Biosurfactant production by Pseudomonas fluorescens 378: growth and product characteristics
Biosurfactant production by Pseudomonas fluorescens 378: growth and product characteristics
复制标题
荧光假单胞菌 378 生产生物表面活性剂：生长和产品特性
DOI：
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发表时间：
1988
影响因子：
5
通讯作者：
M. Dostálek
中科院分区：
文献类型：
--
作者：
A. Persson;E. Österberg;M. Dostálek
荧光假单胞菌菌株378能产生一种新的表面活性化合物（代号AP-6）。该化合物的独特之处在于是高分子量化合物，但在某些方面具有低分子量表面活性剂的性质。该产物是细胞外的，其形成似乎部分与生长相关。使用半合成培养基，在pH 6.8-8.4范围内进行发酵罐培养。产物产率在pH 8.0时最佳，最终浓度为210倍临界胶束稀释。在较高的pH值，比生长速率，最终生物量和产品浓度下降。其分子量为1×106，等电点为pH9.1，主要由碳水化合物和蛋白质组成。其水溶液的表面张力为27 mN/m，在0.9%（w/v）NaCl溶液中的临界胶束浓度小于10 mg/l。在空气-水界面的吸附过程的动力学研究使用滴体积技术，并发现反应是迅速的，考虑到分子的大小。低至0.025 g/l的浓度在70 s内达到30 mN/m的表面张力。
SummaryAn isolate of Pseudomonas fluorescens, strain 378 was shown to produce a novel surface active compound (code name AP-6). The compound is unique in being a high molecular weight compound but has, in some aspects, properties of a low molecular weight surfactant. The product is extracellular and its formation appeared to be partly growth-associated. Using a semisynthetic medium, fermentor cultivations were performed in the pH range 6.8–8.4. The product yield was optimal at pH 8.0 and gave a final concentration of 210 times critical micelle dilution. At higher pH, specific growth rate, final biomass and product concentration decreased. It consists mainly of carbohydrates and protein, the molecular weight is 1×106 and the isoelectric point is pH 9.1.The surface tension of an aqueous solution reached 27 mN/m which is a very low value even compared to other surfactants of considerably lower size and the critical micelle concentration was less than 10 mg/l in 0.9% (w/v) NaCl. The kinetics of the adsorption process at the air-water interface was studied using the drop volume technique, and the reaction was found to be rapid, considering the size of the molecule. A concentration as low as 0.025 g/l reached a surface tension of 30 mN/m within 70 s.