Enhancement of the photosynthetic and removal performance for microalgae-based technologies by co-culture strategy and strigolactone induction

Supplementation with rac-GR24 Facilitates the Accumulation of Biomass and Astaxanthin in Two Successive Stages of Haematococcus pluvialis Cultivation

“…Higher RuBisCO activity was recorded during the macrozooid stage, which is attributable to the addition of 1 μM rac -GR24 (Figure E). Furthermore, cultures treated with 1 μM rac -GR24 had higher carbonic anhydrase activity than the control (Figure F), which is consistent with the findings of other studies. , Therefore, we posit that the addition of rac -GR24 to H. pluvialis cultures increased their CO 2 utilization efficiency by enabling more CO 2 to enter the Calvin–Benson–Bassham (CBB) cycle, for processing by RuBisCO, and the CO 2 fixation pathway, for processing by carbonic anhydrase, which increased the rate of photosynthesis and thus enhanced biomass accumulation in H.…”

“…Similar data have also been obtained in rac -GR24-treated C. vulgaris cultures, which demonstrates that exogenous treatment with this synthetic strigolactone analogue increases photosynthetic performance in microalgae. , …”

“…Furthermore, cultures treated with 1 μM rac-GR24 had higher carbonic anhydrase activity than the control (Figure 1F), which is consistent with the findings of other studies. 38,39 Therefore, we posit that the addition of rac-GR24 to H. pluvialis cultures increased their CO 2 utilization efficiency by enabling more…”

“…Similar data have also been obtained in rac-GR24-treated C. vulgaris cultures, which demonstrates that exogenous treatment with this synthetic strigolactone analogue increases photosynthetic performance in microalgae. 39,58 We also explored the probable mechanism of enhanced photosynthesis and found that the presence of strigolactones significantly enhances CO 2 utilization efficiency, which enables more CO 2 to be utilized by microalgae treated with rac-GR24. The resulting increase in intracellular CO 2 concentrations in 1 μM rac-GR24-treated H. pluvialis cultures led to significant upregulation of RuBisCO (a key enzyme in the CBB cycle) and carbonic anhydrase (a key enzyme in the CO 2 fixation pathway), which caused increases in the rates of photosynthesis and carbohydrate biosynthesis, thereby enhancing biomass accumulation in H. pluvialis cultures at the macrozooid stage.…”

Humic Substances as Microalgal Biostimulants—Implications for Microalgal Biotechnology

“…Their benefits for utilization in microalgal biotechnology to increase microalgae growth and accumulation of metabolites of interest have been reviewed several times in recent years [ 136 , 137 , 138 ]. Recently, strigolactone analogs, phytohormones not detected in microalgae, which appear firstly in Charales [ 139 ], were demonstrated to promote microalgae growth and metabolite accumulation [ 140 , 141 , 142 , 143 ]. Besides phytohormones, HS and polyphenols (ferulic acid, protocatechuic acid, vanillic acid, phloroglucinol) were reported as non-microbial algae biostimulants/growth promotors.…”