Department of Hydrobiology and Protection of Ecosystems, University of Life Sciences in Lublin, Dobrzańskiego 37, 20-262 Lublin, Poland.
Int J Environ Res Public Health. 2022 May 17;19(10):6086. doi: 10.3390/ijerph19106086.
Cyanobacteria, which form water blooms all over the world, can produce a wide range of cyanotoxins such as hepatotoxic microcystins (MCs) and other biologically active metabolites harmful to living organisms, including humans. Microcystin biodegradation, particularly caused by bacteria, has been broadly documented; however, studies in this field focus mainly on strains isolated from natural aquatic environments. In this paper, the biodegradation of microcystin-RR (MC-RR), microcystin-LR (MC-LR), and microcystin-LF (MC-LF) after incubation with and the associated microorganisms (which were cultured under laboratory conditions) is shown. The strongest MC biodegradation rate after nine days of incubation was observed for MC-RR, followed by MC-LR. No statistically significant decrease in the concentration of MC-LF was noted. Products of MC decomposition were detected via the HPLC method, and their highest number was found for MC-RR (six products with the retention time between 5.6 and 16.2 min), followed by MC-LR (two products with the retention time between 19.3 and 20.2 min). Although the decrease in MC-LF concentration was not significant, four MC-LF degradation products were detected with the retention time between 28.9 and 33.0 min. The results showed that MC-LF was the most stable and resistant MC variant under experimental conditions. No accumulation of MCs or their biodegradation products in was found. The findings suggest that the microorganisms (bacteria and algae) associated with could be responsible for the MC biodegradation observed. Therefore, there is a need to broaden the research on the biodegradation products detected and potential MC-degraders associated with plants.
蓝藻在世界各地形成水华，能够产生多种微囊藻毒素（MCs）等生物活性代谢物以及其他对生物（包括人类）有害的物质。微囊藻毒素的生物降解，特别是由细菌引起的生物降解，已经得到了广泛的研究；然而，该领域的研究主要集中在从自然水生环境中分离的菌株上。本文展示了在培养条件下与 共同培养的细菌和相关微生物对微囊藻毒素-RR（MC-RR）、微囊藻毒素-LR（MC-LR）和微囊藻毒素-LF（MC-LF）的生物降解作用。经过九天的培养，MC-RR 的生物降解率最高，其次是 MC-LR。MC-LF 的浓度没有明显下降。通过 HPLC 方法检测到 MC 分解产物，其中 MC-RR 的数量最多（保留时间在 5.6 和 16.2 分钟之间的产物有 6 种），其次是 MC-LR（保留时间在 19.3 和 20.2 分钟之间的产物有 2 种）。虽然 MC-LF 浓度的下降并不显著，但检测到了 4 种 MC-LF 降解产物，保留时间在 28.9 和 33.0 分钟之间。结果表明，在实验条件下，MC-LF 是最稳定和最具抗性的 MC 变体。在 中没有发现 MCs 或其生物降解产物的积累。研究结果表明，与 相关的微生物（细菌和藻类）可能是导致观察到的 MC 生物降解的原因。因此，有必要扩大对检测到的 MC 生物降解产物和潜在的与植物相关的 MC 降解菌的研究。
