Appl Environ Microbiol. 1995 Jun;61(6):2186-92. doi: 10.1128/aem.61.6.2186-2192.1995.
A method that can be used to measure the initial decomposition rates of polysaccharides in sediment samples was developed. It uses toluene to specifically inhibit microbial uptake of carbohydrates without affecting extracellular hydrolysis of polysaccharides. Accumulating carbohydrates were determined by high-performance liquid chromatography. Field-sampled litter from the common reed (Phragmites australis), which contains cellulose and arabinoxylan as its main polysaccharides, was used as a model system. Toluene concentrations of between 1 and 10% resulted in the accumulation of similar amounts of monomeric carbohydrates, which was linear over time for most neutral sugars. Toluene (3%) did not have an effect on extracellular enzyme activities, and microbial sugar uptake was completely inhibited, as demonstrated with (sup14)C-labelled xylose and glucose. Experiments with enhancement cultures and fixed reed litter suggested that enzymatic hydrolysis of polysaccharides in reed litter was the main source of glucose, xylose, arabinose, and galactose accumulation. In contrast, the accumulation of high amounts of the alditols mannitol and glucitol was probably caused by lysis of the microbial population in toluene-treated reed litter. Glucose accumulated at rates of 1.3 and 0.10 (mu)mol (middot) g of dry matter content(sup-1) (middot) h(sup-1) under aerobic and anaerobic conditions, respectively, whereas xylose accumulation rates were only 10% of the glucose accumulation rates.
开发了一种可用于测量沉积物样品中多糖初始分解率的方法。它使用甲苯特异性地抑制微生物对碳水化合物的吸收，而不影响多糖的细胞外水解。通过高效液相色谱法测定积累的碳水化合物。以含有纤维素和阿拉伯木聚糖作为主要多糖的普通芦苇（Phragmites australis）的实地采样凋落物作为模型系统。1%至 10%之间的甲苯浓度导致单体碳水化合物的积累量相似，对于大多数中性糖来说，这是随时间呈线性增长的。甲苯（3%）对细胞外酶活性没有影响，并且微生物糖吸收被完全抑制，这可以用（sup14）C 标记的木糖和葡萄糖证明。增强培养和固定芦苇凋落物的实验表明，芦苇凋落物中多糖的酶水解是葡萄糖、木糖、阿拉伯糖和半乳糖积累的主要来源。相比之下，大量糖醇甘露醇和山梨糖醇的积累可能是由于甲苯处理的芦苇凋落物中微生物种群的裂解所致。在有氧和无氧条件下，葡萄糖的积累速率分别为 1.3 和 0.10（mu）mol（middot）g 干物质含量（sup-1）（middot）h（sup-1），而木糖的积累速率仅为葡萄糖积累速率的 10%。
