Methyl halide production by cultures of marine thraustochytrids, Aurantiochytrium sp., Botryochytrium radiatum, and Schizochytrium sp.
Methyl halide production by cultures of marine thraustochytrids, Aurantiochytrium sp., Botryochytrium radiatum, and Schizochytrium sp.
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DOI：
10.1016/j.marchem.2018.11.009
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发表时间：
2019-01
期刊：
影响因子：
3
通讯作者：
Nanae Sato;Kazuma Hamamoto;M. Kurihara;Minami Abe;S. Hashimoto
中科院分区：
文献类型：
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作者：
Nanae Sato;Kazuma Hamamoto;M. Kurihara;Minami Abe;S. Hashimoto
海洋是卤代甲烷释放到大气中并影响平流层臭氧层的重要来源。已知红细菌和假单胞菌等海洋细菌是海洋环境中卤代甲烷的来源，但尚未研究破囊壶菌（海洋生态系统中的其他分解者）产生卤代甲烷的情况。在这里，我们报告了破囊壶菌培养物中三种卤代甲烷 CH3Cl、CH3Br 和 CH3I 的产生。破囊壶菌在 20°C、25°C 和 30°C 下培养，并使用动态顶空气相色谱-质谱法测定这些培养物上方气相中卤代甲烷的浓度。通过在培养期间测量600nm处的光密度来监测破囊壶菌的生长。还通过在培养期间用浮游生物计数室计数来测量一些破囊壶菌样品的细胞密度。四种测试的海洋破囊壶菌菌株中的三种被发现在培养物中产生卤代甲烷：Botryochytrium radiatum 产生CH3Cl 和CH3I，而Aurantiochytriumsp. 产生CH3Cl 和CH3I。和裂殖壶菌属。产生CH3Br。在三种破囊壶菌的所有培养物中，除了 B 的 30°C 培养物外，在指数生长期观察到 CH3Cl、CH3Br 和 CH3I 浓度增加。辐射。随着培养温度从 20°C 升高到 30°C，破囊壶菌（B. Radiatum）产生 CH3Cl 的最大浓度增加；在20°C、25°C和30°C培养的培养物中CH3Cl的最大浓度分别约为6000、9600和14,000pmolL−1。然而，当温度从 20°C 升高到 30°C 时，破囊壶菌（B. radiatum）产生 CH3I 的最大浓度降低。据我们所知，这是异养破囊壶菌生产卤代甲烷的首次报道。我们的结果表明，破囊壶菌可能是海洋环境中卤代甲烷的来源。
The oceans are an important source of the methyl halides released into the atmosphere and impacting the stratospheric ozone layer. Marine bacteria such asErythrobacterand Pseudomonas are known to be sources of methyl halides in marine environments, but the production of methyl halides by thraustochytrids, the other decomposers in the marine ecosystem, have not been studied. Here, we report the productions of three methyl halides, CH3Cl, CH3Br, and CH3I, in cultures of thraustochytrids. Thraustochytrids were incubated at 20 °C, 25 °C, and 30 °C, and the concentrations of methyl halides in the gas phase above these cultures were determined using dynamic headspace gas chromatography–mass spectrometry. Growth of thraustochytrids was monitored by measuring optical density at 600 nm during the culture period. Cell density was also measured for some samples of thraustochytrids by counting with a plankton-counting chamber during the culture period. Three of the four tested strains of marine thraustochytrids were found to produce methyl halides in culture:Botryochytrium radiatumproduced CH3Cl and CH3I whileAurantiochytriumsp. and Schizochytrium sp. produced CH3Br. Increases of CH3Cl, CH3Br, and CH3I concentrations were observed during the exponential-growth phase in all cultures of the three thraustochytrids, except for the 30 °C culture ofB. radiatum. The maximum concentration for CH3Cl production by a thraustochytrid (B. radiatum) was increased as the culture temperature increased from 20 °C to 30 °C; the maximum concentrations of CH3Cl in the cultures incubated at 20 °C, 25 °C, and 30 °C were about 6000, 9600 and 14,000 pmol L−1, respectively. However, the maximum concentrations for the CH3I production of thraustochytrid (B. radiatum) decreased when the temperature was increased from 20 °C to 30 °C. To the best of our knowledge, this is the first report of methyl halide production by heterotrophic thraustochytrids. Our results suggest that thraustochytrids may be a source of methyl halides in marine environments.