Kim Jinnam, Lee GyuDae, Han Soyeong, Kim Min-Ji, Shin Jae-Ho, Lee Seungjun
Major of Food Science & Nutrition, Division of Food Science, College of Fisheries Science, Pukyong National University, Busan, Republic of Korea.
Department of Applied Biosciences, Kyungpook National University, Daegu, Republic of Korea.
Front Microbiol. 2023 Jul 13;14:1203317. doi: 10.3389/fmicb.2023.1203317. eCollection 2023.
Toxic blooms of cyanobacteria, which can produce cyanotoxins, are prevalent in freshwater, especially in South Korea. Exposure to cyanotoxins via ingestion, inhalation, and dermal contact may cause severe diseases. Particularly, toxic cyanobacteria and their cyanotoxins can be aerosolized by a bubble-bursting process associated with a wind-driven wave mechanism. A fundamental question remains regarding the aerosolization of toxic cyanobacteria and cyanotoxins emitted from freshwater bodies during bloom seasons. To evaluate the potential health risk of the aerosolization of toxic cyanobacteria and cyanotoxins, the objectives of this study were as follows: 1) to quantify levels of microcystin in the water and air samples, and 2) to monitor microbial communities, including toxic cyanobacteria in the water and air samples. Water samples were collected from five sites in the Nakdong River, South Korea, from August to September 2022. Air samples were collected using an air pump with a mixed cellulose ester membrane filter. Concentrations of total microcystins were measured using enzyme-linked immunosorbent assay. Shotgun metagenomic sequencing was used to investigate microbial communities, including toxic cyanobacteria. Mean concentrations of microcystins were 960 μg/L ranging from 0.73 to 5,337 μg/L in the water samples and 2.48 ng/m ranging from 0.1 to 6.8 ng/m in the air samples. In addition, in both the water and air samples, predominant bacteria were (PCC7914), which has a microcystin-producing gene, and . Particularly, abundance of (PCC7914) comprised more than 1.5% of all bacteria in the air samples. This study demonstrates microbial communities with genes related with microcystin synthesis, antibiotic resistance gene, and virulence factors in aerosols generated from cyanobacterial bloom-affected freshwater body. In summary, aerosolization of toxic cyanobacteria and cyanotoxins is a critical concern as an emerging exposure route for potential risk to environmental and human health.
能产生蓝藻毒素的蓝藻有毒水华在淡水中很常见，尤其是在韩国。通过摄入、吸入和皮肤接触接触蓝藻毒素可能会导致严重疾病。特别是，有毒蓝藻及其蓝藻毒素可通过与风驱动波浪机制相关的气泡破裂过程雾化。关于水华季节淡水水体中排放的有毒蓝藻和蓝藻毒素的雾化，一个基本问题仍然存在。为了评估有毒蓝藻和蓝藻毒素雾化的潜在健康风险，本研究的目标如下：1）量化水和空气样本中微囊藻毒素的水平，2）监测微生物群落，包括水和空气样本中的有毒蓝藻。2022年8月至9月，从韩国洛东江的五个地点采集了水样。使用带有混合纤维素酯膜过滤器的气泵采集空气样本。使用酶联免疫吸附测定法测量总微囊藻毒素的浓度。采用鸟枪法宏基因组测序来研究包括有毒蓝藻在内的微生物群落。水样中微囊藻毒素的平均浓度为960μg/L，范围为0.73至5337μg/L，空气样本中为2.48ng/m，范围为0.1至6.8ng/m。此外，在水和空气样本中，主要细菌是具有微囊藻毒素产生基因的聚球藻属（PCC7914）和鞘丝藻属。特别是，聚球藻属（PCC7914）的丰度占空气样本中所有细菌的1.5%以上。本研究证明了在受蓝藻水华影响的淡水水体产生的气溶胶中存在与微囊藻毒素合成、抗生素抗性基因和毒力因子相关的基因的微生物群落。总之，有毒蓝藻和蓝藻毒素的雾化作为对环境和人类健康潜在风险的新暴露途径是一个关键问题。
