Shimane Prefectural Institute of Public Health and Environmental Science, 582-1 Nishihamasada, Matsue, Shimane 690-0122, Japan.
The United Graduate School of Agricultural Sciences, Tottori University, 4-101 Koyama-cho minami, Tottori, Tottori 680-8553, Japan.
Sci Rep. 2017 Feb 14;7:41928. doi: 10.1038/srep41928.
In Lake Shinji, Japan, periodic outbreaks of musty odour have occurred since mid-May 2007. Although the substance responsible for the odour was identified as geosmin, the odour-producing organism was unknown. We cultivated an axenic unialgal strain and determined that a species of Coelosphaerium (Synechococcales) was responsible for the production of geosmin in Lake Shinji. Our analysis was conducted using gas chromatography/mass spectrometry to determine the odorous compound. To determine the algae species, it was observed by optical microscopy to describe its morphological characteristics and the polymerase chain reaction was used to characterise the nucleotide sequence of the 16S rRNA gene and the 16S-23S rRNA internal transcribed spacer region. In addition, we explored the relationship between the number of cells of the Coelosphaerium sp. and the concentration of geosmin. In conclusion, geosmin, the cause of the musty odour in Lake Shinji in autumn 2009, was produced by Coelosphaerium sp., and to our knowledge, this is the first report of a geosmin-producing species in the family Coelosphaeriaceae.
在日本的志津湖，自 2007 年 5 月中旬以来，已经发生了多次恶臭气味的周期性爆发。尽管已经确定了导致这种气味的物质是土臭素，但产生气味的生物体仍然未知。我们培养了一株无菌单细胞菌株，并确定志津湖产生土臭素的生物体是一种球石藻属（蓝藻目）。我们的分析是通过气相色谱/质谱联用技术来确定有气味的化合物。为了确定藻类的种类，我们通过光学显微镜观察来描述其形态特征，并通过聚合酶链式反应来描述 16S rRNA 基因和 16S-23S rRNA 内部转录间隔区的核苷酸序列。此外，我们还探讨了球石藻属细胞数量与土臭素浓度之间的关系。总之，2009 年秋季志津湖的土臭素气味是由球石藻属产生的，据我们所知，这是首次报道该科属产生土臭素的物种。
