Wymer Larry, Vesper Stephen, Struewing Ian, Allen Joel, Lu Jingrang
Center Environmental Measurement and Modeling, United States Environmental Protection Agency, 26 W. Martin Luther King Drive, Cincinnati, OH 45268, USA.
Life (Basel). 2022 May 17;12(5):742. doi: 10.3390/life12050742.
To ensure drinking-water safety, it is necessary to understand the factors that regulate harmful cyanobacterial blooms (HCBs) and the toxins they produce. One controlling factor might be any relationship between fungi and the cyanobacteria. To test this possibility, water samples were obtained from Harsha Lake in southwestern Ohio during the 2015, 2016, and 2017 bloom seasons, i.e., late May through September. In each water sample, the concentration of the filamentous fungus was determined by quantitative PCR (qPCR) assay, and microcystin-gene transcript copy number (McyG TCN) was quantified by reverse-transcriptase qPCR (RT-qPCR) analyses. The results showed that during each bloom season, the concentration and McyG TCN appeared to be interrelated. Therefore, concentrations were statistically evaluated via regression on McyG TCN in the water samples for lag times of 1 to 7 days. The regression equation developed to model the relationship demonstrated that a change in the concentration resulted in an opposing change in McyG TCN over an approximately 7-day interval. Although the interaction between and McyG TCN was observed in each bloom season, the magnitude of each component varied yearly. To better understand this possible interaction, outdoor spore-count data for the Harsha Lake region were obtained for late May through September of each year from the South West Ohio Air Quality Agency. The average spore count in the outdoor air samples was significantly greater in 2016 than in either 2015 or 2017, and the McyG TCN was significantly lower in Harsha Lake water samples in 2016 compared to 2015 or 2017. These results suggest that there might be a "balanced antagonism" between and during the bloom season.
为确保饮用水安全，有必要了解调节有害蓝藻水华（HCBs）及其产生的毒素的因素。一个控制因素可能是真菌与蓝藻之间的任何关系。为了验证这种可能性，在2015年、2016年和2017年蓝藻水华季节（即5月下旬至9月）从俄亥俄州西南部的哈沙湖采集了水样。在每个水样中，通过定量PCR（qPCR）测定丝状真菌的浓度，并通过逆转录qPCR（RT-qPCR）分析对微囊藻毒素基因转录本拷贝数（McyG TCN）进行定量。结果表明，在每个蓝藻水华季节，真菌浓度和McyG TCN似乎相互关联。因此，通过对水样中滞后1至7天的McyG TCN进行回归分析，对真菌浓度进行了统计评估。为模拟这种关系而建立的回归方程表明，在大约7天的时间间隔内，真菌浓度的变化会导致McyG TCN产生相反的变化。尽管在每个蓝藻水华季节都观察到了真菌与McyG TCN之间的相互作用，但各成分的大小每年都有所不同。为了更好地理解这种可能的相互作用，每年5月下旬至9月从俄亥俄州西南部空气质量机构获取哈沙湖地区的室外真菌孢子计数数据。2016年室外空气样本中的平均真菌孢子计数显著高于2015年或2017年，与2015年或2017年相比，2016年哈沙湖水样中的McyG TCN显著较低。这些结果表明，在蓝藻水华季节，真菌与微囊藻毒素之间可能存在“平衡拮抗作用”。
