The data presented in the literature over the course of the last decades indicate that neurotransmitters such as acetylcholine and biogenic amines (serotonin, histamine, norepinephrine, dopamine, etc.) function as communicative signals in representatives of various kingdoms of life. Therefore, their effects on prokaryotes, including cyanobacteria, is of significant interest. The present work is concerned with data on the impact of biogenic amines, a subgroup of neurotransmitters added at concentrations of 0.1, 1, and 10 μM upon inoculating the cyanobacterium Limnospira platensis IPPAS B-256, on biomass accumulation and photosynthetic pigment and fatty acid contents. It was revealed that acetylcholine (ACh), serotonin (5-HT), and histamine significantly increased the biomass dry weight on day 7 (when the control culture reached a plateau in terms of biomass content) but not on day 14 of cultivation, i.e. these neurotransmitters were probably exerting a growth-accelerating effect. In contrast, dopamine (DA) decreased the biomass content on day 7, but not on day 14; norepinephrine (NE) had no effect. All tested neurotransmitters except NE decreased the number of cell strands (trichomes) on day 7 of cultivation; all these agents except histamine, prevented the decrease in trichome number that took place in the control culture by day 14. On day 7 (when the chlorophyll a content reached a maximum in the control culture), ACh and histamine decreased the content of chlorophyll and augmented that of carotenoids; 5-HT and DA increased the contents of all photosynthetic pigments. On day 14 of cultivation, ACh and 5-HT increased and NE decreased the total fatty-acid content. Both 5-HT and NE caused an increased percentage of polyunsaturated fatty acids (PUFAs). The potential applications of the data obtained are considered in terms of microalgal biotechnology.
Cao et al. (Sun,) studied this question.