were dynamically adapted to depolymerize wheat bran and straw.•Hemicellulases gene expression were correlated with global hemicellulases production.•Synergistic action of the thermostable hemicellulases allowed high xylan conversion. Designing more efficient mixtures of enzymes is necessary to produce molecules of interest from biomass lignocellulosic fractionation. The present study aims to investigate the strategies used by the thermophilic and hemicellulolytic bacterium Thermobacillus xylanilyticus to fractionate wheat bran and wheat straw during its growth. Results demonstrated ratios and levels of hemicellulases produced varied during growth on both biomasses. Xylanase activity was mainly produced during stationary stages of growth whereas esterase and arabinosidase activities were detected earlier. This enzymatic profile is correlated with the expression pattern of genes encoding four hemicellulases (two xylanases, one arabinosidase and one esterase) produced by T. xylanilyticus during growth. Based on identification of the bacterial strategy, the synergistic efficiency of the four hemicellulases during the hydrolysis of both substrates was evaluated. The four hemicellulases worked together with high degree of synergy and released high amounts of xylose, arabinose and phenolic acids from wheat bran and wheat straw.