Driving forces for the growth of MIB-producing Planktothricoides raciborskii in a low-latitude reservoir


摘要

In comparison with the middle- and high-latitude regions, the low-latitude regions are less associated with the occurrence of 2-methylisoborneol (MIB) episodes, since most of the previously identified MIB producers favor moderate/low light/temperature conditions. Here, we report a serious MIB outbreak over the period from Jul. 2018 to Jun. 2019 in a low-latitude reservoir with a mean annual water temperature of 25.6 °C. The MIB episode lasted for a long period, from Jul. 2018 to Jan. 2019, and Planktothricoides raciborskii was confirmed to be the main MIB producer. The growth characteristics of P. raciborskii were explored through both laboratory culturing and on-site verification experiments. The results indicated that this strain was not nutrient-sensitive at TN > 800 μg L$^{−1}$ and TP > 10 μg L$^{−1}$, but favored moderate light intensity (54 μmol photon m$^{−2}$⋅s$^{−1}$) and high temperature (30 °C). The two bloom-forming genera, Limnothrix and Aphanizomenon, favoring lower temperature and similar or relatively higher light intensity, showed much greater proliferation, about 13 folds (Limnothrix) and 58 folds (Aphanizomenon), from Dec. to Jun.; by contrast, the high water temperature (29.9 ± 2.8 °C) and light intensity (189.1 ± 87.6 μmol photon m$^{−2}$⋅s$^{−1}$) from Jul. to Nov. were not favorable to Limnothrix or Aphanizomenon, which might have created an opportunity for the growth of MIB-producing P. raciborskii. In addition, we also found that high temperature could promote the release of MIB from P. raciborskii cells, therefore exerting increased pressure on drinking water treatment processes.

出版物
In Water Research
陆金平
陆金平
博士研究生
苏命
苏命
副研究员

我的研究方向:水源地水质安全保障,主要针对水源地由于藻类爆发引起的水体嗅味问题开展研究。

曹腾心
曹腾心
硕士
于建伟
副研究员
杨敏
杨敏
研究员, 中国科学院生态环境研究中心副主任