The interactions between the plant-derived bioflavonoid, naringenin, and prokaryotic microalgae representatives (cyanobacteria), were investigated with respect to its influence on the growth and metabolic response of these microorganisms. To achieve reliable results, the growth of cyanobacteria was determined based on measurements of chlorophyll content, morphological changes were assessed through microscopic observations, and the chemical response of cells was determined using liquid and gas chromatography (HPLC; GC-FID). The results show that micromolar levels of naringenin stimulated the growth of cyanobacteria. Increased growth was observed for halophilic strains at naringenin concentrations below 40 mg L-1, and in freshwater strains at concentrations below 20 mg L-1. The most remarkable stimulation was observed for the freshwater species Nostoc muscorum, which had a growth rate that was up to 60% higher than in the control. When naringenin was examined at concentrations above 40 mg L-1, the growth of the tested microorganisms was inhibited. Simultaneously, an intensive excretion of exopolysaccharides was observed. Microscopic observations strongly suggest that these effects resulted from a structural disturbance of cyanobacterial cell walls that was exerted by naringenin. This phenomenon, in combination with the absorption of naringenin into cell wall structures, influenced cell permeability and thus the growth of bacteria. Fortunately, almost all the naringenin added to the culture was incorporated into to cell substructures and could be recovered through extraction, raising the possibility that this modulator could be recycled.
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机译:就其对这些微生物的生长和代谢反应的影响,研究了植物来源的生物类黄酮,柚皮素和原核微藻代表(蓝细菌)之间的相互作用。为了获得可靠的结果,根据叶绿素含量的测定来确定蓝细菌的生长,通过显微镜观察来评估形态变化,并使用液相色谱和气相色谱(HPLC; GC-FID)测定细胞的化学反应。结果表明,柚皮苷的微摩尔水平刺激了蓝细菌的生长。柚皮素浓度低于40 mg L -1 sup>的嗜盐菌株和浓度低于20 mg L -1 sup>的淡水菌株均观察到生长加快。观察到最明显的刺激是淡水物种Nostoc muscorum,其生长速度比对照高60%。当柚皮苷浓度超过40 mg L -1 sup>时,被测微生物的生长受到抑制。同时,观察到胞外多糖的强烈排泄。显微镜观察强烈表明,这些作用是由柚皮素所引起的蓝细菌细胞壁结构紊乱引起的。这种现象与柚皮苷对细胞壁结构的吸收相结合,影响了细胞的通透性,从而影响了细菌的生长。幸运的是,几乎所有添加到培养物中的柚皮苷都被整合到细胞的亚结构中,并且可以通过提取来回收,增加了这种调节剂可以回收的可能性。
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