Deshors Marine, Guais Olivier, Neugnot-Roux Virginie, Cameleyre Xavier, Fillaudeau Luc, Francois Jean Marie
LISBP, UMR INSA-CNRS 5504 & INRA 792, Toulouse, France.
Cinabio-Adisseo France S.A.S., Toulouse, France.
Front Bioeng Biotechnol. 2019 Jun 26;7:158. doi: 10.3389/fbioe.2019.00158. eCollection 2019.
Wheat bran is a foodstuff containing more than 40% of non-starch polysaccharides (NSPs) that are hardly digestible by monogastric animals. Therefore, cocktails enriched of hydrolytic enzymes (termed NSPases) are commonly provided as feed additives in animal nutrition. However, how these enzymes cocktails contribute to NSPs deconstruction remains largely unknown. This question was addressed by employing an original methodology that makes use of a multi-instrumented bioreactor that allows to dynamically monitor enzymes in action and to extract physical and biochemical data from this monitoring. We report here that the deconstruction of destarched wheat bran by an industrial enzymes cocktail termed Rovabio® was entailed by two concurrent events: a particles fragmentation that caused in <2 h a 70% drop of the suspension viscosity and a solubilization that released <30 % of the wheat bran NSPs. Upon longer exposure, the fragmentation of particles continued at a very slow rate without any further solubilization. Contrary to this cocktail, xylanase C alone caused a moderate 25% drop of viscosity and a very weak fragmentation. However, the amount of xylose and arabinose from solubilized sugars after 6 h treatment with this enzyme was similar to that obtained after 2 h with Rovabio®. Altogether, this multi-scale analysis supported the synergistic action of enzymes mixture to readily solubilize complex polysaccharides, and revealed that in spite of the richness and diversity of hydrolytic enzymes in the cocktail, the deconstruction of NSPs in wheat bran was largely incomplete.
麦麸是一种非淀粉多糖（NSPs）含量超过40%的食物原料，单胃动物很难消化这些多糖。因此，富含水解酶（称为NSP酶）的酶制剂通常作为饲料添加剂用于动物营养。然而，这些酶制剂如何促进NSPs的分解在很大程度上仍不清楚。通过采用一种原始方法解决了这个问题，该方法利用了一种多仪器生物反应器，该反应器能够动态监测酶的作用，并从这种监测中提取物理和生化数据。我们在此报告，一种名为Rovabio®的工业酶制剂对脱淀粉麦麸的分解是由两个同时发生的事件导致的：颗粒破碎，在不到2小时内使悬浮液粘度下降70%；溶解，释放出不到30%的麦麸NSPs。长时间暴露后，颗粒破碎以非常缓慢的速度继续，没有进一步的溶解。与这种酶制剂相反，单独的木聚糖酶C使粘度适度下降25%，颗粒破碎非常微弱。然而，用这种酶处理6小时后，溶解糖中的木糖和阿拉伯糖含量与用Rovabio®处理2小时后得到的含量相似。总之，这种多尺度分析支持了酶混合物协同作用以快速溶解复杂多糖的观点，并揭示尽管酶制剂中水解酶丰富多样，但麦麸中NSPs的分解在很大程度上是不完全的。
