Research Institute for Innovations in Sustainable Chemistry, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5-2, Higashi 1-1, Tsukuba, Ibaraki 305-8565, Japan.
J Biosci Bioeng. 2011 Aug;112(2):137-44. doi: 10.1016/j.jbiosc.2011.04.008. Epub 2011 May 24.
An ustilaginomycetous anamorphic yeast species isolated from the leaves of Saccharum officinarum (sugarcane) in Okinawa, Japan, was identified as a novel Pseudozyma species based on morphological and physiological aspects and molecular taxonomic analysis using the D1/D2 domains of the large subunit (26S) rRNA gene and the internal transcribed spacer 1 (ITS1)-5.8S-ITS2 regions. The name Pseudozyma churashimaensis sp. nov. was proposed for the novel species, with JCM 16988(T) as the type strain. Interestingly, P. churashimaensis was found to produce glycolipid biosurfactants, a mixture of mannosylerythritol lipids (MELs), including a novel tri-acetylated derivative (MEL-A2), from glucose. The observed critical micelle concentration (CMC) and the surface tension at CMC of MEL-A2 were 1.7 × 10⁻⁶ M and 29.2 mN/m, respectively. Moreover, on a water-penetration scan, MEL-A2 efficiently formed different lyotropic liquid crystalline phases, including the lamella phase at a wide range of concentrations, indicating its excellent surface-active and self-assembling properties. The novel strain of the genus Pseudozyma should thus facilitate the application of glycolipid biosurfactants in combination with other MEL producers.
从日本冲绳产甘蔗叶片中分离得到的一株尿囊素八孢裂殖酵母样的丝状真菌，根据形态学和生理学特征以及基于大亚基（26S）rRNA 基因 D1/D2 区和内转录间隔区 1（ITS1）-5.8S-ITS2 区的分子分类分析，被鉴定为假丝酵母属的一个新种。该新种被命名为假丝酵母琉球变种（Pseudozyma churashimaensis sp. nov.），其模式菌株为 JCM 16988(T)。有趣的是，发现假丝酵母琉球变种能够从葡萄糖产生糖脂生物表面活性剂，即甘露糖赤藓糖醇脂（MELs）的混合物，包括一种新的三乙酰化衍生物（MEL-A2）。观察到的临界胶束浓度（CMC）和 MEL-A2 的表面张力在 CMC 时分别为 1.7×10⁻⁶ M 和 29.2 mN/m。此外，在水渗透扫描中，MEL-A2 能够在很宽的浓度范围内形成不同的溶致液晶相，包括层状相，表明其具有优异的表面活性和自组装特性。因此，该假丝酵母属新菌株应该有助于与其他 MEL 生产者一起应用糖脂生物表面活性剂。
