| Quantitative Determination of Poly-β-hydroxybutyrate in Synechocystis sp. PCC 6803
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Author:
Date:
2017-07-20
[Abstract] Cyanobacteria synthesize a variety of chemically-different, high-value biopolymers such as glycogen (polyglucose), poly-β-hydroxybutyrate (PHB), cyanophycin (polyamide of arginine and aspartic acid) and volutin (polyphosphate) under excess conditions. Especially under unbalanced C to N ratios, glycogen and in some cyanobacterial genera also PHB are massively accumulated in the progression of the general nitrogen stress response. Several different technologies have been established for in situ and in vitro PHB analysis from different microbial sources. In this protocol, a rapid and reliable spectrophotometric method is described for PHB quantification in the cyanobacterium Synechocystis sp. PCC 6803 upon nitrogen deprivation as described in (Damrow et ...
[摘要] 蓝细菌合成各种化学上不同的高价值生物聚合物，如糖原（polyglucose），poly-β-β-羟基丁酸酯（PHB），蓝藻素（精氨酸和天冬氨酸的聚酰胺）和挥发物（多磷酸盐） 在超额条件下。 特别是在不平衡的C至N比下，糖原和一些蓝藻属中，PHB在一般氮应激反应进程中大量积累。 已经针对不同微生物来源的原位实验和/或从体外分析，建立了几种不同的技术。 在该协议中，描述了用于蓝藻（Stechocystis）的PHB定量的快速可靠的分光光度法。 如（Damrow等人，2016）中描述的氮缺乏的PCC 6803。
【背景】非重氮营养蓝细菌，例如集胞藻（Synechocystis） PCC 6803通过漂白来解决缺乏组合的氮源，这是一种被称为褪绿的过程（Allen和Smith，1969）。这种驯化反应的特征在于四个主要的结构和形态变化：（i）类囊体层之间的电子致密糖原夹杂物（直径约40nm）的大量积累伴随着（ii）藻糖酵母天线复合物的降解， （iii）类囊体膜层的拆卸，包括数量减少和包装密度，和（iv）形成不同的电子透明PHB颗粒（直径约400-500nm）（Damrow等人，2016）。由于不存在分解代谢酶和PHB缺陷型突变体的明显表型，所以在几种物种中合成的蓝细菌PHB代谢的生理功能是相当不透明的（Beck等人，2012; van ，2010; Damrow等人，2016; ...
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| Rapid Determination of Cellulose, Neutral Sugars, and Uronic Acids from Plant Cell Walls by One-step Two-step Hydrolysis and HPAEC-PAD
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Author:
Date:
2016-10-20
[Abstract] The plant cell wall is primarily composed of the polysaccharides cellulose, hemicellulose and pectin. The structural and compositional complexity of these components are important for determining cell wall function during plant growth. Moreover, cell wall structure defines a number of functional properties of plant-derived biomass, such as rheological properties of foods and feedstock suitability for the production of cellulosic biofuels. A typical characterization of cell wall chemistry in the molecular biology lab consists of a mild acid hydrolysis for the quantification of hemicellulose and pectin-derived monomers and a separate analysis of cellulose by the Updegraff method. We have adopted a streamlined ‘one-step two-step’ hydrolysis protocol that allows for the simultaneous ...
[摘要] 植物细胞壁主要由多糖纤维素，半纤维素和果胶组成。这些组分的结构和组成复杂性对于确定植物生长期间的细胞壁功能是重要的。此外，细胞壁结构限定了植物来源的生物质的多种功能性质，例如食品的流变性质和用于生产纤维素生物燃料的原料适用性。分子生物学实验室中细胞壁化学的典型表征包括用于定量半纤维素和果胶衍生单体的温和酸水解和通过Updegraff方法对纤维素的单独分析。我们采用了一个简化的"一步两步"水解方案，允许通过配对的脉冲安培检测（HPAEC-PAD）的高效阴离子交换层析同时测定纤维素含量，中性糖和糖醛酸样品。在我们的工作中，该方案已经在很大程度上替代了Updegraff纤维素定量和用2μMTFA水解以在微量级上测定基质多糖组成。
[背景] 是基于在121℃下在4％（w/v）硫酸中水解的样品的配对分析。一组样品首先用72％（w/w）硫酸预处理以使纤维素膨胀并使其易于稀释酸水解（图1中的Saeman水解; ...
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