Department of Microbiology, Faculty of Science, Chulalongkorn University, Bangkok, Thailand.
Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan.
J Appl Microbiol. 2017 Dec;123(6):1488-1497. doi: 10.1111/jam.13598. Epub 2017 Nov 7.
In order to add to the existing knowledge about structural diversity of biosurfactants, marine environment was chosen to discover a new type of biosurfactant-producing fungus.
A number of fungi were collected from the Gulf of Thailand and examined for biosurfactant productivities. A dimorphic fungus, Aureobasidium pullulans YTP6-14, produced several different biosurfactants in both heavy oil and aqueous layers of the culture. Surface tension of the aqueous layer was decreased to 31·4 mN m and oil displacement area reached 53 cm /10 μl after 7 days of cultivation. Critical micelle concentration and minimum surface tension values of the crude biosurfactants prepared from the aqueous layer were 39 mg l and 31·6 mN m respectively. Surface tension values remained unchanged over a wide range of pH and NaCl concentrations, suggesting their nonionic feature. LC/MS and NMR analyses revealed that one of the main active compounds in the aqueous layer was 5-hydroxy-2-decenoic acid delta-lactone, known as massoia lactone. Massoia lactone indeed showed significant surface tension reduction capacity of 43·3 mN m at 1 mg ml .
This is the first report for the production of a fragrant biosurfactant, massoia lactone by a fungus A. pullulans. Massoia lactone has been industrially prepared from aromatic bark of an endangered tree species, Cryptocarya massoy, growing in rainforests. This report expands the diversity of biosurfactants produced by A. pullulans and also points to its possibility in contributing to the green sustainable chemistry, and ultimately rainforest conservation.
为了增加关于生物表面活性剂结构多样性的现有知识，选择海洋环境来发现一种新型的生物表面活性剂产生真菌。
从泰国湾采集了一些真菌，并检查了它们的生物表面活性剂产量。一种双相真菌，出芽短梗霉 YTP6-14，在重油和培养物的水层中都产生了几种不同的生物表面活性剂。经过 7 天的培养，水层的表面张力降低到 31.4 mN/m，油驱面积达到 53 cm/10μl。从水层制备的粗生物表面活性剂的临界胶束浓度和最低表面张力值分别为 39 mg/l 和 31.6 mN/m。表面张力值在较宽的 pH 和 NaCl 浓度范围内保持不变，表明它们是非离子的。LC/MS 和 NMR 分析表明，水层中的一种主要活性化合物是 5-羟基-2-癸烯酸 delta-内酯，称为马索亚内酯。马索亚内酯确实在 1 mg/ml 时表现出显著的表面张力降低能力，为 43.3 mN/m。
这是首次报道真菌出芽短梗霉产生芳香生物表面活性剂马索亚内酯。马索亚内酯已从生长在热带雨林中的濒危树种Cryptocarya massoy 的芳香树皮中通过工业方法制备。本报告扩展了出芽短梗霉产生的生物表面活性剂的多样性，并指出其在绿色可持续化学中的可能性，最终有助于雨林保护。
