Division of Marine Ecosystems Functioning, Institute of Oceanography, University of Gdańsk, Av. Piłsudskiego 46, 81-378 Gdynia, Poland.
Interdisciplinary Center of Marine and Environmental Research-CIMAR/CIIMAR, University of Porto, Av. General Norton de Matos s/n, 4450-208 Matosinhos, Portugal.
Mar Drugs. 2020 Mar 27;18(4):179. doi: 10.3390/md18040179.
Organisms belonging to sp. genera are observed in all freshwater, brackish, and marine waters of the world. They play a relevant role in these ecosystems, since they are one of the main primary producers, especially in open ocean. Eventually, they form mass blooms in coastal areas, which are potentially dangerous for the functioning of marine ecosystems. Allelopathy could be an important factor promoting the proliferation of these organisms. According to the authors' best knowledge, there is no information on the allelopathic activity and allelopathic compounds exhibited by different sp. phenotypes. Therefore, the research conducted here aimed to study the bioactivity of compounds produced by three phenotypes of sp. by studying their influence on the growth, chlorophyll fluorescence, and photosynthetic pigments of eighteen cyanobacteria and microalgae species. We demonstrated that three different sp. phenotypes, including a phycocyanin (PC)-rich strain (Type 1; green strain) and phycoerythrin (PE)-rich strains containing phycoerythrobilin (PEB) and phycocyanobilin (PCB) (Type 2; red strain and Type 3a; brown strain), had a significant allelopathic effect on the selected species of cyanobacteria, diatoms, and green algae. For all green algae, a decrease in cell abundance under the influence of phenotypes of donor cyanobacteria was shown, whereas, among some target cyanobacteria and diatom species, the cell-free filtrate was observed to have a stimulatory effect. Our estimates of the stress on photosystem II () showed a similar pattern, although for some diatoms, there was an effect of stress on photosynthesis, while a stimulatory effect on growth was also displayed. The pigment content was affected by allelopathy in most cases, particularly for chlorophyll , whilst it was a bit less significant for carotenoids. Our results showed that sp. Type 3a had the strongest effect on target species, while sp. Type 1 had the weakest allelopathic effect. Furthermore, GC-MS analysis produced different biochemical profiles for the strains. For every phenotype, the most abundant compound was different, with oxime-, methoxy-phenyl- being the most abundant substance for Type 1, eicosane for Type 2, and silanediol for Type 3a.
属于 sp. 属的生物在世界上所有的淡水、半咸水和海水中都有观察到。它们在这些生态系统中发挥着重要作用，因为它们是主要的初级生产者之一，特别是在开阔的海洋中。最终，它们在沿海地区形成大量的水华，这对海洋生态系统的功能可能是潜在的危险。化感作用可能是促进这些生物增殖的一个重要因素。据作者所知，目前还没有关于不同 sp. 表型表现出的化感活性和化感化合物的信息。因此，这里进行的研究旨在通过研究三种 sp. 表型产生的化合物的生物活性，来研究它们对 18 种蓝藻和微藻物种的生长、叶绿素荧光和光合色素的影响。我们证明了三种不同的 sp. 表型，包括富含藻蓝蛋白（PC）的菌株（类型 1；绿色菌株）和富含藻红蛋白（PE）的菌株，含有藻红胆素（PEB）和藻蓝胆素（PCB）（类型 2；红色菌株和类型 3a；棕色菌株），对所选的蓝藻、硅藻和绿藻物种有显著的化感作用。对于所有的绿藻，在供体蓝藻表型的影响下，细胞丰度下降，而对于一些目标蓝藻和硅藻物种，观察到无细胞滤液有刺激作用。我们对光系统 II（PSII）的胁迫估计也显示出类似的模式，尽管对于一些硅藻，光合作用受到胁迫的影响，但同时也显示出对生长的刺激作用。在大多数情况下，化感作用会影响色素含量，尤其是叶绿素，而对类胡萝卜素的影响则稍小一些。我们的研究结果表明，sp. 类型 3a 对目标物种的影响最强，而 sp. 类型 1 的化感作用最弱。此外，GC-MS 分析为 3 种菌株产生了不同的生化图谱。对于每种表型，最丰富的化合物都不同，其中 1 型的主要物质是肟-甲氧基-苯基-，2 型的是二十烷，3a 型的是硅烷二醇。
