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Flocculant and Chemical Properties of a Polysaccharide from Pullularia pullulans

机译：普鲁氏酵母多糖的絮凝剂和化学性质

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An extracellular polysaccharide, PP-floc, was synthesized from glucose by Pullularia pullulans (or Aureobasidium pullulans) in a pilot plant batch fermentor containing 175 liters of culture medium. At 58 h of fermentation, the concentration of PP-floc was 1.03 g/100 ml, giving a 25.8% conversion of initial glucose to polysaccharide. The flocculant activity of the culture medium increased during the fermentation process and reached its maximum at 50 h of culture age. Less PP-floc (0.33 lb/ton of slimes [approximately 149.7 g/0.907 t]) was required to give the same flocculant activity as a synthetic polymer of acrylamide, Separan NP-10 (0.5 lb/ton of slimes [approximately 226.8 g/0.907 t]), at all temperatures from 25 to 100 C. The degree of inactivation of PP-floc and Separan NP-10 at elevated temperatures was almost identical, and they were completely inactivated at about the same temperature (80 C). PP-floc also gave better compaction of slimes than Separan NP-10 at all temperatures tested. PP-floc was soluble in water and its specific optical rotation was [α]D25 + 194° in water (c, 0.4). PP-floc contained 83.3% carbohydrate, 3.2% protein, and 8.1% water. Glucose was found to be the principal sugar monomer with traces (>5%) of galactose and mannose present. Structural studies on the fractions of purified polysaccharide by methylation and by periodate oxidation techniques prove that PP-floc is linear and composed of α-(1 → 4) and α-(1 → 6) glucopyranosyl units in the approximate ratio of 2:1. The action of pullulanase on crude PP-floc suggested the ordered arrangement of two consecutive α-(1 → 4)-linked glucopyranosyl units flanked by α-(1 → 6)-linked glucopyranose residues.
机译：细胞外多糖，PP-絮凝物，是由普鲁氏假单胞菌（Pulularia pullulans）（或Aureobasidium pullulans）在含有175升培养基的中试分批发酵罐中由葡萄糖合成的。发酵58小时后，PP絮凝剂的浓度为1.03 g / 100 ml，从初始葡萄糖到多糖的转化率为25.8％。培养基的絮凝活性在发酵过程中增加，并在50 h的培养期达到最大值。要获得与丙烯酰胺合成聚合物Separan NP-10相同的絮凝活性，需要较少的PP絮凝剂（0.33磅/吨粘液[约149.7 g / 0.907吨]）（0.5磅/吨粘液[约226.8 g] /0.907 t]），在25至100 C的所有温度下。PP-floc和Separan NP-10在高温下的失活程度几乎相同，并且在大约相同的温度（80 C）下完全失活。在所有测试温度下，PP絮凝剂都比Separan NP-10更好地压缩了粘液。 PP-絮凝剂可溶于水，在水中的比旋光度为[α] D25 + 194°（c，0.4）。 PP-絮凝物包含83.3％的碳水化合物，3.2％的蛋白质和8.1％的水。发现葡萄糖是主要的糖单体，存在痕量（> 5％）的半乳糖和甘露糖。通过甲基化和高碘酸氧化技术对纯化多糖的馏分进行结构研究，证明PP-絮凝物呈线性，由α-（1→4）和α-（1→6）吡喃葡萄糖基单元以约2：1的比例组成。支链淀粉酶对粗PP絮凝物的作用表明两个连续的α-（1→6）连接的吡喃葡萄糖残基侧翼的两个连续的α-（1→4）连接的吡喃葡萄糖基单元的有序排列。

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